Annotated bibliography of mirages, green flashes, atmospheric refraction, etc.

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Aristotle
Meteorologica, with an English translation by H. D. P. Lee
(Harvard University Press, Cambridge, 1962).

* Of course, it all begins with ARISTOTLE, who was quoted by Maltézos
* (1912). The oldest account of mirages seems to be Aristotle's brief
* mention in the "Meteorologica" (c. 340 or 350 BC) at 373 b in Book III
* (p.253 of the Loeb Library edition):
* "Distant and dense air does of course normally act as a mirror . . . ,
* which is why when there is an east wind promontories on the sea appear
* to be elevated above it and everything appears abnormally large;. . . "
* but unfortunately he then drags in the Moon illusion.
* So both MIRAGE and LOOMING were known to him.
* As Lee notes there, a similar (but much briefer) mention occurs in
* "Problems" XXVI. 53: "Why, when the east wind blows, do all the things
* seem larger?" Here are the Loeb Library editions:


Aristotle
Problems II, with an English translation by W. S. Hett
(Harvard University Press, Cambridge, 1965).


Theophrastus
Enquiry into Plants, and minor works on Odours and Weather Signs, vol. 2
(Harvard University Press, Cambridge, 1949), p. 411.

* THEOPHRASTUS was Aristotle's successor; he's cited by A. von Humboldt.
* The fragment given in the footnote suggests he was familiar with
* superior mirages as well: "si mons versus aquilonem extenditur . . . ",
* though the translator obviously is not ("with what meaning I cannot
* see.")
* However, it is the inferior-mirage passage that Humboldt refers to:
* "If promontories seem to stand high out of the sea, or a single island
* looks like several . . . ."
* This is the Loeb Library edition; the "weather signs" section is
* apparently just tacked on, after "on odours". The subtitle is
* "with an English translation by Sir Arthur Hort, Bart., . . . ."


Agatharchides of Cnidus
On the Erythrean Sea; translated, and edited, by S.M.Burstein
(Hakluyt Society, London, 1989).

* AGATHARCHIDES (2nd Century BC) is known only from fragments of his
* historical work on the areas around the Arabian peninsula quoted or
* paraphrased by the later writers (Diodorus, Strabo, and Photius) who
* cite him as a source. The book cited here is an attempt to collect what
* remains of his work.
* Let's start with a mangled account of mirages in the desert. On p. 116
* (Book 5, Chapter 66 of Agatharchides) we have:
*      "At the furthest reaches of Egypt and Trogodytice, . . .  because of
* the extreme heat produced by the sun at noon people standing next to
* one another are unable to see each other because of the density of the
* air resulting from its condensation." [Evidently the original story was
* "people standing *near* each other" -- meaning, perhaps, "within hailing
* distance" as opposed to "far away". This is a correct observation of the
* shrinking of the apparent horizon by the inferior mirage, and the hiding
* of objects a few hundred meters away by the mirage. The distortion of the
* sense of the passage in re-copying is quite typical of what copy editors
* do today; it is particularly common in re-told accounts of mirages and
* other refraction phenomena by someone who has not personally seen them.]
*      The next passage appears in both Photius and Diodorus, though in
* quite different forms. Here's Burstein's version of Photius; after
* commenting on the supposed lack of twilight at low latitudes: "Second,
* the sun appears to rise from the middle of the sea." [cf. Le Gentil's
* "whale" remark.] "Third, when it does rise, it is like a blazing coal,
* scattering great sparks, some into the disc of light and some beyond."
* [cf. the GF observers who speak of "flames" shooting out of the Sun.]
* "Fourth, people also say that the shape of the sun is not like a disc
* but most closely resembles a thick column which appears fatter at the
* end as if it had a head." [Ch. 107, p. 171] Here Burstein cites Salt,
* (1814) p. 93, for a similar description (q.v., below).


Diodorus Siculus
Diodorus of Sicily: The Library of History, Books II.35 - IV.58, with an English translation by C. H. Oldfather
(Harvard Univ. Press, Cambridge, 1933), pp. 241–245.

* DIODORUS SICULUS has the next earliest (c. 30 BC) known description of
* mirages. Oldfather's translation makes good sense, but he seems not to
* have appreciated the significance of this passage:
* "And both in this land and in Libya which lies beyond the Syrtis there
* takes place a marvellous thing. For at certain times, and especially when
* there is no wind, shapes are seen gathering in the sky which assume the
* forms of animals of every kind; and some of these remain fixed, but
* others begin to move, sometimes retreating before a man and at other times
* pursuing him, and in every case, since they are of monstrous size, they
* strike such as have never experienced them with wondrous dismay and
* terror. . . . although the natives, who have often met with such things,
* pay no attention to the phenomenon."
* "As for the movements which these shapes make in both directions, these
* . . . indicate no volition on their part, since it is impossible that
* voluntary flight or pursuit should reside in a soulless thing. And yet
* the living creatures are, unknown to themselves, responsible for this
* movement through the air; for, if they advance, they push by their violent
* motion the air which lies beneath them, and this is the reason why the
* image which has formed retreats before them and gives the impression of
* fleeing; whereas if the living creatures withdraw, they follow in the
* opposite direction, the cause having been reversed . . . . Consequently it
* has the appearance of pursuing men who withdraw before it, for the image
* is drawn to the empty space and rushes forward in a mass under the
* influence of the backward motion of the living creature. . . ."
* (from Book III.50 and .51)
* The need for calm air is repeated three times.


J. C. Rolfe
Quintus Curtius, Vol.II
(Harvard Univ.Press, Cambridge, 1956), pp. 162–165.

* QUINTUS CURTIUS RUFUS (History of Alexander, Book VII; c. 40 A.D.)
* The reference here is Curt. 7.5.4:
* "Then too a mist [caligo], aroused by the excessive warmth of the ground,
* obscures the light, and the aspect of the plain is not unlike that of a
* vast and deep sea."
* Many thanks to Prof. J.C.Yardley of the University of Ottawa for finding
* this passage!


H. Rackham
Pliny, Natural History
(Harvard University Press, Cambridge, 1938).

* PLINY in the Loeb Library edition
* This passage from the "Natural History" is obviously not what Kircher
* had in mind: (from Book II, section LVIII)
* "In the third consulship of Marius the inhabitants of Ameria and Tuder
* saw the spectacle of heavenly armies advancing from the East and the West
* to meet in battle, those from the West being routed." (Vol. I, p. 285)


F. Josephus
The Works of Flavius Josephus
(William P. Nimmo, London, 1865).

* William Whiston's translation of FLAVIUS JOSEPHUS (c. 78 A.D.)
* This translation has been widely reprinted, up to the present day.
* It is also available on the Perseus website at http://www.perseus.tufts.edu
* and at http://www.coel.wheaton.edu.
* The passage suggestive of a mirage is in Book VI, Chapter V, section 3
* of the "Wars of the Jews" (near paragraph 289). He enumerates several
* omens around the time of the feast of unleavened bread, almost a week
* before Passover:
* "Besides these, a few days after that feast, on the one-and-twentieth
* day of the month Artemisius, [Jyar,] a certain prodigious and incredible
* phenomenon appeared; I suppose the account of it would seem to be a fable,
* were it not related by those that saw it, and were not the events that
* followed it of so considerable a nature as to deserve such signals; for,
* before sun-setting, chariots and troops of soldiers in their armour were
* seen running about among the clouds, and surrounding of cities."
* This does indeed sound much like a superior mirage or Fata Morgana.
* Cf. l'Astronomie 7, 392-393 (1888).


A. de Ferrariis
Liber de Situ Iapygiae
(per Petrum Pernam, Basileae, 1558).

* Very EARLY MIRAGE descriptions (1558) by Antonius de Ferrariis (1444-1517)
* or Antonio de Ferarri, also known as Antonio Galateo, Galateus Antonus, etc.
* after his place of birth (Galatone).
*      Supposedly written in 1507-1509, but only published in 1558.
* Japygia is the old name; it became Apulia, and then Puglia.
* This passage is translated from the recent (2005) Latin/Italian version
* "La Iapygia" edited by Domenico Defilippis (Mario Congedo, Galatina):
* [18 10] (pp. 92/93): "In these swamps [near Nardò, on the Gulf of
* Taranto], as also in the fields of Manduria and Baleso and Copertino,
* certain apparitions are seen, which are called Mutationes or Mutata .
* The common people tell tales of I don't know what, vampires or witches or,
* as they say in Naples, janare [fairies], or as the Greeks say, nereids.
* It's amazing: this nonsense takes possession of the whole region and
* misleads the poor people. With no reliable authority, no reason, no
* demonstration, everyone believes in things they have not seen and are
* not true. And we oppose the testimony of the most ignorant people; we
* believe they are childish fantasies and old wives' tales, giving more
* trust to the ear than the eye. No one is an eye-witness, all accept
* what they have heard from others." (He then goes off to condemn popular
* beliefs in magic potions that can turn women into various animal forms
* at night; vampires; and other superstitions.) Then: "But let us return
* to those apparitions."
* [18 18] (pp. 96/97) "And sometimes you will see cities and castles and
* towers, and sheep and different colored cattle and images or specters of
* other things, where there is no city, no sheep, not even a thorn bush.
* I myself have sometimes had the pleasure of seeing these plays, this
* lusus naturae .
*      "They do not last long, but change as the vapors in which they appear,
* from one place to another, from one form to another, whence perhaps they
* are called Mutata , or because the sky is changed from sunny to rain
* by these apparitions.
*      "This happens in the morning, with calm air, beginning with a light
* breath of air (customarily) from the south. For as the strong south
* wind ceases, so at first it is gentlest and, as it is warm, it raises
* tenuous mists, which reflect images of cities, flocks, and other things
* like a mirror.
*      "And like the vapors, those images are moved, as things are seen
* moving in mirrors that are moved and shaken. And because the things
* directly face the vapors, they are seen directly, just like a shadow
* which falls opposite a luminous body; those that are oblique and turned
* produce images, which we also see turned, as also in water we see the
* tops of mountains and roofs at the bottom. For when some things are
* closer to the surface of the water, such as a foundation, to our vision
* they would appear far off; the images of rooftops, which are farther
* from the water, come nearer to us, and therefore are seen below.
*      "And so we find that in a closed building, with a little light coming
* through the slits, everything is seen reversed, such as the head of a man
* downward, feet above. For the lines of shadows do not proceed directly,
* but are transposed and intersect in the middle. This same thing happens
* in a concave mirror, so that the upper part of the mirror reflects the
* lower part of the thing seen, and the lower the upper.
*      "These apparitions that I have mentioned often deceive the gaze of
* travelers, who, when they suppose they are near a city, are very far away.
* And there have been seen in this region images in the air of men riding
* horses and marching on foot. And so writers have recorded that armed
* troops arrayed for battle have been seen in the sky, and these (as I
* think) images were of those far away from that place in which the images
* were seen, and could not be seen [directly].
*      "And thus we don't see a coin in the bottom of a vessel, but if the
* same vessel is filled with water, we see not the coin, but its image at
* the surface of the water, which is touching the air. For the surface
* of the water is analogous to the surface of a mirror, but whether these
* images may belong to the mirror, or the outer surface of the air, is
* another question."      And he cites Aristotle.      [18 24] (pp. 98/99)
*      "And as these figures are of mists, they give likenesses of ships
* and sails, where there is no fleet. These apparitions deceive not only
* the inexperienced. It is not long since the whole coast, from Hydrunto
* [Otranto] to Monte Gargano, at one and the same hour before sunrise,
* saw a fleet sailing from the east. It was thought to have been that
* of the Turks, and before that specter or delusion was revealed by
* the lightening dawn, various letters were composed here and there and
* messengers were sent concerning the approach of this imposing fleet."
* [NOTE: a Turkish fleet had just sacked Otranto in 1480, a few years
* before this was written; he assisted in its liberation.] He continues:
* "Perhaps in this way or another of which we shall speak, as I believe,
* someone (I don't know who) from Lilibeo [Marsala] saw a fleet leaving
* the port of Carthage."
*      The 1558 edition was recently republished by Forni.


T. Facellus
De Rebus Siculis decades duae
(Joannes Matthaeus Mayda et Francesco Caracca, Panormi, 1558).

* Thomas Facellus (Tommaso Fazello) briefly mentions mirages
* Cited by Minasi; and, following him, P&E (p.170). They give the citation
* as Dec. 1, lib. II, cap. 1.
* The title page is imaged at
*      http://edit16.iccu.sbn.it/scripts/iccu_ext.dll?fn=60&i=18660#1
* The passage appears on p. 42 of the edition at the HathiTrust website:
*       http://babel.hathitrust.org/cgi/pt?id=ucm.5325123864;view=1up;seq=64
* "Sed & alia in hoc freto res mira frequenter apparet. Nam mitigato
* turbine, quietoq; aere, circa diei exortum illucescente aurora, variæ
* animantium, hominumq; formæ in aere crebrò cernuntur. Quarum aliæ
* penitus immotæ sunt, pleræq; vel in aere discurtunt,vel inter se
* dimicant, quousq; Sole incalescente, è conspectu eripiantur:Harum
* Polycletus lib. de Reb.sicul.& Aristoteles lib.de mirab.aud. memi-
* nerunt, quarum etiam haec à Philosophis redditur ratio : quod cùm in
* ijs regionibus,eo præsertim tempore,quo haec cernuntur,ventos, aut
* omnino non spirare,aut exiles admodum,& aerem quietum esse constet,
* in ipso aere denso atq; obtuso diuersæ animantium effigiantur species,
* quibus formam aer, quem tenues & leues quandoq; mouent auræ, variam
* præbet (quemadmodum æstate in nubibus fieri videmus) qua tandem sol
* incalescens in ventos resoluit."
*      (Panormi = Palermo)


Marc'Antonio Politi
Cronica della nobil' e fedelissima città di Reggio
(Appresso Pietro Brea, Messina, 1617), pp. 18–19.

* MARC'ANTONIO POLITI -- the first to use the term "Fata Morgana"
* Briefly quoted by Costanzo (1903), p. 106.


A. Kircher
Ars Magna Lucis et Umbrae
(Sumptibus Hermanni Scheus ex typographia Ludovici Grignani, Romae, 1646).

* ATHANASIUS KIRCHER (1646)
* This is the work cited by Castberg. The discussion of mirages and other
* meteorological phenomena is in Liber decimus, Pars secunda, pp. 800-804.
* "Liber decimus. Magia Lucis & Vmbrae . . . Pars Secunda. Magia
* Parastatica, siue de repræsentationibus rerum prodigiosis; per Lucem &
* Vmbram . . . Caput 1 De Repræsentationibus aeris: mentions "in libris
* Machabeorum" (p. 800)
* "Parastatis I Naturae, siue de Morgana Rheginorum in Freto Mamertino,
* siue Siculo" -- here, on p. 801, we have "Vocant autem Rhegini hoc
* spectaculum Morganam," followed by Ignatio Angelucci's letter to Leone
* Sanzio, describing a Fata Morgana display on Aug. 15, 1643. [Angelucci's
* letter is also quoted by Capozzo (1840).] Note that Angelucci says he
* saw his F.M. "La mattina dell' Assontione della Beatissima Vergine,"
* and does not give a calendar date. This led to some confusion later.
* [His letter is "Di Reggio", dated the 22. of August.]
*      p.802 mentions "Scipio Mazzellus, Regni Neapolitani; fol. 117".
* p. 803: "Refert Pomponius Mela, in Mauritania retro Atlantem regiones
* esse, in quibus circa meridiem inter montes varia spectra comparere
* soleant, quae gestus hominu' in omnibus æmulentur: videas ibi choreas,
* audias tubarum, tympanorumque strepitus. Refert quoque Plinius, intra
* Imaum in Scythia regionem esse, in qua quot-annis in vasta planitie
* appareant varia spectacula rerum sub figura hominum animaliumque, &
* instar exercitus; quibus viatores non rarò in auia, & deuia
* præcipitia ac denique in manifestam perniciem deducantur. Ad
* flumen Oby refert Haithon Armenus regionem esse, ad quam nullus adhuc
* penetrauerit, ob formidabilium, spectrorum, quae ex illa fluminis parte
* comparent, multitudinem."
* The reference to Pomponius Mela seems to be nonsense; there is nothing
* like this in his book. I have not found the Pliny passage, either.
* (For more evidence of Kircher's unreliability, see Lohne's 1959 paper
* on Harriot.)
*      NOTE: a revised edition of this was printed in Amsterdam in 1671.
* Due to the removal of some material, Angelucci's letter appears in
* it on pp. 704-705 rather than p. 801. Many later commentators have
* referred to that edition instead of the original; see the entries for
* Giardina (1758), Minasi (1773), Boccara (1902), etc.


P. Reina
Delle Notizie Istoriche Della Città Di Messina
(Pietro Brea, Messina, 1658).

* Placido Reina quotes Politi, Facellus, etc.
* The Fata Morgana begins on p. 64, and "similar things" on p. 65.
* Politi is cited on pp. 65 and 67. See Costanzo's (1903) discussion
* at his p. 107; esp. the footnotes there.
* Available at Google Books.


[E. ] Mariotte
Traitté du nivellement
(Jean Cusson, Paris, 1672).

* EDME MARIOTTE's short monograph on the optical level and its use
*      Mainly of historical interest; first, because of Forel's use of his
* technique for the easy measurement of absolute altitudes; and second,
* for his discussion of temporal VARIATIONS in TERRESTRIAL REFRACTION.
* That discussion is mainly on pp.19-20; but it arises from the calculations
* on p. 18, where the diameter of the Earth is taken to be 40 million feet.
* His concern there is that the height of a distant object on the tangent
* plane at the observer is above the observer's height. But, he says,
* "Il est encore necessaire de sçavoir que dans les grandes distances
* un mesme objet paroist de differentes hauteurs par les refractions,&
* change presq'uà toutes les heures du jour,c'est à dire que s'il est le
* matin au lever du Soleil en une mesme ligne droite avec un objet prochain,
* il paroistra plus bas une heure aprés le Soleil levé, & encore plus bas
* quand l'air sera plus échauffé,& plus les matinées seront fraisches &
* l'air serain, plus les objets éloignez paroistront élevez, & quelques
* fois les objets qui sont à une distance d'environ 500 pas paroistront
* s'élever, & en mesme tems ceux qui sont beaucoup éloignez s'abaisser,
* principalement lors que le Soleil luit, comme on a reconnu par plusieurs
* observations faites en divers lieux & diverses saisons,mesme à l'égard
* des objets moins élevez que observateur,ou d'égale hauteur ; & on a
* remarqué quelquefois, qu'un objet qui avoir paru à midy plus bas que
* le plan de niveau, paroissoit le lendemain matin plus de 20 pieds plus
* haut que ce plan, en une distance d'environ 2 lieuës, d'où il s'ensuit
* que le plus seur moien pour bien niveller de grandes distances, est
* de le faire à plusieurs fois: . . . " whereupon he gives an example,
* referring to Figs. 12 and 13 at the end of the volume. This discussion
* of refraction continues on to p. 22.
*      He mentions refraction again on p. 27 and p. 31, where he remarks that
* the refractions are "irregular" when the Sun shines; on the next page,
* he says that reliable measurements can be made when the sky is covered
* with clouds. So, although he give no systematic measurements, it's clear
* from the numerous examples that he was familiar with the variations and
* regularities in terrestrial refraction.
*      A good PDF of this work is available at
*
*       https://gallica.bnf.fr/ark:/12148/bpt6k6514207h?rk=21459;2
*
* which scrupulously puts "[sic]" after Mariotte's odd title spelling.
* However, BNF's OCR frequently renders the long-s as "f".


Hevelius
“A certain Phenomenon, seen by Monsieur Havelius (sic), Feb. 5. 1674. St. No. not far from Marienburg in Boroussia - about the Sun a little before his setting . . .,”
Phil. Trans. Roy. Soc. Lond. 9, 26–27 (1674).

* HEVELIUS (1674)
*
* "Under the Sun, towards the Horizon, there hung a somewhat dilute small
* Cloud, beneath which there appear'd a Mock-Sun, of the same bigness (to
* sense) with the true Sun, and under the same Vertical, of a somewhat red
* colour. Soon after, the true Sun more and more descending to the Horizon,
* towards the said Cloud (as may be seen Fig. 4) the spurious Sun beneath it
* grew clearer and clearer, so as that the reddish colour in that apparent
* Solar disk vanish'd, and put on the genuine Solar light, and that the more,
* the less the genuine disk of the Sun was distant from the false Sun: Till
* at length the upper true Sun passed into the lower counterfeit one, and so
* remained alone; as appears Fig. 5.
*
* "Which Appearance being unusual, and having never been seen by me, I took
* the freedom of imparting it unto you, especially since here the Mock-Sun
* was not found at the side of the true Sun, as 'tis wont to be in all
* Parhelia's seen by me, but perpendicularly under it; not to mention the
* Colour, so different from that which is usual in Mock-Suns; nor the great
* length of the Tayl, cast up by the genuine Sun, and of a far more vivid and
* splendid light, than Parhelia's use to exhibit. Upon this appearance there
* soon follow'd here an exceedingly intense and bitter Frost, whereby the
* whole Sinus Puzensis was frozen up from this Town of Dantzick, as far as
* Hela in the Baltick Sea, which lasted unto the 25th of March; and the Bay
* was frozen so hard, that with great safety people run out into it with Sleds
* and Horses, for several of our Miles. Whether the recited Phaenomenon have
* had any influence for this extream Cold, I know not, but leave it for
* Astrologers to examine. Whether the like Appearance have ever been
* observ'd in England, I should be glad to be informed of."


P. Perrault
On the origin of springs, translated by Aurele LaRocque
(Hafner, New York, 1967).

* Translation of Pierre Perrault's "De l'origine des fontaines" (1674)
* and so filed here instead of at 1967. Orig. pub. by Pierre le Petit,
* Paris (1674).
* "Moreover the astronomers are certain that humid vapors either of the
* Sea, or of the Earth, cause much refraction, and cause many things to be
* seen otherwise than they really are: as when the Sun or the Moon
* sometimes appear to be oval, when they rise or set; . . . ." He then
* mentions their appearance "on the horizon before they have risen up to
* it," and offers the coin in a basin filled with water as an illustrative
* demonstration. In section (111): "I have made another more elaborate
* experiment, which shows that the vapors of the earth, according to their
* arrangement, can make distant objects appear now higher now lower, as if
* these objects were really raised or lowered. . . . I took as an object a
* pavilion about thirty-two feet in height half a league away, which I
* observed with a spyglass attached to and rendered motionless on a window
* sill in a large wall; and having aimed it at the top of this pavilion,
* which was on the thread of my spyglass, and level with it; I found that
* from two o'clock in the afternoon, when I began my observation, until
* night, the top of this roof had seemed to rise by eight feet, so that
* more than half this roof was above the thread of my spyglass." [He goes
* on to relate several days' observations, during which the building rose
* and fell by more than its full height.] "I have repeated the same
* experiment at another time when there was a great drought, which had
* lasted more than six weeks without respite, and I have always seen the
* same thing . . . the rising of my object happened regularly from noon to
* evening, and the lowering from morning to noon. . . ." (pp. 58-60)
* The translator suggests (p.182) that "this may be the earliest study"
* of such DIURNAL VARIATIONS in atmospheric refraction. N.B.: "half a
* league" is about 2 km; the building was about 10 m high; so the variations
* cover a range of about 1/200 radian or some 16' of arc.
*      Note that the book is dedicated to Christiaan Huygens, who picked up
* the refraction variations in his "Traité de la Lumière" (1690).


J. Picard
Voyage d'Uranibourg
(Imp.Royale, Paris, 1680), p. 8.

* Jean Picard's inferior mirage seen at Tycho's old observatory
* "Je mets à part les changemens qui arrivent à cause des Réfractions,
* & je diray seulement une chose que nous remarquasimes en faisant
* les Observations que nous venons de rapporter. Il y a proche de
* Copenhague une Isle appellée Amac, dont le terrain qui est assez bas
* nous estoit caché par la rondeur de la mer, en sorte néanmoins que nous
* y découvrions les sommets de quelque arbres. Or venant à pointer le
* quart de cercle vers l'endroit où ces arbres me paroissoient tranchez,
* j'estois asseûré que mon Rayon visuel recontroit l'extrémité visible
* de la surface de la mer, & néanmoins on auroit dit que ces arbres
* estoient dans le Ciel, & que la mer estoit terminée bien au dec,à de
* l'endroit où nous sçavions qu'il falloit pointer. La raison de cette
* apparence, est que la mer estoit fort unie, faisoit à nostre égard si
* exactement l'effet du miroir, que nous la confondions avec le Ciel."
* (Probably this is the island of Amager, where Copenhagen's airport is
* today -- about 30 km south of Hven.)
*      This memoir contains much else of interest: an eyewitness account of
* Tycho's original records, and his celestial globe: "nonobstant toutes
* les fortunes qu'il a couruës, ayant esté premiérment transporté de
* Dannemarck en Boheme, puis en Silesie, & enfin rapporté in Dannemarck,
* il est en dans son entier comme s'il venoit d'estre fait : son diametre
* est précisément de quatre pieds, sept pouces & une ligne, mesure de
* Paris." (p. 4)
*      Picard also enjoyed the collaboration of Erasmus Bartholin, who
* accompanied him to Uraniburg, as well as "un jeune Danois nommé
* Olaüs Romer, que M. Bartholin m'avoit fait connoitre, & qui estant
* ensuite venu en France avec moy, fut de l'Académie des Sciences, où
* il a donné plusieurs marques de son rare génie & se son esprit." (p.5)
*      He found Tycho's observatory completely destroyed, and the remains
* scattered. Placing his instruments on the surviving foundations of
* Tycho's observatory, he determined its location: the ground was about
* 27 toises [52.6 m] above the sea (p. 7); a latitude of 55° 54' 15''
* (p. 25); and a longitude 42m 10s or 10° 32' 30'' E of Paris. (p.28)
*      His stay in November 1671 was so difficult that "enfin le travail des
* veilles durant un froid auquel je n'estois pas accoustumé, & l'air de
* la Mer Baltique me causerent une langueur qui renoit un peu de scorbut,
* & qui me fit à la fin résoudre à quitter cette solitude, pour me
* retirer dans un lieu de secours avant que les glaces me fermassent
* le passage." (p.12) (He notes on the next page that scurvy was common
* "aux personnes sedentaires".) But he sent Romer back in the spring,
* to finish the observations.
*       Then, on p. 18, we find he has noticed (but not understood) the
* effects of annual aberration, "que j'observe depuis dix ans." Not bad!
*      Thanks to Sharron Huling for providing a photocopy!



*** NEW HAVEN GHOST SHIP FILE ***

[John Winthrop]
in Winthrop's Journal, ``History of New England'', Volume II , James Kendall Hosmer LL. D. , ed.
(Charles Scribner's Sons, New York, 1908).

*
* Earliest mention seems to be in JOHN WINTHROP's Journal
* In the entries for 1648, we find on p. 346:
*      ``There appeared over the harbor at New Haven, in the evening, the
* form of the keel of a ship with three masts, to which were suddenly
* added all the tackling and sails, and presently after, upon the top of
* the poop, a man standing with one hand akimbo under his left side, and
* in his right hand a sword stretched out toward the sea. Then from the
* side of the ship which was toward the town arose a great smoke, which
* covered all the ship, and in that smoke she vanished away; but some saw
* her keel sink into the water. This was seen by many, men and women, and
* it continued about a quarter of an hour.''
* [cf. the FOG FILE for the "smoke".]
* A footnote says: "The spectral ship of New Haven, the tradition of
* which was taken up and characteristically developed by Cotton Mather, is
* one of the most weird of New England legends, and has become familiar to
* the later generations."


L. Bacon
Thirteen Historical Discourses, on the Completion of Two Hundred Years, from the Beginning of the First church in New Haven, with an Appendix
(Durrie and Peck, New Haven, 1839), p. 107.

* Leonard Bacon's account, largely taken from Winthrop's
* Here, after describing the loss of the ship sent out in January, 1646,
* he says: ``Two years and five months from the sailing of that ship, in
* an afternoon in June, after a thunder storm, not far from sunset, there
* appeared over the harbor of New Haven, the form of the keel of a ship
* with three masts, to which were suddenly added all the tackling and
* sails; and presently after, upon the highest point of the deck, a man
* standing with one hand leaning against his left side, and in his right
* hand a sword pointing towards the sea. The phenomenon continued about a
* quarter of an hour, and was seen by a crowd of wondering witnesses, --
* till at last, from the farther side of the ship, there arose a great
* smoke, which covered all the ship; and in that smoke she vanished
* away.''
* A footnote calls it an "atmospheric phenomenon"; mirages were well known
* by 1839, when this was published.


C. Mather
Magnalia Christi Americana, Books I and II, Edited by K.B.Murdock
(Belknap Press, Cambridge, 1977), pp. 169–170.

* COTTON MATHER's belated third-hand account
* This quotes a secondary source -- a letter from James Pierpont, who
* was pastor of the First Congregational Church of New Haven from 1685 to
* 1714, and therefore could not himself have been a witness. His
* second-hand account, reported to Mather in a letter, has the year of the
* original sailing wrong; and the details are by now vastly exaggerated by
* the fading memories of the (unnamed) witnesses:
*      "In Compliance with your Desires, I now give you the Relation of
* that Apparition of a Ship in the Air , which I have received from the
* most Credible, Judicious and Curious Surviving Observers of it.
*      "In the Year 1647, besides much other Lading, a far more Rich
* Treasure of Passengers, (Five or Six of which were Persons of chief Note
* and Worth in New-Haven ) put themselves on Board a New Ship , built at
* Rhode-Island , of about 150 Tuns; but so walty, that the Master,
* (Lamberton ) often said she would prove their Grave. In the Month of
* January , cutting their way thro' much Ice, . . . they set Sail. Mr.
* Davenport in Prayer with an observable Emphasis used these Words,
* Lord, if it be thy pleasure to bury these our Friends in the bottom
* of the Sea, they are thine; save them!      The Spring following no
* Tidings of these Friends arrived with the Ships from England:
* New-Haven's Heart began to fail her: This put the Godly People on
* much Prayer , both Publick and Private, That the Lord would (if it was
* his Pleasure) let them hear what he had done with their dear Friends,
* and prepare them with a suitable Submission to his Holy Will.      In
* June next ensuing, a great Thunder-storm arose out of the
* North-West : after which, (the Hemisphere being serene) about an Hour
* before Sunset a SHIP of like dimensions with the aforesaid, with her
* Canvas and Colours abroad (tho' the Wind Northernly) appeared in the Air
* coming up from our Harbour's Mouth, which lyes Southward from the Town,
* seemingly with her Sails filled under a fresh Gale, holding her Course
* North, and continuing under Observation, Sailing against the Wind for
* the space of half an Hour. Many were drawn to behold this great Work
* of God; yea, the very Children  cry'd out, There's a Brave Ship!      At
* length, crouding up as far as there is usually Water sufficient for
* such a Vessel, and so near some of the Spectators, as that they imagined
* a Man might hurl a Stone on Board her, her Maintop seem'd to be blown
* off, but left hanging in the Shrouds; then her Missen-top ; then all
* her Masting seemed blown away by the Board: Quickly after the Hull
* brought unto a Careen , she overset, and so vanished into a smoaky
* Cloud, which in some time dissipated, leaving, as everywhere else, a
* clear Air."
* To which, Mather adds: "Reader, There being yet living so many
* Credible Gentlemen, that were Eye-Witnesses of this Wonderful thing, I
* venture to Publish it for a thing as undoubted , as 'tis wonderful ."
* (Mather's book originally appeared in 1702.)


H. W. Longfellow
“The Phantom Ship,” in Outre-Mer: a pilgrimage beyond the sea
(George Routledge & Co., London, 1851).

* Mather's account enshrined by the poet Longfellow
* (Thanks to Penny Porter for pointing this out!)


I. MacBeath Calder
The New Haven Colony
(Yale University Press, New Haven, 1934), pp. 160–161.

* A brief modern mention by Isabel MacBeath Calder
* On pp. 160-161 there is a description of "the attempt to build
* transatlantic vessels on Long Island Sound." The launch of the first
* ship, ``ill built and very `walt-sided,' '' in January, 1646, is
* described. On p. 161: ``After the lapse of many months a mirage of
* the ship was said to have appeared over the harbor at New Haven, but the
* vessel itself neither reached its destination nor returned to its port
* of departure.''
* Numerous citations are offered: New Haven Colonial Records,
* 1638-1649 , pp. 147, 283, 329-333, and ``Roxbury Land and Church
* Records,'' Record Commissioners of the City of Boston, Sixth Report ,
* p. 190 are not available to me; the others are cited here.



*** MIRAGE FILE ***

N. Desroches
Dictionnaire des Termes propres de Marine
(Amable Auroy, Paris, 1687), p. 352.

*       (see also "Crocker Land" and "W.H.Lehn" files)
*
* ORIGIN of the word "MIRAGE":
*
* The 1687 French dictionary that defines "La terre se mire":
*      "Cela se dit lors que les vapeurs font paroître les terres comme si
* elles étoient élevées sur de basses nuées." (p. 352)
* by Nicolas Desroches
*      At
* https://www.livres-anciens-et-modernes.fr/accueil/300-nicolas-desroches-dictionnaire-des-termes-propres-de-marine-1687.html
* we read that "Nicolas Desroches fut lieutenant de vaisseau en 1671 et
* capitaine en 1693."
*      Thanks to Eric Frappa for finding this reference!
* available at Google Books;
* https://books.google.fr/books?id=HcoeqZRLeKsC&printsec=frontcover&hl=fr#v=onepage&q&f=false
*


N. Aubin
Dictionaire de Marine
(Pierre Brunel, Amsterdam, 1702), p. 565.

* ORIGIN of the word "MIRAGE":
*      The old French/Dutch dictionary by Nicolas Aubin
* Defines "La terre se mire" on p. 565. The wording given there is almost
* identical to that used by Le Gentil (1789), who says he got it from the
* 1736 edition; there was also a 1742 (3rd) edition. The first edition was
* this one, in 1702. Its definition seems taken from the 1687 dictionary by
* Desroches, with minor changes.
*      Thanks to Eric Frappa for finding this reference!
* available at Google Books


J. Gronier
“Milton and the mirage,”
New Scientist 10, No. 239, 669–670 (15 June, 1961).

* Modern comments on the origin of "mirage"
* Jacques Gronier, Attaché to the French Consulate at Malta, responds to
* Richard Beck's article (16 March), supplying good English translations:
*      "In the report of Monge, entitled `On the optical phenomenon known
* under the name of mirage', and published in the Reports of the
* Institute of Cairo, one reads textually the following: 'It [the
* phenomenon] is well known to sailors, who frequently observe it at sea
* and who have given it the name of mirage. In truth, the cause which
* produces the mirage at sea may well be different from that which produces
* it on land; but the effect being absolutely the same in the two cases,
* I did not believe it necessary to employ a new word.'
*      "It is plainly apparent from this that the term had not been
* invented by Monge and that it was in previous use. Some years later,
* the physicist Biot, also a member of the Academy of Sciences, gave the
* theory of the phenomenon. His report, read on 8 August, 1808, began thus:
*      "'Physicists and astronomers have for a long time observed that
* objects which are seen very near to the horizon sometimes transmit to
* the observer two images, one upright, the other inverted. No one is
* better placed than sailors to observe this phenomenon and it is well
* known to them: they designate it by a very expressive name in calling
* it the mirage, because indeed it then seems that objects are reflected
* as in a mirror.
*      'In the volume of the History of the Royal Academy of Sciences, for the
* year 1753, printed in 1757, one finds on page 253, in the account made to
* the Academy by M. de Chabert, Lieutenant-Commander, of the voyage which he
* made by order of the King, in 1750 and 1751, to rectify the maps of Acadia
* and of Newfoundland, the following paragraph:
*      'While M. de Chabert was occupied in drawing up the plans of which we
* spoke above, he was often stopped by a singular phenomenon, that is called
* a mirage: it is an apparent change in the aspect of the shores a little
* way away, which the inhabitants attribute to the reflection of the sky
* which, mirrored in the water, makes the shore appear lifted in the air
* and which M. de Chabert believes, with great probability, is caused by
* the irregularities of refraction often undergone by terrestrial objects.'
*      "These extracts open the way to new researches.  In effect,
* this phenomenon of refraction, although it has often given place to
* interpretations scientifically incorrect, seems to have been observed,
* from very distant times, by the navigators who have certainly not omitted
* to report it.
*      "It is probable that in the archives of the Musee de la Marine in
* Paris and, in particular, in the old 'log books' which are preserved
* there, the oldest references to the word mirage may be discovered."


[J. P. ] Maraldi
“Détermination géographique de l’Isle de Corse,”
Mem. Acad. Roy. Sci. 1722, 348–355 (1724).

* MIRAGE OBSERVATIONS
*
* EARLIEST LOOMING? (Maraldi, cited by de Chabert, 1755); and indirectly
* referred to by Biot (1805).
* Giacomo Filippo Maraldi -- by now, Jacques Philippe Maraldi -- was
* the nephew of Giovanni Domenico (or Jean Dominique) Cassini.
*      This is indeed mostly about determining the coordinates of several
* places on and near Corsica; but our interest is in the introductory
* remarks:
*      "On voit des Côtes de Genes & de Provence les Montagnes de l’Isle de
* Corse, qui paroissent quelquefois élevées au-dessus de l'horison
* sensible , comme si elles sortoient de l’eau , & qui disparoissent
* en d'autre temps par un Ciel également pur & serein , comme si elles
* s’étoient plongées dans la Mer.
*      "Il y a des saisons plus propres pour découvrir cette Isle des
* côtes de Genes, qui sont le Printemps & l’Automne. On la voit aussi
* quelquefois l‘Hiver; & les heures du jour qu’elle paroît , sont le
* matin au lever du Soleil , & un peu avant , ou bien le soir , un peu après
* son coucher. On la voit aussi quelquefois dans le même jour le matin &
* le soir , & elle se perd entierement de vûe le reste de la journée.
*      "Toutes ces apparences se font sur les Côtes de Genes, par rapport
* à un Observateur qui esi toujours dans la même situation & à la même
* hauteur sur la surface de la Mer.
*      "On pourroit attribuer cette diverfité d’apparence à la variation
* qui arrive à la hauteur des eaux de la Mer , qui sont entre Genes &
* la Corse; car quoique , suivant l’opinion commune des Philofophes , la
* surface de la Mer soit sphérique, il faut avouer que cette figure est
* sujette à des variations qui lui arrivent par des causes extérieures ,
* dont les principales font les courants, aussi-bien que le flux &
* le reflux, & qui font varier confiderablement la hauteur de l’eau
* dans le même lieu.
*      "Suivant cette idée, on pourroit dire que l’Isle se découvre
* lorsque la mer est basse : au contraire la Corse se doit perdre de vûe
* du même lieu , lorsque la Mer s’éleve & se place entre deux.
*      "Mais cette explication n’est pas la plus naturelle , & il est
* plus vrai-semblable d‘attribuer ces apparences aux réfractions ,
* & de supposer que les rayons visuels qui viennent de cette Isle à
* l‘Observateur qui est sur les Côtes opposées, se rompent diversement
* dans les vapeurs qui sont entre deux; ainsi, lorsque les vapeurs sont
* plus denses ou en plus grande quantité, les réfractions des rayons
* sont plus grandes, & font paroître l'Isle au-dessus de la Mer, &
* lorsque les vapeurs sont moins denses , ou qu’il y en a une moindre
* quantité répandue dans l’air , les réfractions des rayons étant
* plus petites , l’Isle reste cachée par la Mer.
*      "Cette explication paroît d’autant plus vrai-femblable , qu’elle
* est également propre à rendre raison des apparences semblables qui
* arrivent au milieu des Terres ; car on a remarqué depuis longtemps à
* l’Observatoire, des maisons éloignées de fept ou huit lieues ves [sic]
* le Nord , qui étant cachées pendant le jour par d’autres maisons qui
* sont plus proches, & placées seulement à une demi-lieue de distance,
* paroissent souvent le matin au lever du Soleil, élevées au-dessus de
* celles qui sont proches. Ces maisons éloignées s’abaissent ensuite
* peu à peu , jusqu'à ce qu’elles se cachent entierement pendant le
* jour par les Maisons qui sont proches. Cette apparence est donc une
* preuve évidente , que les rayons se courbent dans l’air différemment ,
* suivant les différentes densités de l’air, ou suivant la différente
* quantité de vapeurs par où ces rayons passent. Cela prouve aussi que
* le matin les vapeurs sont plus denses , ou bien qu’il y en a dans
* l’air une plus grande quantité que le reste du jour. L’apparence
* que fait la Corse , vûe de Genes , étant semblable à celle que nous
* venons de rapporter , on en peut rendre raison de la même maniere.
*      "M. le Marquis Saluago a observé très souvent ces apparences que
* fait l’Isle de Corse , d’une Maison qu’il a proche de Genes vers
* le Nord . . . ." -- and here he takes up the details of the surveying,
* remarking that the height of that observatory was 50 toises (about
* 97 meters) above sea level.
*      On p. 351, he says that this height, together with the size of the
* Earth's radius determined by the Academy, predicts a geometrical dip
* of the horizon of 18 minutes; but the observed dip is only 16' 0" to
* 17' 30", which is smaller. This difference should be attributed to the
* refraction of the rays between the horizon and the quadrant.
*      The first paragraph describes an appearance corresponding to inferior
* mirages. Subsequent descriptions of variations in terrestrial refraction
* correspond to looming and sinking; and the diurnal variations are a more
* detailed description of those reported in Perrault's "De l'origine des
* fontaines" (1674).
*      The best visibility of the distant mountains (over 260 km from Genoa)
* just before sunrise and just after sunset is due to the illumination
* of the intervening lower atmosphere by the Sun, when it is above the
* observer's horizon. When the Sun is just below the horizon, the distant
* peaks are silhouetted against the brightly illuminated upper troposphere.
*      The apparent motion of distant houses relative to nearer ones that are
* visible at daybreak and sink out of sight in the middle of the day, is
* direct observation of changes in the apparent curvature of the Earth's
* surface, due to changes in lapse rate in the boundary layer.
*      In short, lots of good observations of DIURNAL VARIATIONS in refraction
* that are understandable today, but were remarkably mysterious four
* centuries ago.
*      Cited by de Chabert (1753), and mentioned by Le Gentil (1789).
* [cf. Perrault (1674); Delambre (1814); Williams, Mudge, and Dalby (1795);
* Atkinson (1826); etc.]
* Dated 28. Mars, 1722.
*      Available at BHL., and at Gallica:
*
* https://gallica.bnf.fr/ark:/12148/bpt6k3524k/f1.item
*


T. Shaw
Travels, or Observations Relating to Several Parts of Barbary and the Levant
(Theatre, Oxford, 1738), p. 362.

* EARLIEST LOOMING? (THOMAS SHAW, D.D.; cited by T.Jefferson, 1787)
*      On the title page, Shaw is merely "Fellow of Queen's-College in
* Oxford, and F.R.S."; but on the title page of the 1746 Supplement
* (bound together with the original in the copy I managed to borrow), he
* is also "Principal of St. Edmund Hall, and Regius Professor of Greek,
* in the University of OXFORD."
* In Chap. III, p. 358, "Physical Observations &c. or an Essay towards
* the Natural History of Syria, Phœnice, and the Holy Land," we find
* the passage cited by Jefferson:
*      "We are likewise to observe further with Regard to these strong
* Easterly Winds, that Vessels or any Objects which are seen, at a
* Distance, appear to be vastly magnified, or loom , according to the
* Mariners expression." [N.B.: p. 362 -- not 302!]
*      But more surprising is the passage in Chap. IV, "Physical Observations
* &c. or an Essay towards the Natural History of Arabia Petræa" (p.377):
*      "Where any Part of these Deserts is sandy and level, the Horizon
* is as fit for astronomical Observations as the Sea, and appears,
* at a small Distance, to be no less a Collection of Water1. It was
* likewise equally surprizing, to observe, in what an extraordinary Manner
* every Object appeared to be magnifyed within it; insomuch that a Shrub
* seemed as big as a Tree, and a Flock of Achbobbas might be mistaken
* for a Caravan of Camels. This seeming Collection of Water, always
* advances, about a Quarter of a Mile before us, whilst the intermediate
* Space appears to be in one continued Glow, occasioned by the quivering
* undulating Motion of that quick Succession of Vapours and Exhalations,
* which are extracted by the powerful Influence of the Sun." [pp.378-379]
*      P.378 footnote at "Water":  "The like Observation is taken notice of
* by Diodorus Siculus in his Account of Africa, l. 3, p. 128" -- and the
* passage is quoted in the original Greek.
*      This theme is continued in the Supplement, which is dated 1746;
* pp. vi and vii of its Preface contain a Note to p. 378:
*      "To Note  1. add this  learned Remark, and corroborating Proof,
* from Dr. Hyde ; who in his Annotations on Peritsol's Itinerary,
* p. 15 deduces the Name of Barca and Libya , from this Phænomenon .
* [Quotation italicized in the original:] Et quidem (ut denominationis
* causam & rationem exquiramus) dictum nomen [Arabic transcription]
* [Hebrew transcription] splendorem seu splendentem regionem notat,
* cum ea regio radiis solaribus tam copiose collustretur, ut reflexum
* ab arenis lumen adeo intense fulgens, a longinquo spectantibus (ad
* instar Corporis Solaris) aquarum speciem referat; & hicce arenarum
* splendor & radiatio Arabibus dicitur [Arabic] serâb i.e. aquæ
* superficies , seu superficialis aquarum species . --- Hinc etiam
* nominis [Greek] ratio peti potest - cum [Hebrew] contractum sit pro
* [more Hebrew], a [Hebrew] flamma - a fulvescentibus arenis ardore
* pene inflammatis."
*      The full title of the Supplement is:  A Supplement to a Book Entituled
* Travels, or Observations, &c. wherein Some Objections, lately made
* against it, are fully considered and answered: with several additional
* Remarks and Dissertations."
*      The long s is used throughout; curious spellings such as "antient"
* are regularly used. Note the capitalized Nouns as well. . . .
* Note that Jefferson's editor (William Peden) appears to have mis-read
* the page reference from TJ's MS note: it is 362, not 302.


J. G. Gmelin
D. Johann Georg Gmelins Reise durch Sibirien . . . , Dritter Theil
(Abraham Vandenhoeks seel., witwe, Goettingen, 1752), p. 129.

* EARLY LOOMING (cited by Cranz)
* "Fuer einen gewissen Vorboten eines bevorstehenden großen Sturmes in
* der See, oder auch in den unteren Gegenden des Jenisei wird dieses
* gehalten, wenn Inseln oder jaehe Felsen, die bey stillem Wetter niedrig
* aussehen, groeßer als gewoehnlich zu seyn scheinen."
* NOTE: the umlauts are written as a small letter e over each vowel.


[J.-B. ] de Chabert
Voyage fait par ordre du Roi en 1750 et 1751 . . .
(Imprimerie Royale, Paris, 1753), p. 136.

* FIRST appearance of "MIRAGE" in print? (1753)
* Chabert's full account: the 'mirage' explanation is on p. 136.
* It is taken from his journal entry for 23 Juin 1751, when he was
* observing:near Cape Sable (the southern tip of Nova Scotia).
*      "Je m'occupai pendant trois jours à la suite des opérations de la
* carte, commencées le 23 à la pointe du cap, & dans lesquelles je fus
* souvent arrêté par l'effet du mirage . C'est ainsi que plusieurs
* marins appellent un changement qui, quelquefois se fait en apparence
* dans l'aspect des côtes un peu éloignées, parce qu'ils l'attribuent
* à la réflexion du ciel, qui se peignant dans la mer au dessous de la
* côte, fait paroitre cette côte comme élevée dans le ciel. Ce même
* phénomène semble bien plûtôt venir de la grande réfraction à
* laquelle sont sujets les objets vûs à travers des vapeurs fort denses :
* cette densité n'étant point égale dans toute l'étendue d'une côte,
* les rayons diversement brisés la rendent méconnoissable. C'est la
* raison qu'en a donné feu M. Maraldi, dans les Mémoires de l'Académie
* de l'année 1722."
*      The remark about the mirage stopping his surveying operation is
* very similar to the report by Boscovich & Maire (1755). Notice that in
* this version, the word comes from "several sailors"; in the abstract in
* "Hist.", the word is attributed to "the inhabitants" of the coast.
*      This page is cited in the Index as a peculiar entry: "Mirage. Idée
* de cette illusion d'optique, 136."
*      Note that Bouguer was one of the referees who approved this work for
* publication (pp.i and iv).
*      The first page has a nice woodcut showing the surveyors with all their
* equipment, observing the Moon with their quadrant to determine the time.
*      This was reprinted in 1966; copies of the original sell for over $1000.
* Available at Google Books. The example digitized by Google bears the
* stamps of the National Library of Naples.
* https://www.google.com/books/edition/Voyage_fait_par_ordre_du_roi_en_1750_et/lJzIEAa6cuwC?hl=en&gbpv=1&dq=mirage&pg=PA136&printsec=frontcover


R. J. Boscovich and C. Maire
De Litteraria Expeditione per Pontificiam Ditionem . . .
(Typographio Palladis, Rome, 1755), pp. 94–96.

* ROGER BOSCOVICH sees some EARLY INFERIOR MIRAGEs, and looming
* The mirage observations are in paragraphs 173 and 174.
* These seem to be the first circumstantial descriptions of mirages.
*      To understand para.173, some explanation is required:
* They were starting the triangulation at the mouth of the Ausa river
* (near Rimini) in July, 1752, using a baseline measured along the shore
* some months previously. The "sign" used at each end of the baseline
* was three posts stuck in the ground, with a whitewashed sheet wrapped
* around their upper ends as a target to sight on. The angles were
* measured with a portable quadrant. Now read on:
*      "As soon as the signs were erected, we went there to take angles, and
* at least at the Ausa's mouth everything went quite well. But as soon as
* we reached the other end, a quite wonderful phenomenon appeared to us.
* The second sign is separated from the first by only eight thousand
* paces [about 12 km in modern units], and more than 20 spans [1.5m] high;
* we had seen it quite plainly first thing in the morning. But when we
* arrived at this second end a little after noon, allowing for the
* curvature of the sea (for a straight line about eight miles long joining
* the two heads would pass well above the sea) could only hide much less
* of its height in this interval, for it was raised 20 spans; yet now with
* the telescope pointed to a place we knew very well, corresponding to
* a place at the port of Rimini next to the building where those who are
* accustomed to be cared for are liberated to health from a fear of
* pestilence [i.e., the quarantine hospital], nothing appeared at all.
* Really only the highest part of the buildings was seen, and even that
* wonderfully contracted, as also the sails of ships in the harbor, many
* of which were spread and appeared completely distorted. Struck by the
* novelty of the thing, I brought a ladder to the post of the sign, and
* having climbed up a few steps, with the telescope pointed to the place,
* I saw the webbing of the sign at Ausa, not emerging from the waters
* gradually, though it was broad, but all at once, at first as through a
* haze, then much clearer, and at first the thinnest line, then as I
* climbed higher it enlarged more, until it returned to its own form,
* as did that building I have mentioned, and the sails of the ships. Both
* Maire and I have watched this phenomenon quite astonished, again and
* again, now raised up higher by the steps, now lowering the eye; but toward
* sunset we had to return to our angles, which we could take even at this
* sign, by moving a wagon, which fortunately was there, to the very place of
* observation, and raising up the quadrant in it, we saw the sign quite
* plainly, and we completed our observations."
* [This is a fine description of an inferior mirage; the "all at once"
* business being a particularly nice touch; cf. Hardcastle (1905).]
* In para.174, he remarks that he has often seen "the ends of
* promontories, or the points of islands, as if raised in the air," and
* that this is a phenomenon of the same kind. He has noticed that this
* occurs only when the line of sight grazes the surface of the sea, and
* that it vanishes if viewed more obliquely from a higher location.
* In section 175, he mentions an instance of variable looming, which he
* correctly attributes to an "inequality" of the horizontal refraction.
* Thanks to Classics Prof. James Smith for assistance with the translation!
* According to the E.B., Christopher Maire was an English Jesuit.
* O'C #9


[J.-B. ] de Chabert
“Voyage fait par ordre du Roi en 1750 et 1751 . . . ,”
Hist. Acad. Roy. Sci. 1753, 242–256 (1757).

* Early use of the word "MIRAGE" by Joseph-Bernard de Chabert
* "Cette année M. de Chabert, Lieutenant des vaisseaux du Roi, Chevalier
* de l'Ordre de Saint-Louis, Membre de l'Académie de Marine, de celle de
* Berlin & de celle de l'Institut de Bologne, présenta à l'Académie la
* Relation du voyage qu'il a fait par ordre du Roi en 1750 & 1751 dans
* l'Amérique septentrionale, pour rectifier les cartes des côtes de
* l'Acadie, de l'isle Royale & de celle de Terre-Neuve, & pour en fixer
* les principaux points par des observations astronomiques." (pp.242-243)
*      "Pendant que M. de Chabert étoit occupé à lever les plans dont nous
* venons de parler, il fut souvent arrêté par un phénomène singulier,
* qu'on appelle mirage : c'est un changement apparent de l'aspect des
* côtes un peu éloignées, que les habitans attribuent à la réflexion du
* ciel, qui, se mirant dans l'eau, fait paroître la côte comme élevée
* en l'air, & que M. de Chabert croit, avec plus d'apparence, causé
* par l'irrégularité de la réfraction qu'ont souvent à souffrir les
* objets terrestres." (p. 253)
* (See Gronier, 1961, for a good translation.)
*      From the collected tables of contents, it appears that this text is
* on p.358 of the reprinted edition of Hist. Acad. Roy. Sci.
* This account in the Hist. Acad. Roy. Sci. is just an extended abstract
* of the book published in 1753.
*      Many thanks to Éric Frappa for discovering this at Gallica:
*
* http://gallica.bnf.fr/ark:/12148/bpt6k3551g/


D. Giardina
“Discorso sopra la Fata Morgana di Messina,” in Opuscoli di Autori Siciliani, Tomo Primo , Gioachimo Pulejo, ed.
(G.Pulejo, Catania, 1758), pp. 117–148.

* DOMENICO GIARDINA explains the Fata Morgana of Aug. 1643
* The day here (the 14th) is the day before Angelucci's FM observation
* quoted by Kircher (1646); but the two accounts are substantially
* identical, as noted by Consolo; Allegranza seems to be the only source
* for the 14th as the date.
* [Cf. Boccara's (1902) denunciation of Kircher, Giardina, and Allegranza.]
*
* The motivation for publishing all this nonsense seems to have been the
* ambition of the publisher, Gioachimo Pulejo, a printer in Catania who
* published several works promoting the reputations of local cities and
* their inhabitants -- e.g., "L'ardenza e tenacità dell'impegno di
* Palermo, nel contendere a Catania la gloria di aver dato alla luce la
* regina delle vergini, e martiri siciliane Sant'Agata" (1747). The
* present case is another example: in the dedication, and on the prefatory
* pages I and II, "from the publisher to the reader", we see how he
* is concerned with promoting Sicilian works.
*
*      The full title preceding Giardina's text is:
*
*
*                   D  I  S  C  O  R  S  O
*
*                         S O P R A
*                                L A
*
*                   F A T A      M O R G A N A
*
*                    DI MESSINA, COMPARSA
*      NELL' ANNO MDCXLIII.  AL DI XIV. D'AGOSTO
*
*                                DEL
*            P.  DOMENICO       GIARDINA
*
*              DELLA COMPAGNIA DI GESU'
*
*                   CON  ALCUNE  NOTE
*              DELL'  ERUDITISSIMO
*                  SIG. ANDREA GALLO
*                        MESSINESE.
*
*
* (which takes up all of p. 117.)
*
* Giardina and Gallo are briefly described in pp. II and III of the preface.
* As Giardina died in 1747, in his 50th year, he could not have observed
* the 1643 display he tries to interpret here; Marina Warner is confused.
* Unfortunately, her confusion has become a "viral" sensation on the Web.
* This falsehood continued to be spread by other readers who believed the
* fabrications added to the story by Capozzo (1840), such as Consolo
* (1993) and Séstito (2011).
*
* The numerous informative footnotes were inserted by Gallo; they refer to
* "the author" (Giardina) in the third person.
*      In particular, note [c] (p. 121) criticizes the author for not being
* "concordant with modern Philosophy" which distinguishes the real ascent
* of sulfurous and bituminous material in the air from the "apparent,
* formed by the refraction of the solar rays."
*
* Giardina's essay ends on p. 143, where a letter from Giuseppe Allegranza
* begins. Allegranza attempts to derive "Morgana" from the German "Morgen".
* Strangely, he has the page wrong in "Ars Magna", and calls Angelucci
* "Andreucci". In fact, the page number given (704) corresponds to the
* 1671 edition published in Amsterdam in; but that one still has
* "Angelucci" correctly. Apart from minor editorial changes in spelling
* and punctuation, Allegranza's text here is exactly the same as a text
* published without attribution in "Giornale de' Letterati" for the year
* 1755, dated "Messina 15. Feb. 1751", pp. 46 - 55. In particular, both
* that version and this one have the "Andreucci" error. So Allegranza's
* 1751 text appears to be the origin of both the "Andreucci" error and the
* dubious date: he says the observation was made "in una Vigilia dell'
* Assunzione" -- i.e., the 14th. (p. 144) Boccara (1902) dismisses all
* of them: Kircher, Giardina, and Allegranza.
*
* The attribution of the Fata Morgana to reflections by "polyhedral
* crystals" seems to be inspired by Mariotte's explanations of halos
* by refraction and reflection in ice crystals, in 1679.
*
* Available in two copies from Google Books. One, from Oxford:
* https://books.google.com/books?id=3r0TAAAAQAAJ&vq=Giardina&source=gbs_navlinks_s
* is lower quality; the other, from U.Michigan:
* https://books.google.com/books/about/Opuscoli_di_autori_Siciliani_Dunning.html?id=LvgDAAAAMAAJ
* has had the name "Dunning" unaccountably appended to the title, and is
* also available at the HathiTrust site. Note that Vol. 2 is bound
* together (and scanned) with Vol. 1.
*      This is the work Brydone (1773) mentions but was unable to find.
* Cited by P&E in a footnote on p.186.


M. Warner
Phantasmagoria: Spirit Visions, Metaphors, and Media Into the Twenty-first Century
(Oxford University Press, Oxford, 2006).

* MARINA WARNER's garbled account (placed here for her citation of Giardina)
* Chapter 7 is devoted to "Fata Morgana ; or, Castles in the Air".
* Her Fig. 9b on p. 94 was the best reproduction of Fortuyn's engraving for
* Minasi that I had seen in print, until Séstito's (2011). But she failed
* to get the facts right:
*      "Kircher described one instance in his book . . . , in response to a
* fellow Jesuit who had written to him [sic!] . . . about a . . . fata morgana
* he had witnessed himself in Sicily [sic!]." (p. 95)
* So she confuses Giardina with Angelucci, and Kircher with Sanzio.
*      "Giardina . . .  goes on to describe how he saw [sic] `a city all floating
* in the air . . .'" (p. 96)
*      Note 2 on p. 96 links to p. 391; the note there cites both Giardina
* and Minasi -- who explained that Giardina was referring to Angelucci.
*       She also parrots much common nonsense about mirages: "Technically
* now known as a `superior' or `looming mirage', fata morgana appears
* above the horizon, often rising to great heights among the clouds." (p. 97)
* Then follows: "Layers of the atmosphere at different temperatures develop
* [sic] different densities, and the sun's rays, hitting the surface
* of the sea and the layers of air at a certain angle (45 degrees) turn
* them into an infinite recession of mirrors, multiplying and inverting
* reflections, diffracting [sic] and refracting the light so as to project
* images of far distant scenes and objects onto the clouds; these images,
* turned upside down and superimposed [sic] on one another, then mingle
* and change rapidly as the layers move up and down from the observer's
* vantage point." Well, this is all nonsense! She has thrown some words
* together without understanding their meaning, and produced gibberish.
*      On top of this, she cites as references on fata-morgana mirages some
* so-so websites, rather than the standard references on these topics
* (e.g., P&E; Humphreys; not even Minnaert or Greenler are cited.)
* A pretty sorry showing.
*       (snippet view on Google Books)
*
* Much of this is taken from her Tanner lecture in 1999; see
*            http://tannerlectures.utah.edu/_documents/a-to-z/w/Warner_01.pdf
*      [all reprinted in Raritan 21, No.4, pp. 264-301 (Spring, 2002)]
* where she cites both Giardina and Minasi in note 3 on p. 67. There,
* she explicitly refers to Angelucci's letter in Kircher's book, and even
* says that Giardina's "Discorso" came "More than a hundred years later".
* So how did she later arrive at the wrong chronology?
*      Note that her Tanner lecture contains more errors of its own; e.g.,
* her mistranslating of the phrase "delle sustruttioni di Salomone" as
* "the somersaults of Salome" instead of "the constructions of Solomon."
* This "Salome" appears as a typo in the text of the 1671 Amsterdam
* edition of "Ars Magna"; apparently she got it from that:
* https://books.google.com/books?dq=Kircher+%22Ars+Magna%22&jtp=704&id=wYlDAAAAcAAJ#v=onepage&q=Kircher%20%22Ars%20Magna%22&f=false
* -- and she gave 1646 as the date of Kircher's book, but cited the page
* (701) where this error appears in the 1671 edition. Evidently, she
* only consulted the later edition, citing the earlier one without
* actually reading it.
*      Furthermore, she attributes Minasi's term "l'iride fregiata" (1773)
* to Giardina, who died in 1747, when Minasi (born in 1736) was still a
* schoolboy. (Giardina used "iride", but only in the phrase "iride
* marina".) And she mis-translates Minasi's phrase as "the festooned
* rainbow." Some historian!
*      [And in the introductory Acknowledgments in the book, she gives the date
* of her 1999 lecture as 1992.]


A. Leanti
Lo stato presente della Sicilia o sia breve, e distinta descrizione di essa
(Francesco Valenza, Palermo, 1761).

* ARCHANGIOLO LEANTI's mention of Fata Morgana, based on Giardina
*      This is the source of Brydone's (1773) exaggerated account.
* Although modern references to Leanti spell his given name "Archangelo",
* his historical monograph uses "Archangiolo" consistently. The title
* page describes him as "sig. Abate Arcangiolo Leanti da Palermo".
*      The reference to the Fata Morgana is on pp. 3 and 4; he cites mainly
* the Giardina/Gallo/Allegranza work, but mentions Kircher, Fazello,
* Pliny, and Pomponius Mela as earlier sources.


Maire & Boscovich
Voyage Astronomique et Geographique, dans l'État de l'Eglise . . .
(Tilliard, Paris, 1770), pp. 94–96.

* BOSCOVICH translated into French
* The same section numbering is used as in the original. There is a
* detailed map included, showing the region surveyed.
*      NOTE on UNITS:  There is a handy Table for converting between
* Roman feet and palms and Paris toises and feet on p. viii.
*      Typographical note:      The use of the accented "E" is extremely
* haphazard. On the title page, it only occurs in "État". In the
* preface and table of contents, no uppercase E is accented; but the
* lowercase é is abundant. The heading on p.1 of the main text says
*
*                  V O Y A G E
*
* ASTRONOMIQUE ET GÉOGRAPHIQUE
*
*      DANS L'ÉTAT DE L'ÉGLISE
*
* and the body type all has accents where you'd expect them.
*
* See
*      https://gallica.bnf.fr/ark:/12148/bpt6k9629131h/f25.item.texteImage


J. Byron
in Byron's Journal of his Circumnavigation, 1764-1766; , R. E. Gallagher, ed.
(Cambridge Univ.Press, Cambridge, 1964), pp. 29–30.

* John Byron's probable superior mirage
* Nov. 12, 1764: "At 4 PM it thunder'd & Lightened very much, & looked
* very black almost round the Horizon, I was then walking the Quarter Deck
* when all the People upon the Forecastle called out at once Land right a
* head, I looked under the Foresail & upon the Lee Bow, & saw it to all
* appearance as plain as ever I saw Land in my life, It made at first like
* an Island with two very scraggy Hammocks upon it, but looking to Leeward
* we saw the Land joining it & running along way to the SE, we were then
* steering SW. I sent Officers to the Mast head to look out upon the
* weather Beam & they called out immediately they saw the Land a great way
* to Windward. I brought too & sounded & had 52 fm -- I now thought I was
* embay'd & as it looked very wild all round I wished myself out before
* night. We made Sail & steered ESE. All this time the appearance of the
* Land did not alter in the least, the Hills looked very Blue as they
* generally do at some little distance in dark rainy weather, & many of the
* People said they saw the Sea break upon the Sandy Beaches. After steering
* for about an hour, what we took for Land all at once disappeared to our
* great astonishment, & certainly must have been nothing but a Fog Bank.
* Tho' I have been at sea now 27 years & never saw such a Deception before,
* & I question much if the oldest Seaman breathing ever did, except it was
* some in that Ship when the Master made Oath of seeing an Island between
* the West End of Ireland & Newfoundland, & even distinguishing the Trees
* upon it, & which since has never been heard of tho' Ships have been sent
* out on purpose to look for it. And had the weather come on very thick
* after the sight we had for some time of this Imaginary Land so that we
* could not have seen it disappear as we did, I dare say there is not a Man
* on board but would have freely made Oath of the certainty of it's being
* Land. Course So 47° Wt. Dist 108 Ms Latt in 43° 46' So.
* Longde made 19° 47' Wt."
*      Note the reference to (evidently) "St. Brendan's island".
* [mentioned in Beauford's 1802 review of mirages.]


D. Cranz
Historie von Groenland
(Heinrich Detlef Ebers, Barby, 1765), pp. 64–65.

* VERY EARLY MIRAGE seen by David Cranz (FATA MORGANA + SUPERIOR MIRAGE)
* "Aber nichts hat mich mehr surprenirt und artiger anzusehen geduenkt,
* als wenn bey heiteren, warmen und stillen Sommer-Tagen die Kookoernen,
* oder die zwey Meilen von Godhaab gen Westen gelegenen Inseln, eine ganz
* andere Gestalt, als sie natuerlich haben, vorstellen. Nicht nur sieht man
* sie, wie durch einen Tubum , weit groesser, und alle Steine und die mit
* Eis angefuellten Ritzen so deutlich, als ob man nahe dabey stuende;
* sondern wenn dieses eine Weile gewaerht hat, so sehen sie alle wie ein
* einiges Land aus, und stellen einen Wald, oder eine geschorne Baum-Wand
* vor. Darauf sieht man sie allerley seltsame Figuren, als Schiffe mit
* Segeln, Wimpeln und Flaggen, alte Berg-Schloesser mit ruinierten Thuermen,
* Storch-Nestern und hundert dergleichen Dingen, vorstellen, welche sich in
* die Hoehe oder Weite ziehen und sodann verschwinden. Die Luft is alsdann
* zwar ganz still und klar, aber doch, wie bey sehr heissem Wetter, mit
* subtilen Duensten angefuellt, durch welche sich, nach meinen Gedanken,
* wenn sie zwischen dem Auge und den Inseln in einem gehoerigen Abstand
* sich befinden, die Objecte, wie durch ein convexes Glas, weit groesser
* vorstellen; und gemeiniglich folgt ein paar Stunden darauf ein sanfter
* West-Wind mit einem sichtbaren Nebel, da dann dieser Lusus naturae
* gleich ein Ende hat.(*)"
* FOOTNOTE: "(*) Etwas dergleichen habe ich bey Bern und Neufchatel von
* denen gegen Sueden gelegenen Gletschern observirt. Wenn sich dieselben
* naeher, deutlicher und groesser als gewoehnlich vorstellen, so rechnet
* der Landmann auf einen baldigen Regen, der sich auch gemeiniglich den
* folgenden Tag einstellt. Und die Tartern an der Muendung des
* Jenisei-Flusses in Sibirien haltens fuer einen Vorboten des Sturms, wenn
* die Inseln groesser scheinen. Gmelins Reise Th. III S. 129."
* Orthographic note: All double-s's are simply spelled out, using the long
* s for both. Umlauts are written as a raised e over the vowel.


H. Hamilton
Philosophical Essays. II. An Essay on the Ascent of Vapours, the Formation of Clouds, Rain, and Dew, and on several other Phænomena of Air and Water
(W.Sleater, Dublin, 1766), pp. 31–88.

* HUGH HAMILTON
* Early mirage publication (mentioned by Huddart.)
* Footnote, pp.43-44: "This Fleece of vapourous Air that some times hangs
* over Water, is very discernable when we stand by the Sea-side in a hot
* calm Day, and is the Cause of some odd Appearances. For the lower Part
* of the Air, which is then much impregnated with Water, refracts the Rays
* of the Light more strongly than at other Times, and by this unusual Degree
* of Refraction, Houses on the Shore at a Distance from us appear almost as
* high as Steeples, remote Ships and Islands and the extreme Parts of
* Head-lands or Promontories appear to be raised quite out of the Water, and
* to hang in the Air above its Surface."


W. Wales
“Journal of a Voyage, Made by Order of the Royal Society, to Churchill River, on the North West Coast of Hudson's Bay; Of Thirteen Months Residence in That Country; and of the Voyage Back to England; In the Years 1768 and 1769,”
Philosophical Transactions Roy. Soc. 60, 100–136 (1770).

* WILLIAM WALES reports looming in "haze" (i.e., "FOG") at Hudson's Bay
* Observations of LOOMING, CONCAVE surface, NEGATIVE DIP, etc.:
*      pp. 115-116: "August 7th.  About 5 saw the low land of Cape Churchill,
* bearing from the S to S. W. b. S. but the haziness of the horizon made
* the land put on a different appearance every 4' or 5'. I cannot help
* taking notice of one circumstance, as it appears to me a very remarkable
* one. Though we saw the land extreamly plain from off the quarter deck,
* and, as it were, lifted up in the haze, in the same manner as the ice
* had always done; yet the man at the mast head declared he could see
* nothing of it. This appeared so extraordinary to me, that I went to the
* main-top-mast-head myself to be satisfied of the truth thereof; and though
* I could see it very plain both before I went up, and after I came down,
* yet could I see nothing like the appearance of land when I was there.
* I had often admired the singular appearance of the ice in these parts,
* which I have seen lifted up 2° or 3° at a distance of 8 or 10 miles,
* although when we have come to it, we have found it scarcely higher than
* the surface of the water."
*      P. 131: "The prodigious difference between the latitude of Churchill
* factory, as laid down from observations made by Hadley's quadrant, and
* that deduced from the observations made with our astronomical quadrant on
* shore, has often employed my most serious attention; but I cannot think on
* any probable cause for such difference, unless it lie in the very great
* refractive power of the air in these parts. I have mentioned how the
* ice and land appear to be lifted up, when we stand on the ship's deck:
* and if the visible horizon be lifted up in like manner, it must make its
* apparent distance from the sun, or, which is the same thing, the sun's
* apparent altitude less than it otherwise would be; and consequently,
* the latitude greater than the truth; and also greater than it will be
* shewn by a land quadrant, which depends not on the horizon, agreeable
* to what we find it in the case before us*."
*      The footnote (*) continues onto p. 132:
*      "*Having mentioned this circumstance to the reverend Mr.
* Maskelyne, it immediately occurred to him, that the longitude
* deduced from observations of the moon’s distance from the sun or a
* star, would be considerably affected by this cause, as not only
* the altitudes of the sun, from whence the time at the ship is
* found ; but also the latitude of the ship, found by an observa-
* tion of the sun’s meridional altitude, or otherwise, will conspire
* to encrease the sun’s distance from the meridian, or angle at the
* pole.
*       "I have therefore recomputed the longitude from my observa-
* tion of the moon's distance from the sun, taken August the 5th,
* 1768, on a supposition that the mean error in any altitude taken
* by Hadley's quadrant, arising from this cause, is 10 minutes;
* and find that, on such a supposition, which it must be allowed
* appear to be extremely well founded, the longitude will be 11'¼
* less than what I found it at the time when I made the observa-
* tion, and therefore the longitude of Churchill will in this case be
* only be 94° 30'¾ W. And by making a similar correction of 15' to
* Mr. Dymond’s observation of the 6th, it will give the longi-
* tude of Churchill 95° 18' W." [Modern long. = 94° 13'.]
* [This may be the EARLIEST mention of this problem.]
*      William Wales later made similar observations in the Antarctic, as
* one of the astronomers on Captain James Cook's second voyage. A good
* biography is at
*
*        http://biographi.ca/009004-119.01-e.php?id_nbr=2203
*
* and a complete bibliography of his publications is at
*
* http://www.captaincooksociety.com/home/detail/articleid/95/manuscripts-and-published-work-involving-william-wales
*
* Available from JSTOR; but their OCR is worse than tesseract's.
* Their URL is
*       http://www.jstor.org/stable/105882?seq=1#page_scan_tab_contents


J. de Viera y Clavijo
“La famosa cuestión de San Borodón,” in Noticias de la Historia de Canarias, Tomo I , Dr. A. Cioranescu, ed.
(Cuspa Editorial, Madrid, 1978).

* JOSEPH VIERA Y CLAVIJO (1772) -- Early mirage observations in CANARIES
* After recounting the legend of the mythical island, and quoting some
* first-hand observations, he concludes it is all due to atmospheric
* refraction.
* The mirage section is unusually long and detailed. It is Chapter 28 of
* Book 1.
* (Originally published by La Imprenta de Blas Roman, Madrid, 1772-1783)
* Thanks to Guy Vincent for calling this to my attention!


P. Brydone
A Tour through Sicily and Malta. In a series of letters to William Beckford, Esq. of Somerly in Suffolk; from P. Brydone, F.R.S. In two volumes
(W.Strahan and T.Cadell, London, 1773).

* PATRICK BRYDONE's account of the Sicilian mirages
* Though this is clearly a description of the Fata Morgana, that name
* never appears; instead, the apparitions are attributed to Old Nick
* [Note: "this place" is Messina]:
* "Do you know, the most extraordinary phœnomenon in the world is often
* observed near to this place? -- I laugh'd at it, at first, as you will do;
* but I am now thoroughly convinced of its reality; and am persuaded too,
* that if ever it had been thoroughly examined by a philosophical eye,
* the natural cause must long ago have been assigned.
*      "It has often been remarked, both by the antients and moderns, that
* in the heat of summer, after the sea and air have been greatly agitated
* by winds, and a perfect calm succeeds, there appears, about the time of
* dawn, in that part of the heavens over the Straits, a vast variety of
* singular forms, some at rest and some moving about with great velocity.
* These forms, in proportion as the light increases, seem to become more
* aerial; till at last, some time before sun-rise, they entirely disappear.
*      "Some of the Sicilian authors represent this as the most beautiful
* sight in nature; Leanti, one of their latest and best writers, came here
* on purpose to see it: He says, the heavens appear crowded with a variety
* of beautiful objects: He mentions palaces, woods, gardens, &c. besides
* the figures of men, and other animals, that appear in motion amongst
* these objects. -- No doubt the imagination must be greatly aiding, in
* forming this aerial creation; but as most of their authors, both antient
* and modern, agree in the fact, and many give an account of it from their
* own observation, there certainly must be some considerable foundation
* for the story. There is a Jesuit, one Giardina, that has lately writ
* a treatise on this phœnomenon, but I have not been able to find it:
* The celebrated Messinese Gallo has likewise published something on this
* singular subject; if I can procure them in the island, you shall have
* a more perfect account of it. The common people, according to custom,
* give the whole merit of it to the devil; and indeed it is by much the
* shortest and easiest way of accounting for it: Those who pretend to
* be philosophers, and refuse him this honor, are greatly puzzled what
* to make of it. They think it may be owing to some uncommon refraction,
* or reflection of the rays, from the water of the Straits; which, as it
* is at that time carried about in a variety of eddies and vortexes, must
* of consequence, say they, make a variety of appearances on any medium
* where it is reflected. -- This, I think, is nonsense; or at least very
* near it; and till they can say more to the purpose, I think they had
* much better have left it in the hands of the old gentleman. I suspect
* it is something in the nature of our Aurora Borealis; and, like many of
* the great phœnomena of nature, depends upon electrical causes; which,
* in future ages, I have little doubt, will be found to be as powerful an
* agent in regulating the universe, as gravity is in this age, or as the
* subtile fluid was in the last." (Vol. I, pp. 86-89)
* (Brydone's scientific specialty was electrical phenomena.)
*      NOTE: Brydone's comments on Leanti are off the mark: Leanti was born
* in Sicily, and spent his whole life there; so the ". . . came here on
* purpose to see it" part is bogus [he probably confused Leanti with
* Kircher in this case]. Likewise, "the heavens appear crowded with"
* the images is Brydone's invention; Leanti merely says "in the air".
*      [Brydone's references to Giardina and Gallo correspond to Gallo's
* notes added to Giardina's useless rediscussion of Angelucci's letter.]
*      This went through dozens of editions, in English and several other
* languages. In the "new edition" of T. Cadell and W. Davies (1806), the
* text has been tidied up a bit by minor editing, and changes in punctuation
* and spelling (making "ancients" and "phænomenon" instead of the variants
* above, for example); and the passage then falls on pp. 50-52.
*      I read somewhere that this originally appeared in the Gentleman's Magazine
* in 1773, but find no reference to it.
* Copies of the 1773 London (1st) and 1806 editions are on Google Books.


A. Minasi
Dissertazioni sopra diversi fatti meno ovvi della Storia Naturale, Dissertazione prima sopra un fenomeno volgarmente detto Fata Morgana, o sia apparizione di varie, successive, bizzarre immagini, che per lungo tempo ha sedotti i popoli, e dato a pensare ai dotti. A Sua Eminenza il Signor Cardinale di Zelada
(per Benedetto Francesi, Roma, 1773).

* ANTONIO MINASI's account of the Fata Morgana
*      There are many interesting details here that were omitted by Nicholson
* in his translation. This 102-page monograph is more informative than
* some later reviews (Nicholson; Reinecke; Büsch; Gilbert; P&E) suggest.
* The last 4 all depend on German translations of Nicholson's English.
*      In the footnote on p. 18, he says "I have observed a little Fata
* Morgana near Rome. . . " at 11:30 on April 21, in the lake of Castel
* Gandolfo.
*      In the discussion, he reviews all earlier accounts, including de
* Ferrariis, Angelucci, Kircher, etc. -- even including the Maccabees.
* He reprints (with some minor changes) almost all of Angelucci's letter,
* from the 1671 (Amsterdam) edition of Kircher.
*      Notice his extensive discussion of Giardina's paper (§4, pp. 21 ff.)
* Minasi makes plain his disbelief of the Giardina discussion in Cap. IV;
* see the additional discussion in his footnotes 2 and 7 to this chapter.
* See his footnotes on p. 35, and the derivation of the "45°" on p.41.
*      Minasi buried much valuable information in his footnotes.  For
* example, the note on p.17 in Cap. III mentions the "spring, and the
* first months of summer" as the time when the images are reflected;
* and these are exactly the classical superior-mirage season (cf. Forel!)
* And on the next page, he cites the months of April through August as
* most favorable for these reflections.
*      Note that Minasi's footnotes are numbered consecutively on each page .
* This leads to some confusion in their cross-references: the note at the
* foot of p. 17, where § 8 begins, is actually referenced in § 7, and
* numbered 1. The "nota 1" of § 8 that is referenced in the notes in
* later chapters is the note numbered 1 on p. 18, but continued on p. 19.
* The next note, cited as "§8. nota 2" in later chapters, is numbered 1 on
* p. 19, but continues on p. 20.
*      Note on UNITS: the "Italian palms" used by Minasi are probably the same
* as the "Roman palms" that are converted to Paris measures in the Table on
* p. viii of the 1770 French translation of Maire & Boscovich.
*
* This is available at Google Books:
*
* https://books.google.com/books?id=yh3SLkLf9NYC&printsec=frontcover&dq=Minasi+%22Fata+Morgana%22&hl=en&sa=X&ved=0ahUKEwi_-vuR3f7dAhWlct8KHSiCCCIQ6AEILDAB#v=onepage&q=Minasi%20%22Fata%20Morgana%22&f=false
*
* but unfortunately the text of the PDF file they provide is badly
* garbled. Apparently, because of the mixture of Italian, Latin, Greek,
* and Hebrew in the text, everything available in UTF-8 encoding turns up.
* There are snatches of Chinese and Japanese characters, as well as
* Cyrillic. This makes any kind of machine translation impractical.
*      A more practical re-publication of Minasi's text is in Consolo's
* 1993 book "Vedute dello Stretto di Messina"; but that is marred by
* his credulous acceptance of Capozzo's (1840) fallacious inventions.
* (Evidently, Consolo never bothered to read Minasi.) Yet another
* republication of Minasi's text is in Séstito's book (2011); it copies
* errors from Consolo, and appears to be copied from his version rather
* than from Minasi's original.
*
*      A high-resolution scan of Fortuyn's engraving is available at
*
* http://dr.casanatense.it/drviewng.html#action=jumpin;idbib=1582;idpiece=-1;imageNumber=1;idpiece=-1
*
* [click on the "IIP" icon in the header to see the full resolution.]
*
* The engraving is discussed in Maria Toscano's thesis:
*      http://www.fedoa.unina.it/777/1/Tesi_Toscano.pdf
* and in her article:
*      "Lo strano caso di Guglielmo Fortuyn. Un tentativo di attribuzione"
* Neoclassico, No. 23/24, pp. 39-68 (2003)
*
* Finally, a biography of Minasi written by Enrico Pescatore was published
* in the "Scilla News" on 20 April, 2020, and archived on the publisher's
* website:
*
* http://www.strettoweb.com/2020/04/scilla-storia-don-antonio-minasi/1003141/
*


J. Marra
Journal of the Resolution's Voyage in 1771-1775
(N.Israel, Amsterdam, 1967).

* Possible mirages in the Antarctic in JOHN MARRA's Journal (1775)
*      [Dec. 15, 1773:] "Here the ice islands presented a most romantic
* prospect of ruined castles, churches, arches, steeples, wrecks of ships,
* and a thousand wild and grotesque forms of monsters, dragons, and all the
* hideous shapes that the most fertile imagination can possibly conceive."
* (p. 111)
*      [Jan. 26, 1774:] "At nine in the morning every body on deck imagined
* they saw land; and accordingly preparations were made for getting all
* things in readiness to cast anchor. At eleven crossed the antarctic
* circle to the southward for the 2d time, and hauled up S. E. by E. where
* they were persuaded land was. But to their great disappointment, the
* farther they sailed, the farther the land seemed to bear from them;
* and at length it wholly vanished." (p. 123)
* [Jan. 30, 1774:] "Came in sight of a fog bank, which had a great
* appearance of land, and many who were thought the best judges asserted
* that it was land; however it proved upon trial a deception, as well as the
* former. . . . Taking a view from the mast-head nothing was to be seen but
* a dreary prospect of ice and sea. Of the former might be seen a whole
* country as far as the eye could carry one, diversified with hills and
* dales, and fields and imaginary plantations, that had all the appearance
* of cultivation; yet was nothing more than the sports of chance in the
* formation of those immense bodies of congregated ice." (p. 125)
*
* This is a heavily-edited account, nowadays attributed to the journal of
* John Marra, a gunner's mate on the Resolution . Supposedly his editor
* was David Henry, of the Gentleman's Magazine . No author appeared
* on the title page of this when it was originally published, 18 months
* before Cook's official account (which does not mention these appearances,
* but only ice fields). The original title was:
*
*                                      J O U R N A L
*                                            of the
*                                RESOLUTION's VOYAGE,
*                        In 1772, 1773, 1774, and 1775.
*                                                 on
*                  DISCOVERY to the SOUTHERN HEMISPHERE,
*                                           by which
*       The Non-Existence of an undiscovered Continent,
* between the Equator and the 50th Degree of Southern
* Latitude, is demonstratively proved.
*
* Sources on the Web indicate that a French translation was published
* in Amsterdam in 1777, and it is evidently that which Biot had read.
*      This modern edition is Bibliotheca Australiana #15.


W. Wales and W. Bayly
The original astronomical observations made in the course of a voyage towards the South Pole, and round the world, in His Majesty’s ships the Resolution and Adventure, in the years MDCCLXXII, MDCCLXXIII, MDCCLXXIV, and MDCCLXXV
(J. Nourse: J. Mount & T. Page: W & A Strahan, London, 1777).

* WALES & BAYLY (astronomers with James Cook's second voyage)
* William Wales was the editor of this volume, which contains various
* sections written by himself and by William Bayly; Wales was aboard
* the Resolution (James Cook's flagship); Bayly, on the Adventure.
*      Our interest is in Wales's "Meteorological Journal", pp. 335-366.
* The excerpt reprinted by Sir Napier Shaw in 1930/1942 was from
* p. 351; cf. Pernter (1902).
*      The publication details are complex: the volume was printed by
* W. & A. Strahan, and sold by J. Nourse, in the Strand, and J. Mount
* and T. Page, on Tower-Hill, Booksellers to the Board of Longitude,
* which paid for the observations:
* "Published by order of the Board of Longitude, at the Expence of which
* the Observations were made."
*      See
*
*      http://acms.sl.nsw.gov.au/album/albumView.aspx?itemID=852703&acmsid=0
*
* for the Introduction and Contents.
*


Le Gentil
Voyage dans les Mers de l'Inde, Tome premier
(Imp.Royale, Paris, 1779).

* LE GENTIL's observations in India
*
*      There are several sections of interest here, all in the Seconde Partie
* of Vol. 1:
*
* Ch. I, Art. III. Observations sur les Réfractions horizontales (p. 393)
* Remarques sur l'Observation des Hollandois dans la nouvelle Zemble en
*                                                                  1596 & 1597  (p. 416)
* Ch. I, Art. IV. Observations sur les Réfractions, à différens
*                                                        degrés de hauteur  (p. 426)
* Then, after the Supplément:
*                                    Observations sur les Réfractions terrestres  (p. 701)
*
* Full title:
*                                                 VOYAGE
*                                                  dans
*                                     LES MERS DE L'INDE,
*                                FAIT PAR ORDRE DU ROI ,
*                         A l'occasion du Passage de Vénus,
*                   sur le Disque du Soleil, le 6 Juin 1761,
*                        & le 3 du même mois 1769.
*


T. Gruber
Herrn Tobias Grubers Briefe hydrographischen und physikalischen Inhalts aus Krain, an Ignaz Edlen von Born
(bey Johann Paul Krauß, Wien, 1781), pp. 54–57.

* TOBIAS GRUBER's letter
*
*
* An amazingly perceptive summary of the salient points: flat, smooth
* ground; the hiding of objects below a limiting ray; the dependence
* on season, height of the eye and distance to the object --
* all here in just a few pages. P. 55 has a nice ray diagram, too.
*      "Ein merkwürdiges Phänomen, welches ich auf meinen Reisen im
* Temeswarer Bannate so oft gesehen, und hier auf dem ebenen Seeboden
* samt meinen Gefährten wieder zu bemerken Gelegenheit hatte, kann ich
* unmöglich ganz vorbeylassen. Blos in sehr flachen, und auf viele
* Meilen weit sich erstreckenden Gegenden, besondere, wenn sich der
* ebene Horizonte in dem Himmel hinaus verliert, habe ich den über die
* Erde etwa 6 Schuh hoch liegenden Theil der Atmosphäre also verdicket
* gefunden, daß die unter einem sehr spitzigen Winkel darauf einfallenden
* Lichtstrahlen nicht durchgelassen, sondern abgeprellet werden; welches zu
* vielen optischen Blendungen Anlaß giebt. Also habe ich in einer Ferne
* von 1000 bis 2000 Klaftern blos die Dächer von Dorfgebäuden gesehen,
* welche mir wie ein durchsichtiges Wäldchen vorkamen. Also erschienen
* die hie und da auf der Ebene stehenden Warthügel ohne Grundlage.
* Also wurden die etwas höher emporragenden Objecte, als Bäume, Gebäude,
* Thürme, u. s. w. doppelt so hoch gezeigt, weil sie nämlich wie auf
* einer Wasserebene gespiegelt wurden. Also sah ich in der weiten Ferne
* zerstreute große Seen, die bis an den Horizont hinaus wie Meere wurden.
* Nach Maaß der Annäherung verschwanden sie, und entfernten sich immer.
* Ja so gar, wenn ich von meinem Sitze im Kalesche, wo ich sie noch sah,
* aufstund, und mich etwa 3 Schuhe in die Höhe richtete, so nahmen sie
* ab, oder erschienen nicht mehr. Als ich die Ursache dieses Spielwerkes
* der Lichtstrahlen noch nicht kannte, ward ich überdiemaßen durch diese
* Seltsamkeiten gerührt. Die öftere Ansicht in verschiedenen Umständen,
* das Erscheinen und Verschwinden nach Verhältniß der Erhöhung und
* Erniedrigung, und die Analogie aus optischen Experimenten entdeckten
* mir endlich das ganze Geheimniß." He explains it, with the use of the
* ray diagram. "Es ist eine ganz natürliche Sache, daß, wenn ein
* Lichtstrahl sehr schief in ein Mittelding einfällt, dessen Verdickung
* verhältnißmässig anwächst, derselbe den Grund des Mitteldings
* nicht erreiche, sondern in einer Entfernung vom Grunde, unter eben
* dem Winkel, unter welchem er einfiel, abgeprellet werde. Newton hat
* diese Eigenschaft bey allen spiegelnden Flächen aus der Theorie der
* abstossenden Kräfte erwiesen. Kommt nun die Direction ch vom Himmel,
* oder aus einer lichtgrauen Ferne, (wie es beym Zirknitzer See geschah,)
* so sieht man nichts von den Objecten, die unter der Linie ch stehen,
* und die reflektirte wird dem Wasser ähnlich seyn. . . .
*      "Auf diese Art erklärte ich mir alle ähnliche Erscheinungen.
* Die Sache fordert aber eine nähere Bestimmung, zu welcher ich zu
* wenig Zeit für diesmal habe. Ueberhaupt scheine ich mir mit Grunde
* schließen zu können, daß die durch gröbere Dünste nahe an der Erde
* verdickte Luft (welches ich meistens im Frühjahr bemerkte) bloß auf
* einer gewissen Höhe über den weiten Flächen (vielleicht auf 6 bis 7
* Schuhe) diese optischen Betrügereyen hervorbringen könne."
*      [The line ch  mentioned is not Minnaert's "vanishing line," but the
* lowest ray of an erect image. Thus Gruber failed to appreciate that
* there are in fact bits along the way that lie above Biot's caustic but
* below this ray, and so are visible. He neglects the general curvature
* of the rays, as well as that of the Earth.]
*      This is actually a Postscript (Nachschrift ) to the Fifth Letter,
* beginning on p. 40, and dated 20 April 1779, from Zirknitz.
*      The "Kalesche" was an open horse-drawn carriage with a folding top,
* usually rendered as "calash" or "caleche" in English.
*      Typographical note: this is all set in Fraktur, with little e's over
* the vowels as umlauts. There are numerous ligatures: ch, ck, ff, fi, fl,
* si, ss, st, sz, tz. ["Krausz" is actually set with the tz ligature,
* which differs from the ß used in "durchgelaßen" and "abstoßenden".]
* Proper names are set in a slightly broader and less angular font than
* the Fraktur body text.
*
* Full title page reads:
*
*                               Herrn Tobias Grubers,
* Weltpriesters und k. k. Bau- und Navigationsdirektors
*                               im Temeswarer Banat,
*
*                                B  r  i  e  f  e
*                                hydrographischen
*                                            und
*                          physikalischen Inhalts
*                               a u s      K r a i n
*                                           an
*                          Ignaz Edlen von Born,
*                         k. k. wirklichen Hofrath
*
*
* Available today at
*
* https://books.google.com/books?hl=en&lr=&id=zehnX5qi9YIC&oi=fnd&pg=PA3&dq=Grubers+Briefe+1781&ots=KZk9HfEjaY&sig=NspSHz-thBbqj_Tczwe-EBfI3Uk#v=onepage&q=Grubers%20Briefe%201781&f=false
*
* [Pogg. says "eigentlich Grüber."] See also Acta Carsologica 33,
* 277-298 (2004), available at
*        http://www.zrc-sazu.si/izrk/Carsologica/Acta332/Pdf3332/juznic.pdf
* for more information about Gruber and his book.
*      Ignaz von Born is profiled in European History Quarterly 36, 61 (2006);
* see
*        http://ehq.sagepub.com/cgi/reprint/36/1/61.pdf
*
* Despite the name on the title page, this was often cited as written by
* Johann Gruber. There are also obscure references to a "patriotic"
* commentary on Gruber's letters, published the same year in Laibach.


J. G. Büsch
Tractatus duo optici argumenti
(apud Carolum Ernestum Bohnium, Hamburgi, 1783).

* Joh. Georg BÜSCH's TRACTATUS DUO OPTICI ARGUMENTI (1783)
*
* Only the first 78 pages deal with mirages; the second "argument"
* of the tract is devoted to myopia -- which is how I discovered that
* the Becker Medical Library of Washington University (St. Louis) has
* a copy (see their website).
*      The preface explains that he was inspired to write by the problem
* posed by the Royal Danish Academy of Sciences ("Societas Hafniensis")
* in 1781. He also says he has translated his observations into Latin to
* make them available to the learned societies.
*      Here the "miles" are specifically German ones; and the barometric
* readings are explicitly in Paris inches and lines. Unfortunately,
* he scrupulously gives barometric readings, but no temperatures!
*      On pp. 9 and 10, he discusses Fig. 1, which shows the difference
* between the apparently calm reflecting surface in the distance, and the
* surface roughened by the wind in the foreground. This effect is also
* shown in Figs. 3, 4, and 6 (discussed on pp. 16, 17, and 36).
*      On p. 12, he notes that this mirage is more likely to be seen in the
* morning, with a clear sky, and warm air. And he does discuss the effect
* of changing the height of the eye.
*      On p. 20 is the original "chamberpot" quotation in the original
* English: "Indeed, it looks like a Chamberpot turn'd upside down."
*      The first 38 pages are observations; then comes his theory: he
* thinks it has to do with electricity, and lightning. . . . He also
* supposes that (because only distant objects are miraged) the curvature
* of the ray depends on distance. . . .
*      Still, on p. 39 he says ". . .  refractionem, quae indubia causa est,
* . . . "
*      Interestingly, he does invoke total internal reflection (p. 53).
* But (p. 59) "there must be something by which the light is reflected."
*
* On p. 61, he quotes from Gruber's 1781 letter, translated from German
* to Latin. (For a while we have "Gruner" for "Gruber"; but the given
* name "Tobias" certainly identifies him, as well as the reference to
* Carniola; apparently Büsch confused Gruber with the Swiss naturalist
* and geologist G. S. Gruner, who also worked about that time.) Büsch
* discusses Gruber's letter extensively, saying at the outset that
* "hunc virum primum omnium praeter me phaenomenon integrum observasse."
*      Büsch adds notes to Gruber's text -- perhaps his dissent from some
* of Gruber's remarks explains Gruber's later hostility toward Büsch.
*      Notably, "Non in vaporibus causa est sita."  (p. 68)  But he thinks
* the air is always denser at the ground than higher up (p.70), and
* argues that that the denser air cannot separate from the lighter to form
* a visible surface, "like two immiscible liquors, such as terebinth oil
* [turpentine] and spirit of wine".
*      He ends by offering advice to those who would investigate further:
* make observations in all seasons from a fixed place; use an instrument
* capable of measuring small angles; an achromatic telescope "for avoiding
* all confusion of the image that deceives the naked eye"; a level to
* observe "how much objects are raised and lowered for various conditions
* of the air". And it would also be useful, if convenient, to observe
* from the same place the Moon rising and setting over the sea. (pp.76-77)
*      There is a table of Corrigenda on p. 132.
*
* Title page reads:
*
*            Ioannis Georgii Büsch
*        Math. Prof. Hamburgensis
*                  Tractatus duo
*              optici Argumenti
*                   cum figuris.
*
* The internal title page of the first essay reads:
*
*                               I.
*                   Observata nova
*                              in
*        refractione horizontali
*                    et inde nata
*       mira imaginum reflexione.
*
*
* [Extracts were translated into German by Gilbert in 1800.]
*      Special thanks to the ILL people for this one at last!
*
* This is now available at
* https://books.googleusercontent.com/books/content?req=AKW5QafMp1bX3Vg_h8zvgBFeb6uKD2tNk6E1B4k5Urt-Fk-7Tl15AWPzA5YL5Il7CeESrYwKzHj0Rv44UjJAgLTihElDz3hPUr80LxTqdV-mYcz5CltbsDZSmrM6-Nob7bdLDFa9xQl6wfZqB6J-2Ub0NtDCCXVBAuOmPuBThOkqdU1OaYmBJtmebweLhAO0ELIWoVbpA99UL91Sl2WLMhYn5gSrihV0IY33_OM8AD8BCbxUlSqNv4cbIexDe4PfkdJt_HCPaQaLFa2xtzXb111elMg1M5_s7Q
* It contains the figures, placed on the 94th page of the PDF, after
* the title page of the second "argument".
*


H. Swinburne
Travels in the two Sicilies, by Henry Swinburne, esq., in the years 1777, 1778, 1779, and 1780
(P. Elmsly, London, 1783-1785).

* HENRY SWINBURNE's description of the FATA MORGANA
* Our interest is in pp. 263-266 of Vol. 2 of the 1790 Second Edition;
* presumably this first appeared in 1785. Here is what he says:
* . . . "Messina rises out of the waves like a grand amphitheatre; and
* the Faro, lined with villages and towns, seems a noble river, winding
* between two bold shores.
*      "Sometimes, but rarely, it exhibits a very curious phænomenon,
* vulgarly called La Fata Morgana *. The philosophical reader will find
* -------------------------------------------------------------------------
* [the footnote on p. 263 says: "The name is probably derived from an
* opinion, that the whole spectacle is produced by a Fairy or a Magician.
* The populace are delighted whenever the vision appears, and run about
* the streets, shouting for joy, -- calling every body out to partake of
* the glorious sight."]
* -------------------------------------------------------------------------
* its causes and operations learnedly accounted for in Kircher, Minasi,
* and other authors. I shall only give a description of its appearance
* from one that was an eye-witness. Father Angelucci is the first that
* mentions it with any degree of accuracy, in the following terms:
*      ``On the fifteenth of August, 1643, as I stood at my window, I was
* ``surprised with a most wonderful, delectable vision. The sea that
* ``washes the Sicilian shore swelled up, and became, for ten miles in
* ``length, like a chain of dark mountains; while the waters near our
* ``Calabrian coast grew quite smooth, and in an instant appeared as
* ``one clear polished mirror, reclining against the aforesaid ridge.
* ``On this glass was depicted, in chiaro scuro , a string of several
* ``thousands of pilasters, all equal in altitude, distance, and degree
* ``of light and shade. In a moment they lost half their height, and
* ``bent into arcades, like Roman aqueducts. A long cornice was next
* ``formed on the top, and above it rose castles innumerable, all perfectly
* ``alike. These soon split into towers, which were shortly after lost
* ``in colonnades, then windows, and at last ended in pines, cypresses,
* ``and other trees, even and similar. This is the Fata Morgana , which,
* ``for twenty-six years, I had thought a mere fable.''
*      "To produce this pleasing deception, many circumstances must concur,
* which are not known to exist in any other situation. The spectator must
* stand with his back to the east, in some elevated place behind the city,
* that he may command a view of the whole bay; beyond which the mountains
* of Messina rise like a wall, and darken the back-ground of the picture.
* The winds must be hushed; the surface quite smoothed; the tide at its
* height; and the waters pressed up by currents to great elevation in the
* middle of the channel. All these events coinciding, as soon as the sun
* surmounts the eastern hills behind Reggio, and rises high enough to form
* an angle of forty-five degrees on the water before the city, -- every
* object existing or moving at Reggio will be repeated a thousand fold upon
* this marine looking glass; which, by its tremulous motion, is, as it were,
* cut into facets. Each image will pass rapidly off in succession, as the
* day advances, and the stream carries down the wave on which it appeared.
*      "Thus the parts of this moving picture will vanish in the twinkling
* of an eye. Sometimes the air is at that moment so impregnated with
* vapours, and undisturbed by winds, as to reflect objects in a kind of
* aërial screen, rising about thirty feet above the level of the sea.
* In cloudy, heavy weather, they are drawn on the surface of the water,
* bordered with fine prismatical colours."
*      Evidently, Swinburne's account (largely translated from his mentioned
* sources) was the inspiration for a burst of interest in these mirages
* in the English journals. For the next 20 years, refraction phenomena
* were often compared to Swinburne's account, until Wollaston's (1803)
* introduction of the French term "mirage" (and Nicholson's longer
* translation from Minasi) superseded it.
*      Google Books has the Second Edition (1790, 4 vols.) on-line.
* Apparently the passage above is on p. 365 of the first volume of the
* two-volume (first?) edition.


T. Jefferson
Notes on the State of Virginia
(Norton, New York, 1982).

* THOMAS JEFFERSON's observations: notes the importance of DISTANCE
* " Having had occasion to mention the particular situation of Monticello
* for other purposes, I will just take notice that its elevation affords
* an opportunity of seeing a phænomenon which is rare at land, though
* frequent at sea. The seamen call it looming . Philosophy is as yet in
* the rear of the seamen, for so far from having accounted for it, she has
* not given it a name. Its principal effect is to make distant objects
* appear larger, in opposition to the general law of vision, by which they
* are diminished. I knew an instance, at York town, from whence the water
* prospect eastwardly is without termination, wherein a canoe with three
* men, at a great distance, was taken for a ship with its three masts.
* I am little acquainted with the phænomenon as it shews itself at sea;
* but at Monticello it is familiar. There is a solitary mountain about
* 40 miles off, in the South, whose natural shape, as presented to view
* there, is a regular cone; but, by the effect of looming, it sometimes
* subsides almost totally into the horizon; sometimes it rises more
* acute and more elevated; sometimes it is hemispherical; and sometimes
* its sides are perpendicular, its top flat, and as broad as its base.
* In short it assumes at times the most whimsical shapes, and all these
* perhaps successively in the same morning. The Blue ridge of mountains
* comes into view, in the North East, at about 100 miles distance, and,
* approaching in a direct line, passes by within 20 miles, and goes off
* to the South-west. This phænomenon begins to shew itself on these
* mountains, at about 50 miles distance, and continues beyond that as far
* as they are seen. I remark no particular state, either in the weight,
* moisture, or heat of the atmosphere, necessary to produce this. The only
* constant circumstances are, its appearance in the morning only, and on
* objects at least 40 or 50 miles distant. In this latter circumstance,
* if not in both, it differs from the looming on the water. Refraction will
* not account for this metamorphosis. That only changes the proportions of
* length and breadth, base and altitude, preserving the general outlines.
* Thus it may make a circle appear elliptical, raise or depress a cone,
* but by none of its laws, as yet developed, will it make a circle appear
* a square, or a cone a sphere."
*      At the word "diminished", there is a note, which is apparently due
* to the editor, William Peden; it says: "MS note by TJ . Dr. Shaw in
* his Physical observations on Syria, speaking of the Easterly winds,
* called by Seamen Levanters, says `we are likewise to observe further
* with regard to these strong Easterly winds, that vessels, or any other
* objects, which are seen at a distance, appear to be vastly magnified,
* or loom , according to the mariners expression.' Shaw's travels, 302.
* Ed. note. Thomas Shaw (1674-1751), English traveller and educator,
* author of Travels or Observations Relating to Several Parts of Barbary
* and the Levant (Oxford, 1738)." [p. 280]
*      N.B.: The page (302) that Peden attributes to TJ in this note is
* incorrect. The correct page number is 362. [Cf. Shaw, 1738.]
*      This was written in 1781 and revised in 1782.  Jefferson had a small
* edition privately printed in 1784 in Paris. A French translation
* appeared in 1786; the original English was published in 1787.
* The passage on "looming" appears on pp. 80-81 of the 1982 Norton
* paperback in our library, at the end of Chapter 7.
* Cited by Talman in his 1932 article in Yachting .


T. Gruber
“Physikalische Abhandlung über die Stralenbrechung und Abprellung auf erwärmten Flächen,”
Abhandlungen der Böhmischen Gesellschaft der Wissenschaften 2, 298–330 (1786).

* Early mirages: Claims to have written to Abbe v. Herbert in 1776;
* cites his letter in 1781, published before Büsch's
* "Tractatus duo argumenti optici" of 1783.
*
* N.B.: "Klafter" = "die Länge des Menschens" (approx. 1.9 m)
* according to Grimm; Brockhaus says "6 Fuß; 10 Fuß; 1.7 m im Mittel"
* See also:
*
*        Hercule Cavalli
*        Tableaux comparatifs des mesures, poids et monnaies, modernes et anciens
*        (Dupont, Paris, 1874)
*
* (available at Google Books) for such obsolete units.
*
* First observations published in letters from Krain = Carniola, on the
* bed of seasonally-varying Zirknitzer See = Cirknisko Jezero = Lago
* Periodico near Zirknitz = Cerknica = Cirkonico, south of Laibach =
* Ljubljana. This southern former crownland of Austria, later titular
* duchy, was annexed by the Hapsburgs in 1335. Note the use of Viennese
* measures. This area is currently Slovenia.
*
* Both field measurements and indoor experiments with air heated by an
* iron strip. He repudiates his earlier error (of thinking that the
* surface air was thickened) in the Nachschrift , and now states that the
* heated air is thinned, as shown by the rising air over a candle flame,
* etc. He also notes the wavy appearance of the heated air as it rises.
* Detailed explanations of double images and image elongation at the
* fold line, with good ray diagrams.
*
* Abbé Tobias Gruber, K.K.Kameral-Baudirektor
*      note obsolete spelling: "Stralenbrechung"!
* The umlauts are tiny e's printed over the vowels.
* N.B.: Brechmonat = June; Wintermonat = Nov.|Jan.; Christmonat = Dec.
*      Pernter gives 1786 for the year, and in the bottom margin at the end
* of every signature my photocopy says "Abh. d. B.Ges. 1786".
* The text (but, of course, NOT the Plates!) is available at Google Books.


N. J. Wetterling
“Von zwo an den schwedischen Küsten bemerkten Erscheinungen, Erhebung und Seegesicht,”
Neue Abh. Kongl. Schwed. Akad. Wiss. 9, 3–24 (1788).

* EARLY TREATMENT OF LOOMING & FATA MORGANA, with SUPERIOR MIRAGES
* more "FOG" (p.16)
* ". . . hier wähle ich zum Beyspiele meiner Beschreibung die bekannten
* Gunnilas Felsen, (Gunnilas Oerar) 3/4 schwedische Meilen ostwärts in der
* See von den Svenska Högar.
*      "Vermutlich sind diese Gunnilas Felsen auf gewisse Art vor mehr als
* zwei Jahrhunderten bekannt gewesen. . . ."


Le Gentil
“Extrait d'un mémoire sur des observations astronomiques faites sur les réfractions, en 1786, 1787 et 1788,”
Mém. Acad. Roy. Sci. , 224–236 (1789).

* GUILLAUME JOSEPH HYACINTHE LE GENTIL's posthumous work on refraction
* Notable not only for an early OMEGA description, but also for the early
* use of the term se mirer and descriptions of mirages (pp. 233 ff.).
*      A comment on the RARITY of clear sunsets: ". . .  sur quatre mois
* entiers je n'ai vu qu'une seule fois le soleil se coucher complètement
* à l'horizon de la mer . . . ." (p. 227)
*      He also notes that Bouguer found a smaller horizontal refraction at
* sea in the tropics (25' to 27') (p. 227)
*      His own VARIATIONS in horizontal refraction were 5' at Pondicherry;
* but "il semble . . . que la réfraction à 10'' [sic; he means degrees]
* soit assez bien constatée . . . ." (p. 228)
*      The OMEGA descriptions are on pp. 229-232.  ". . .  c'étoit comme si deux
* soleils se fussent détachés l'un de l'autre, l'un avoit monté pendant
* que l'autre descendoit." (p. 230)
*      The etymology is on p. 233: "Les habitans des bords des côtes de
* Basse-Normandie, presque tous marins, appelent ces apparences se mirer .
* Ils disent qu'une isle se mire , qu'un rocher se mire ." He then
* disputes the French translation of a Dutch sailors' dictionary that
* invokes clouds in explaining this term, as "Cela n'arrive que dans un
* très-beau temps, et lorsqu'il n'y a pas la moindre apparence de nuages."
* (p. 234) -- Later on the same page is a classical description: "Je
* vis à la place comme des ruines d'une ancienne ville ou d'une ancienne
* colonnade, qui paroissoit au-dessus de l'horizon, et comme en l'air,
* sans distinguer ni voir de nuages quelconques."
* NOTE: The dictionary was Aubin's 1736 edition; see Aubin (1702) here.
*      Finally, he quotes from Maraldi's descriptions of mirages and looming
* of Corsica as seen from Gênes and Provence. (p. 235)
*      A footnote says Le Gentil died 22 Oct. 1792, just as the memoir was
* being printed.


G. M. Giovene
“Discorso meteorologico-campestre su l'anno 1790 del Sig. Don Giuseppe Giovene, Canonico della Cattedrale di Molfetta,”
Opuscoli Scelti sulle Scienze e sulle Arti, Parte I, vol. 14, 3–21 (1791).

* GIUSEPPE MARIA GIOVENE's original account -- very good!
* The mirage observations are on pp. 15-21: "It remains for me to speak
* of a phenomenon seen by me on the evening of 9 February, and of other
* similar phenomena, which are observed in these regions. For greater
* accuracy I shall copy almost literally from my journals for those which
* I have observed, and the reports of my friends, for those I have not
* seen with my eyes. The previous days were fine and clear, with rather
* strong winds from N. to W., and I found myself in a small country house
* which I prefer just because, enjoying a wide horizon there, I have the
* convenience of better observing the meteorological phenomena. It was
* one of those beautiful evenings that can happen in winter, and close
* to half past 5 in the evening I was stopped at a window that had a view
* directly to the SSW. I was enjoying the clear air, which was calm, as
* shown by the smoke from the chimneys of the nearby towns of Terlizzi,
* Ruvo, and Corato, which lay beneath my view; it had not any movement,
* but covered those towns motionlessly like an umbrella. Looking around,
* I thought I saw some clouds rising in the western part just along the
* horizon, which occupied about 20 degrees of the same. I determined to
* try to observe their path, with only the idea of being able to predict
* which way the wind would blow the next day, and consequently what could
* be the state of the air, which, as I found myself in the countryside,
* interested me. In fact, I observed that the supposed clouds rose more
* and more above the horizon until they had ascended about two degrees.
* But suddenly they began to take various shapes, so that finally I
* realized they were quite different from clouds. I therefore invited
* Dr. Andrea Tripaldi, a young man well versed in good physics, and who
* had had the courtesy to join me for some days in tranquil solitude,
* to observe with me. We placed ourselves to observe more attentively.
* The originally supposed clouds were always changing shape. They first
* gave us the impression of a city standing along the horizon. We saw the
* shapes of buildings, of towers, of campaniles. At that moment, we came
* to suspect that the landscape of Cerignola, reflected to be situated in
* the direction of the phenomenon, but thirty-four Italian miles distant
* from the place of observation, was presented to our eyes by a powerful
* refraction of light in the atmosphere. But we saw the scene gradually
* change, and two little hills appeared, one facing the other, and these
* later were raised up, and squared off into magnificent towers with great
* apertures like windows, which let the light of the twilight pass through.
* I would hardly be able to describe the diverse shapes and the varied forms
* that were presented to our eyes. But later on our surprise increased.
* The twilight was very bright, and I noticed that waves of more vivid
* light were rising from time to time from the edge of the horizon up to
* an altitude of six or seven degrees. I first believed it could be an
* illusion of my eyes, and informed Sig. Tripaldi, who affirmed that he too
* saw what I said I saw. To assure ourselves, we agreed to inform each
* other when one of us perceived these waves of light. We always found
* ourselves in agreement. We went to another window, which faced directly
* to the WNW, and the thing appeared the same. The waves of light extended
* as far as the twilight extended, and were more vivid where it was more
* vivid, and less vivid where it ended. Five or six waves would come, and
* then a pause for one or two minutes, then they would recommence again.
* Meanwhile, the most capricious shapes were appearing on the line of the
* horizon. The spectacle lasted, charming and pleasant, near half an hour.
* As the twilight grew darker, so the striking appearance decreased in
* beauty, and ended completely after three quarters of an hour. The calm
* lasted all night. In the morning of the following day, 10 February, some
* mists rose, and cloudlets, from the W. At 10 1/2 in the morning the wind
* came from the W rather strong, but near evening the air clouded up, and
* the wind shifted to the N.W. with strong force; on the following day (the
* 11th), the thermometer suddenly fell by many degrees, there was a shower
* of snow, which even froze in some places more exposed to the cold wind.
*      "This phenomenon, although peculiar in its circumstances, is
* nevertheless not new in Puglia, as it is not even new in Iapigia, today
* called the Province of the Land of Otranto, and I shall expand a little
* on this article so much more willingly as this class of phenomena is
* either completely unmentioned by the writers, or reported confusedly,
* or even with changes engendered by the ignorance and superstition of the
* populace. The one who has mentioned them with the greatest vivacity and
* accuracy is the celebrated Antonio Ferrari, called Galateo after his
* birthplace, a writer of the last years of the fifteenth, and the first
* of the sixteenth Century. in his elegant little book, reprinted so many
* times, De Situ Iapygiæ :" -- and here he quotes from Ferrari's Latin
* account (1558) in extenso .
*      "The reader will forgive the long quotation.  But it is not only in
* the places named by the Galateo that the mutate are seen. I find
* from the reports, it is also seen at Galatone, Soleto, and many other
* towns and villages of the cape of Lecce, that is, Cape Japigio.
* The mutate (as is written to me from there) consist of seeing in a
* great plain, now a sea, now a woods, now a town. These apparitions are
* observed only at the rising and setting of the sun.
*      "In Puglia Peucezia, similar phenomena are also seen, and are called
* lavandaja [washerwoman], for what reason, I cannot say. They have
* taken it as a sign of change of weather. In fact, when after the wind
* has blown for a long time from a point on the horizon, the atmosphere
* calms to give place to an opposite flow, then is precisely the time when
* the lavandaja shows itself most beautifully. So too the season in
* which it most frequently appears is the autumn, and the winter too,
* although it is not rare in summer, and not extremely rare in spring.
* Indeed in summer there takes place almost daily a sort of little
* lavandaja , after midday, while the time of the phenomenon is properly
* around sunrise and sunset.
*      "The ordinary appearance of the lavandaja  from Molfetta is on
* Mt. Gargano. This mountain, about 50 miles distant from that city,
* appears like a cloud of a fairly deep blue color resting upon the
* horizon from the W.N.W. to the N.N.W. Of course, I shall not say
* that this mountain is the barometer of the Puglian sailors, and that
* visible or invisible, high or low, covered either completely by clouds,
* or as if by an umbrella of clouds, lets them predict the wind and the
* state of the Puglian atmosphere; I shall speak only of the lavandaja .
* The first time I saw this meteor, knowing nothing of the thing,
* I confess to have been distressed by it in the first moments. I was
* seeing the whole mountain shake, and undulate, as if an extremely violent
* earthquake shook its foundations, and made it totter. So I was seeing
* one part of the mountain collapse, forming a great valley; and then
* this, little by little, rose to form a new peak superimposed on the
* mountain. Beside this peak rose a second, a third; and these, little
* by little, were squared off into high towers; then they too collapsed
* and became valleys again. In sum, I was seeing that mountain in the
* most terrible convulsions. Afterwards, accustomed to observing such
* phenomena, I have very many times seen with the greatest pleasure the
* varied scenes that the view of this mountain offers. It assumes the
* most varied and the most capricious forms, and a warped or slightly
* heated imagination, comparing these figures to well-known objects,
* believes it sees horses, and armies, castles, ships, towers, and towns.
*      "And too, a partial lavandaja  is seen from the Town of Molfetta,
* especially when a soft wind blows from the east after sunset. That
* peak, of which Lucan sang,
*
*              Apulian Garganus extends into the Adriatic waves
*
* continually takes on new forms and figures, now seeming extremely
* long, now shrinking and then dividing into many pieces, which look like
* islands in the open sea. It also happens that sometimes one portion of
* the sea appears notably higher than another, and some other time the sea
* in the distance looks as if in the greatest storm, when in reality it
* was completely calm. But to finish the little story of these phenomena,
* I shall describe another charming display that presented itself to me
* one morning in October, 1789, at the appearance of the sun on the horizon.
*      "I found myself in my customary countryside retreat, and as it was
* a beautiful morning with little, or indeed no wind, I hastened to enjoy
* it at a window that looked directly to the N.E., and to observe the
* thermometer and the hygrometer, which hung there. I was really
* surprised to see the most delightful and certainly moving scene.
* The town of Biseglie, which was in my view, in the N.W. part, although
* it was seven miles away, appeared so near that I would have believed
* it only two miles off. I was seeing the pavement of a wide square,
* which is there before the walls of the town, was almost counting the
* houses, and the vision was made not only with the greatest distinctness,
* but also with a certain vividness, which absolutely touched the soul.
* It was observable that the houses seemed more elongated than widened,
* as it was most observable that the bell towers were in their natural
* state. That is to say that at a certain height of the land, the view
* was the normal one. In the part to the W., all the little hovels and
* the houses scattered through the countryside appeared as high pyramids
* or spacious towers. I enjoyed this display, which later became more
* delightful, for almost an hour, in the company of my inseparable friend,
* the aforesaid Dr. Andrea Tripaldi. The town of Trani, placed a little
* more to the W. at a distance of perhaps more than eleven miles, and
* which, in the ordinary state of the air, cannot be seen, except for
* just one cathedral with its high campanile, began to be seen entirely,
* and with the greatest distinctness, so that it seemed to have approached
* by at least six miles. At the start of the next hour, while Biseglie
* was slowly going away, Barletta began to be seen. It is even more to
* the west than Trani, and about eighteen miles distant, and completely
* invisible in the ordinary state of the atmosphere. And this town seemed
* no more remote than seven or eight miles. My colleague and I distinctly
* saw the coast between Barletta and Trani, and were counting all the little
* boats that were fishing along there. Near nine in the morning, that is,
* after more than three hours since we had begun to observe the phenomenon,
* everything seemed to return to normal. But I wanted to go onto the
* terrace, which was higher than the window by about twenty Paris feet.
* I was more surprised to find that from that height the phenomenon
* could still be seen in all its beauty, and Barletta and Trani seemed a
* few miles away. I informed Sig. Tripaldi of it as he stood at the window
* while I was on the terrace. We assured ourselves that the phenomenon was
* now invisible at the height of about 40 Paris feet, extremely visible from
* about 60 feet from the ground. In the whole duration of the phenomenon
* the thermometer was between 12 and 15 degrees Reaumur, and the hygrometer
* between 21 and 25 degrees absolute, which means in temperate heat,
* and moderate dryness; or at least, certainly not in great humidity.
*      "By comparing my observations with the little left written of it by
* Antonio Galateo , it is easy to see that the mutate of Japigia and
* the lavandaja of Peucezia are the very same thing, although I will admit
* that the fuochi fatui [will-o'-the wisps] and the capre saltanti ,
* which are not seen by us at all in Peucezia, are extremely frequent
* in Nardò, and in Copertino. The complex of these meteors, and of
* the phenomena described above, gives credence to the tales of witches
* and magicians among the people of Nardò and Copertino; fables that
* nevertheless have begun to lose credit today even among those low people.
*      "Meanwhile, everyone sees that the mutate  and the lavandaja
* are nothing but the play of variable refraction of visual rays in the
* atmosphere, as from variable refraction comes the increase and decrease of
* our visual horizon by twenty or thirty miles. But a conversation on the
* phenomenon I had seen on the evening of 9 February with the celebrated
* Sig. Thouvenel (whose coming to Molfetta expressly to visit the famous
* natural nitrate deposit of this City gave me the honor of accomodating
* him in my house, and the pleasure of hearing him, . . . ) made my ideas
* go a little farther, and formed conjectures, which will be appraised
* by the Physicists for what they are. Why does this lavandaja always
* have to appear on the western side and never to the east of Molfetta?
* Why must it always be seen along the line going from the famous Apulian
* [Mt.] Vulture, an extinct volcano, as everyone knows, and entering the sea
* at the farthest promontory Gargano, passing by the island of Pelagosa,
* recognized as volcanic by the celebrated Sig. Ab. Fortis, and going
* directly to the N.E. to join the volcanos of Morlachia? Why are the
* mutate of Lecce seen along the line of Galatona, Nardò, Copertino,
* and adjacent towns, put on land where there is some rising heat, and
* where pyrites and coal are found? Why is the famous fata morgana of
* Reggio in Calabria, which nevertheless is very similar to the lavandaja
* of Puglia, and to the mutate of Salento, is found just on the line
* of coal, which passed directly under the Faro of Sicily in Calabria,
* and is also seen in the open air behind Messina, and at Briatico on the
* opposite side? This phenomenon of the lavandaja , that is, of the
* mutate , is certainly, as I have said, a play of refraction, and to
* make such a play it is necessary that a certain quantity of vapors and of
* exhalations change the state of the atmosphere. Even this is not enough.
* Because the striking appearance, despite the calm, means that the wind is
* in continuous movement, the very air is like an uprising, and agitated.
* Those waves of light that I saw the evening of 9 February must be the
* effect of a shaking given to the air. So it seems that either electrical
* fluid or other emanations of some gas rise from the regions above which
* are seen the described phenomena, and force the incumbent atmosphere to
* be disturbed or to undulate. The violent agitations and convulsions,
* to which the same atmosphere is accustomed, occur after the appearance of
* such meteors, which indicate the same. I have not thought it necessary
* to give a complete history of this kind of phenomenon in our regions in
* this memoir. For me, it is enough to have given a small sample of it.
* Meanwhile, one must confess that meteorology is still, at most, in its
* early adolescence, and that there would never be as many careful observers
* of meteorological instruments as observers in the open countryside,
* and with a free horizon."
*
*      This was mostly translated into German by Zimmermann later, and then
* reprinted by Gilbert in 1802. (See the entry for Zimmermann's version.)
*      Thanks to Maria Toscano for supplying the citation to this, and
* helping with the translation!
*      Available at Google Books:
* https://books.google.com/books?id=BN0WAAAAYAAJ&pg=PA3&f=false#v=onepage&q&f=false


A. Ellicott
“Extract of a letter from Andrew Ellicott, to David Rittenhouse, Esq. dated at Pittsburg, November 5th 1787, containing observations made at Lake-Erie,”
Trans. Am. Phil. Soc. 3, 62–63 (1793).

* Early looming and mirage observation (apparently a 3-image mirage)
* "On the thirteenth of last month [i.e., October], while we lay on
* the banks of Lake-Erie, we had an opportunity of viewing that singular
* phenomenon, by Seamen termed looming. . . . the 13th was cloudy; but
* without rain: about ten o'clock in the morning, as I was walking on the
* beach, I discovered something that had the appearance of land, in the
* direction of Presque-Isle; about noon it became more conspicuous and;
* when viewest by a good Achromatic-Telescope, the branches of trees
* could be plainly discovered --- From 3 o'clock in the afternoon, till
* dark, the whole Peninsula was considerably elevated above the horizon,
* and viewed by all our company with admiration. --- There was a singular
* appearance attending this Phenomenon, which I do not remember to have
* seen taken notice of by any writer --- The Peninsula was frequently
* seen double, or rather two similar Peninsula's, one above the other,
* with an appearance of water between:--- the separation, and coincidence
* was very frequent, and not unlike that observed in shifting the index
* of an adjusted Godfrey's quadrant. . . . The next morning Presque-Isle
* was again invisible, and remained so during our stay at that position.
* Presque-Isle was about twenty-five miles distant, its situation very low."
* The marginal note says "Read Nov. 21, 1788".


S. Dickenson
“A Description of a Phaenomenon caused by Haze seen at Sea Aug. 10, 1759,”
Gentleman's Magazine 63, 601–602 (1793).

* EARLY DRAWING of SUPERIOR MIRAGE (FATA MORGANA + SUPERIOR MIRAGE)
* by the Rev. Samuel Dickenson, LL.B. the Chaplain of the Dunkirk
* Man of War. . .
* "The term haze , prefixed to the foregoing account, is adopted from the
* phrase then used by the sailors, perhaps improperly; for, there was not
* the least appearance of mist or fog, or thickness of atmosphere; on the
* contrary, the air seemed uncommonly clear."


E. Williams, W. Mudge, and I. Dalby
“An Account of the Trigonometrical Survey Carried on in the Years 1791, 1792, 1793, and 1794, by Order of His Grace the Duke of Richmond, Late Master General of the Ordnance. By Lieut. Col. Edward Williams, and Capt. William Mudge, of the Royal Artillery; And Mr. Isaac Dalby. Communicated by the Duke of Richmond, F. R. S.,”
Phil. Trans. Roy. Soc. 85, 414–591 (1795).

* INFERIOR MIRAGE and variable refraction reported by
* Lieut. Col. Edward Williams, and Capt. William Mudge,
* of the Royal Artillery; and Mr. Isaac Dalby.
* Dalby's observation in April, 1793 (pp. 586-588):
*      "I observed . . .  a very uncommon effect of terrestrial refraction. . . .
* ". . . when the eye was brought to about 2 feet from the ground, the top
* of the hill appeared totally detached, or lifted up from the lower part,
* for the sky was seen under it. This phænomenon I repeatedly observed."
* The discussion continues: ". . . it is more than probable, that moist
* vapours were the principal cause of the very unusual refractions:
* the truth of which conjecture seems to be verified by the following
* circumstance. In measuring the base on Hounslow Heath, we had driven
* into the ground, at the distance of 100 feet from each other, about 30
* pickets, so that their heads appeared through the boning telescope to be
* in a right line; this was done in the afternoon. The following morning
* proved uncommonly dewy, and the Sun shone bright; when having occasion to
* replace the telescope, we remarked that the heads of the pickets exhibited
* a curve, concave upwards, the farther-most pickets rising the highest;
* and we concluded they were not properly driven till in the afternoon,
* when we found that the curve appearance was lost, and the ebullition in
* the air had subsided."
* (available at JSTOR; no paper copy filed)


[Woltmann]
“Göttingen,”
Göttingische Anzeigen von gelehrten Sachen 1796:1, 809–818 (21 Mai, 1796).

* Woltman's newsletter announcement (1796)
*      This is the lead item in the issue, attributed to "Hr. Dir. Woltmann"
* (with 2 "n"s.) "zu Cuxhaven". There is no title; the general heading
* is "Göttingen". This is an account of a paper sent to "der königl.
* Societät" [i.e., the "Königliche Gesellschaft der Wissenschaften" in
* Göttingen], and presented by "Hr. Hofrath Kästner". (The Göttingische
* Gelehrte Anzeigen was its official organ, published almost daily.)
*      This extended abstract begins with Gruber's 1786 paper, and goes
* directly into an account of Woltman's measurements of dip by using two
* stakes driven into the dikes, with the distant house as target. This
* seems to be the first appearance of the phrase "Spiegelung unterwärts" in
* print. The basic data (distances between the sights and the house, and
* some angles) are given, with the Hamburg foot as the unit of length.
*      The part of his later complete table that summarizes the results for
* Feb. 1795 is printed, showing that the terrestrial refraction is
* greatest in the morning and least in the evening; the total range is
* 10 min. 16 sec.
*      "Diese Bilder können nicht ganz allein aus Reflection entstehen, weil
* keine Spiegelfläche in der Luft vorhanden ist; es muss dabey eine
* Refraction mitwirken, die den Strahl unterwärts krümmt." (p. 812)
* He also describes briefly the effects of superior mirages, and for
* further information refers to his forthcoming paper in the "nächsten
* Bande der kaiserl. königl. Gesellschaft zu Prag". The heat has the
* strongest effect of all meteorological variables: "Ist das Wasser 2 oder
* mehr Fahrenheitische Grade wärmer, als die Luft, so findet sich allemal
* Erniedrigung der Strahlen, die sich über die Wasserfläche erstrecken;
* aber Hebung, wenn die Luft über dem Wasser 2 oder mehr Grade wärmer ist,
* als das Wasser." (p. 815)
*      At the end, Woltman describes some inferior mirages he has seen over
* land: "Man muss zu dem Ende eine ganz offene Ebene vor sich haben ,
* oder über Gebüsche und dergl. von einer hohe wegsehen können. Dann
* scheint die ganze Landschaft in einem unbeweglichen Glanzmeere zu stehen ,
* worin alle die erhobenen Gegenstände sich unterwärts spiegeln. So hat
* Hr. W. oft von den Geesthöhen herab die Marschen gesehen , als wären
* sie ganz mit glänzendem Wasser überzogen. Diese Bemerkungen . . . findet
* er Uebereinstimmung der Strahlen über Land und über Wasser, der Strahl
* krümmt sich allemahl nach der wärmsten Seite; die Refraction ist desto
* grösser, je grösser der Unterschied der Wärme zwischen beyden Materien
* ist, . . . ." (p. 817)
*      He continues with remarks on distortions of the low Sun: "Sieht man
* die Sonne des Morgens heiter aufgehen , so gibt ihre Gestalt ein
* untrügliches Merkmahl , ob Hebung oder Depression Statt finden wird.
* Nähmlich im letztern Falle ist sie nie rund , sondern ein Theil
* der Sonnenscheibe spiegelt sich unterwärts ; der kann , nachdem die
* Depression schwacher oder stärker ist, wohl ein Achtel oder ein Viertel
* des Sonnendurchmessers betragen, Hr. W. bildet dergleichen
* Erscheinungen ab , als wenn unten an der Sonnenscheibe , auch an den
* aufgegangenen Theil, der Anfang einer andern Scheibe angesetzt wäre ;
* dergleichen hat er auch an dem Vollmonde wahrgenommen. Findet dergleichen
* Depression Morgens und Abends Statt, so ist ihre Dauer auf dem festen
* Lande denselben Tag keinem Zweifel unterworfen , weil sie hier um Mittag
* allemahl zunimmt." (p.818)
*      Evidently the editor --- at that time,  Christian Gottlob Heyne, the
* head of the University Library, and "perpetual secretary" of the Society
* --- thought highly of this report: "Das viele Merkwürdige und Neue
* aus einer noch ungedruckten Schrift wird die Länge dieses Auszugs
* entschuldigen."
*      This journal did not have conventional volume numbers; the Bände were
* given year numbers, starting in 1753. The title page of this volume says
* "Der erste Band, auf das Jahr 1796." There were two volumes in 1796;
* this is the first one. The "piece" number is 82, dated 21. Mai. This
* first volume for 1796 ends on page 1040 of the 104th Stück, dated 10 Jun.
* The second volume of 1796 follows on p.1041 of the 105th St.; at its end
* (at page 2105) come the alphabetical indices (separately paginated) and
* a list of printer's errors.
*      This is the 82. St. of 1796.
*
*      Available at
* https://www.google.com/books/edition/G%C3%B6ttingische_Anzeigen_von_gelehrten_Sac/ujtKAAAAcAAJ?hl=en&gbpv=1&bsq=809
* or
* https://gdz.sub.uni-goettingen.de/id/PPN31973076X
*


E. A. W. von Zimmermann
Allgemeine Blick auf Italien
(Verlag des Industrie-Comptoirs, Weimar, 1797).

* Eberhard August Wilhelm von Zimmermann's translation of Giovene
*      The introduction refers to Swinburne's work, and briefly enumerates
* the various sources, and their translators.
*      Giovene's interesting mirage passage is on pp. 171-181.  Zimmermann
* does indeed copy "S.S.O." literally from the original, which garbles
* the directions, as "O." is "Ovest" in Italian. So the error is the
* translator's and not Gilbert's.
*      Note: the umlauts are tiny e's above their vowels.
* Available at
* https://digitale.bibliothek.uni-halle.de/vd18/content/titleinfo/8125331


J. Huddart
“Observations on horizontal Refractions which affect the Appearance of terrestrial Objects, and the Dip, or Depression of the Horizon of the Sea,”
Phil. Trans. Roy. Soc. Lond. 87, 29–42 (1797).

* EARLY OBSERVATION & EXPLANATION OF INFERIOR MIRAGES and DIP
*      "The variation and uncertainty the dip, in different states of the
* air, taken at the same altitude above the level of the sea,, was the
* occasion of my turning my thoughts to this subject; as it renders the
* latitude observed incorrect, by giving an erroneous zenith distance of
* a celestial object.
*      "I have often observed that low lands and the extremity of headlands
* or points, forming an acute angle with the horizon of the sea, and
* viewed from a distance beyond it, appear elevated above it, with an
* open space between the land and the sea. . . .      I believe it arises,
* and is proportional to the evaporation going on from the sea; and in
* reflecting upon this phænomenon, I am convinced that those appearances
* must arise from refraction, and that instead of the density of the
* atmosphere increasing to the surface of the sea, it must decrease from
* some space above it; . . . ."
*      His observations of the miraged ship, made from a height of 40 feet,
* [=12 m] plainly showed the contraction of the inverted image. (p.32)
*      His figures show accurate ray diagrams for the inferior mirage;
* he notes the vanishing line ("a little below the maximum of density,
* where inversion begins; therefore no land lower than this can be seen;
* . . . " (p. 37); and he points out the effects seen at the fold line:
* "There are always confused or ill defined images of the objects at
* the height of the dotted line, fig. 1, above the level of the sea, as
* before mentioned; and instead of the points of d [i.e., the apparent
* land horizon] ending sharp in that line, they appear blunted . . . ."
*      Notable for having used measurements of the Sun at noon at both
* northern and southern (i.e., opposite) horizons to infer the actual DIP.
*      He says "The effect indicated by the barometer and thermometer is
* insufficient;" but he fails to understand why, being fixed on the idea
* that humidity is the main problem.
*      Cites Hamilton (1766) on "Ascent of Vapours".  Also cites the paper by
* Williams, Mudge, and Dalby (1795).
*      Joseph Huddart read his paper to the Royal Society on November 24.
* 1796. It was published on Jan. 1, 1797.
* Available at JSTOR, and at the Roy. Soc. website.


J. Huddart
“Observations on horizontal Refractions which affect the Appearance of terrestrial Objects, and the Dip, or Depression of the Horizon of the Sea,”
William Nicholson's "A Journal of Natural Philosophy, Chemistry and the Arts" 1, 145–152 (July, 1797).

* The same, reprinted:
* Note: Nicholson's Journal merged with Phil. Mag. in 1813.


W. Nicholson
“An Account of the Fata Morgana; or the Optical Appearance of Figures, in the Sea and the Air, in the Faro of Messina. With an Engraving.,”
William Nicholson's "A Journal of Natural Philosophy, Chemistry and the Arts" 1, 225–227 (1797).

* Nicholson's summary of MINASI's Fata Morgana paper
* He begins by quoting James Thomson's lines from "The Castle of Indolence",
* Canto i. Stanza 30: "As when a shepherd of the Hebrid' Isles. . .
*        (Whether it be lone fancy him beguiles,
*        Or that ae"rial beings sometimes deign
*        To stand, embodied, to our sense plain) . . .
*        A vast assembly moving to and fro:
*      Then all at once in air dissolves the wondrous show."
* -- an interesting reference, considering the reports of mirages from
* the Orkneys and other northern outliers of Britain.
*      He then cites Brydone and Swinburne as making "mention of a very
* striking phenomenon . . . known by the name of Fata Morgana, or, as some
* render it, the Castles of the Fairy Morgana. The accounts differ from
* each other . . . . How far the effects themselves may be subject to
* variation, or to what extent the imagination of the narrators, who speak
* of the exhibition as calculated to produce astonishment, may be subject
* to irregularity, would admit of discussion. . . ."
*      Nicholson borrowed a copy of Minasi's work from Sir Joseph Banks,
* and says, "In this treatise the facts are related with much simplicity
* and precision, and the philosophical reasoning of the author is kept
* distinct from the narrative." [But see Gilbert's scathing commentary!]
*      Now comes Nicholson's loose translation of Minasi's description:
*      "When the rising sun shines from that point whence its incident
* ray forms an angle of about forty-five degrees on the sea of Reggio,
* and the bright surface of the water in the bay is not disturbed either
* by the wind or the current, the spectator being placed on an eminence
* of the city, with his back to the sun and his face to the sea; -- on
* a sudden there appear in the water, as in a catoptric theatre, various
* multiplied objects, that is to say, numberless series of pilasters,
* arches, castles well delineated, regular columns, lofty towers, superb
* palaces, with balconies and windows, extended alleys of trees, delightful
* plains with herds and flocks, armies of men on foot and horseback, and
* many other strange images, in their natural colours and proper actions,
* passing rapidly in succession along the surface of the sea during the
* whole of the short period of time while the above-mentioned causes remain.
*      "But if, in addition to the circumstances before described, the
* atmosphere be highly impregnated with vapour, and dense exhalations not
* previously dispersed by the action of the wind or waves, or rarefied by
* the sun, it then happens that in this vapour, as in a curtain extended
* along the channel to a height of about thirty palms, and nearly down
* to the sea, the observer will behold the scene of the same objects not
* only reflected from the surface of the sea, but likewise in the air,
* though not so distinct or well defined as the former objects from the sea.
*      "Lastly, if the air be slightly hazey and opake, and at the same time
* dewy and adapted to form the iris, then the above-mentioned objects
* will appear only at the surface of the sea, as in the first case,
* but all vividly coloured or fringed with red, green, blue, and other
* prismatic colours." [Minasi actually says "purple" rather than "other
* prismatic colors."]
*      Nicholson's translation seems to have become the canonical version
* of Minasi's account in English (though in Brewster's 1830 "Edinburgh
* Encyclopedia" and some later copies, "alleys" became "valleys").
* (Google Books shows dozens of copies, right up to the present day.)
* Minasi just says "very high trees" -- no alleys or valleys.
*      Nicholson refers to Minasi's note on "the etymology of Morgana
* . . . which is so foreign to the Roman idiom, . . . considering the great
* exultation and joy this appearance produces in all ranks of people, who
* on its first commencement run hastily to the sea, exclaiming Morgana,
* Morgana!"
*      "In the second chapter the author describes the city of Reggio,
* and the neighbouring coast of Calabria; by which he shews that all the
* objects which are exhibited in the Fata Morgana are derived from objects
* on shore." (I take "derived from" in a different sense, though!)
*      In dealing with Minasi's observation (in the 3rd chapter) that the
* tides have something to do with it, he takes from Minasi that "It is high
* water, that is to say, the northern current ceases, at full and change,
* at nine o'clock. There is probably a small rise and fall, though the
* annotation to a large chart before me affirms that there is none."
*      The various crank ideas following the 4th chapter, in which Minasi
* "collects the opinion and relations of various writers . . . , namely,
* Angelucci, Kircher, Scotus, and others," are elided, "because it seems
* difficult to make any clear or productive statement either from the
* narrative or the reasoning." [Pace , Gilbert!]
*      His summary includes: "3. That the Morgana Marina presents inverted
* images below the real objects, which are multiplied laterally as well
* as vertically; and that there are repetitions of the same multiplied
* objects at more considerable vertical intervals. This I gather from
* the appearance of the dome and other objects in the plate." And:
* "8. By attentive reflection upon the facts and reasonings in Mr.
* Huddart's paper, we may form a theory to account for the erect and
* inverted images . . . ; but for the lateral multiplication we must have
* recourse to reflecting or refracting planes in the vapour, which appear
* nearly as difficult to deduce or establish, as those which have been
* supposed on the water."
* Issue dated August 1797


W. Latham
“Account of a singular Instance of atmospherical Refraction. In a Letter from William Latham, Esq. F.R.S. and A.S. to the Rev. Henry Whitfield, D.D. F.R.S. and A.S.,”
Phil. Trans. Roy. Soc. Lond. 88, 357–360 (1798).

* William LATHAM's observations of LOOMING, seen from Hastings
* "On Wednesday last, July 26, about five o'clock in the afternoon, . . .
* the coast of France was plainly to be distinguished with the naked eye.
* I immediately went down to the shore, and was surprised to find that,
* even without the assistance of a telescope, I could very plainly see the
* cliffs on the opposite coast; which, at the nearest part, are between
* forty and fifty miles distant, and are not to be discerned, from that
* low situation, by the aid of the best glasses. They appeared to be only
* a few miles off, and seemed to extend for some leagues along the coast.
* . . . the cliffs gradually appearing more elevated, and approaching
* nearer, as it were . . . .
*      "Having indulged my curiosity upon the shore for near an hour, during
* which the cliffs appeared to be at some times more bright and near,
* at others more faint and at a greater distance, but never out of sight,
* I went upon the eastern cliff or hill, which is of a very considerable
* height, when a most beautiful scene presented itself to my view; for
* I could at once see Dengeness, Dover cliffs, and the French coast,
* all along from Calais, Boulogne, &c. to St. Vallery; and, as some of
* the fishermen affirmed, as far to the westward even as Dieppe. . . . This
* curious phenomenon continued in the highest splendour till past eight
* o'clock, (although a black cloud totally obscured the face of the sun
* for some time,) when it gradually vanished.
*      "I should observe, the day was extremely hot, as you will perceive
* by the subjoined rough journal of a small thermometer, . . . and the three
* preceding days were remarkably fine and clear. . . . Not a breath of wind
* was stirring the whole of the day . . . .
*      Latham's temperature log shows that at 10 A.M. each of the previous
* 3 days, the temperatures were 65, 66, and 66 (F), and 68 on the day of
* looming; but at 5 P.M. it was 76. The 10 A.M. temperatures on the next
* 4 days were 72, 70, 72, and 70; so it appears the looming accompanied
* the arrival of a warm front.
*      Reprinted in Nicholson's Journal 2, 417-419 (1799).
* Cf. the similar observations of Parnell (1869).


R. Woltman
“Bemerkungen über ein Katoptrisches Phänomen, welches an den Gegenständen nahe am Horizont nicht selten sichtbar ist,”
Neuere Abhandlungen der königlichen Böhmischen Gesellschaft der Wissenschaften 3, 69–97 (1798).

* REINHARD WOLTMAN's 1798 paper
* This is the paper partly reprinted by Gilbert in Ann. Phys. 3, 397 (1800)
*
* At this time, Woltman was "Baudirektor im hamburgischen Amte Ritzebüttel"
* A footnote on the first page says that Woltman began this work toward the
* end of the year 1794, continued it in 1795, and finished on 8. Nov., and
* communicated it in part with Abbe Gruber. It was extensively reviewed in
* the "Götting. Anzeigen 82ten Stück, 21ten May 1796."
*      There is some background information on Woltman in the prefatory pages.
* On p. III we see that he was not a member of the Bohemian Scientific
* Society, but had submitted his manuscript to it through Abbe Gruber.
* On p. XXIII we learn that he was "Direktor der Ufer und Wasserbauwerke im
* hamburgischen Amte Rützebütl", and a member of several scientific
* societies, some in Harlem and Rotterdam; but here he is in a list of
* foreign members.
*      He begins with a classic description of inferior mirages:
*      "The phenomenon is that objects, houses, trees etc. near the horizon
* often are separated from the visible ground surface by a bright strip of
* air, and almost seem to stand in the air; or as if a shining empty space
* were present between the visible horizon and the objects; or if the eye is
* considerably raised, and sees several distant objects behind one another,
* as if these houses, mills, churches, trees etc. stood in a calm shining
* sea, in which the entire landscape were immersed and reflected."
*      This is followed by an extensive list of "Alle, die davon geschrieben
* haben: Gruber's 1781 "Briefe"; Büsch's 1783 "Tractatus duo"; Gruber's
* 1786 response. "Diese zwey Abhandlungen hat H. Hofrath Kästner in seiner
* Dioptrik 1792 nebst mehreren Beyspielen angeführt; unter andern, dass H.-
* Justizrath Niebuhr einen Araber auf einem Kamele in freyer Luft reiten
* gesehen. Siehe dessen Reisebeschreibung nach Arabien 1. Theil, S. 253."
*      "Ich habe selbst mit einem achromatischen Fernrohr sehr deutlich
* wahrgenommen, dass die entfernten Häuser, Bäume, Schiffe in umgekehrter
* Gestalt sich sehr deutlich abbilden, wie eben dieselben Gegenstande
* in de Nähe thun, wenn zwischen ihnen und dem Auge ein ganz ebener
* Wasserspiegel befindlich ist."
*      VISIBILITY IN RAIN:
* "Auch sieht man das Phänomen so gut gleich nach einem Regen, als vor
* demselben; und selbst im Regen verschwindet es nicht eher, als bis die
* Undurchsichtigkeit der Luft das Sehen in der Ferne verhindert." (p. 71)
*      He then describes the qualitative effects of object distance and eye-
* height. "Woraus folgt, dass nur diejenigen Strahlen von den Objecten
* durch Reflexion ins Auge kommen, die unter sehr kleinen Winkeln auf
* die spiegelnde Fläche fallen." And he describes how the "bright strip"
* shrinks and vanishes as the miraged object approaches the observer;
* and similarly describes the effects of increasing the height of the eye.
* "Therefore the bright strip is no object, like a luminous surface, . . .
* but is itself an image of a reflected bright object." (p. 72)
*      On the next page, he tries to explain the phenomena with ray diagrams;
* he knows that the curvature of the Earth is important, but he draws all
* the rays as straight lines, except where they are reflected. Still, this
* allows him to explain why the apparent horizon is lowered by the mirage.
* He also explains that all the miraged objects lie beyond the effective
* distance to the horizon. (p. 74)
*      In §.10. (p.75) he points out that "the images are always considerably
* smaller than their objects." He has found the images generally about
* half the size of the object, and shows an example in Fig. 7. Unfortunately,
* he neglects the curvature of the Earth; so he thinks this might be due to
* the rays being reflected under a smaller angle than that of incidence!
* But "maybe the refraction has something to do with it." On the next page,
* we find the real cause: his eye (in his house at Cuxhaven) is 3 toises
* (almost 6 meters) above the high-water level.
*      He goes through a very rough argument that neglects the curvatures of
* both the surface and the rays, and then weasels out: "Zu genauern
* Bestimmungen wären genauere Beobachtungen mit einem Mikrometer nöthig;
* auch musste wohl die Refraktion in Betracht gezogen werden; welches zu
* unternehmen ich mir nicht getraue." (p.77)
*      In §.13. he begins by discussing the trembling motion of the images,
* and compares it with the appearance of objects seen through the "vapors"
* above a coal fire. But then in the middle of the paragraph he gets into
* a description of superior mirages: "Eben diese Dünste im aufgelösten,
* durchsichtigen Zustande vergrössern zuweilen die horizontale Refraktion
* dermassen, dass die Meeresfläche, entlegene Ufer, Küsten und Sandbänke
* eine ganz ungewöhnliche Gestalt annehmen. Die Meeresfläche wird concav
* gekrümmt, die nähern Schiffe erniedrigen sich, oder vielmehr der entlegne
* Horizont scheint über ihnen fast hervor, entfernte niedrige Ufer erscheinen
* wie hohe Küsten; und diese, wenn sie auch 7 oder 8 Meilen entfernt, und
* weit unterm Horizont sind, erscheinen wie Gewölke über demselben; ganze
* Landschaften, die man sonst wegen der vorliegenden Sandhügel nicht sehen
* kann, erscheinen über dieselben hervor." (p. 78)
*      Next, he worries about how to explain the "reflection".  "Die Erdfläche
* selbst, so wie auch das Wasser, wenn es vom Winde in Unruhe gesetzt wird,
* sind zu rauh, um Bilder zu machen."
*      "Mein würdiger Lehrer, der Hr. Prof. Büsch pflegte in der Optik zu
* bemerken, dass die zurückwerfung nicht unmittelbar an den Flächen,
* sondern in einer kleinere Entfernung von denselben . . . geschehe."
* He then describes a case where the mirage was seen at both high and
* low tide, when the water was 1½ toise lower; "Die Erniedrigung der
* Meeresfläche hat also denselben Effekt, den eine wirkliche Erhöhung
* des Auges oder des Objects haben würde . . . ."
*      In the second part (p. 81) he considers whether the reflecting surface
* shares the curvature of the Earth, and whether this can explain the
* reduced size of the images. Unfortunately, because he neglects some
* small quantities, he thinks the reflection at a spherical surface will
* be the same size as the object, just as if the surface were flat.
*      On p. 86, he says that mirages were sometimes still visible in late
* January, when the ground and the ice on the river were covered with snow.
*      DIP and the inferior MIRAGE:
*      His quantitative measurements of terrestrial refraction (given in
* the Table facing p. 86) clearly show a correlation between refraction and
* the inferior mirage: "bey verstärkter Refraktion oder Hebung des Hauses
* niemals Spiegelung gewesen; oder umgekehrt, dass bey der Spiegelung das
* Haus allezeit weniger erhaben gewesen, folglich eine relative Depression
* der Objekte wenigsten bey der Spiegelung statt habe."
*      These measurements clearly establish the connection between refraction
* and the air-water temperature difference, and likewise the connections
* between the inferior mirage and depression, and the superior mirage and
* looming. Here is his memorable "2 deg. Fahr." rule; "unter mehr als 150
* Beobachtungen hat diese Regel keine Ausnahme." (p. 95)
*      Woltman's final remark is that these phenomena are very well described
* by Martinet in the Verhandelingen der holländ. Gesellsch. zu Harlem XXVII.
* Deel. II. Stück, under the title "Warneemingen omtrent het opdoemen van
* Zee en Land".
*
* Woltman's figures are at the very end of the volume; in Google's scan at
*
* https://www.google.com/books/edition/Neuere_Abhandlungen_der_k%C3%B6niglichen_B%C3%B6/nqpeAAAAcAAJ?hl=en&gbpv=1&dq=Woltman+Bemerkungen+1798+katoptrisches&pg=PA69&printsec=frontcover
*
* they come after Gruber's figures, at image 491.
*
*      Notice the correct spelling of his name here.


T. Gruber
“Abbé Gruber's Thcorie dieses katoptrischen Phänomens, von Senkung und Hebung der Objekte am Horizonte,”
Neuere Abhandlungen der königlichen Böhmischen Gesellschaft der Wissenschaften 3, 97–107 (1798).

* Gruber's comments on Woltman's immediately preceding paper
* [partly reprinted by Gilbert in Ann. Phys. 3, 439 (1800).]
*      Gruber's ray diagrams are all drawn for a flat Earth, so he has to
* violate symmetry in them in trying to explain the compression of the
* inverted image in the inferior mirage.
*      The Tafel showing Gruber's figures is image 475 in the Google Book.


L. A. Milet-Mureau
Voyage de La Pérouse
(Imp. de la République, Paris, 1797).

* early report of SUPERIOR MIRAGE, by Jean François Galaup de La Pérouse:
* (filed slightly out of order to stay with the English translations)
* The mirage observation itself is on p. 10 of Tome 3:
*      "Les journées du 15 et du 16 furent très brumeuses ; nous nous
* éloignâmes peu de la côte de Tartarie, et nous en avions connaissance
* dans les éclaircis ; mais ce dernier jour sera marqué dans notre
* journal par l'illusion la plus complète dont j'aie été témoin depuis
* que je navigue.
*      "Le plus beau ciel succéda, à quatre heures du soir, à la brume la
* plus épaisse ; nous découvrîmes le continent, qui s'étendait de l'Ouest
* un quart Sud-Ouest au Nord un quart Nord-Est, et peu après, dans le
* sud, une grande terre qui allait rejoindre la Tartarie vers l'Ouest,
* ne laissant pas entr'elle et le continent une ouverture de 15d. Nous
* distinguions les montagnes, les ravins, enfin tous les détails du
* terrain ; et nous ne pouvions pas concevoir par où nous étions entrés
* dans ce détroit, qui ne pouvait être que celui de Tessoy, à la recherche
* duquel nous avions renoncé. Dan s cette situation, je crus devoir serrer
* le vent, et gouverner au Sud-Sud-Est ; mais bientôt ces mornes, ces ravins
* disparurent. Le banc de brume le plus extraordinaire que j'eusse jamais vu
* avait occasionné notre erreur : nous le vîmes se dissiper ; ses formes,
* ses teintes s'élevèrent, se perdirent dans la région des nuages, et nous
* eûmes encore assez de jour pour qu'il ne nous restât aucune incertitude
* sur l'inexistence de cette terre fantastique. Je fis route toute la nuit
* sur l'espace de mer qu'elle avait paru occuper, et au jour rien ne se
* montra à nos yeux ; l'horizon était cependant si étendu que nous voyions
* parfaitement la côte de Tartarie, éloignée de plus de quinze lieues."
*      This observation was made the 16th of June, 1787 -- just in the middle
* of superior-mirage season, for mid-latitudes (they were about 44° N).
* The location was off the coast of the Sikhote-Alin mountain range, ENE
* of present-day Vladivostok. The introductory remark indicates that
* La Pérouse was familiar with mirages.
*      Furthermore, they had directly observed a strong thermal inversion a
* few weeks earlier (May 26), a little farther south in the Sea of Japan:
*      "Si les nuages ne nous avaient par annoncé ce changement, nous avions
* eu néanmoins un avertissement que nous n'entemdîmes pas, et qu'il n'est
* peut-être pas facile d'expliquer : les vigies crièrent du haut des mâts
* qu'elles sentaient des vapeurs brûlantes, semblables à celles de la
* bouche d'un four, qui passaient comme des bouffées et se succédaient
* d'une demi-minute à l'autre. Tous les officiers montèrent au haut
* des mâts et éprouvèrent la même chaleur. La température était alors
* de 14d sur le pont ; nous envoyâmes sur les barres des perroquets un
* thermomètre, et il monta à 20d : cependant les bouffées de chaleur
* passaient très-rapidement, et, dans les intervalles, la température de
* l'air de différait pas de celle du niveau de la mer." (T.2, p.389-390)
*
* Title page reads:
*
*                          V O Y A G E
*             D E      L A      P É R O U S E
*                        AUTOUR DU MONDE,
*                               publié
* conformément au décret du 22 avril 1791,
*                          ET RÉDIGÉ
*        par M. L. A. MILET-MUREAU
*
* Thanks to Luc Dettwiller for discovering the mirage report!


L. A. Milet Mureau
The Voyage of La Pérouse round the World
(John Stockdale, London, 1798).

* 1st English translation of La Pérouse:
* This edition uses the long-s, and seems to have been the "popular"
* rather than the "official" translation. The mirage story reads:
*      "The 15th and 16th of June were very foggy days.  We kept within a
* small distance of the coast of Tartary, and got sight of it at intervals;
* but the last of these days will be distinguished in our journal by the
* most complete illusion I have witnessed since I have been a seaman.
*      "At four in the afternoon a perfectly clear sky succeeding to the
* thickest fog. we descried the continent extending from W. by S. to N. by
* E. and soon after, an extensive land in the south, running towards Tartary
* in the west, where it left an opening of less than fifteen degrees.
* We distinguished the mountains, hollows, and all the variations of the
* ground, but could not imagine how we had entered this strait, which must
* necessarily be that of Tessoy, of which we had given up the pursuit.
* In this situation I thought it necessary to haul the wind, and steer
* S. S. W.; but these hills and hollows soon disappeared. The most
* extraordinary fog-bank I had ever beheld occasioned this deception,
* and we soon witnessed its dispersion. Its forms and its tints mounted,
* and vanished in the atmosphere among the clouds; and enough of day still
* remained fully to demonstrate that land to be unsubstantial and imaginary.
* I stood on, during the night, over the space it had appeared to occupy,
* and at day-break no object presented itself to our view. The horizon was
* even sufficiently extensive to admit of our distinctly seeing the coast of
* Tartary, although more than fifteen leagues distant. I shaped my course
* towards it, but at eight in the morning the fog again surrounded us."
* [The above passage appears on pp. 27-28 of Vol. II.]


L. A. Milet Mureau
A Voyage round the World, performed In the Years 1785, 1786, 1787, and 1788, by the Boussole and Astrolabe, Under the Command of J. F. G. de la Pérouse
(G.G. and J.Robinson, London, 1799).

* 2nd English translation of La Pérouse:
* This edition uses the short s, and is written in a more formal style.
* The mirage story is on p. 7 of Vol. II:
*      "The 15th and 16th were very foggy.  We sailed along the coast of
* Tartary at no great distance, and had sight of it at intervals, when
* the fog dispersed a little; but the 16th will be distinguished in our
* journal by the most complete illusion that I ever witnessed since I have
* been at sea.
*      "At four in the evening the most beautifully clear sky succeeded the
* thickest fog. We discovered the continent, which extended from west by
* south to north by east; and very soon after, to the south, an extensive
* land, running west towards Tartary, so as not to leave an opening of
* 15° between it and the continent. We distinguished the mountains,
* the valleys, and all the particulars of the land; and could not conceive
* how we had entered into this strait, which could be no other than that
* of Tessoy, the search after which we had given up. In this situation
* I thought it advisable to haul our wind, and steer south-south-east.
* But soon these hills and valleys disappeared. The most extraordinary
* fog-bank I had ever beheld was the cause of our illusion. We saw it
* disperse; it's shapes, it's colours, ascended, and vanished in the region
* of clouds; and we still had day-light enough left to remove every doubt
* about the existence of this fantastic land. I sailed all night over
* the space of sea it had appeared to occupy, and at day-break nothing of
* it was visible, though our horizon was so extensive, that we distinctly
* saw the coast of Tartary upwards of fifteen leagues distant."
* [NOTE: the abnormally large distance to the horizon shows that inversion
* conditions were still present.]
*      The previous inversion observation appears in this edition on p. 537
* of Vol. I:
*      "The sky was clear and serene, but it grew very black, and I was
* obliged to stand off the shore, that I might not be embayed by the
* easterly winds. If the clouds did not give us warning of this change,
* we had an indication of it, which we did not understand, and which it
* is not perhaps easy to explain. The men at the mast-head cried out,
* that they felt burning vapours, resembling those of the mouth of an
* oven, coming in puffs every half minute. All the officers went to the
* mast-head, and felt the same heat. The thermometer at that time was
* at 14° upon deck. We sent one up to the cross-trees, and it rose
* to 20°. These puffs of heat, however, passed with great rapidity,
* and in the intervals the temperature of the air did not differ from that
* of the temperature of the level of the sea."
*      Note: this edition has the dates in the margins, like the original.


S. Vince
“Observations upon an unusual horizontal Refraction of the Air; with Remarks on the Variation to which the lower Parts of the Atmosphere are sometimes subject,”
Phil. Trans. Roy. Soc. Lond. 89, 13–23 (1799).

* early report of SUPERIOR MIRAGE, by Vince:
* ``The uncertainty of the refraction of the air near the horizon has long
* been known to astronomers, the mean refraction varying by quantities
* which cannot be accounted for from the variations of the barometer and
* thermometer. . . .''
* ``In fact, the images were visible, when the whole ship was actually below
* the horizon. . . . The discovery of ships in this manner might, in some
* cases, be of great importance. . . .''
* ``As the phenomena are very curious, and extraordinary in their nature, . . .
* They appear to be of considerable importance; as they lead us to a
* knowledge of those changes to which the lower parts of the atmosphere are
* sometimes subject.      . . .  it might throw further light upon this subject,
* and lead to useful discoveries respecting the state of the atmosphere. . . .''
*
* This was the Bakerian lecture.
* According to the paper's title, Vince was the Plumian Prof. of Astronomy
* & Experimental Philosophy (i.e., physics) at Cambridge.


[Monge]
“Copie des procès-verbaux des séances de l'Institut d'Égypte, envoyés à l'Institut national de France,”
Décade Philosophique, An VII, 2me. Trimestre , No. 10, 4–5 (1798).

* The Décade Philosophique meeting abstract of Monge's lecture
*      The full title is "La Décade Philosophique, Littéraire et Politique"
* and the publication date is 10 Nivôse = Dec.30, 1798. The article is headed
*
*             Institut d'Égypte
*
* and on p. 2 is the sub-head:
*
* Copie des procès-verbaux des séances de l'Institut
* d'Égypte, envoyés à l'Institut national de France
*
* followed by the account of the first meeting, on 6 Fructidor an VI.
*
* The minutes of the second meeting (11 Fructidor) begins on p. 4, with
* Monge's abstract beginning there and continuing to p. 5. The third
* meeting (16 Fructidor) begins near the foot of p. 5. Later meetings
* continue through p. 11.
*
* Available at Gallica:
*      https://gallica.bnf.fr/ark:/12148/bpt6k5616321s/f11.item.r=mirage


G. Monge
“Sur le phénomène optique, nommé MIRAGE par les marins,”
Ann. Chim. 29, 207–208 (1799).

* The Ann.Chim. lecture abstract of Monge's mirage memoir
*
* "A la mer, il arrive souvent qu'un naivre appercu de loin, paroit
* tout-à-fait dessiné dans le ciel, et n'être point supporté par l'eau. (1)"
* ------------- (the footnote says): -------
* (1) Cette illusion optique nous paroit avoir quelque rapport avec ces
* apparitions dans la mer et dans l'air pres du phare de Messine, connus
* sous le nom de fée Morgan , dont il est fait mention tom.XXV de ces
* Annales, pag. 80. Note des Rédacteurs .
* [This is a brief mention of Nicholson's translation of Minasi.]
* ------------------------------------------
* "Un effet analogue a frappé tous le Francais pendant la marche de l'armée
* à travers le désert. . . .
*       "Le cit. Monge attribue cet effet à la diminution de densité de la
* couche inférieure de l'atmosphère. Cette diminution dans le désert est
* produite par l'augmentation de température qui est la résultat de la
* chaleur communiquée par le soleil aux sables avec lesquels cette
* couche est en contact immédiat. A la mer, elle a lieu lorsque, par des
* circonstances particulières, telles que l'action des vents, la couche
* infèrieure de l'atmosphère tient en dissolution une plus grande
* quantité d'eau que les autres couches. Dans cet état de choses, les
* rayons de lumière qui viennent des parties basses du ciel, étant arrivés
* a la surface qui sépare la couche la moins dense de celles qui sont
* au-dessus, ne pénètrent pas dans cette couche; ils sont réfléchis, et
* vont peindre, dans l'œil de l'observateur, l'image du ciel. . . . "
*      So here we have water vapor and a fictitious reflecting "surface",
* from the very beginning.
*
* The text is almost identical to that appearing in Décade Philosophique,
* An 7, No. 10, pp. 4-5, where it is part of the report for the second
* meeting of the Institut d'Egypte.
*
*
*              Page 207 is headed:
*
*                        E X T R A I T
*
*Du mémoire lu à la séance de l'institut
*      du Caire, du 11fructidor, an 6;
*
*                  Par le cit. M O N G E
*
*      (That date is 28 August 1798.)
*
*
* However, the issue of Ann. Chim. in which this reprint appears is dated
* 30 Nivôse = 19 janvier 1799.
*
*      Available at Gallica:
* https://gallica.bnf.fr/ark:/12148/bpt6k65712092/f7.item.r=mirage


G. Monge
“Mémoire sur le phénomène d'optique connu sous le nom de mirage,”
La Décade égyptienne 1, No. 2, 37–46 (1799).

* The text of Monge's mirage memoir
*      Monge says that the mirage in the desert may be due to heat, but that
* the mirage at sea is different: "En effet, l'air a la faculté de
* dissoudre l'eau, et même d'atteindre le point de saturation, sans perdre
* sa transparence; et Sassure a fait voir due la pesanteur spécifique de
* l'air décroit à mesure qu'il tient une plus grande quantité d'eau en
* dissolution. Lors donc que le vent qui souffle en mer apporte un air
* qui n'est pas saturé d'eau, la couche inférieure de l'athmosphère qui
* est en contact avec la surface de la mer, dissout de l'eau nouvelle, et
* se dilate. Cette cause, jointe à la légère augmentation de température,
* peut enfin amener les circonstances favorables au mirage, et produit en
* effet celui que les marins observent assez fréquemment." (p. 45)
*      This differs by many minor changes in spelling and punctuation from
* the final version (below), which has the addendum on rainbows.
*      According to Gallica, this was published in 1799.  The title page
* says only " An VII ". This first volume was supposedly printed every 10
* days; as Gallica dates the volume at Jan. 1, this second number might
* have been printed on Jan. 11, 1799. The signature footers say "1.er
* Trimestre, AN 7."


G. Monge
“Sur le phénomene d'optique, connu sous le nom de Mirage,”
Memoires sur l'Égypte 1, 64–79 (1800).

* GASPARD MONGE explains the INFERIOR MIRAGE as total internal reflection,
* and reports REFLECTED RAINBOWS
* He leans very heavily on total internal reflection, and attributes
* the inferior mirages seen at sea to the effect of water vapor on the
* refractivity of air, confusing optical "density" with mechanical density.
*      ". . .  ce phénomene pourroit ne pas être ignoré des habitants du
* département des landes; mais il est très connu des marins, qui
* l'observent fréquemment à la mer, et qui lui ont donné le nom de
* Mirage ."  (p. 65)      [Cf. Le Gentil (1789) for "se mirer".]
*      He takes the internal-reflection picture very literally, repeatedly
* referring to "la surface qui sépare la couche inférieure et dilatée
* de l'atmosphere de la couche plus dense qui est au-dessus d'elle" (p. 71)
* and "la surface réfléchissante, qui sépare les deux couches d'air des
* densités différentes, n'est ni parfaitement plane" (p. 73). This
* mistaken idea was immediately challenged by Reinecke (see below), and
* by Wollaston (1803). Nevertheless, we still see it stated in physics
* textbooks today.
*      This volume simply says "An VIII" on the title page, and no more
* precise date is indicated. As most of that year in the Republican
* calendar was in Gregorian year 1800, I adopt "1800" as the date.
* This also is the date in most library catalogs.
*      NOTE: the spelling "phénomene" (without a grave accent) is used
* consistently throughout; it is not a typo here in his title.


G. Monge
“Memoir relative to the optical Phenomenon, known by the name of {\textsc{MIRAGE,” in Memoirs relative to Egypt
(K.Phillips, London, 1800), pp. 74–90.

* Monge's memoir translated into English
* The translator is not named, though there is an Advertisement of the
* Translator -- in which we read that "Some of the Memoirs bear the marks
* of being hastily composed, but . . . no omissions or alterations have been
* made by the English Editor, which might render the translation any thing
* else than an accurate and complete copy of the original Work."


Anon.
“Paris,”
Göttingische Anzeigen von gelehrten Sachen 1800, 1849–1852 (22 Nov., 1800).

* Brief mention of Monge's memoir in a review of the whole "Memoires"
* We are interested only in the lines on p. 1850:
*      "Abhandlung über die unter dem Nahmen Mirage  bekannte optische
* Erscheinung, von G. Monge. Mit der Beschreibung dieses Phänomens wird
* man besser zufrieden seyn, als mit der Erklärung, die M. davon zu geben
* versucht."
*      This is the 186. St. of 1800.
*      Available at Google Books.


[J. M. Reinecke]
“Über die Fata Morgana , das Seegesicht und die Erhebung .,”
Allgemeine Geographische Ephemeriden 5, No. 3, 195–222 (1800).

* Interesting REVIEW of mirages by Dr. JOHANN CHRISTOPH MATTHIAS REINECKE
*      He begins with the Fata Morgana, "or the Castles in the Air of the
* fairy Morgana," immediately naming Angelucci, Kircher and Scotus as
* the older writers who have tried to offer descriptions and explanations.
* Of the newer writers, he mentions only Minasi, whose work he knows only
* from Nicholson's 1797 extract in the Philosophical Journal. Fortunately,
* it includes Minasi's illustration of the whole thing, which is copied
* here as Tafel I. So it's necessary to translate Minasi's description
* from the English. . . . And in doing so, he refers to the details of the
* engraving.
*      Among other things, he points out the Sun low in the sky at the
* left edge of the image -- a detail that seems to have escaped all other
* students of the image. Evidently, he thinks Minasi's "45 degrees"
* refers to an azimuthal angle, not a solar altitude. (Note his remark
* on p. 209 about 9 a.m. being the favorable hour.)
*      He also points out the impossibility that the city depicted could be
* Reggio, as it is Messina that lies on the opposite shore. The doubling
* of the images must make the city unrecognizable; and the random angles
* at which the "reflected" towers stand, without falling down, make them
* "true fairy-castles" which could "exist on the coast of neither Italy
* nor Sicily". Then comes a salient point: "Only through precise drawings,
* both of the phenomenon and of the view of the city of Reggio from the
* seaside, which, as has happened in the present copper engraving, were
* placed next to each other, could one part of the riddle and the origin of
* these fairy-castles be found." So he understood the need for photographic
* evidence decades before photography was invented, and centuries before
* photographs of Fata Morgana displays were actually obtained. "Here I
* regret that Minasi is not more detailed." But he generally accepts
* Minasi's account of both the phenomena and their cause as correct.
*      So he thinks the sides of the waves generally have an inclination to
* the horizontal of 45 degrees, and supposes that the inclination of the
* mean surface can be similarly large, so that the waves could actually
* have vertical surfaces (as shown in Fig.1 of Tafel II) -- thus making
* the vertical mirror that Minasi imagined.
*      He then gives a German translation of Nicholson's English translation
* of Minasi's Italian. This is a different German translation of
* Nicholson than the one published by Gilbert two years later (see the 1802
* entries below). Gilbert clearly used parts of Reinecke's discussion in
* making his own, and cites Reinecke -- though not by name.
*      In the end, Reinecke tries to explain how Minasi's wave-facet scheme
* might work because of the shape of the Strait. It is all very contrived.
*      However, on p. 206, there is the useful idea that Minasi probably meant
* Puglian miles, of 7000 Neapolitan palms each, in specifying distances.
*      Apart from the supposed interactions of local causes, Reinecke admits
* that "it would always appear striking that this phenomenon is not also
* visible at other coasts . . . ". (p.210) In searching for examples, the
* best he can find is Wetterling's 1788 discussion of the Erhebung and
* the Seegesicht . [His accouunt of the virtual "cliffs" seen in Sweden
* in August, 1774, seems quite similar to Forel's identification of a
* "striated zone" as the hallmark of the Fata Morgana a century later.]
* Surprisingly, Reinecke knew of accounts by de Ferrariis and others
* of similar mirages in southern Italy, citing Giovene as well.
*      Having identified the Seegesicht  as being at least related to
* the Fata Morgana, Reinecke turns to looming. (p.219) Unfortunately,
* he says that it is the same thing as Kimmung , which is the appearance
* of floating or suspension produced when a strip of miraged sky is seen
* beneath objects at the apparent horizon -- but in an inferior mirage;
* the inverted image seems to hang down from the fold line. (P&E call
* this effect "Schwebung oder Kimmung" on their p.137). However, Reinecke
* correctly describes Erhebung as making "objects that lie under the
* horizon, or are hidden by other objects, become visible above it."
* He adds that the phenomenon is mostly observed on the Baltic Sea.
* As examples, he offers both Wetterling's discussion and that of
* Prof. Büsch (in his Tractatus .)
*      His first impression was that just one kind of phenomenon had been
* called the Erhebung ; but on closer examination, he found that "many of
* them, especially those in which the images of ordinary objects appear cut
* off in the air, are really Morganas ." He cites examples from Wetterling
* that show extreme vertical exaggeration and rapid variations, noting the
* similarity of circumstances (position of the Sun, calm air) and location
* (near the sea), and compares these with Giovene's Lavandaja observations.
* But he is puzzled: if the circumstances and locations are so similar,
* why are the appearances so varied? (pp. 220-221)
*      NOTE: as Reinecke was primarily a cartographer, geographer, and
* paleontologist, his ignorance of physics in general and optics in
* particular is to be expected; so his acceptance of Minasi's nonsense
* "theory" is not surprising. Given this ignorance, his connection of
* looming with Fata Morganas is a substantial accomplishment.
*      The first page of this number says "V Bds. drittes Stück.  März 1800."
* in italics; and then "A B H A N D L U N G E N".
*      No author is named in this issue; but his identity is revealed in the
* July issue. This Abhandlung is numbered I. After the title is another
* italic note: "Hierzu gehören die Kupfer --- Tafeln I und II."
*      I do not have a copy of these plates.  However, they have been
* reprinted in Marcello Séstito's "Fata Morgana" book, which cites these
* papers by Reinecke, Büsch, and Monge, translating them all into Italian.
*      Special thanks to Marcella Giulia Pace for bringing these important
* references to my attention!


[J. G. ] Büsch
“Schreiben des Hrn. Prof. Büsch in Hamburg, an d. Herausgeber der A.G.E.,”
Allgemeine Geographische Ephemeriden 6, No. 1, 3–14 (1800).

* Reinecke's discussion of mirages is commented on by Büsch, followed by
* Reinecke's rejoinder and translation of Monge's article, and Reinecke's
* further comments on Monge. I list these components separately here,
* as they are assigned separate numbers in the Abhandlungen. All are
* in the Appendices to Séstito's book, translated into Italian.
*      The first page of this number says "VI. Bds. erstes Stück.  Julius 1800."
* in italics; and then "A B H A N D L U N G E N".
*      Here is Abhandlung I., divided into four numbered sub-sections; they
* are sometimes cited by the collective title of the whole Abhandlung:
*
*       "Fernere Beyträge und Bemerkungen über die Fata Morgana, das Seegesicht
*            und die Erhebung."
*
*      Büsch had himself already read Minasi's Büchlein  some years before,
* and thinks it's better to see the original than Nicholson's English
* translation. And he doesn't think much of Minasi's original, either:
* "There is only one place in the book, p. 74, that makes me believe he
* had seen the phenomenon himself. But instead of describing it exactly,
* he immediately turns to the glorification of God. . . . So I almost
* believe that he himself knows no more about it than his father had
* told him. Then, it seems, this marvel appears only rarely, though even
* so M. produces a theory whereby it should appear very often and regularly
* under his defined conditions." (p.4)
*      "Such a marvel should, if it's possible, be seen from more than one
* place, and from different viewing points and distances. But that should
* be easy, as it includes such a great space in the atmosphere.
*      "It is a phenomenon of the atmosphere, so M. should have guessed to
* observe the state of the atmosphere at the same time, even if only by
* the height of the barometer. A thermometer would have been no trouble
* at all.
*      "All this didn't stop him from devising a theory, but which?  It
* should 'come from the different currents that meet in the Strait of
* Messina, pressing hard, and working against one another, create a
* mirror-smooth surface.' But that would be remarkable in a strait where
* a Scylla and Charybdis make currents that already the Ancients
* described as dangerous. But M. has surely never attentively observed
* a body of water in which several streams encounter one another. We have
* several such places in the Elbe , where the water is always restless,
* even if it is moved by no wind from the side. . . . " (p.5)
*      After describing those examples in detail, he asks: "Should Nature be
* so completely different in the Strait of Messina, and even form a smooth
* concave mirror whose figure would have to be not just spherical, but
* that of a hollow cylinder?" (p.6)
*      Büsch then adds a few more comments on "theorifying", and thanks the
* author [Reinecke] for mentioning his own Latin thesis on mirages. Then
* he returns to the Fata Morgana:
*      "In regard to the Fata Morgana , one of three [sic] things must be true.
* 1) Either the whole phenomenon has been described falsely until now,
* or magnified through the desire for the miraculous. . . . Minasi is free
* of such monks'-dreams, but he seems to me not to have seen quite clearly
* yet. 2) But if Minasi has seen correctly, even if it were only one
* observation, then the phenomenon is something completely different from
* what I have seen and described a hundred times. Then we could completely
* lay the Fata Morgana aside, and so it will come to the point that
* Teutons will examine the matter more closely with Teutonic diligence,
* and seek to explain the results, which certainly lie in the study of
* the determination of the refraction. For no one but Gruber and me has
* yet thought to give an explanation of how it occurs over dry land ."
*      He then relates some of his own mirage observations made while
* traveling on the Baltic coast. These were clearly inferior mirages,
* "which had been so remarkable to the French, but from which they learned
* nothing." [So much for Monge!] "I saw them at all hours of the day,
* and not a single time with different or unfamiliar circumstances. It
* amuses me when I read so many differences in the description. But then
* I think: 'The man did not see what you saw, or his power of imagination
* has added what yours did not, because you yourself know to keep it in
* bounds.'" (p.9)
*      He then mentions Humboldt's observations of mirages, and says that he
* has just received the first part of the British Transactions for 1799
* with the observations by Vince; but he was not able to understand
* Vince's figure. [Obviously, because he only is familiar with inferior
* mirages.] (p.11)
*      On the next pages is an amusing anecdote about showing the mirage to
* Graf von Czeczeny from Hungary, while traveling in the Harkshaide [sic]
* on the road from Hamburg to Kiel, in July, 1790. This is followed on p.14
* by a brief mention of the 1798 publication of Latham's observation of
* looming at Hastings.
*
*      A footnote on the first page explains that the unsigned review in the
* March issue was written by Dr. Reinecke, a frequent contributor.
*      Büsch's letter here is cited in a footnote on p. 133 of Pernter & Exner
* (1922), where it is attributed to Bertuch and Gaspari, the publishers of
* Allgem. geogr. Ephemeriden; Reinecke is not mentioned. Likewise, in
* Gilbert's 1802 discussion of Minasi (see his note on p.30 there).
*      This must be nearly the last thing Büsch wrote; he died August 5, 1800.


Dr. J. M. Reinecke
“Antwort auf das Schreiben des Hrn. Prof. Büsch ,”
Allgemeine Geographische Ephemeriden 6, No. 1, 14–15 (1800).

* Reinecke's reply to Büsch
*      Reinecke begins by quoting Büsch, and correcting the "3 for 2" error
* on p.7. He declares that the second is obviously the correct choice.
* And he emphasizes that Büsch has a single observation that seems to have
* some similarity with the Fata Morgana in his Tractatus .
*      "That Minasi observed superficially may well be true; but where are
* the better observers?" [Note: Minasi was a medicinal botanist, not a
* physicist.]
*      The first page of this number says "VI. Bds. erstes Stück.  Julius 1800."
* in italics; and then "A B H A N D L U N G E N".
*      This is part 2 of Abhandlung I.


G. Monge [in translation]
“Abhandlung über ein optisches Phänomen, die Kimmung genannt, von Gaspard Monge,”
Allgemeine Geographische Ephemeriden 6, No. 1, 15–25 (1800).

* Reinecke's translation of Gaspard Monge's paper in Memoires sur l'Egypte
* There is a footnote to the title word "Kimmung" that says:
* "Gewönlich Erhebung , Franzos. Mirage , in Niederteutschland
* Währkatten , Updracht , Holl. Opduining , Schwäd. Hägring ."
*      The first page of this number says "VI. Bds. erstes Stück.  Julius 1800."
* in italics; and then "A B H A N D L U N G E N".
*      This is part 3 of Abhandlung I.


Dr. Reinecke
“Zusatz des Übersetzers,”
Allgemeine Geographische Ephemeriden 6, No. 1, 25–30 (1800).

* Reinecke's additional comments as translator of Monge
*      Reinecke does not mince words: "The above theory requires a correction,"
* is his first sentence. ["Die obige Theorie bedarf einiger Berichtigung."]
* (Cf. Büsch's similar remarks in his 1783 "Tractatus".)
* Of Monge's "einzigen bestimmten Fläche", he says:
*      "Eine so genau abgeschnittene Fläche findet aber, wie auch schon Hr.
* Prof. Büsch bey Gelegenheit der Gruberschen Erklärung desselben
* Phänomens bemerkt, in der Natur nicht statt; sondern die Dichtigkeit der
* Luft nimmt fortgehend und allmählich ab oder zu, und es ist kein Grund
* vorhanden, warum sie an einer Stelle mehr als an der andern reflectieren
* sollte. Statt einer einfachen Reflexion erleidet vielmehr ein
* Lichtstrahl, wenn er durch ein Medium von abnehmender Dichtigkeit geht,
* auf jedem Puncte seines Weges eine Brechung, und beschreibt daher eine
* krumme Linie, die, je nachdem die Dichtigkeitszunahme schneller oder
* geringer, und der Weg des Lichtstrahls länger oder kürzer ist, von
* verschiedener Art seyn kann." He goes on to explain that the usual
* state of the atmosphere makes the rays concave toward the Earth; but
* if we invert the usual decrease of density upward, the rays will be
* concave upward and turn their convex sides to the Earth -- "obgleich
* keine wirkliche Reflexion erfolgt."
*      "Dies ist nun auch das Phänomen, von dem Hr. Prof. Büsch  in
* seinem Tractate und in obigem Briefe handelt. Seine Erklärung, die
* Monge nicht gekannt zu haben scheint, weicht von der hier gegebenen
* ganz ab, aber wie? --- Nach Hr. Büsch erklärt sich alles aus der
* gewöhnlichen --- verstärkten horizontalen Strahlenbrechung, statt
* dass wir es eben aus der umgekehrten horizontalen Strahlenbrechung
* erklären." He goes on to explain that either explanation will work; that
* is, he sees that it is the change in the ray curvature that is needed
* to produce the inverted images. Both explanations produce "the same
* phenomenon, a variation of the horizon." Büsch's model should produce
* "eine Erhebung der Gegenstände über den Horizont"; in Reinecke's
* model, "die Gegenstände müssen . . . unter den Horizont hinabsinken."
* He decides that Hebung is the usual case in northern latitudes, and
* thus accounts for Büsch's observations of looming.
*      So he notes the problem: "Monge  hat keine Winkelmessungen
* angestellt, und überhaupt auf diesen Punct, wie es scheint, nicht
* Rücksicht genommen." So Reinecke recognized that the absolute values of
* the altitudes near the horizon are needed to understand the full details
* of the mirages. The DIP is an essential feature of mirages.
*      "Inzwischen ist es sehr zu wünschen, dass Beobachter, die sich in
* Rücksicht ihres Wohnorts in einer dazu günstigen Lage befinden, ---
* denn bey Erscheinungen, die den Beobachter ganz unvorbereitet auf der
* Reise überraschen, ist das nicht zu erwarten, --- ihre Beobachtungen
* mit Winkelmessungen, und was sich ohnehin versteht, mit Thermometer-
* und Barometer-Beobachtungen verbinden mögen, wie schon Hr. Büsch am
* Schlusse seines Tractats empfiehlt, weil ohne diess nothwendig manches
* schwankend bleiben muss."
*      Reincke's perceptive remarks here show a much better understanding of
* the mirage problem than his earlier comments would suggest.
*
*      The first page of this number says "VI. Bds. erstes Stück.  Julius 1800."
* in italics; and then "A B H A N D L U N G E N".
*      This is part 4 of Abhandlung I.
* Available from Google Books:
* https://www.google.com/books/edition/Allgemeine_geographische_Ephemeriden/OJgPbBBjqpQC?hl=en&gbpv=1&dq=Monge+Reinecke+mirage&pg=PA15&printsec=frontcover
* and
* https://www.google.com/books/edition/Allgemeine_geographische_Ephemeriden/aRiKHZFw3zUC?hl=en&gbpv=1&dq=Monge+Reinecke+mirage&pg=PA15&printsec=frontcover


J. G. Büsch
“Beobachtungen über horizontale Strahlenbrechung und die wunderbaren Erscheinungen, welche sie bewirkt,”
Gilberts Ann. Phys. 3, 290–301 (1800).

* EARLY MIRAGES; DISTORTED MOONRISE
* extracted and translated from:
* Jo. Geo. Büsch tractatus duo optici argumenti, Hamburgi 1783, 132 S. 8.
* "Ich bemerkte dieses Phänomen schon in meiner Jugend bey den
* Ueberfahrten von Hamburg nach dem eine Meile entlegnen Harburg, wo mein
* Grossvater lebte. Wenn der Wind die Wellen mitten im Strome ziemlich
* heftig um das Schiff bewegte, schien das Wasser am Ufer vollkommen ruhig
* zu seyn, gleich einer Spiegelebene. Dieses komme, sagten mir die
* Uferbewohner, von den Untiefen am Strande her; allein, wenn wir eine Höhe
* erstiegen, und von da nach dem entgegengesetzten Ufer sahen, war auch das
* Wasser voll Wellen."
* (cf. Abbott, 1854, who reports the same phenomenon in India!)
* (also, Forel, p. 526 of his 1895 monograph; and Manning, 1912.)
*
* includes a distorted moonrise: "Der Mond, der beynahe voll war, ging
* auf, wie ihn Fig. 6 zeigt. Als ich die anderen Passagiers fragte, ob
* ihnen nicht etwas besonderes am Monde vorkomme, antwortete einer:
* `Meiner Treu, er gleicht einem umgestürzten Nachtgeschirr.'"
* [See Büsch, Tractatus duo (1783) for the original quote in English.]
*
* Prof. Johann Georg Büsch (1728 - 1800) taught at the academic
* Gymnasium in Hamburg. About 1780 he allowed Reinhard Woltman to attend
* his lectures and use his extensive library. Woltman in turn became the
* supervisor of Heinrich Wilhelm Brandes, who was in charge of the water
* works on Neuwerk in 1794-95, and was recommended by Woltman to the post
* of "Deichconducteur" in Eckwarden in 1801, where he continued Woltman's
* observations of refraction phenomena.
*      This is Part 3 of Band 3, mostly devoted to refraction and mirages.  It
* begins with a German translation of Huddart's paper on dip, followed by
* General Roy and Dalby's work. The issue date is not known, but Gilbert's
* preface to the whole volume is dated "den 2ten Februar 1800".


J. Huddart
“Beobachtungen über die horizontale Strahlenbrechung bey irdischen Gegenständen und über die Vertiefung des Seehorizontes (dip of the sea),”
Gilberts Ann. Phys. 3, 257–280 (1800).

* HUDDART translated by Gilbert
*      With the usual copious comments by Gilbert!  Already on p. 259, he
* inserts a footnote referring to Gruber and Büsch, "die der Leser im
* nächsten Bande der Annalen in kurzen Auszügen finden wird".
* This volume of Gilb. Ann. is available at
* https://www.google.com/books/edition/Annalen_der_Physik/_3zqQ4mRhO8C?hl=en&gbpv=1&dq=Gilbert+Annalen+Physik+1800+Huddart&pg=PA265&printsec=frontcover


L. W. Gilbert
“Beobachtungen besonderer Strahlenbrechung von Boscowich, Monge und Ellicot,”
Gilberts Ann. Phys. 3, 302–308 (1800).

* EARLY MIRAGES
* summaries of the work of others by Ludwig Wilhelm Gilbert:


Anon.
“Domestic Literature,” in The New Annual Register for the Year 1800
(G.and J.Robinson, London, 1801), p. 270.

* 1801 review of Monge's final paper
*      Buried in a long paragraph on a variety of technical publications,
* we find: "One other optical phenomenon has been illustrated by the
* publications of the present year, viz. what is called the Mirage, in the
* Collection of Memoirs published by the Philosophers who followed Bonaparte
* to Egypt. The author is M. Monge, whose account is neither very clear
* nor scientific." (This follows a mention of Wollaston's 1800 paper.)
*      As this is mentioned under "Domestic Literature", I suppose it is based
* on the official English translation of the Memoirs published in London.
*      Full title: "The New Annual Register or General Repository of History,
* Politics, and Literature, for the Year 1800."
*      NOTE: the several sections of this volume are separately paginated.
* This is in the last one, which starts with "Biographical Anecdotes and
* Characters"; its sub-section "Domestic Literature of the Year 1800" runs
* from p. 225 to p. 336. The subsection "Foreign Literature . . . " begins
* on p. 337. No authors' names are given.


T. Gruber
“Beobachtungen über die Strahlenbrechung auf erwärmten Flächen,”
Gilberts Ann. Physik 3, 377–396 (1800).

* EARLY EXPERIMENTAL DEMONSTRATION OF MIRAGE
*      Abbé Tobias Gruber (Grüber?) -- see his 1786 paper.
*      Gilbert says this is an extract of Gruber's "Physikalischer Abhandlung
* über die Strahlenbrechung und Abprallung auf erwärmten Flächen" in
* Abhandlungen der böhmischen Gesellschaft der Wissenschaften, B.II, (1787).
* Pernter and I both have 1786 for its date; Gilbert's date might be the
* actual year of publication -- or that of the Dresden offprint.
*      Büsch's reference to Gruber in his comments in Vol. 6 of A.G.E.
* [see above], and his contributions to Gilbert's Annalen in the next few
* years suggest that Gilbert reprinted Gruber's work at Büsch's suggestion.
*      Gilbert's preface ("Vorredé) to the volume is dated "de 2ten Februar".
*      This begins the fourth part of Band 3.


R. Woltmann
“Beobachtungen über die Brechung der Lichtstrahlen, die nahe über der Erdfläche hinfahren,”
Gilberts Ann. Physik 3, 397–438 (1800).

* QUANTITATIVE MEASUREMENTS of MIRAGES and VARIABLE REFRACTION
* Reinhard Woltman (Not "Woltmann", says Pogg.)
* [It seems that Woltman was Brandes's supervisor in 1794-95.]
* Gilbert attributes the term "Spiegelung" to Woltman.
*
* Mirages visible in RAIN and on overcast days (cf. Ashmore, 1955):
* ". . . selbst im Regen verschwindet sie nicht eher, als bis die
* Undurchsichtigkeit der Luft die Aussicht in die Ferne verhindert.
* Ueberhaupt ist die Erscheinung (wenigstens um Cuxhaven) weit häufiger
* als man sie mit blossen Augen gewahr wird, indem an dunkeln Tagen der
* Luftstreifen, welcher die Gegenstände von der Erde zu trennen scheint,
* nicht so als an hellen Tagen ins Auge fällt." (p. 399)
*
* REDUCED SIZE of image attributed to reflection at a convex surface (p.403):
* "Bey unserm Phänomen sind . . . die Bilder allemal beträchtlich
* kleiner , als ihre Objecte." (Cf. Bravais, 1853; Riccò et al., 1888)
*
* VARIATIONS:
* "Auch die astronomische Horizontalrefraction würde daher wenigstens
* um eben so viel, d.i. etwa um 1/6 ihrer ganzen Grösse veränderlich und
* ungewiss seyn." (p. 421)
*
* Gruber's footnote, pp. 429-430, on CORRELATION of DIP & MIRAGEs:
* ". . . so ist bey allen Spieglungen ohne Ausnahme Depression , so wie bey
* Spieglungen aufwärts, Hebung über diese scheinbare Horizontallinie."
*      See Gruber's paper on this in the following item.
*
* VERTICAL STRIPES at the fold line of SUPERIOR MIRAGES:
* "Zuweilen trennt ein Luftstreifen das verkehrte Bild von dem darunter
* stehenden Gegenstande; doch stossen häufiger Bild und Gegenstand
* zusammen , und vermischen sich so, dass keins von beiden kenntlich ist,
* und das Ganze wie eine hohe Seeküste, mit vielen senkrechten Strichen,
* erscheint." (p.430)
*
* Relation of "seeing" (TURBULENCE) to inferior mirage (pp. 432-433):
* "Die Bilder der Spieglung unterwärts sind sehr unbeständig und
* wandelbar; sie werden bald grösser, bald kleiner, bald in Stücken
* getrennt, und sind zuweilen eine Zeitlang in steter Bewegung."
*
* TEMPERATURE DIFFERENCE between AIR and WATER:
* ". . . allemal, wenn das Wasser um 2° Fahrenh. oder mehr wärmer als
* die Luft war, eine Erniedrigung der Strahlen, die sich über die
* Wasserfläche erstreckten, und (vorausgesetzt, dass die Gegenstände
* sichtbar waren) eine Spiegelung herabwärts stat find. War dagegen das
* Wasser um 2° F. kälter als die Luft, so fand Hebung der Strahlen
* und nie eine Spiegelung herabwärts statt." (pp. 434-435)
* SEASONAL and DIURNAL variations: p. 435.
*      OMEGAs are described, p. 438:
* "Sieht man die Sonne oder den Mond aufgehn oder untergehn , so
* giebt ihre Gestalt ein untrügliches Merkmal, ob Hebung oder Senkung
* statt findet. Im letztern Fall scheint die Sonnen- oder Mond-scheibe
* nicht rund, sondern in die Länge gezogen. Ein Theil derselben spiegelt
* sich unterwärts; das umgekehrte Bild kann 1/8 bis 1/4 des Durchmessers
* betragen, und es ist, als ob an dem auf- oder untergegangnen Theile der
* Anfang einer andern Scheibe angesetzt wäre." (p. 438)
*
*      Gilbert's footnote on p. 397 says this is an extract of two works of
* Woltmann's "under the above title, one still unpublished, reported in
* the Götting-gelehrten Anzeigen J. 1796, St. 82; and from Woltmanns
* Bemerkungen über ein (scheinbar) katoptrisches Phänomen , welches
* an den Gegenständen nahe am Horizont nicht selten sichtbar ist , . . . in
* den Neuen Abhandl. der kön. böhmischen Gesellsch. d. Wiss. B. 3.
* Prag 1798. S. 67-97. 4."
* Note that Gilbert prints double-s as a long followed by a short s.
*      This continues the fourth part of Band 3.


T. Gruber
“Theorie der mit Spiegelung verbundnen Senkung und Hebung der Objecte am Horizont,”
Gilberts Ann. Physik 3, 439–446 (1800).

* EARLY THEORY OF MIRAGE; connection of MIRAGE and DIP
* Abbé Tobias Gruber (Grüber?) comments on Woltman's preceding paper;
* possibly an extract of his 1793 "Theorie . . . Senkung und Hebung" ??
*      He uses ray diagrams, assuming a flat Earth, and thereby has some
* difficulties in explaining the reduced size of the inverted images in
* inferior mirages, and the vertical striation associated with superior
* ones.
*      There is also extensive editorial discussion of terminology in Gilbert's
* long footnotes; e.g., he criticizes Gruber and Woltman for using the
* words "Abprellung" and "katoptrisches" for inferior mirages: "allein
* da sie das wirklich nicht, sondern ganz und gar eine dioptrische
* Erscheinung ist . . . ". (p. 441)
*      This continues the fourth part of Band 3.


J. L. Heim
“Eine merkwürdige Erscheinung durch ungewöhnliche Strahlenbrechung,”
Gilb. Ann. Physik 5, 370–375 (1800).

* a simple case of LOOMING in the mountains
* Gilbert unaccountably makes more of this than it deserves. His final
* footnote contains: "Auch bei uns, mitten im Deutschland, ist also die
* Fata Morgana zu Hause, obwohl bei weitem seltener als in dem heissen
* Unter - Italien und unfern der See. Denn dass die wundervolle
* Fata Morgana zu dieser Klasse ungewöhnlich starker Refractionen
* gehört, glaube ich in einem der folgenden Stücke der Annalen ziemlich
* ausser Zweifel setzen zu können." But he recognizes that it's similar
* to Latham's observation.
* This may be the earliest MIS-USE of "FATA MORGANA" for a simpler case.
*      In the fourth part of Band 5.


W. H. Wollaston
“On double Images caused by atmospherical Refraction,”
Phil. Trans. Roy. Soc. Lond. 90, 239–254 (1800).

* William Hyde WOLLASTON's paper on mirage theory:
* Wollaston re-invents Hooke's (1665) two-liquid demonstration here.
* He distinguishes between "two opposite states of the atmosphere" that
* produce double or triple images; he also notes what we would call
* looming, and explicitly mentions mirages on roads.
*      His laboratory experiments on liquids showed the focusing effect:
* ". . . adjacent portions of the converging rays will form a focus, beyond
* which they will diverge again; and the varied medium will produce
* effects similar to those caused by a medium of uniform density having
* a surface similar to the curve of densities . . . ." (p. 242)
*      "When an oblique line . . .  is viewed through any variable medium . . . ,
* it appears bent into different forms . . . .
*      "If it be at the distance of the principal focus, one point of it is
* bent into a vertical line . . . ." (p. 244)
*
*      He also discovers the laminar sub-layer, via the third image:
* "To explain why red-hot iron occasions two [additional] images, while
* solar hear produces but one, I imagine that the intense heat in the
* former case rarefies the air for some small distance uniformly, and
* thereby affords the same series of variations as between other fluids
* of uniform density; but that, in the latter, the heat is conveyed off
* as fast as it is generated . . . ." (p. 248)
*      On the next page, he mentions that "a level open road" is best for
* observing what we would call inferior mirages. He also uses "a pocket
* telescope magnifying about 16 times".


[J. A. ] de Luc
“Über eine scheinbare Erhöhung der Gegenstände über den Horizont,”
Neue Schriften der Ges. Naturf. Freunde zu Berlin 3, 168–179 (1801).

* Jean André de Luc's inferior-mirage observation, and disbelief
* A curious paper: "Es ist allgemein bekannt, dass am Ufer der Seen und
* der breiten Flüsse und am Strande der Meerbusen eine gewisse optische
* Täuschung oft statt findet, wenn der Zuschauer sich auf einem erhöhten
* Standpunkte befindet; er sieht nemlich alsdann unter gewissen Umständen
* das entgegengesetzte Ufer wie in der Luft schwebend, und man pflegte
* dieses Phänomen auf die Strahlenbrechung zu reduciren: ich glaube aber
* nicht, dass es von dieser Ursache herrühre."
* He nicely describes the effects of eye height; but manages to convince
* himself the apparent "sky" is just a band of haze, "eine Dunstschicht",
* that manages to be indistinguishable from the sky. (This seems incredible
* to anyone living in a dry climate, but is perhaps not so far-fetched
* for someone living in hazy Germany.) At the end of the 10th page
* of the paper (p.177), he lets the cat out of the bag: "Ich zweifle
* kaum dass dies der wahre Grund aller Erscheinungen dieser Art wirklich
* sei, und zwar um so weniger, da ich nie habe begreifen können, wie
* Strahlenbrechung etwas dergleichen hervorbringen könnte."
*      The observation was made over a peat-bog; the miraged trees were
* "ohngefahr eine deutsche Meile" away (6 or 7 km).
*      The GNF had a number of well-known members, including Adelbert von
* Chamisso, Alexander von Humboldt, Adolf Traugott, and Johann Elert Bode.
*      Reuss fails to give the year, but other citations to this volume say
* 1801 [confirmed by e-mail from Hans-Ulrich Raake of the
* Universitätsbibliothek, Humboldt-Universität Berlin (30 July 2002).]
* Prof. De Luc was Swiss.


W. H. Wollaston
“Untersuchungen, wie durch atmosphärische Strahlenbrechung doppelte Bilder von Gegenständen entstehen,”
Gilb. Ann. Phys. 11, 1–65 (1802).

* Gilbert's translation of Wollaston's 1800 paper, with copious notes:


J. Giovene
“Wunderbare Phänomene nach Art der Fata Morgana, beobachtet vom Canonicus J. Giovene, Grossvicar des Bischofs von Molfetta in Apulien,”
Gilb. Ann. Physik 12, 1–19 (1802).

* Gilbert's version of Giovene's observations, heavily annotated
* Here Giuseppe Maria Giovene is Germanized to "Johannes"; the whole
* thing is taken from Zimmermann's "Allgemeiner Blick auf Italien" (1797).
* A good first-hand account of a Fata Morgana observation from near
* Molfetta, on the Adriatic coast (about 300 km north of Reggio):
* "Die von mir selbst beobachteten Phänomene dieser Art schreibe ich
* wörtlich aus meinen Journalen ab; von den übrigen theile ich die
* Nachricht meiner Correspondenten unverändert mit.
*      "Ich befand mich am 9ten Februar 1790 auf einem kleinen Landhause,
* wo ich mich wegen des freien Horizonts vorzüglich gern aufhalte.
* Die Tagen vorher waren heiter gewesen, und es hatte ein mässiger
* Nordwestwind geweht. Der ausnehmend schöne Winterabend lockte mich
* ungefähr eine halbe Stunde nach Sonnenuntergang an ein Fenster, das
* sich gerade nach S.S.O. öffnet. [Giovene's original Italian indeed has
* "S.S.O."; but "O" stands for "ovest"; so the directions are wrong here.]
* Die Luft war so still, dass der Rauch von den Städten Terlizzi , Ruvo
* und Corato , auf die ich die Aussicht hatte, sich gar nicht bewegte,
* sondern über diesen Städten wie ein grosser Sonnenschein hing.
* [Certainly "Sonnenschirm" was intended here; this correction is made
* by P&E on p. 164, without comment.] Indem ich am Horizonte umher sah,
* schienen mir an dem äussersten Ende desselben gegen Westen einige Wolken
* aufzusteigen, die etwa 20 Grad einnahmen. Um daraus auf den Wind und auf
* die Witterung des folgenden Tages urtheilen zu können, wollte ich ihren
* Zug beobachten. Sie stiegen bald auf 2° Höhe, fingen dann aber an
* mannigfaltige Gestalten anzunehmen, und dieses Spiel überzeugte mich,
* dass sie ganz etwas anderes waren, als Wolken.
*      "Ich bat daher den Doktor  T r i p a l d i ,  einen sehr unterrichteten
* Mann, der mich gerade auf einige Tage besucht hatte, an der fernern
* Beobachtung Theil zu nehmen, und wir schickten uns beide dazu auf das
* sorgfältigste an. Die vermeinten Wolken nahmen alle Augenblicke eine
* andere Gestalt an. Zuerst sahen wir im Hintergrunde eine Menge Palläste
* und Thürme, die eine grosse Stadt vorstellten, so dass wir glaubten,
* vermittelst einer sehr verstärkten atmosphärischen Refraction den
* Flecken Cerignola zu sehn, der in der Richtung lag, jedoch über 8
* deutsche Meilen, (in gerader Linie nur 6,) enfernt war. Allein gar bald
* veränderte sich das Schauspiel: wir sahen zwei Hügel gegen einander
* über, die immer höher und höher wurden, und sich dann in viereckige
* Thürme mit grossen Fenstern verwandelten, wodurch das Licht von der
* Abenddämmerung einfiel. Doch ich kann unmöglich alle die verschiedenen
* Figuren beschreiben, die mit der grössten Schnelligkeit abwechselten.
*      "Unsre Verwunderung wurde indess bald noch sehr vermehrt.  Die
* Dämmerung war sehr hell, und ich sah verschiedne Mahl Lichtströme
* vom äussersten Horizonte bis zu einer Höhe von 6 bis 7° aufsteigen.
* Ich hielt dieses anfangs für eine Täuschung, allein D. T r i p a l d i
* sah sie gerade so, und der Zeitpunkt, worin wir einen neuen Lichtstrahl
* wahrnahmen, stimmte jedes Mahl vollkommen überein. Wir stellten uns
* darauf vor das eine Fenster, das gerade nach W.N.W. lag, und sahen das
* Phänomen eben so. Die Lichtwellen gingen gerade bis an die Grenzen
* der Dämmerung; da, wo die Dämmerung stärker war, waren sie lebhafter,
* und gegen die Grenzen der Dämmerung zu schwächer. Fünf oder sechs
* lichte Ströme erschienen unmittelbar nach einander, darauf erfolgte
* eine Pause von 1 oder 2 minuten, worauf sich neue Ströme zeigten, und
* während dieses Spiels wechselte eine unendliche Mannigfaltigkeit der
* seltsamsten Figuren am äussersten Rande des Horizonts ab. Dieses schöne
* Schauspiel währte etwa eine halbe Stunde; es verlor an Schönheit, so
* wie die Dämmerung abnahm, und nach 3/4 Stunden war es gänzlich vorbei."
*      Giovene points out that such phenomena are not rare in Apulia and
* Lecce province (Terra d'Otranto, the old Japygia). But writers have
* ignored it, except in folklore, with one exception: he cites Antonius
* de Ferrariis (Galatheus) (De situ Japygiæ , 1558) for reporting the
* name of Mutata . (p. 9)
*      A useful common observation: "Nach Versicherung der Einwohner des
* Vorgebirges von Lecce ist die Zeit dieser Erscheinung vor Aufgang
* oder nach Untergang der Sonne, und in der Ebene soll man dabei bald ein
* stürmisches Meer, bald eine Stadt, bald einen Wald sehn." (pp. 10-11)
*      He also says: "Die Seeleute von Molfetta nennen sie Lavandaja
* (Wäscherinn,) -- warum, weiss ich nicht -- und halten sie für Vorboten
* einer Veränderung in der Witterung. In der That erscheint die
* Lavandaja in ihrer grössten Schönheit, wenn der Wind lange Zeit geweht
* hat und nun eine Stille erfolt. Im Herbste und Winter ist sie häufiger
* als in den übrigen Jahreszeiten, wiewohl man sie auch oft im Sommer
* und zuweilen im Frühling sieht. Im Sommer haben wir fast alle Tage
* eine Art kleiner Lavandaja des Nachmittags; indess ist sie auch hier
* vor Sonnenaufgang und nach Sonnenuntergang am prächtigsten.
*      "In Molfetta sieht man die Lavandaja mehrentheils über dem Monte Gargano ,
* einem Gebirge, welches in die See vorspringt, von Molfetta 60 ital.,
* (15 deutsche,) Meilen entfernt ist, sich von dort am äussersten Horizonte
* zwischen W.N.W. und N.N.W wie eine dunkelblaue Wolke zeigt, und aus dessen
* Ansicht, je nachdem es sichtbar oder unsichtbar ist, und die Wolken den
* Fuss oder den Gipfel desselben bedecken, oder einen grossen Hut darüber
* bilden,) die Schiffer das Wetter mit vieler Zuverlässigkeit vorhersagen.
* Beim ersten Mahle, als ich daran die Lavandaja , ohne noch von ihr
* gehört zu haben, sah, wurde ich wirklich unruhig. Das ganze Gebirge
* war in einer zitternden Bewegung ; ein Theil des Berges versank und
* liess ein grosses Thal zurück; an derselben Stelle erhob sich einige
* Minuten nachher ein neuer Berg, höher als der vorige, und neben diesem
* stiegen mehrere andere kegelförmige empor, nahmen aber sogleich die
* Gestalt grosser viereckiger Thürme an, die sich eben so in einem
* Augenblicke versenkten und grosse Thäler eröffneten. Endlich schien
* mir der ganze Berg fürchterliche Erschütterungen zu leiden. --- Ich
* habe diese Abwechselungen oft mit dem grössten Vergnugen beobachtet.
* Die wunderbarsten Figuren folgen in einem Augenblicke auf einander,
* und eine nur etwas warme Phantasie wird sich sehr leicht überreden,
* Pferde, Menschen, Schiffe, Thürme und Städte zu sehn.
*      "Noch eine besondere Lavandaja zeigt sich hier, besonders wenn die
* Sonne gegen Westen steht und ein leichter Ostwind weht. Das Vorgebirge
* Gargano verändert dann mit der grössten Geschwindigkeit seine Gestalt
* auf eine unendlich mannigfaltige Weise. Es verlängert sich, zieht
* sich wieder zusammen, und scheint in viele Theile zerstückt, die das
* Ansehn von Inseln im offenen Meere haben. Zuweilen scheint ein Theil des
* Meeres viel höher zu seyn als das übrige, und das Wasser in der Ferne
* scheint von einem heftigen Sturme bewegt zu seyn, ob es sich gleich in
* vollkommner Ruhe befindet." (pp. 11-14).
*      He then goes on to describe a case of looming at sunrise on 15
* Oct. 1789, "in meinem Landsitze eine halbe Meile von Molfetta," which
* brought into view several towns normally hidden. This was also seen by
* Dr. Tripaldi. "Um 9 Uhr, nachdem wir 3 Stunden beobachtet hatten, war
* alles wieder wie gewöhnlich. In Hoffnung, das Phänomen wieder zu sehn,
* wenn ich höher träte, stieg ich auf eine Terasse, die ungefähr 20 par.
* Fuss über dem Fenster liegt, und wirklich sah hier das Schauspiel noch
* in seiner ganzen Schönheit.  . . .      Da  D.  T r i p a l d i  am Fenster
* geblieben war, so überzeugten wir uns, dass damals das Phänomen 40 Fuss
* über der Erde gar nicht, in 60 Fuss Höhe aber vollkommen sichtbar war."
* (p. 16)
*      Giovene recognized that these were all refraction phenomena; but he
* tried to connect them with minerals in the ground. As usual, "Dünste"
* get the blame. Still, he suspects "eine . . . wellenförmige Bewegung" of
* the air is responsible for the motions.


A. Minasi, W. Nicholson, and L. W. Gilbert
“Des P. Minasi Beschreibung der Fata Morgana oder der See- und Luftgebilde bei Reggio im Faro di Messina, ausgezogen von Nicholson und beurtheilt vom Herausgeber,”
Gilb. Ann. Physik 12, 20–33 (1802).

* ANTONIO MINASI's classic (if rather exaggerated) Fata Morgana review
* This is Gilbert's translation into German of Nicholson's translation
* into English from Minasi's original Italian, with commentary by
* both Nicholson and Gilbert. . . .
* Gilbert is very hard on Minasi: "Ich entlehne diesen Aufzug aus Minasi's
* Werke über die Fata Morgana aus Nicholson's Journal of nat. philos.,
* Vol. I, p. 225. Da Minasi's Träumereien selbst bei einem so
* nüchternen und scharfsinnigen Physiker, als Nicholson, Eingang gefunden
* haben, so hielt ich es für nicht unverdienstlich, darzuthun, dass
* Minasi's Nachrichten mit so viel Einbildungen versetzt sind, dass man
* sie im Ganzen kaum für etwas mehr, als für ein Mährchen nehmen darf,
* und sie bei einem Versuche, die Fata Morgana zu erklären, lieber ganz
* bei Seite legt." [footnote attached to the title!]
*      Here I credit all three as authors; none is named explicitly.  Notice
* that most of pp. 24 - 30 is occupied by a long commentary by Gilbert on
* Minasi's dissertation.
*      Furthermore, Gilbert refers to Reinecke's discussion of Minasi in the
* footnote on p. 26 here, as "der Verf. des Aufsatzes in den Allg. ge. Eph.
* 1800, S. 199," and again in the notes on pp.30 ("Verfasser des angeführten
* Aufsates [sic] in den geogr. Ephem. ) and 32.
*      The harsh and rather dismissive treatment of Minasi here resembles
* Büsch's scornful comments on Minasi in A.G.E. Vol. 6 (1800).


W. Beauford
“A dissertation on the reflection and refraction of light from vapours, fogs, mists, &c.; with an account of some curious phænomena proceeding from those causes, seen in Ireland in the years 1796, 1797, and 1801,”
Phil. Mag. 13, 336–341 (1802).

* William Beauford's perceptive review, just before Wollaston's
* Probably this should be an entry in the FOG file. However, his
* perceptive remarks require its presence here, despite his curious
* explanation: "Of all the phænomena exhibited by nature in her various
* operations, there are none more curious and extraordinary than those
* represented by the reflection and refraction of light from fogs and
* vapours arising from the sea, lakes, and morasses, replete with marine
* and vegetable salts. For such vapours, by means of the said salts,
* form various polished surfaces, which reflect and refract the light of
* the sun, and even the moon, in various directions; thereby not only
* distorting but multiplying the images of objects represented to them in
* a most surprising manner; forming not only images of castles, palaces,
* and other buildings, in various styles of architecture, but the most
* beautiful landscapes, spacious woods, groves, orchards, meadows, with
* companies of men and women, with herds of cattle, walking, standing,
* lying, &c., and all painted with such an admirable mixture of light and
* shade that it is impossible to form an adequate conception of the
* picture without seeing: not any scenery represented by the
* camera obscura can be more beautiful, or more like faithful
* representations of nature."
* Nice discussion of TERMINOLOGY: "The only ones which seem at present
* to have attracted the attention of the curious, are those frequently,
* during the summer season, seen on the southern coasts of Italy, near the
* antient city of Rhegium; and even to this attention they were directed
* by the fishermen and country peasants, who in their native tongue call
* them fata morgana , or dama fata morgana . They are, however,
* frequently noticed by the English, Erse, and Irish peasants, fishermen,
* and mariners; and denominated in the languages of the two latter
* feadhreagh mairethmhe , or sea fairies, and duna feadhreagh , fairy
* castles. . . . On the eastern and western coasts of South America, even
* on the highest summit of the Andes, the fata morgana is met with.
* Also far out at sea, in the midst of the Atlantic and Pacific oceans,
* the adventurous mariner sometimes observes them; and though well known
* under the name of fog banks , yet has their appearance been so imposing
* as to illude the nicest scrutiny, and to promise refreshments to the
* fatigued and sea-worn mariner which he could not obtain. The most
* antient account of these aërial castles and islands which has been
* transmitted to us, is the representation of a beautiful island situated
* nearly in the middle of the Atlantic ocean, between the coasts of
* Ireland and Newfoundland, first observed by Danish and Irish fishermen
* about the year 900, and from that period to the commencement of the 14th
* century frequently by the Anglo-Saxon, English, and French fishermen and
* mariners.
*      "But, as this island could never be approached, it was called the
* inchanted island , and supposed by the maritime inhabitants of Scotland,
* Ireland, France, and Spain, to be the country of departed spirits, and
* consequently denominated in Erse Flath Innis , or the Noble Island; in
* Irish Hy Brasil , or the Country of Spirits; by the Anglo Saxons,
* Icockane , or the Country in the Waves; and by the French and Spanish,
* who supposed it to consist of two distinct islands, Brasil and
* Assmanda ; or the Islands of Ghosts."
* He then describes the Irish mirages in agonizing detail: "The country
* seemed laid out in lawns and improvements, in which were situated three
* gentlemen's seats; the houses well defined, the windows and doors
* distinct; some of the windows appeared open, and brass knockers were
* seen on the doors." [etc., etc., at some length.]
* Then we get more factual details: ". . . none of those aërial
* exhibitions continue any length of time, and always in calm weather and
* a clear sky, if the picture is brilliant; for, though those fog banks
* often appear in dark or cloudy weather, the reflection is imperfect, and
* represents only confused images of rocks, mountains, and capes."
* Then the final, fatal admission: "For the vapour, being formed into
* different parts, the light refracted through them causes the confused
* appearance of ruins, houses, woods, lawns, &c. in the same manner as a
* board covered in an irregular manner with black and white spots mixed
* with lines, will at a certain distance resemble a landscape with woods,
* ruins, houses, trees, castles, &c., and under such imposing forms as to
* appear real representations. Of this species of the fata morgana seem
* to be those seen at Youghal in 1801 before spoken of; but in whatever
* manner the representations from vapours and fogs are formed, the weather
* must be calm and serene, otherwise the vapours will be broken and
* dispersed by the wind." (cf. Baur, 1857)
* There is a passing mention of Commodore Byron's Voyage round the World.
* Note that Beauford cites both Swinburne's Travels and Crantz's
* History of Greenland . The long s is used throughout.
*      NOTE: In his letter to me of 2 Feb. 2002, Irish folklore expert
* Miceal Ross has some harsh words for Beauford's scholarship here:
* "I do not know where he gets his Irish from. I never heard a word
* called feadhreagh and if it existed the declension would be faulty and
* also the spelling. The 'e ' after dh would be impossible. . . . Duna should
* be Dúnta. It looks like the same William had no Irish and probably
* little access therefore to tradition.
*      "Flath Innis [recte Flaith Inis] means the isle of princes; Hy Brasil
* or Brazil is in Irish `Í Bráth-saol' The island of eternal life."
*      [Yet the criticized words appear in some 19th-Century books; cf.
* M`Farland, 1853. . . .]


W. H. Wollaston
“Observations on the Quantity of horizontal Refraction; with a Method of measuring the Dip at Sea,”
Phil. Trans. Roy. Soc. Lond. 93, 1–11 (1803).

* WOLLASTON picks up Monge's use of "mirage" in his Bakerian Lecture:
*      He starts by refuting Monge's density discontinuity:
* "The definite reflecting surface which he [Monge] supposes to take
* place between two strata of air of different density, is by no means
* consistent with that continued ascent of rarefied air which he himself
* admits; and the explanation founded on this hypothesis will not apply
* to other cases, which may all be satisfactorily accounted for, upon the
* supposition of a gradual change of density, and successive curvature of
* the rays of light by refraction." (p.2)
*      There is also a fine illustration of the SMOOTH BEND where the erect
* and inverted images meet; the figure on p. 3 is the same one reprinted
* as Tafel VII, Fig. 6 in Gilb. Ann. vol. 23, showing the bent oar. It
* is worth quoting his passage about this (pp. 3 and 4):
*      "I was sitting in a boat near Chelsea, in such a position that my eye
* was elevated about half a yard from the surface of the water, and had a
* view over its surface, that probably somewhat exceeded a mile in length,
* when I remarked that the oars of several barges at a distance, that were
* then coming up with the tide, appeared bent in various degrees, according
* to their distance from me. The most distant appeared nearly in the form
* here represented; dd being my visible horizon by apparent curvature
* of the water; ab the oar itself in its inclined position; and bc
* an inverted image of the portion be . By a little attention to other
* boats, and to buildings on shore, I could discern that the appearance
* of all distant objects seen near the surface of the water was affected
* in a similar manner, but that scarcely any of them afforded images so
* perfectly distinct as the oblique line of an oar dipped in the water.
*      "A person present at the time (as well as some others to whom I have
* since related the circumstance) was inclined to attribute the appearance
* to reflection from the surface of the water; but, by a moderate share
* of attention, a very evident difference may be discovered between
* the inversion occasioned by reflection, and that which is caused by
* atmospherical refraction. In cases of reflection, the angles between the
* object and image are sharp, the line of contact between them straight and
* well defined, but the lower part of the image indefinite and confused,
* by means of any slight undulation of the water. But, when the images
* are caused by refraction, the confines of the object and its inverted
* image are rounded and indistinct, and the lower edge of the image is
* terminated by a straight line at the surface of the water."
* (Similar advice is given by Bravais, 1853.)


H. W. Brandes
Gilb. Ann. Physik 14, 250–253 (1803).

* Brandes's first communication about refraction mentions Woltman
* "Ich hoffe Ihnen nächstens eine Reihe von Beobachtungen über
* die Refraction , denen ähnlich, die Sie von Hrn.      W o l t m a n n
* kennen, übersenden zu können."
* This item is under the heading "Auszüge aus Briefen an den Herausgeber"


Dr. Castberg
“Ueber die Fata Morgana und ähnliche Phänomene,”
Gilberts Ann. Physik 17, 183–199 (1804).

* Castberg's FATA MORGANA review (translated by Gilbert)
* Several very early references here: Pomponius Mela, Thomas Facellus,
* Athanasius Kircher, Pliny and Haithon. But he is mostly concerned with
* the F.M. classics: Minasi and Angelucci. There are also references to
* then-recent discussions by Gilbert, including looming and mirages.
* Castberg leans heavily on the idea that, if this were a simple mirage,
* the locals would recognize the miraged objects: they don't, so it isn't.
* He makes the good point that the cities are too far apart (6500 toises):
* at this distance, one would be hard pressed to make out individual
* buildings, let alone individual figures, trees, sheep, etc.
* [This matter of DISTANCE is often overlooked in fantastic reports.]
* Furthermore, if it were a mirage of Messina seen from Reggio, then the
* reverse should be true; but (he says) there are no reports of the
* Morgana being seen from Sicily.
* He concludes that it is the shadows of the city cast on mists!


Doctor Brandes
“Einige kritische Bemerkungen über Höfe, Ringe, Nebensonnen, Fata Morgana, u.s.w.,”
Gilb. Ann. Physik 19, 363–371 (1805).

* Brandes comments on atmospheric optics, including FATA MORGANA
* The Fata Morgana is discussed on p. 367, where he comments on Castberg's
* report in Ann. 17, 183. There is an amusing crack: "Die Bilder sind
* gewöhnlich so verzerrt, und der Gegenstand selbst erscheint unter so
* veränderter Gestalt, dass man leicht mit Hülfe einer italiänischen
* Phantasie Säulengänge, Wasserleitungen, u. s. w., in diesen
* Erscheinungen finden kann."
*      See also the Brandes papers from vols. 17 & 18 in "Terrestrial Refr."
* [from a letter dated 2ten Febr. 1805]


H. W. Brandes
“Fortgesetzte Beobachtungen über die irdische Strahlenbrechung,”
Gilb. Ann. Physik 20, 346–353 (1805).

* Brandes reports his progress to Gilbert
* There is some interesting background here: he explains how he was led
* by Pictet's observations of the diurnal cycle of temperature gradients
* at different heights, which showed the same pattern he had already seen
* in his own observations of variable terrestrial refraction, to make such
* temperature measurements himself.
* [from a letter dated 16ten Mai 1805]


J. B. Biot
Traité Élémentaire d'Astronomie Physique
(Bernard, Paris, 1805).

* Biot's astronomy textbook (1805)
*      Astronomical refraction is discussed on pp. 36-38; mirages on p. 40
* In §43 (p. 39), he refers to Maraldi's work on terrestrial refraction.
* The description of mirages in lower Egypt is taken almost verbatim from
* Monge's text, though edited down slightly: "Monge a expliqué ce phénomène
* d'apres les lois de l'optique, dans le premier volume de la Décade
* Egyptienne." (p. 41)
*      The Plates that follow p. 330 indicate by simple diagrams the effect of
* astronomical refraction; but there are no mirage pictures. [Those appear
* in the 2nd edition (1810).]
*      The first volume bears a dedication to Laplace (cf. Biot's anecdote!)
* Often, the two volumes of this work are bound together.
*      The 1st volume is available at Google Books:
* https://books.googleusercontent.com/books/content?req=AKW5QaeMiMxzOhQ-yyV3yUE1sfwPMeOJxlGy0n44v6jKTIzjiWVTQN0sgG8bQy_wREdv7JVSaNvq7NZ1oUAq3S4Z2cO1OXn8Le43gtuy6IAdsWATwEFjMv4Oxh6cr0gLh7stxiARR3OipKqTX09mp5R4oCPd_AF9VLLFLlLlx62bXX7KfipBo5kKxM0KJVCwGTMCVKZ15gTEb6jJZ-MOn_2N3rS4RjqY5EPzBDVPxbthL289HJiq3H2hw0-b9LisxfXBMP9-rVUesYPs1gGwBcZB1QWbYJFac5kuAnDsN5iEzF4GlC3XhxQ


Professor Kries
“Ueber Luftspiegelung,”
Gilberts Ann. Physik 23, 365–379 (1806).

* Friedrich Christian Kries points out the lack of explanation in the
* reports of Vince and Wollaston, and tries to explain away Wollaston's
* experimental results as an artifact due to surface tension at the
* edge of the glass. However, his explanation of the 2-image superior
* mirage is exactly the same as Wegener's, apart from using (here) a flat
* Earth. Because of omitting this vital detail, he fails to understand
* how a 3rd, upright, image can be formed. So he introduces the crazy
* notion of a perfect reflection in the sea , which he supposes is
* inverted to form the uppermost, erect, image.
*      But there is a prophetic phrase in which he foresees the actual
* complexity of thermal inversions:
* "Und da Luftspiegelung oberwärts mit starken Hebung verbunden zu
* seyn pflegt, so ist es nicht unwahrscheinlich, dass alsdann mehrere
* Luftschichten von verschiedener Dichtigkeit über einander liegen."
*      According to Pogg., Kries was born in "Thorn, Westpreuss." -- the
* home town of Copernicus.


D[r]. Brandes
“Einige kritische Bemerkungen zu den in den Annalen befindlichen Aufsätzen über die irdische Strahlenbrechung, und Nachricht von der Vollendung seiner Refractions-Beobachtungen,”
Gilb. Ann. Physik 23, 380–393 (1806).

* Brandes comments at length on earlier reports, and announces his
* forthcoming ("um Michaelis") monograph (1807) [below].
* Several nice quotes here. On p. 383, good advice for astronomers:
* EARLIEST MENTION of NOCTURNAL INVERSIONS ???
* "Da wohl ohne Ausnahme über einer Erdfläche die Luft Nachts, dicht
* an der Erde kälter ist, als in der Höhe, . . . ." He notes that, with
* strong looming, the sea often appears concave rather than convex (p.385).
* [Note observation of CONCAVE surface.]
* [The concave appearance is also described by Forel (1895), p. 541.]
* Remarking on the stories Busch was told by the dike-workers, he says:
* "Ueberhaupt hat der gemeine Mann selten die Gabe, eine Erscheinung so zu
* beschreiben, dass der Physiker die Erzählung gebrauchen kann." (p. 386)
* On the next page is another suggestion for the origins of strange
* reports: "Ich sah neulich auch früh Morgens von hier aus das weiss
* übertünchte Schloss zu Varel und einige andere Gegenstände mit blossen
* Augen so auffallend hell, dass ich es wohl für näher hätte halten
* können; von besonderer starker Refraction war aber nichts zu bemerken,
* sondern ich konnte keinen anderen Grund finden, als dass diese
* Gegenstände hell von der Sonne beschienen wurden und die übrige Gegend
* im Schatten von Wolken lag. Grösser erschienen die Gegenstände auch
* nicht, aber bei so starker Beleuchtung kann ein scharfes Auge einzelne
* Theile der entfernten Gegenstände erkennen, und dies mochte die
* Täuschung verursachen, dass man sie für grösser hielt."
* The Figures show a distorted sunset, probably with mock mirage.
* He wonders if Heemskerk's observations on Nova Zembla were not this?
* [From letters dated 18ten April & 15ten Mai 1806.]
*      Note that his drawing of a mock mirage in Tafel VII, Fig. 3 & 4,
* is probably the EARLIEST such sunset recorded pictorially.


W. H. Wollaston
“Bemerkungen über die horizontale Strahlenbrechung, und über die Vertiefung des Seehorizonts,”
Gilb. Ann. Physik 23, 394–407 (1806).

* Wollaston's 1803 article translated by Gilbert.
* His Fig.6 is remarkable for showing the smooth bend in a miraged oar
* extending from a barge to the water. This vertical magnification
* is what makes the inferior-mirage flash visible to the naked eye.


Dangos
“Observations sur les réfractions terrestres,”
Mém. Présent. Inst. Savans Étrangers, Sci. Math. Phys. 1, 463–468 (1806).

* DANGOS reports his observation of early OMEGA (and looming of Etna)
* "Ayant lu depuis peu, dans la connoissance des temps de l'an 12, une
* observation curieuse sur les réfractions terrestres, faite par un
* savant physicien anglois, j'ai pensé que l'Institut national verroit
* avec plaisir les détails d'un phénomène à peu près semblable, qui se
* montra à Malte en 1784, et dont tous les habitans de l'île furent les
* témoins.
*      "Le 20 mars vers 1 heure de l'après-midi, je fus instruit par des
* grands cris qui retentissoient dans les rues, qu'une île venoit de
* s'élever dans le canal de Malte, et j'aperçus bientôt, de dessus les
* terrasses de l'observatoire, une terre très-blanche, entourée d'eau,
* et dont la forme étoit celle à peu près d'un cône droit
* irrégulièrement tronqué. Des marins et des pêcheurs étoient déja
* partis pour aller reconnoître cette île et pour en prendre possession.
*      "La figure de cette terre, sa blancheur et surtout sa position, qui
* se trouvoit exactement dans la direction de la mire que j'avois tracée
* depuis long-temps vers le mont Etna, me firent reconnoître bien vîte
* que cette terre n'étoit autre chose que le sommet toujours neigé de ce
* mont élevé de 3326 mètres . . . ." [The modern figure is 3323 m.]
*      ". . .  cette apparence extraordinaire dura environ 30 minutes depuis
* l'instant où j'en eus connoissance. . . . La mer étoit calme, le vent
* nord-est foible, le thermomètre à 14° 4'; . . . le temps étoit
* humide, et il avoit régné un brouillard épais toute la matinée,
* ainsi que la veille."
*      From his further description of a repeat of this performance on 17
* April 1785 at 6:10 a.m., it appears that the island had been hidden by a
* superior mirage that reflected the sea: ". . . l'horizon de la mer qui
* l'entouroit étoit extrêmement net. . . . L'île . . . survint un instant
* de confusion, et lorsque je la cherchois dans les airs, je la vis, avec
* étonnement, assise à sa place. Tout le mont et les côtes de Sicile,
* qui avoient été invisibles, se montrèrent bientôt en entier, et
* furent visibles le reste du jour." On this occasion, he measured the
* "depression" and found it 15' 17'', "ce qui donneroit pour sa distance
* apparente de l'observatoire, à peu près 18000 mètres . . . ."
* [The actual distance is about 130 km.]
*      He notes this cannot be a simple reflection, "comme on le prétendit
* dans les journaux d'Italie : car alors l'image auroit dûe être
* renversée, et elle étoit droite . . . ." So I suppose it is the isolated
* 3rd image of a 3-image mirage.
*
*      Now comes the OMEGA report:
*      "Je finis en rappelant un phénomène assez curieux qui tient à
* l'objet de ce mémoire, phénomène bien connu des marins, des
* astronomes qui ne sont pas fort éloignés de la mer, que j'ai vu assez
* souvent à Malte et surtout à l'observatoire de Rouen.
*      "Le soleil prend quelquefois, vers son lever, une forme un peu
* allongée qui se rétrécit tout-à-coup dans sa partie inférieure, et
* qui est terminée par le bas, par une ligne droit, de sorte qu'il
* ressemble à une urne sur son piédestal." (Jules Verne, did you read
* this?)
*      "La cause de ce fait est bien simple, d'après la théorie de
* M. Monge sur le mirage . . . ."
*
*      ``Lu le 27 prairial an 10'' which works out to June 15, 1803 if my
* arithmetic is correct.
*
* NOTE: I have filed the 1814 German translation in the Colton file.
* It lacks the last paragraph connecting the Omega display with Monge's
* mirage. (Cf. Jacques Cassini's Omega sunrise, nearly a century earlier!)
*
*      This is indexed under different titles; I have not seen the actual
* title page of the volume. The Royal Society Catalogue says it was
* ``Mémoires présentés à l'Institut des Sciences, Lettres, et Arts par
* divers Savans, et lus dans ses Assemblées : Sciences Mathématiques et
* Physiques'' for Vols. I and II (1806-1811). The later title, according
* to the same source, was ``Mémoires présentés par divers Savans à
* l'Academie [Royale] des Sciences de l'Institut de France; ou Collection
* des Mémoires des Savans Étrangers'' from 1827 on. However, the
* page headers read ``Mémoires présentés a la classe des sciences
* mathém. et physique'' and the footer has ``Sav. Étrangers. 1. T. 1.''
* The ILL people got a copy by asking the Bibliothèque de l'Institut for
* ``Memoires de l'Institut national de France.'' Take your pick.


T. Young
A Course of Lectures on Natural Philosophy and the Mechanical Arts, Vol.II
(Joseph Johnson, London, 1807).

* THOMAS YOUNG's remarks on refraction, in his "Lectures" book
*      A good source of early references on refraction & mirages.
* EARLY treatment of the RN = const. model: Section 461 (cited in his
* paper below) is pp. 80-81. [Cf. Kummer!]
* On p. 81, he seems to lose the factor of 2 in terrestrial refraction,
* saying ". . . the terrestrial refraction, instead of being 1/7 of the arc
* intervening between two places, is seldom more than 1/10."
* Available at https://archive.org/details/lecturescourseof02younrich
* and http://www3.nd.edu/~powers/ame.20231/young1807.pdf


"EMERITUS" [Thomas Young]
“Article I [remarks on looming, or horizontal refraction],”
Journal of Natural Philosophy, Chemistry, and the Arts 17, 153–156 (1807).

* THOMAS YOUNG's remarks on mirage theory
* Young comments on the inadequacy of Wollaston's demonstration.
* He proposes a model very similar to that of August Schmidt (1878)!
* "If the variable medium be only thick enough to admit the passage of
* rays below [the height where the conjugate point turns around], there will
* be no direct image, but an inverted one only. . . . the case being nearly
* similar to a very oblique internal reflection." (p. 154) -- cf. Wegener!
* "The points K and ε may be considered as conjugate foci, with
* respect to the refraction of the variable medium."
*      He considers DUCTING and CRITICAL REFRACTION: the assumed temperature
* gradient of 1 degree (F?) per foot of height produces a ray curvature of
* 1 second of arc in 16 feet of path length; "The curvature of the earth's
* surface becomes a second in 102 feet; consequently . . . a change of
* temperature of a degree in 6 or 7 feet, would be sufficient to produce
* a refraction equivalent to the apparent depression of a distant object
* arising from this cause, and to elevate the coasts of a wide channel,
* so as to make them visible to each other. This result may also be more
* simply obtained from Simpson's investigations respecting atmospheric
* refraction, the refractive density being inversely proportional to the
* distance from the centre of the earth, when the temperature varies 1°
* in 6 or 7 feet; for, as Dr. Young observes in his extensive system of
* natural philosophy lately published, Vol. II, Art. 461, `If the refractive
* density of a medium vary as a given power of the distance from a certain
* central point, the angular deviation of a ray of light will be, to the
* angle described round the centre, as the exponent of the power to unity.'"
* (p. 155)      [cf. Kummer (1860)]
*      Then there is a Postscript (pp. 155-156) that continues the discussion,
* finding the image position (cf. Gergonne, Nölke, etc.).
*      Note that Plate V faces p. 153, the title-page of the article.
* This is usually known as "Nicholson's Journal"; dated July.


H. W. Brandes
Beobachtungen und theoretische Untersuchungen über die Stralenbrechung
(in der Schulze'schen Buchhandlung, Oldenburg, 1807).

* Heinrich Wilhelm BRANDES uses temperature gradient info
*
* Here is the first paragraph (p. 3):
* "Obgleich es eine lange bekannte Wahrheit ist, daß nur in sehr
* wenigen Fällen die Lichtstralen von einem entfernten Gegenstande auf
* der Erde in gerader Linie zu unserm Auge kommen, und daß wir daher
* selten oder vielleicht niemals die Gegenstände in derjenigen Richtung
* sehen, in welcher wir sie sehen würden, wenn der Lichtstral durch einen
* gänzlich leeren Raum oder durch ein völlig gleichartiges Medium zu uns
* gelangte, so ist doch die Anzahl der Beobachtungen über diese Brechung
* des Lichtstrals in den untern Luftschichten noch immer nicht so groß
* als es bei einem so interessanten Gegenstande zu wünschen wäre, und
* noch immer fehlt es uns an sichern Regeln, um die wahre Höhe eines
* Gegenstandes auf der Erde aus seiner scheinbaren Höhe zu bestimmen."
*
* ". . . die großen Aenderungen, denen die scheinbare Höhe eines
* bestimmten Gegenstandes, den man aus einerlei Standpunkt betrachtet . . . "
* "Schon mehrere Beobachter hatten zwar die ungleiche Erwärmung der Luft
* in verschiedenen Höhen, als einen vorzüglichen Grund mancher hier
* vorkommende Phänomene angegeben; aber so viel mir bekannt ist, hatte
* noch keiner durch Beobachtungen gezeigt, daß die Aenderungen der Refraktion
* ganz genau mit der Aenderung der Unterschiede der in verschiedenen
* Höhen statt findenden Wärme übereinstimmen. Dieses darzuthun,
* waren meine ferneren Beobachtungen bestimmt, und wenn die ersten
* Beobachtungen nur dahin leiten konnten, empirische Regeln für die
* Bestimmung der gleichzeitigen Aenderungen der scheinbaren Höhe
* verschiedener Gegenstände anzugeben, so müssen die leztern,
* wofern sie ihren Zweck erreicht haben, uns in der theoretischen Bestimmung
* der Refraktion einen Schritt weiter bringen." [p. 5]
*
* The INFERIOR MIRAGE discussion begins on p. 111 (section 61). On p. 114
* he mentions the reduced size of the inverted image; if this were due to
* simple reflection, ". . . wo sollte hier die polierte Fläche sein, auf
* welcher sich der Gegenstand abspiegelte? Vielmehr ist das Phänomen aus
* einer Refraction der Lichtstralen zu erklären . . . ." And in §65:
* "Je mehr die Erdfläche erwärmt ist in Vergleichung der höheren
* Luft-Schichten, desto stärker ist die Spiegelung, . . . ." -- and he gives
* several examples from his own measurements. A ray-traced example is
* treated in §66 (p. 115) and Fig. 10. He trips over the horizontal-ray
* paradox, but talks himself out of it by asserting that it is the
* spherical curvature of the refracting surfaces that allows the ray
* to find its way back up from the perigee point!
* §67 (p. 116) discusses the ray vertices: ". . . und deswegen erscheint das
* untere Bild umgekehrt." (p. 117) Then in §68 he has a nice argument to
* determine the point where the erect and inverted images join, by
* interchanging object and observer.
*      §68b then discusses the location of the apparent horizon: ". . .  die
* scheinbare Tiefe des Horizonts ist also um etwas sehr erhebliches
* grösser, als sie bei gradlinigtem Fortgange der Lichtstralen sein
* sollte. . . . so is offenbar, dass der sichtbare Horizont sich mit der
* Erniedrigung des Auges sehr merklich verkleinern muss, welches auch
* wirklich sehr auffallend der Fall ist, wenn man auch die Höhe des Auges
* nur wenig ändert." (p. 118)
*
* The SUPERIOR MIRAGE discussion begins on p. 121 (section 72).
*
* EARLY MIRAGE OF SUN (cf. the similar publication in Gilberts in 1806.)
* (section 78, p.126): "Eine Erscheinung muß ich noch erwähnen, die
* ebenfalls hier gehört. Am 8. April 1806 nämlich erschien die Sonne beim
* Untergange in einer solchen Gestalt, wie Fig. 18. zeigt. Hier ist offenbar
*      a c b      das aufrechte,      d c e      das umgekehrte und      d f e      das zweite
* aufrechte Bild. Ich hatte damals kein Fernrohr zur Hand, aber am folgenden
* Tage, wo die heitre Witterung mit Ostwind fortdauerte, zeigte sich beim
* Untergange der Sonne etwas ähnliches, obgleich die Spiegelung
* schwächer war, und diese Erscheinung habe ich mit dem Fernrohr beobachtet.
* Die Sonne erschien nämlich wie Fig. 19. und als sie tiefer sank,
* trente sich das Stück oberhalb des Einschnitts ab, schwebte noch
* abgesondert einen Augenblick und verschwand dann. Etwas später trente
* sich noch ein zweiter solcher Streifen. -- Die Sonne erschien zitternd und
* daher schlecht begrenzt, indeß war diese Erscheinung sehr deutlich. --
* Tages vorher waren Nachmittags auch einige südlich liegende
* Gegenstände oberwärts gespiegelt.
*      "Diese Spiegelung der Sonne könte, dünkt mich, gar nicht statt
* finden, wenn die Schichte, worin die starke Brechung erfolgte, sich sehr
* weit, z.B. über den ganzen Gesichtskreis, erstreckt hätte.
* Stellt nämlich (fig. 20.)      d c      die oberfläche der Erde,      b      die
* Gegend vor, wo der Scheitel des Strals [sic] lag, so würde, wenn in      a
* eben so starke Brechung, als in      b      statt finde, keine Vervielfachung des
* Bildes möglich gewesen sein."
*
* Google Books has the text, but it is made useless by their usual failure
* to open the gatefolds of tables and figures.


H. W. Brandes
“Darstellung seiner Untersuchungen über die irdische Strahlenbrechung, und über die sogenannte Luftspiegelung; und was in dieser Materie noch zu thun ist,”
Gilb. Ann. Physik 34, 133–151 (1810).

* Further observations by Brandes, with an appeal for support by Gilbert
*      The letter from Brandes to Gilbert actually begins on p. 135; the
* first 2 pages are Gilbert's comments, citing the earlier works.
*      Most of Brandes's letter is a summary of the high points of his book.
* However, he has a few comments at the end about what needs to be done,
* which would be good advice to mirage observers generally (pp. 148 ff.).
*      He notes the TRIPLE IMAGE often associated with superior mirages:
* "Eine genaue Betrachtung der Umstände, welche diese Spiegelung fast
* unstreitig bewirken, zeigt, dass man eigentlich dann immer drei
* vollständige Bilder und in dem höchsten alle Mahl die Spitzen der
* Gegenstände sehen sollte . . . ." (p. 146) as well as its association
* with the Fata Morgana.
*      There is also a nice comment about the Fata Morgana : "Sie scheint
* mir eine veränderliche Spiegelung zu seyn, die in einem Augenblicke
* vielleicht in demselben Punkte des Horizonts einen Gegenstand zeigt, der
* Meilen weit hinter dem liegt, welchen man im nächst vorhergehenden
* Augenblicke sah. . . .      Freilich könnte auch dann noch, wegen der
* Mannigfaltigkeit der Gegenstände, die hinter einander in einerlei
* Richtung liegen, sich mancherlei zeigen; aber gewiss würde man bei
* solchen Beobachtungen doch eher zu einer Erklärung gelangen, als durch
* die Beschreibung von Feenschlössern und andern Herrlichkeiten, die
* gewiss nur die Fantasie sah, und nicht das Auge." [p. 147]
*      And (p. 151): "Allem, was ich bis jetzt von Beschreibung dieser
* Phänomene kenne, scheint ganz der philosophische Geist zu fehlen,
* welcher nötig ist, um gerade das Rechte zu treffen, und aus dem Chaos
* von zerstreuenden Nebendingen nur den Hauptpunkt hervor zu heben."
*      He also notes the bad seeing that accompanies the inferior mirage:
* ". . . mit dieser Spiegelung . . . fast ohne Ausnahme ein heftiges Zittern
* der Gegenstände verbunden ist . . . ." [p. 150]


J. B. Biot
Notices sur les Opérations exécutées en Espagne, en France, en Angleterre et en Écosse, pour mesurer la courbure de la Terre et la variation de la pesanteur sur l'arc du méridien qui s'étend depuis l'îsle de Formentera, la plus australe des Pythiuses, jusqu'à Unst, la plus boréale des îsles Shetland
(Academie des Sciences, Paris, 1810).

* Biot and Arago's expedition recounted
* The "Notice sur les Opérations d'Espagne et de France" (pp. 1-30
* here), "Lue à la séance publique de la classe des Sciences de l'Institut,
* le 2 janvier 1810" is the account quoted in the 1821 book by Biot & Arago;
* see below (at 1821) for excerpts.
* Now available at
* http://www.academie-sciences.fr/membres/in_memoriam/Biot/Biot_pdf/Notice_EsFr_1810.pdf
* but they don't give the exact citation; probably this appeared in one of
* the Academie's serial publications. . . .
*      This was reprinted in Biot's  Mélanges Scientifiques et Littéraires
* (M. Levy, Paris, 1810), pp. 47 - 68.
* Thanks to Luc Dettwiller for pointing out the availability of this item!


[Poisson]
“Mathematiques. Mémoire sur les réfractions extraordinaires qui s'observant très-près de l'horison,”
Paris, Soc. Philom. Bull. 1, No. 15, 262–264 (Dec., 1808).

* Abstract of the 8 Aug. talk by J. B. BIOT on refraction phenomena
*      A marginal note says:
*
* Instit. Nat.
* 8 Août 1808.
*
* and the signature footers say "Tome I. N°. 15, 2e. Année." The title
* page of the volume is dated 1807, and a few Roman-numeraled pages at
* its front explain the interruption in publication of the Society's
* Bulletin in 1805. On p. vi is the editorial staff of the revived
* Bulletin; Mathematics is handled by Poisson ("P.") The first number
* of this volume is dated Oct. 1807.
*      Here, Monge, Wollaston, and Humboldt are mentioned, and their
* explanations are summarized. Poisson says:
*      "On ne peut donc pas douter que cette explication ne donne la vraie
* cause du Mirage. Mais, pour ia mettre dans tout son jour, il étoit bon
* de déduire de l'analyse mathématique, les diverses circonstances que
* peut présenter ce phénomène, et qui sont relatives à l'élévation de
* l'observateur au-dessus du sol, à sa distance aux objets mirés, et à
* la rapidité du décroissement de la température. C'est ce que M. Biot
* s'est proposé de faire dans le mémoire que nous annonçons. On trouve
* aussi dans ce mémoire, l'explication de plusieurs phénomènes qui ont
* un rapport plus on moins éloigné avec le Mirage. Le plus remarquable de
* ces phénomènes est la double image du soleil à l'horison, observée par
* Le Gentil à Pondichéri et sur les côtes de Normandie. M. Biot attribue
* cette parélie à la même cause qui produit le Mirage. En général,
* M. Biot a rassemblé dans son mémoire les nombreuses observations de
* Mirage ou de phénomènes analogues, qui ont été faites jusqu'ici,
* afin qu'on puisse en comparer les résultats à ceux du calcul."
*      This is available at the BHL website:
* https://www.biodiversitylibrary.org/page/31774998#page/278/mode/1up
*      Full title of publication is:
* Nouveau Bulletin des Sciences, par ls Société Philomatique. Paris.
* (A variety of local scientific societies called themselves "Philomathic"
* in this period; so it's necessary to specify which one by location.
* The Roy. Soc. Cat. calls this "Paris, Soc. Philom. Bull." The BHL
* calls it "Nouv. Bull. Sci. Soc. Philom. Paris".
*      Note the spelling "horison" with an "s" rather than a "z", in both the
* title and the text.
* The abstract is signed with the initial "P." = Poisson.


[L. Brugnatelli]
“Estratto di una memoria: Sopra le refrazioni straordinarie che si osservano vicinissime all'orizzonte; del Sig. Biot,”
Giornale di Fisica, Chimica e Storia Naturale, Vol. 2, 63–65 (1809).

* Italian report on Biot's mirage memoir: first use of "miraggio" ?
*      The title page of the volume says:
*
*                        GIORNALE
*
*             DI FISICA, CHIMICA
*              E STORIA NATURALE
*
*                          ossia <-- (in small caps)
*
* Raccolta di Memorie sulle Scienze, Arti, <-- (in flowery script)
*             e Manufatture ad esse relative
*
*                   DI L. BRUGNATELLI
*
* [followed by a long paragraph of his degrees, awards, memberships in
*                         numerous foreign learned societies.]
*
*                         TOMO II
*
*              CON TAVOLE IN RAME
*
*
* PAVIA nella Tipografia Capelli 1809.
*
* -----------------------------------------
* Page 3 is headed "PRIMO BIMESTRE 1809"
* -----------------------------------------
* Successive pages are headed "Giornale" and "di Fisica, Chimica, ec."
*
* This item beginning in p. 63 is headed:
*
*              ESTRATTO DI UNA MEMORIA
*
* Sopra le refrazioni straordinarie che si osservano
*            vicinissime all'orizzonte; del Sig. Biot
*
*      (Instit. Naz. di Francia 8. Agosto 1808. l. c.)
*
*      The footnote about Pliny on p.65 is signed "L'Edit." so I think I am
* safe in attributing it to Luigi Valentino Brugnatelli (as does the Royal
* Society Catalogue), Considering the timing and the dates, this must be
* based on the Philom. Soc. Bull. abstract; and in fact this is just a
* translation into Italian of that abstract.
*      This is available at:
* https://www.google.com/books/edition/Giornale_di_Fisica_Chimica_e_storia_natu/ObVUAAAAcAAJ?hl=en&gbpv=1&dq=miraggio&pg=PA65&printsec=frontcover
*


J.-B. Biot
“Recherches sur les réfractions extraordinaires qui s'observent très-près de l'horizon,”
Mémoires de la classe des sciences mathématiques et physiques de l'Institut de France, Ann. 1809, 1–266 (1810).

* The first full version of Biot's monograph; read 8 Aug. 1808
*      The Mémoires are for the year 1809; but the publication date is Aug. 1810,
* and observations made in 1809 are discussed in several places. Clearly,
* lots of material was added after 8 Aug. 1808.
*      The first 98 pages of this volume contain the history of the Institute.
* (The "Histoire" and the "Mémoires" are bound together as one volume here,
* each beginning with p. 1, just like those of the Académie des Sciences.)
* After this "Histoire" comes the table of contents for both it and the
* Mémoires that follow.
* The edition scanned by Google has "1809." in its signature footers.
*      The Google scan is available at HathiTrust:
* https://babel.hathitrust.org/cgi/pt?id=ucm.532436086x&view=1up&seq=9
* -- but it completely lacks the figures!
*      Its table of contents on the unnumbered page after p. 98 gives the
* title as "Recherches sur les réfractions extraordinaires qui s'observent
* très-près de l'horizon", as does p. 1. Notice that the odd-numbered
* pages in both versions have the "très-près" in their headers.
*      This seems to be the version that is often cited as 1809.
* Both the Readex and the stand-alone version of the mirage monograph have
* the same page numbers, and seem to be printed from the same type, except
* for some minor changes from the Google version, such as the title,
* and the end of the third line of the body text, which ends in a comma
* in the Google scan but a semicolon in the Readex/monograph version.
* The last line of text on the first page of the monograph appears at the
* top of p.2 of the edition scanned by Google. Yet the two versions must
* be printed from the same type: look at the pale e-acutes in the word
* "détachés" in line 9 of the Google scan (line 8 of the monograph) on
* page 2. (There are other pale é types in the text; evidently this glyph
* was cast separately and shrank a little more on cooling than the main
* font.)
*      On p. 11, the bottom line of the monograph version appears at the top
* line of p. 12 in the Google scan. The bottom two lines on p. 12 of the
* monograph are at the top of p. 13 in the Google scan. After this there
* is a steady creep of text, with the monograph generally having one more
* line per page than the Google version. But at p. 15, the monograph
* absorbs the accumulated space by adding a 4-line footnote about Arago.
*      The two versions then remain in step until Biot's text ends on p. 266.
* That page says "FIN" in the monograph; but the Mémoires continue with
* several more mathematical papers by Lagrange, Laplace, et al.
*      The signatures are all marked "1809" in the footer at the first
* page of each in this Mémoire; but that date was removed from most of
* the signature labels in the monograph (see, e.g., p.201 which begins
* signature 26, or p.193 which begins sig. 25.)


J. B. Biot
Recherches sur les réfractions extraordinaires qui ont lieu près de l'horizon
(Garnery, Paris, 1810).

* BIOT's MIRAGE MONOGRAPH
* This is the stand-alone reprint of the monograph.
* It contains BIOT + ARAGO's multiple-image red/green observation:
*      "Bientôt nous ne vîmes pas seulement deux lumières, mais trois,
* quatre ou davantage. Elles se formoient et disparoissoient ensuite sans
* que le nombre de celles qui paroissoient ensemble eût rien de
* déterminé. . . .      Cette formation successive a beaucoup d'analogie avec un
* autre phénomène que nous avons observé plusiers fois dans l'autres
* stations. On voyoit le point lumineux s'allonger comme une petite colonne
* de feu sous le fil vertical de la lunette, et s'étendre ainsi jusqu'à une
* certaine longueur, après quoi la colonne se rompoit tout à coup et
* formoit deux images dont le plus basse étoit sensiblement rouge, et la
* supérieure sensiblement verte; ou bien elle se concentroit de nouveau sur
* elle-même; et redevendroit un point lumineux unique, de dimension
* insensible, comme auparavant. . . . " (p.15 -- his experiments with Arago)
* See their 1821 report for more details!
* [cf. M.O. 24, 13 (1954)]
*
* This is a remarkable work: it is not only the first theoretical
* monograph on mirages, it explores many important ideas later forgotten
* and rediscovered, such as the effect of uneven ground in truncating the
* inverted image of the inferior mirage (pp. 28-33), based on Wollaston's
* (1800) measurements on a sandy road -- even including a warning about
* radiation-induced errors in air thermometry; the relation between
* the locus of the minima in the ray-paths and the occurrence of erect
* or inverted images (pp. 41 - 63; cf. Tait, 1883); the divergence of
* rays above the horizon, and hence the need for the minimum to occur
* between observer and object if a mirage is to occur (p. 65; cf. Meyer,
* White, Fraser, et al.); an observation of conjugate inferior mirages
* over uneven ground (p.84); the importance of the Earth's curvature, and
* caustic curves (pp. 151 ff.); the role of temperature in determining
* the dip of the horizon; the possibility of ducting (p. 196), and hence
* of negative dip and a false horizon (p. 203); etc. -- and all supported
* by quantitative measurements!
*      The circulating ray is on p. 154.  Measurements in thermal inversions
* begin on p. 163; negative dip is discussed on pp. 167 ff.
*      MULTIPLE HORIZONS are mentioned on p. 265.
*      August Schmidt's (1878) comments are appropriate.
* [cf. the German treatment by Brandes, 1814.]
*      A "Table des Matières" follows p. 266.  It contains a one-paragraph
* abstract of each major section of this long paper. The figures are
* immediately after this Table.
*
*      This is occasionally cited as:
* Recherches sur les réfractions extraordinaires qui s'observent
* très-près de l'horizon, avec 9 planches; lu le 8 août 1808
* (Mémoires de l'Institut national des sciences et arts 10, pp.1-266)
* as that title (from "sur" on) appears on the first page of the text.
* That was the original title published in the Mémoires, and is repeated
* here in addition to the slightly changed wording on this volume.
*      The title page gives the date of publication as 1810; but a few
* individual signatures bear the date 1809: see pp. 129 and 169.
*      P. 169 discusses observations made in Dec., 1808, and p. 168 shows dip
* measurements of 6 Feb. 1809. Data measured on 8 March 1809 are on p. 31
* and 82. The last line in the table on p.32 is a Dunkirk observation on
* 23 March, 1809.
*
*      Note that the drawings are by Claude Louis Mathieu (cf. Delambre, 1827)
*
*      Google Books has finally made available a PDF of the whole book,
* INCLUDING Mathieu's drawings! Here's the URL:
*
* https://books.googleusercontent.com/books/content?req=AKW5Qaf5mZ7iXOyoE33ib1IUaF5cGMjYL82QdYt45kk1Al3V3dK_QSJg3RrzkyZqakad4i2v6I6zAUALrPoPI0aGCBImDkNAksaI5yfYJA33Z_UTN5aBdH1yoPm3B2eEIp_nilM_SninhFW4mFe0NEVhR5VLkAVJv9eGnDMAbfUraiZ6s1YJ_X-4JiSQKc4nHKX1RdnWzkxG3DI0xC06Ksl_o1nGnbcS57hmgrSAZPkS7bRDnl2fP3zocHpjWIyFS-m4zYpi4OBEK6JGIMKenze0VjYbHHaw3gnM_nzRUSrGeiPK9Y-Kig8
*
* Jean Baptiste Biot


J. B. Biot
Traité Élémentaire d'Astronomie Physique, Seconde Édition
(Klostermann, Paris, 1810), pp. 224–234.

* Some of the same figures appear in Biot's revised (1810) textbook:
* The miraged man is (Fig. 41); the distorted sunsets (42 & 43) are in Pl.9
*      ORIGIN of the term "MIRAGE" (cf. Le Gentil, 1789!):
* After describing the ordinary inferior mirage over hot sand, such as was
* seen by the French army in Lower Egypt, he says: "On observe
* à-peu-près la même chose à la mer dans des tems très-calmes. Un
* navire, vu dans le lointain et à l'horison, offre quelquefois deux
* images, l'une directe, l'autre renversée; celle-ci absolument pareille à
* l'autre, souvent égale en intensité, en un mot parfaitement semblable à
* l'effet de la réflexion dans un miroir. De là est venu le nom de
* mirage que les marins ont donné à ce phénomène." (p.229)
*      The first volume bears a dedication to Laplace (cf. Biot's anecdote!)
*
*      Sergey Kivalov points out that in the second volume of this 3-volume
* work, on pp. 558-560, Biot calculates the flattening of the full Moon
* at the horizon; this establishes a long-standing interest in this topic
* that helps explain his discovery of the magnification theorem in 1836.
* [NOTE: we have this book in our Special Collections; when I went to look
* at those pages, I found them uncut. I was the first person ever to have
* read that passage in our copy, in nearly 200 years!]
*      Unfortunately, the treatment here is oversimplified: he supposes the
* Moon so small that its image is symmetrical, and (worse) repeats Kepler's
* error of supposing the difference in refraction of the upper and lower
* limbs to correspond to the difference in altitudes of the true (rather
* than diminished) vertical diameter. Having neglected an appreciable
* second-order effect, he then evaluates the effect of refraction on
* the horizontal diameter, which he finds diminished by about 3 parts
* in ten thousand.
*      The publication date of the second volume is 1811.
* A very poor copy is available from Gallica. Google Books also.
* The HathiTrust website has the 3rd edition -- but only the Google scan,
* so no plates. There, the discussion of the Moon's diameter is in Vol. 3,
* pp. 19 ff., published in 1845.


Biot
“Untersuchungen über die ungewöhnlichen Strahlenbrechung, welche zuweilen nahe am Horizonte Statt findet, frei bearbeitet von H.W.Brandes, Prof. d. Math. in Breslau,”
Gilberts Ann. Physik 47, 237–313 (1814).

* The German treatment of Biot's monograph, by Brandes
* In the first 2 pages, Brandes explains why and how he has abridged this
* partial translation.
* This is only the first of two installments. As usual in Gilberts Ann.,
* the notes are as valuable as the text.
*      On p. 245, commenting on Biot & Arago's observation of red/green
* dispersion of the signal light (p. 15 of Biot's book), Brandes remarks
* on "die prismatischen Farben," and cites Herschel's 1785 double-star
* catalog, p. 52 [an error: really p. 83]. His translated quotation
* attributed to W.H. is very much abbreviated, however.
*      On p. 257 [Biot p. 26] appears the "magic number" of 1° 23'.
*      On p. 275 [Biot p. 65] is the discussion of the minimum of the
* trajectory. Biot says the rays must be horizontal to give a mirage
* -- this is the later mis-named "Fraser's theorem". Brandes explains
* that the order of inclination of the rays at the eye is also their order
* in any layer, in the branch above the horizontal. And immediately
* afterward is Tait's belated rediscovery about the ordering of the
* minima and the nature of the image (Biot p. 66). This is discussed in
* detail later [p. 279 = Biot p. 72], after the locus of the minima is
* discussed [Brandes p. 278; Biot p. 71].
*      NOTE: "Breslau" is now Wrocłow, Poland.


Biot
“Untersuchungen über die ungewöhnlichen Strahlenbrechung, welche zuweilen nahe am Horizonte Statt findet, frei bearbeitet von Brandes, Prof. d. Math. in Breslau,”
Gilberts Ann. Physik 47, 366–441 (1814).

* The German treatment of Biot's monograph, by Brandes -- part 2


E. Polehampton
The Gallery of Nature and Art; or, A Tour through Creation and Science, Vol.IV
(R.Wilks, London, 1815).

* Rev. Edward Polehampton's review of natural phenomena
*      There is a fuller summary of Minasi's work than one usually finds.
* Mirages begin on p. 504; see pp. 509-514 for the section covering the
* Fata Morgana.
*      "Fellow of King's College, Cambridge" says the title page.
* So this is the Edward P. who was rector of Greenford, Middlesex (1822-30).
* He was born in 1776 and died in 1830.
* This is "Vol. IV" of "six volumes".
* Evidently this is the source for Thomas Milner's similar work (1846+).
* Available on Google Books


J. F. Erdmann
“Beobachtungen über die Strahlenbrechung und sogenannte Luftspiegelung in den Steppen des Saratowschen und des Astrachanschen Gouvernements,”
Ann. Physik 58, 1–28 (1818).

* MANY OLD REFERENCES and some current observations (MIRAGE HISTORY)
* Cites Quintus Curtius Rufus, as well as many references to mirages
* ("Sarab") in the Koran and other Arab writings
* (Johann Friedrich von Erdmann, according to Roy.Soc. index)
* Available at:
*        http://books.google.com/books?vid=OCLC05854993&id=-QUAAAAAMAAJ


W. Scoresby
An account of the Arctic regions with a history and description of the northern whale-fishery, Vol. I
(Constable, Edinburgh, 1820).

* William Scoresby's "Arctic Regions" book
* The mirages are described in Sect. V, on pp. 383-392:
*      "Under certain circumstances, all objects seen on the horizon, seem
* to be lifted above it a distance of 2 to 4, or more minutes of altitude,
* or so far extended in height above their natural dimensions. Ice, land,
* ships, boats, and other objects, when thus enlarged and elevated, are
* said to loom . The lower parts of looming objects, are sometimes
* connected with the sensible horizon, by an apparent fibrous or columnar
* extension of their parts, which columns are always perpendicular to the
* horizon : at other times, they appear to be quite lifted into the air,
* a void space being seen between them and the horizon." (pp. 384-385)
*      A typical Fata Morgana display is well described on pp. 385-386, with
* "lofty spires, towers and battlements," converted in a few minutes into
* "a vast arch, or romantic bridge." "A mass of ice on the horizon,
* appeared of the height of a cliff, and the prismatic structure of its
* front, suggested the idea of basaltic columns. It may be remarked,
* that these phenomena took place on a clear evening, after an uncommonly
* warm afternoon." So, a textbook case; July 16, 1814.
*      On the next page, another example of "variegated basaltic columns" was
* see on the coast of Spitzbergen, in June. An iceberg became "a
* prodigious cliff of alabaster pillars." Likewise, on May 13, he saw
* "a dense appearance in the atmosphere," which "advanced with the wind
* toward the N.W." The horizon under this apparent density "was
* considerably elevated; . . . a separation of seven minutes extent of the
* altitude, showed the division of the true and refracted horizons." The
* refracted horizon "had the appearance of a line drawn nearly parallel to
* the true horizon, distant from it 7 minutes, with an open space between.
* Two ships lying beset about fourteen miles off, the hulls of which,
* before the density came on, could not be wholly seen, seemed now from the
* mast head, not to be above half the distance, as the horizon was visible
* considerably beyond them. . . . Their hulls were much enlarged and
* elongated, and their masts very much shortened. They had precisely the
* prospective appearance of ships in a heeling position." (pp. 387-388)
* [This description resembles Minasi's tilted ships.]
*      On p. 389 is another observation, April 28, 1811: a ship "at such
* a distance, that her hull was not visible ; and when viewed from an
* elevation of ninety feet, with a good telescope, half her lower masts were
* intercepted by the ice on the horizon. Now, at the elevation from which
* this ship was seen, the horizon, under common circumstances, would be nine
* miles distant ; and from the knowledge of the dimensions of her masts,
* I estimated the portion of the hull and masts intercepted by the horizon,
* at about 22 feet ; consequently, her distance beyond the horizon must have
* been at least 4½ miles, and her distance from us not less than 13½."
* [In addition to the quantitative estimates, notice that all these were
* seen during the normal superior-mirage season.] It had been a bright,
* sunny day; at 11 p.m., the officer of the watch reported "that the ship to
* the eastward of us, appeared to he forced by the ice upon her beam ends ,
* or into an heeling posture. I immediately ascended the deck, and having
* cleaned the glasses of a good telescope, I hastened to the mast-head. I
* at once attributed the cause of the deception to unequal refraction. This
* ship, which, two hours before, was 4½ miles beyond the visible horizon,
* now appeared as far within it, and was in every respect deformed like the
* ships above mentioned." The intervening ice was "compact and motionless".
*      "The horizon on this occasion, between the east and north, though
* continuous, appeared curiously undulated. There appeared a difference of
* nearly a quarter of a degree, between the elevation of the highest and
* lowest portions of the circumferential boundary." (p.390)
*      On p. 391, Scoresby notes that these refractions "have usually
* occurred in the evening or night, after a clear day." He correctly
* infers that "two streams of air of different temperatures" are involved;
* but unfortunately supposes that "an irregular deposition of imperfectly
* condensed vapour" may produce the phenomenon.
*
*      Also noteworthy for a brief discussion of halo phenomena on p. 393:
* here Scoresby criticizes Huygens's suggestion of circular cylinders as
* the cause, remarking that "It is, however, probable, that such a form
* of hail does not occur in nature, though snow or hail of a prismatic or
* spicular form is not uncommon in the polar regions."
*      There are also remarks on the ice-blink on pp. 299-300; and an
* interesting discussion of sea-ice and icebergs in Chapter IV, where the
* word "effulgence" occurs in connection with seeing icebergs at night.
*
*       Available at
* https://archive.org/details/accountofarcticr01scor/page/390/mode/2up
*
* and at the Biodiversity Heritage Library.
*
* On the title page of the original volume, the author's name is
*       W. Scoresby Jun.  F.R.S.E.
* Cited by Prof. Everett (1874).
*      Thanks to Eric Frappa for pointing this out!


Biot & Arago
Recueil d'Observations Géodésiques, Astronomiques et Physiques
(Courcier, Paris, 1821).

* BIOT & ARAGO (details)
* This gives the real story of the expedition: how Delambre and Méchain
* began the project, to determine the length of the meter; how the
* southern part of the arc was lost by Méchain's death; and how the
* completed part was published by Delambre in Base du Système
* métrique . The work reported here was done in 1806-07. The very
* breezy Introduction (it is explained in a somewhat apologetic Note) "est
* tirée d'une notice lue par M. Biot, à la séance publique de
* l'Académie des Sciences, pour l'année 1810." It gives the general
* public the bare outlines of how geodesy is done -- along the way,
* offering one of the earliest comparisons of the smoothness of the Earth
* to the peel of an orange (p. vi) -- and reviews the great
* accomplishments of French geodesists, from Picard (1670) and the
* Cassinis, through "Bouguer, Godin, la Condamine, Clairaut, le Monnier,
* Maupertuis et La Caille, tous nos compatriotes, et membres de
* l'Académie des Sciences".
*      "Malgré tant d'efforts, malgré tant d'entreprises, on pouvait
* faire mieux encore; . . . les instrumens d'Astronomie étaient bien
* éloignés alors de la perfection qu'ils ont maintenant acquise,
* perfection telle, qu'on peut régarder comme le dernier terme de la
* précision que l'on atteindre par des évaluations mécaniques, surtout
* depuis qu'un autre français, Borda, aussi membre de l'Académie des
* Sciences, eut trouvé le secret d'atténuer indéfiniment les erreurs
* des observations partielles, en les faisant suivre et succéder les unes
* aux autres sur le limbe circulaire de l'instrument auquel il a donné le
* nom de cercle répétiteur." (p. viii)
*      So (p. ix), the Bureau des Longitudes has chosen Arago and Biot to
* finish the job. The big problem (p. xi) is that one of the sides of the
* Yvice triangle must be some 160 km long, "environ quarante et une lieues
* de longueur. [ Assuming, as the footnote says, a league of 2000 toises;
* "je n'ai employé cette dénomination vague que pour rendre sensible à
* l'esprit la grandeur de nos triangles, par des évaluations encore
* habituelles pour beaucoup de personnes, mais que, sans doute, avec le
* temps, on finira par abandonner pour les évaluations métriques qui ont
* sur les autres l'avantage d'avoir toujours, et partout, la même
* signification." -- now, read on: ] A de si grandes distances, des
* signaux de jour auraient été complètement invisibles. On devait y
* suppléer per des lampes à courant d'air, derrière lesquelles on
* plaçait de grands miroirs de métal poli, pour réfléchir la lumière,
* et toutes les observations devaient se faire de nuit."
*      Desierto de las Palmas  is so called "parce qu'il y croît en
* abondance une petit espèce de palmier à feuilles en éventail, que les
* botanistes nomment le chamærops humilis ." (p. xii)
* Then come all the anecdotes: Biot's ship is driven by a storm to the
* tiny islet of Espalmador, inhabited only by a lighthouse keeper and a
* family of poor fishermen. "Jamais on ne vit de plus profonde misère;
* mais, dans cette misère même, il y avait encore de la vanité: le
* gardien de la tour méprisait beaucoup les pauvres pêcheurs." (p. xiv)
* There are the French consuls who helped the expedition, only to lose
* everything later, having to seek refuge in France. (p. xvi) There is
* the loss of one repeating circle, broken in shipment (p.xvii). He
* describes the wonderful view of the Kingdom of Valencia (p. xviii),
* including the site of Méchain's death and entombment; and "les tours
* de la brillante ville de Valence, heureux séjour du peuple le plus
* insouciant et le plus frivole. Mais ces beautés . . . n'avaient alors
* pour nous aucun attrait. Tout remplis, de la seule idée qui nous
* occupait, nous ne songions, nous ne pouvions songer qu'à nos travaux,
* et aux invincibles obstacles qui . . . ." (Well, you get the idea.)
* Here is the story of the tents blown into the sea by a gust of wind;
* "et nous n'avions pu en préserver notre pauvre cabane qu'en passant
* par-dessus des câbles, et la liant au rocher." (p. xix)
*      After 2 months of futile effort, they figured out how to spot the
* signals at Ybice, by pointing the telescope to the summit of Campvey
* just after sunset. "Je ne saurais exprimer l'émotion que nous
* éprouvâmes, lorsqu'après tant de peines et tant de doutes, nous
* eûmes enfin la certitude de réussir." (p.xxi) And then Biot
* dramatically reveals Méchain's letter, to top it off!
*      We also have the story of the station in the Favaretta mountains
* where Arago tried to establish a station; "mais nous fûmes obligés d'y
* renoncer, à cause de l'abondance des neiges qui couvraient presque
* tout-à-fait les tentes, et aussi parce que les brigands, maîtres de
* ces montagnes, exigeaient que l'on fît un traité avec eux pour avoir
* le droit d'y séjourner." (p. xxii)
*      Then there is the episode where Biot leaves the English safe-conduct
* with Arago and promptly gets himself captured by Ragusan pirates. (p. xxvi)
*      The original note of 1810 is now available as a PDF file at
* http://www.academie-sciences.fr/Membres/in_memoriam/Biot/Biot_pdf/Notice_EsFr_1810.pdf
*
* But of course our real interest is in the refraction observations.
* These commence on pp. 84-85: "en observant Iviza un instant auparavant,
* la lumière de cette station nous paraissait partagée en plusieurs
* lumières distinctes et bien séparées . . . ." (25 Dec. 1806) This
* story continues on p. 106: "Tems parfaitement calme depuis plusieurs
* jours. . . .      Mais à la quatrième ou à la sixième . . . , l'un de nous
* commenc,a de voir à Campvey deux lumières, exactement dans la même
* verticale et éloignées l'une de l'autre d'une quantité que, sur le
* fil, on estima au moins de trois minutes. La vraie lumière . . . était
* à sa place ordinaire; l'autre . . . était plus élevée dans le ciel
* . . . ; elle était aussi plus grosse, plus dilatée, plus irisée." They
* first took it to be a star. There was a problem caused by the two
* observers requiring different eyepiece settings; but when "l'autre
* observateur dut amèner sa lunette sur ce même point, non-seulement il
* apperçut deux lumières, mais il en vit trois et quatre les unes
* au-dessous des autres. . . . Quelquefois on appercevait plus de quatre
* lumières . . . . Le autres, toujours plus élevées dans le ciel, se
* formaient ensuite successivement . . . ." The regular image brightened as
* the others appeared; sometimes the extra images were still brighter than
* the bottom one. No color reported. Biot's monograph is cited.
*      Similar phenomena are reported on pp. 134-135, in observing the signal
* at Desierto from Cullera. Again, the multiplicity of images is
* accompanied by brightening.
* It gets really interesting in the observation from Mongò (p. 144),
* in which DISPERSION is at last reported (though not recognized):
* "Tems parfaitement calme, mais vaporeux; lumière de Cullera bien
* visible; celle du Desierto faible, quelquefois diffuse comme si on la
* voyait à travers une gaze; d'autres fois alongée en un
* parallélogramme vertical; d'autres fois brillante et bien terminée.
* Pendant la 16e observation, on l'a vue double; on l'a vue double aussi
* pendant la 20e. Dans ces deux cas, l'une des deux lumières paraissait
* rouge, l'autre paraissait d'un vert pâle. La première nous a semblé
* à tous deux répondre à la place qu'occupait un instant auparavant la
* lumière véritable; le seconde image, celle qui était verte,
* paraissait, dans le champ de la lunette, au-dessous de la lumière
* rouge, ce qui la mettait au-dessus en réalité, puisque les lunettes de
* nos cercles renversent les objets; en sortant de la cabane, nous
* observâmes qu'il y avait des masses de brouillards moutonnées sur la
* mer, comme lorsque nous observâmes de la station de Desierto plusiers
* lumières à Campvey." (13 Feb. 1807; both B&A again.)
*      Another DISPERSION report comes from La Mola de Formentera;  "Les
* habitans de cette petite île sont très-peu nombreux, et ceux d'Yviza
* les regardent comme des sauvages, quoiqu'ils ne soient pas eux-mêmes
* très-civilisée." (p. 170) But I digress; the good stuff is on p.
* 175, where we have both Arago and Biot observing again, 27 April 1807.
* The light on Mongò was ordinarily "un petit point rond bien terminé;
* mais quelquefois elle s'alongeait verticalement et occupait plus d'une
* minute décimale. Il nous a semblé remarquer alors que cette image
* n'était point de même couleur dans toute son étendue. le rouge était
* en haut, le verd en bas dans la lunette qui renverse. . . . Tems calme."
* Full title is:
* Recueil d'Observations Géodésiques, Astronomiques et Physiques,
* exécutées par ordre du Bureau des Longitudes de France, en Espagne, en
* France, en Angleterre et en Ecosse, pour déterminer la variation de la
* pesanteur et des degrés terrestres sur le prolongement du Méridien de
* Paris, faisant suite au troisième volume de la Base du Système
* métrique; rédigé par MM. Biot et Arago, Membres de l'Académie des
* Sciences, Astronomes adjoints du Bureau des Longitudes, etc.
* (Umberto Eco mentions this in section 84 of ``Foucault's Pendulum'',
* calling this title ``phantasmagorical''!)
* available at Google Books


W. Scoresby
“Description of some remarkable Atmospheric Reflections and Refractions, observed in the Greenland Sea,”
Trans. Roy. Soc. Edinburgh 9, 298–305 (1823).

* SUPERIOR MIRAGES of SHIPS
* cf. Rees, 1988, and Lehn & Rees (1990) for inversion


W. Scoresby
Journal of a Voyage to the Northern Whale-Fishery
(Constable, Edinburgh, 1823).

* WILLIAM SCORESBY's Journal
* The full title is "Journal of a Voyage to the Northern Whale-Fishery;
* Including Researches and Discoveries on the Eastern Coast of West
* Greenland, Made in the Summer of 1822, in the Ship Baffin of Liverpool"
*      The refractions are discussed on pp. 96-97: "Hummocks of ice assumed
* the forms of castles, obelisks, and spires; and the land presented
* extraordinary features. In some places, the distant ice was so
* extremely irregular, and appeared so full of pinnacles, that it
* resembled a forest of naked trees; in others it had the character
* of an extensive city, crowded with churches, castles, and public
* edifices."
*      NOTE the footnote on pp. 96-97 (spanning Plate II) warning the reader
* that phenomena that were not contemporaneous are depicted together in
* the Plates!
*      Looming of distant land, well over 100 miles away, is described on
* pp. 106-108.
*      There is another short account of mirages on pp. 117-119: "The ice
* about the horizon assumed various singular forms: -- hummocks became
* vertical columns, -- floes and fields arose above the horizon, like
* cliffs of prismatic-formed spar, -- and, in many places, the ice was
* reflected in the atmosphere at some minutes elevation above the horizon."
* He then describes mirages of ships. . . . "The most remarkable effect
* produced, was on the most distant objects, the interesting appearances
* of which not being discernable without the use of a telescope, probably
* escaped general observation."
* [Note observation of CONCAVE surface.]
*      The main account of mirages is on pp. 163-173; see Plate V, between
* pp. 164 and 165. "Often the hummocky parts of the horizon were reared
* into various architectural figures of extraordinary elevation : and
* occasionally, as observed in a former instance, the whole distant margin
* of ice was deeply serrated, in resemblance of an innumerable collection
* of spires and pinnacles, or in the form of a thick forest of naked trees."
* (p. 164) . . . .      ". . .  the space in which the ship navigated seemed to
* be one vast circular area, bounded by a mural precipice, of great
* elevation, of basaltic ice.  . . .      And it should also be observed, that
* these phenomena were principally telescopic, both the ships and images
* being so distant, that, to the naked eye, they only appeared as
* indistinct specks." (p. 165)
*      "The general telescopic appearance . . .  is frequently that of an
* extensive ancient city, abounding with the ruins of castles, obelisks,
* churches, and monuments, with other large and conspicuous buildings.
* Some of the hills often appear to be surmounted with turrets,
* battlements, spires, and pinnacles; while others, subjected to another
* kind of refraction, exhibit large masses of rock, apparently suspended in
* the air, at a considerable elevation above the actual termination of the
* mountains to which they refer. The whole exhibition is frequently a grand
* and interesting phantasmagoria. Scarcely is the appearance of any object
* fully examined and determined, before it changes into something else.
* It is, perhaps, alternately a castle, a cathedral, or an obelisk: then
* expanding and coalescing with the adjoining mountains, it unites the
* intermediate valleys, though they may be miles in width, by a bridge of
* a single arch of the most magnificent appearance." (pp. 166-167)
*      He continues: "The cause of these phenomena, as far as they depend on
* refraction, is, I imagine, the rapid evaporation which takes place in a
* hot sun, from the surface of the sea; and the unequal density occasioned
* by partial condensations, when the moist air becomes chilled, by passing
* over considerable surfaces of ice. The vapour produced by evaporation
* and partial condensation, is sometimes perceptible to the eye, rising
* like transparent steam in all directions, in little curling clouds, and
* passing along with the breeze near the surface of the sea. Its influence
* can sometimes be perceived at the distance of a few fathoms, or, perhaps,
* half a furlong, by the tremulous motion it appears to give to all bodies
* on the water or near it. In this case, it has a tendency to produce a
* serrated or basaltic appearance of the ice on the horizon, similar to
* what occurred on the 10th and 19th of June. But at other times, when
* repeated, well-defined and proportionate images of ships appear in the
* air, the vapour giving rise to the unequal density, obtains more of a
* stratified arrangement. In its distortive effect, it seems to act like
* clear glass, of unequal surface or thickness; consequently it disfigures
* all objects seen through it. In its looming effect, or that property
* of it by which bodies on the horizon, or beyond, appear to be greatly
* elevated, or suspended, as it were, in air, it seems to act by that kind
* of refraction common to other mediums, when the density about the object
* seen is greater than at the eye of the observer. The lesser density of
* the air about the observer, arises from the elevated position he occupies
* when at the mast-head, where the phenomena are always the most striking.
* Hence, while near objects, which are seen through a very rare portion of
* this vapour, are little or nothing elevated: bodies at the distance of the
* horizon, which are seen through a mass of it several miles in thickness,
* are elevated ten, fifteen, twenty, or even thirty minutes of altitude.
* And when ships or ice within a few furlongs distance are disfigured by
* the action of this vapour, so as to present a varying and tremulous
* outline; other similar objects, at the distance of several miles,
* are, perhaps, steadily elevated. In most cases, the refracted portion
* of the distant ice is closely connected with the ice of the horizon,
* from whence it takes its rise; and when it assumes the columnar form,
* it presents the appearance of a vast amphitheatre, which is so disposed,
* that every observer, whatever may be his position, imagines himself to be
* in the centre of it. But in some instances, and these not unfrequent,
* the stratum of refracted ice is completely detached from the horizon,
* and appears to form a white horizontal streak in the lower part of the
* atmosphere. And occasionally, multiplied images of the ice, as well as
* other objects, occur, forming a parallel vertical series." (pp. 167-169)
* [This is followed by a long footnote, referring to Wollaston's paper,
* and Brewster's works, of a similar nature.]
*      He then describes the appearance of the highest parts of the land seen
* above the duct, and correctly concludes that "the tops of the mountains
* were above the vapour, . . . so that no influence could be exerted by the
* refractive medium, but on the base of the land, which was concealed by
* the looming of the ice." (pp. 171-172)
*      "As the more extraordinary and beautiful effects of unequal
* refraction cannot be fully discovered, without the use of a telescope,
* they escape general observation; and as the looming of the distant ice,
* or distortion of objects, is the most common effect of this state of the
* atmosphere, it becomes a considerable annoyance to persons not interested
* in the phenomena. As in this case, the vapour gives an indefinite and
* tremulous outline to every object beyond a certain distance;— ships, a
* mile or two off, cannot be recognised ;—a wall of ice seems to surround
* the navigator, the openings and leads in which cannot be discerned at
* a distance;—and, of the actions and employment of remote vessels,
* within sight, a knowledge of which is often of great importance to the
* unoccupied fisher, no correct conception can be formed." (pp. 172-173)
*      Now comes the incident of seeing his father's ship miraged (July 24):
*        "On my return to the ship, about 11 o'clock, the night
* was beautifully fine, and the air quite mild. The atmosphere,
* in consequence of the warmth, being in a highly refractive state, a
* great many curious appearances were presented by the land and icebergs.
* The most extraordinary effect of this state of the atmosphere, however,
* was the distinct inverted image of a ship in the clear sky, over the
* middle of the large bay or inlet before mentioned,---the ship itself
* being entirely beyond the horizon. Appearances of this kind I have
* before noticed, but the peculiarities of this were,--- the perfection
* of the image, and the great distance of the vessel that it represented.
* It was so extremely well defined, that when examined with a telescope by
* Dollond, I could distinguish every sail, the general `rig of the ship,'
* and its particular character; insomuch that I confidently pronounced it to
* be my Father's ship, the Fame, which it afterwards proved to be;---though,
* on comparing notes with my Father, I found that our relative position
* at the time gave our distance from one another very nearly thirty miles,
* being about seventeen miles beyond the horizon, and some leagues beyond
* the limit of direct vision. (Plate V. fig. 2.) I was so struck by the
* peculiarity of the circumstance, that I mentioned it to the officer of
* the watch, stating my full conviction that the Fame was then cruizing
* in the neighbouring inlet. (pp. 189-190; the Plate, between 164/165)
*
* Thanks to Mila Zinkova, for prompting me to include this item!
*
*      Available at Google Books:
*
* https://books.google.com/books?id=n-MUAAAAQAAJ&source=gbs_navlinks_s
*


H. H. Blackadder
“On unusual atmospherical refraction,”
Edinburgh Philosophical Journal 13, No. 25, 66–72 (1825).

* Info kindly supplied by A.R.Macdonald, librarian at ROE:
* Henry Home Blackadder
* "In adverting to this subject, one can hardly avoid noticing the
* remarkable inattention of not a few to what is passing under their
* immediate view, while they eagerly search after that which is distant,
* and far removed from the sphere of their contemplation. . . . Is nothing
* interesting but what is distant?"


H. H. Blackadder
“On some phenomena of vertical and lateral mirage observed at King George's Bastion, Leith,”
Edinburgh Journal of Science 3, No. 5, 13–15 (1825).


G. del Re
Descrizione Topografica, Fisica, Economica, Politica dé Reali Dominj al di qua del Faro nel Regno delle due Sicilie, Tomo I
(Tipografia dentro la Pietà de Turchini, Napoli, 1830), pp. 32–33.

* GIUSEPPE DEL RE's comments on Minasi and the terminology
* (dedicated to the Duke of Calabria)
*      The tides and associated flows are discussed on pp. 30-31.
* Then comes the interesting discussion (p. 32):
*      "A rare and surprising phenomenon in the Strait of Messina is the
* Iride Mamertina , called the Fata Morgana by the natives." He cites
* Ribaud for information on this as well as the tides.
*      "P. Minasi of Silla . . .  claims that the beautiful Fata Morgana is
* seen only from Reggio; but it seems undoubted that it is seen also from
* Catona, from Gallico, from Villa s. Giovanni and from Messina, city
* where it has the name of Iride Mamertina ."


R. R. Madden
Travels in Turkey, Egypt, Nubia, and Palestine, in 1824, 1825, 1826, and 1827 (Vol. II)
(Carey & Lea, Philadelphia, 1830), p. 123.

* This is the reference mentioned (but not cited) by Bayfield (1835)
* whose quotation is not strict. The original reads:
* "At one moment, the rippled surface of a lake was before my eyes; at
* another time, a thick plantation appeared on either side of me; the
* waving of the branches was to be seen, and this view was only changed
* for that of a distant glimpse of a city; the mosques and minarets were
* distinct, and several times I asked my Bedouins if that were not Suez
* before us; but they laughed and said it was all sand; and what appeared
* to me a city, a forest, or a lake, the nearer I endeavoured to approach
* it the farther it seemed to recede, till at last it vanished altogether,
* `like the baseless fabric of a vision, leaving not a wreck behind.'
*      "If I were to speak of the nature of the Mirage  from my own
* sensations, I should say, it was more a mental hallucination than a
* deception of the sight; for, although I was aware of the existence of
* the Mirage, I could not prevail on myself to believe that the images
* which were painted on my retina were only reflected, like those in
* a dream, from the imagination, and yet so it was."


H. W. Bayfield
in The St. Lawrence survey journals of Captain Henry Wolsey Bayfield, 1829-1853; , R. McKenzie, ed.
(Champlain Society, Toronto, 1984-1986).

* Background on the next two items. Henry Wolsey Bayfield had spent
* several years in mapping the Great Lakes; the Royal Navy was worried
* about naval warfare on the Great Lakes after the War of 1812, and
* needed maps. As the war scare on the border between Canada and the
* United States calmed down, the Navy reduced the mapping effort; but
* Bayfield, who had grown to enjoy his work in Canada, persuaded the
* Admiralty to extend the effort to the largely unmapped St. Lawrence
* estuary. But his exertions under harsh conditions had brought him
* some severe medical problems; so in staffing the new vessel under his
* command, he asked that a medical officer be added to the crew. This
* turned out to be Dr. William Kelly, "an experienced naval surgeon".
*      These are volumes 54 and 55 of the Publications of the Champlain
* Society. The index to both volumes is at the end of the second one.
*      The first volume contains Bayfield's notes on two mirages later
* published: the first (on pp. 175-176) is the mirage of June 19,
* 1832, published in Bayfield's 1835 note in the Nautical Mag.; the other
* (pp. 380-381) is the mirage of 13 Sept. 1835.


W. Kelly
“On the temperature, fogs and mirages of the river St. Lawrence,”
Transactions of the Literary and Historical Society of Quebec 3, 1–45 (1832).

* Dr. William Kelly's first mirage paper
* Here he introduces some half-baked ideas, later retracted. But he has
* already discovered for himself the difference between the inferior and
* superior mirages. In the original text, he cites only Humboldt; in the
* later commentary, he reviews the papers by Latham, Vince, Huddart,
* Wollaston (whom he consistently calls "Woolaston"), Biot, and Parry.
* He says he has seen the mirage in Egypt. Note the FOG in the title;
* also (p.11): "There was generally with the mirage an appearance of a fog
* bank on the horizon . . . . The air within the horizon was at the same time
* perfectly clear."
* Effect of HEIGHT OF EYE mentioned repeatedly: "All these unusual
* appearances were generally lost in ascending the rigging from ten to
* thirty steps, when objects were seen in their natural shapes."
* Effect of DISTANCE noted: "The appearances differ much; owing,
* apparently, to the ships being more or less remote." And, in discussing
* Vince's report on p. 34, he says, "The refracted objects were all without
* the natural line of the horizon; those within it retaining their usual
* appearance." (This point was already made by Vince.)
* HEIGHT and DISTANCE COMBINED: (p. 12): ". . . during the mirage, which
* occurred in a calm with a considerable swell of the sea, the appearances
* presented by two small islands or rocks, at different distances from us,
* was very remarkable; for as the vessel rose on the wave, the more
* distant seemed to sink, and the nearer to be raised up; and again as the
* vessel sank, the first rose, and the near one was lowered. Even the
* different parts of the same island were variously affected, appearing to
* dance as the vessel rose and fell."
* Reflection in an apparently SMOOTH MIRROR (inf. mir.): "The portion of
* reflected sky between the inner islands and the vessel, resembles a
* perfectly smooth lake." (p. 17)
* MIRAGE and DIP: (p.20): he found the large dip of the inferior mirage
* ". . . so remarkable a feature, that I distinguished this in my notes as
* the mirage with shortened or depressed horizon, whilst the other was
* designated the mirage with elevated horizon, on account of the contrast
* between them . . . ", citing Humboldt's earlier work.


H. W. Bayfield
“Terrestrial refraction in the St. Lawrence,”
Nautical Mag. 4, 91–93 (1835).

* Captain Bayfield's first 3-image report (with Kelly); seen June 19, 1832
* With air 5° F warmer than sea surface, a vessel 7 miles away was seen
* "with her hull occasionally raised, so as to shew it distinctly above
* the horizon, although the height of our eyes was not over eleven feet.
* Her sails appeared elongated laterally, but were perhaps only shortened
* vertically, which made then appear so elongated." (This probably
* explains many other reports of APPARENT HORIZONTAL MAGNIFICATION as well.)
* There was a very light breeze from the west.
*
* This item is followed by two rather ordinary inferior-mirage reports
* from A. Inderwick in Mexico, and R. R. Madden in Egypt, on pp. 93-94, and
* p. 94, respectively. The latter's comment, taken from his "Travels in
* Turkey, Egypt, . . . ", that "I should say it was more a mental hallucination
* than a deception of the sight; for, although I was aware of the existence
* of the mirage, I could not prevail on myself to believe that the images
* which were painted on my retina were only reflected, like those in a
* dream, from the imagination, and yet so it was" -- is apposite.
* (Though to him "the mosques and minarets were distinct," the Bedouins
* "laughed at me, and said it was all sand.")


W. Kelly
“On some extraordinary forms of mirage,”
Nautical Mag. (London) 8, 394–399 (1839).

* FIRST observation of FIVE IMAGES?
* William Kelly, M. D. was an acute observer:
* "When my attention was directed, some years since, to the different
* forms of objects, seen through mirage in the St. Lawrence, one of these,
* which I particularly remarked, was the flower-pot shape assumed by small
* islands, when affected by the mirage, which depends on the contact of warm
* moist air with a surface of water colder than its dew point. Whatever
* the real shape of the island, or rock might be, its top seemed raised and
* flattened; generally extending in a straight horizontal line so far on
* each side, as at least to equal the base in extent; often beyond it;
* whilst, midway between the base and distorted top, the figure was
* contracted, having the appearance of a neck. When two islands lay close
* together, these flattened tops sometimes met, giving the appearance of an
* arch from one to the other. In all cases of mirage, depending on the same
* cause, the tops of objects seemed straight and horizontal in the same way,
* but the sides were like a wall. They frequently presented an appearance
* as if they were horizontally stratified."
* He describes an instance in detail: "A line answering to the horizon,
* was also seen on a level with the upper flat part of the inverted image of
* the island, and extending from it to a sandy point on the main. The true
* horizon was quite distinct, and well marked beneath. The sandy beach
* between us and the point seemed raised like a wall."
* Another case "presented to the naked eye nothing more than the flat top
* and walled sides usually seen in this form of mirage. But on examining it
* carefully with a telescope, in some parts of the flattened top, the
* picture of a beach was seen above the trees; thus shewing that this form
* also depended upon a second inverted image lying above, and confounded
* with, the upright one."
* "All the various forms assumed by objects, under the influence of this
* mirage, seem to be the result of two or more images, alternately erect and
* inverted, either distinct or mingled together in a greater or lesser
* degree."
* In June, 1832, "in passing Point des Monts, where the breadth of the
* river is very considerable, we saw the three images distinctly marked,
* such as they have been described by Vince and Scoresby. . . . We have
* frequently since seen treble images in the estuary and gulf . . . ."
* GOOD ADVICE TO OBSERVERS:
* "A telescope, if at hand, should always be employed in observing mirages
* of any kind, as it enables us to detect particulars, that would escape the
* naked eye. On one occasion, to the naked eye, the hull of a ship seemed
* raised to an enormous height, and the sails very small, the telescope
* shewed three distinct images. . . . By the help of the telescope we were
* afterwards enabled to detect five distinct images, though the whole gave
* to the naked eye the impression of only one almost shapeless mass. . . ."
* Another time, with the air 48° and the water 39°.5, ". . . a vessel
* with all sail set, at one moment looked like an immense black chest, no
* sails or masts being visible. On observing her for a time the black body
* seemed to seperate horizontally into two parts; and two sets of mingled
* sails occupied the intervening spaces, with one set of very small sails
* above. The figures afterwards became more distinct, and three images were
* clearly discerned. Another vessel changed also from the form of a great
* square flat-topped chest, to five distinct images, the upper with sails
* erect, and the two lower double images with their sails rather confusedly
* intermingled. A raised horizon was parrallel to the upper figure of the
* hull. . . . Captain Bayfield and Mr. Bowen observed five distinct images of
* another vessel after I left the deck. When I first noticed extraordinary
* appearances, like those I have endeavored to describe, I was not aware of
* the advantage of employing a telescope for the examination of objects at
* inconsiderable distances." [spelling errors all sic ]
* "It seems probable that the horizontally stratified appearance, which
* the coast often assumes under this species of mirage, may be the effect
* of multiplied images of the horizon, or level sea at its base. The number
* of images may well exceed five, as we find they do three, which I believe
* was the greatest number hitherto noticed by any observer."
* IMPORTANCE OF MIXING in stratified waters:
* "Several rivers empty themselves into the sea at this place [the Mingan
* islands], the waters of which, in calms, float on its surface, which thus
* is sometimes several degrees warmer than the water at a depth of a few
* inches. A moderate current of air, which amongst small islands is often
* partial, sometimes, by agitating the water at one place, renders the
* surface there cold, whilst it continues warm in places sheltered from the
* wind. We have hence occasionally strange combinations of mirage." Thus,
* starting from an ordinary inferior mirage, where "The horizon on this side
* was low and near -- a rock, three miles distant, seemed above it. As the
* breeze sprung up from the S.W. the horizon receded beyond this rock, and
* the islands generally appeared to have flattened tops, shewing the mirage
* of the opposite kind. But the extreme points of the most distant island
* seemed still in the air, notwithstanding, the island generally presented
* the same flat level top as the others -- thus shewing, in its different
* parts, the opposite forms of mirage at the same time."
* ALTERNATION OF ERECT AND INVERTED IMAGES DISCOVERED:
* "Whatever the number of images may be, they appear in every instance to
* be alternately erect, and inverted."
* DISCONTINUOUS HORIZON:
* "But on one occasion near the Labrador coast, the point of junction of
* the two species of mirage was so well marked that it appeared like a step
* in the horizon."
* ASSOCIATION WITH STRAITS:
* "The most remarkable mirages over water have occurred in straits; those
* seen by Mr. Vince at Dover, and the celebrated Fata Morgagna at Measina.
* In the St. Lawrence they are most frequently observed, and present the
* greatest varieties in similar situations: as at Bic, Point des Monts,
* and the strait of Belle-isle." [typos strictly sic .]
* VARIATIONS IN DIP:
* He also cites a case in which the dip, measured with the dip sector,
* increased from 3' 15" to 4' 11" as the water temperature changed from 43.5
* to 46.5 F (both as seen from 12 ft. 6 inches elevation).
* Footer says "ENLARGED SERIES. -- No. 6".


M. Saffioti
Lettera intorno al fenomeno Fata Morgana
(Tipografia Salita Infrascata N.344, Napoli, 1837).

* MICHELE SAFFIOTI's letter
* This is the second edition (1837), placed here to be next to Capozzo's
* disastrous derivative. The author's name is spelled "Saffioti" on the
* title page, and at the end. That spelling (according to Google Books's
* "Ngram viewer") was the more common in written material before 1874.
* Both Boccara (1902) and Costanzo (1903) spell his name "Saffiottï
* (with two t's); since then, the two-t spelling has dominated. The two
* spellings are about equally common on the Web today . . . .
*      He hoped to see images vaguely colored with the colors of the rainbow.
* (pp. 9, 10) These colors are mentioned again on pp. 14 and 20 (referring
* to Minasi),
*      He quotes Facellus (p. 14), and Angelucci's letter (p. 15).
* Then there are reports of the 26 April 1828 display, beginning with a
* "current of transparent vapor." (p. 17)
*      Kircher, Allegranza (!) and Minasi appear on p. 19; he thinks none of
* them were observers, and that only Angelucci saw the Fata Morgana.
*      The second part, beginning on p. 21, describes the geography around
* the strait. The tidal currents are treated on pp. 25 - 28. Then comes
* his theory, full of crystals and "vesicular vapors" (!) (p. 33)
* At least he understands that the sea and the air must both be perfectly
* calm to produce the F.M.
*      Available on the Web at
* https://archive.org/details/bub_gb_HOxu7xksWzMC


G. Capozzo
Memorie su la Sicilia : tratte dalle più celebri accademie e da distinti libri di società letterarie e di valent'uomini nazionale e stranieri (Vol. 1)
(Bernardo Virzì, Palermo, 1840), pp. 71–92.

* GUGLIELMO CAPOZZO's review of the Fata Morgana (via Saffiotti)
*      The Introduction, and particularly the "Literary Appendix" on pp. 36
* to 38, shows that this is another work devoted to Sicilian patriotism;
* so the uncritical acceptance of Giardina as an authentic F.M. observer
* is hardly surprising.
*      Quotes Giardina (1758) and Angelucci/Kircher in extenso on pp. 74-76,
* evidently believing that Giardina actually observed the 1643 display.
*      After quoting Angelucci's account in full, the author says:
* "Our Padre Domenico Giardina of the society of Jesus describes more
* fully the same phenomenon seen in Messina on the 14th of August of that
* same year 1643." But, of course, Giardina didn't see that display;
* so the "added" details are all fabricated. (Cf. the growing embroidery
* of the New Haven "ghost ship", or the spurious details added to Minasi's
* account by Nicholson and Brewster.)
*      There are many errors.  He consistently calls Saffiotti "Salfiotti",
* consistently calls Angelucci "Angellucci", and mentions Allegranza
* (footnote, p. 72). And, as he plainly knows little about physics or
* optics, his attempts to explain the reflections with "vesicular vapors"
* and the like (p. 88) are useless nonsense.
*      A final note, at the end (p. 92), says this article is an extract of
* the letter from Saffiotti cited on p. 72, note 1, with some additions.
* Those additions include the notion that Giardina saw the 1643 F.M.
* from Messina!
*
*      Unfortunately, this wrong account has been propagated by careless
* readers: Consolo (in his 1993 Italian original, and then again in
* translation in 2006), and the ignorant Marina Warner (also in 2006).
* Then Capozzo's Italian was republished again in 2011 by Séstito.
* This is just as useless as Boccara (1902) says.
*      The title page of the volume adds “con aggiunte e note per
* Guglielmo Capozzo” to the title given below; and Capozzo signed the
* dedication, the preface "to the readers", and the Introduction.
* The footers on pp. 17, 33, 49, 65, 82, etc. say "Capozzo Vol. I."
* So he is clearly the editor and effectively the publisher.
*       Available at Google Books, and at the HathiTrust site.


V. Consolo
Vedute dello Stretto di Messina
(Sellerio, Palermo, 1993).

* VINCENZO CONSOLO's essay on the Strait of Messina, with Fata Morgana errors
* repeats Capozzo's phony story (hence its placement here).
*
* A beautiful "coffee-table" book (quarto: 9x13 inches = 24x33 cm), with
* 34 color plates and 65 b/w in the text. The body type is large (about
* 12/15); the references and notes are about 11/13; and the photo credits
* on p. 183 are about 8/10.
*      The contents exactly fit the title: it's mostly a picture book of
* views of the Strait of Messina, from the Middle Ages to the middle of
* the 19th Century.
*      The subtitle "Con un saggio di Gioacchino Barbera" refers to Barbera's
* essay "Per un'iconografia dello Stretto di Messina" on pp. 41-64,
* followed by 3 pages of notes -- considerably longer than Consolo's text
* on pp. 15-37, followed by only 3 column-inches of notes on p. 38.
*      The last 5 pages of Consolo's text are enclosed in quotes here, and
* set off by a break, as they are taken from his 1988 publication "Fra
* Contemplazione e Paradiso" with N. Rubino, as indicated by his final
* note on p. 38 here. The transitional paragraph on p. 33 that leads in
* to this story was reduced to a single sentence when this was translated
* by Mark Chu for Bouchard and Lollini's 2006 book.
*      Barbera's essay is followed by 6 pages of biographical notes, and
* 18 pages of short notes on some of the works of art that are reproduced,
* prepared by Giovanni Molonia. Five of these are works by Willem Fortuyn,
* including his engraving for Minasi's Fata Morgana review.
*      Then comes a 5-page bibliography, which mentions an unpublished letter
* by Gallo on the Fata Morgana of 18 Aug. 1768.
*      The emphasis of the book is on art history; but it's garbage history,
* with no regard for factual accuracy in Consolo's text.
*
*      Considering Consolo's repetition of Capozzo's false account of the
* 1643 Fata Morgana display, the main value of this for our purposes is
* the re-publication of Minasi's dissertation in full.
*      Pages 159-168 contain a verbatim transcript of Minasi's dissertation,
* complete with its notes. Here there are some discrepancies with the
* original, starting with the extract from Pliny's Historia Naturalis:
* the original cites this as book VII, but Consolo's copy says book IV.
* The formal closing of the dedication has also been edited slightly: a
* comma was inserted after "Roma", and the tildes over the m's in the
* signature were omitted.
*      Similar edits were made in the Proemio, including the addition of
* typos like "gravissimus" for "gravissimis" and "dibiis" for "dvbiis"
* in the quoted inscription. [As "i" and "u" are adjacent keys on modern
* keyboards, it's obvious how these were produced.] These same copying
* errors appear in the version of Minasi's text reproduced in Séstito's
* book; so that was probably copied from Consolo, rather than from the
* original.
*
* Likewise, there are changes in the reproduction of Minasi's footnotes,
* which have been converted to end-notes here, with re-numbering within
* each Chapter (instead of each page, as in the original.) The change
* in format from Minasi's small single columns to much wider double
* columns with narrow margins has compressed Minasi's 102 pages to just
* 20 pages.
*      However, the re-numbering was not extended to the cross-references
* within the Notes. So "Cap. III, § 8, nota 1" that is cited in notes
* 7 and 30 to Cap. V is now note 11; and the "Cap. III, § 8, nota 2"
* cited in note 28 is now note 12. But everything is here, including
* the notes in Cap. IV that discuss the plagiarism of Angelucci's account
* by Giardina.
*      Evidently, Consolo was another of those careless writers who cite
* references (and, here, even re-publish them) without reading them.


V. Consolo
in Reading and writing the Mediterranean: essays by Vincenzo Consolo , Norma Bouchard and Massimo Lollini, eds.
(University of Toronto Press, Toronto, 2006).

* VINCENZO CONSOLO (in translation) serving up Capozzo (1840)
* (and so placed here out of chronological order):
*      The translator has rendered Angelucci's account in graceful English,
* on pp. 196-197. Then we have:
*      "And the Calabrian Jesuit sees that Fata Morgana precisely on
* the feast of the Assumption -- the great feast of the patron saint
* in Messina on the day of 15 August -- creating the suspicion that
* his might be a devout fantasy. This is all the more so for the fact
* [sic!] that another Jesuit, Father Domenico Giardina, has the same,
* identical vision, like the reflection on the second side of a double
* mirror, with only the temporal displacement of barely a day, on 14
* August of that same year of 1643, from the opposite side, from Messina.
* [Here, footnote 21 cites Capozzo as the reference.] The story of the
* Calabrian is identical to that of the Messinese (which we would like to
* reproduce here if we were not afraid of boring the reader); the details
* are identical, except for the number of the pillars: ten thousand for
* Angelucci, one hundred thousand for Giardina."
*      "Identical"!  So why didn't Consolo suspect that Giardina's account
* was copied from Angelucci's? And why didn't his editors suspect this,
* and investigate? Instead, he wanders off into airy lyricism, and
* reality and truth are abandoned. Shameful.
*      The translator of this essay was Mark Chu, another person very
* interested in Sicilian matters; which may have dampened his critical
* sense.
*      This essay (pp. 188-) is called "Views of the Strait of Messina".
* On p. 294, we find it comes from "Vedute dello Stretto di Messina"
* in "Di qua del faro" (1999), pp. 67-91; though I also see it listed as
* a separate publication by Sellerio, Palermo, dated 1993.
*      The book says copyright 2006; the publisher's website says 2007.


C. Lyell
Travels in North America in the years 1841-42; with Geological Observations on the United States, Canada, and Nova Scotia (Vol. II)
(Wiley and Putnam, New York, 1845), p. 85.

* Sir Charles LYELL's textbook example of LOOMING:
* "June 14, 1842. - From Queenstown we embarked in a fine steamer for
* Toronto, and had scarcely left the mouth of the river, and entered Lake
* Ontario, when we were surprised at seeing Toronto in the horizon, and
* the low wooded plain on which the town is built. By the effect of
* refraction, or `mirage,' so common on this lake, the houses and trees
* were drawn up and lengthened vertically, so that I should have guessed
* them to be from 200 to 400 feet high, while the gently rising ground
* behind the town had the appearance of distant mountains."
* (No photocopy; this is on P-10 microform.)


T. Milner
The Gallery of Nature: A Pictorial and Descriptive Tour through Creation, Illustrative of the Wonders of Astronomy, Physical Geography, and Geology
(William S.Orr & Co., London, 1846).

* THOMAS MILNER's update of Polehampton's 1815 work
* This version went through many editions; the 1855 one is on Google Books.
* It bears the label "A NEW EDITION, CAREFULLY REVISED" on the title page.
* A copy of the 1848 edition from the U.C. libraries is at the HathiTrust
* website. It seems identical to the 1855 one; and the quality is better.
* The 1846 edition is also at the HathiTrust site.
*      In all 3 editions, mirages are in Section 5, "Spectral Illusions",
* of Chapter XVI on "Optical Phenomena": pp. 535-540. It then goes on
* to deal with the Brocken spectre and similar images on mists, which are
* attributed to "reflection". The text returns to mirages on p. 542: "In
* northern latitudes the effects of atmospheric reflection and refraction
* are very familiar to the natives. By the term of uphillanger the
* Icelanders denote the elevation of distant objects . . . ." The mirage
* discussion then continues with Scoresby's observations, Wollaston,
* Jurine & Soret, etc. until p. 543. [Cf. Milner's 1850 book.]
*      Note: "upphillingar" seems to be the correct spelling.
*      Minasi's stuff about the tides is omitted.


W. Kelly
“On the dip of the horizon, and mirages of the Gulf and River St. Lawrence,”
Nautical Mag. (London) 15, 393–398 (1846).

* Dr. William Kelly seems to have been as sharp an observer as Willard Fisher
* "On The Dip Of The Horizon, and Mirages of the Gulf and River St.
* Lawrence. By William Kelly, M.D., Surgeon, R.N., attached to the Naval
* Surveying Party on the St, Lawrence.
*
* "Every one conversant with nautical astronomy is aware that some
* uncertainty always attends observations made with the natural horizon,
* from the varying amount of the dip occasioned by terrestrial refraction.
* The cause of these variations is very obscure. The best authorities seem
* to regard differences of temperature in the air and water as the sole
* cause of the irregular density of the lower strata of the atmosphere on
* which the varieties of the dip depend. It is known that, in general, when
* the water is warmer than the air, the dip is greater than that given in
* the tables; and that when the water is colder than the air, the dip is
* less. But cases occur where the deviations from the tables are found to
* bear little relation, at least in amount, to the relative temperatures of
* the air and water. Some other property of the atmosphere must therefore be
* sought after, by the influence of which the effects of temperature are
* modified."
* He recognizes the two main types: "In one (the mirage of Arctic regions)
* the horizon is elevated, the forms of objects distorted, and frequently
* two, three, or even as many as five images of the same object are seen,
* alternately erect and inverted -- the lowest always being erect. This
* kind of mirage is only met when the water is colder than the air. In the
* other kind of mirage, (the mirage of the desert), the horizon is
* depressed, distant points of land seem raised into the air, the form of
* objects is seldom materially changed, there are never more than two images
* of an object, and when a second is seen, the lower is always inverted, the
* upper erect. When this kind of mirage is seen, the water is usually
* warmer than the air."
* "The mirage with depressed horizon was constantly seen if we had an
* opportunity of observing distant points of land when the water was warmer
* than the air."
* Kelly grants that the temperature difference between water and air is
* the main factor, but thinks humidity plays a part as well.
* "The occurrence of either form of mirage, and its intensity, seemed to
* be affected by other circumstances besides the relative temperatures of
* the air and surface water, and the hygrometric states of the air. Thus
* they appeared more frequently, and their phenomena were more intense in
* calms or light winds than in a fresh breeze." -- with a footnote:
* "Still I have seen both forms in fresh breezes, and the mirage with
* depressed horizon during a strong gale."
* He gives a few extreme examples of dip, and notes a DIURNAL VARIATION in
* dip. The variations of dip parallel those of the mirages:
*      "The force of the winds had the same effect on the dip as on the
* mirages. Either the elevation or the depression was comparatively greatest
* in a calm, and least in a breeze. This was often very observable when a
* set of observations was commenced in a calm, and a breeze happened to
* spring up before it was finished."
* On the whole, a careful, cautious argument; should be taken seriously.
*      NOTE: This and other selections from Nautical Mag. were plagiarized
* in Vol. 2 of The American Merchant (1859) by "Capt. John H. Bell".
* No.8, August, 1846. Title page says "The Nautical Magazine and Naval
* Chronicle". Available at Google Books.


G. A. Bedford
“Observations on the phenomena of terrestrial refraction,”
Nautical Mag. (London) 16, 67–70 (1847).

* Commander Bedford thinks it has to do with water vapor, not temperature.
* See detailed discussion below, following the reprint in J. Franklin Inst.
* I have only a very bad copy of this from a scratched microfiche.
* Full title is "The Nautical Magazine and Naval Chronicle".


G. A. Bedford
“Observations on the phenomena of terrestrial refraction,”
J. Franklin Inst. , series 3, 13, 279–282 (1847).

* Commander Bedford thinks it has to do with water vapor, not temperature.
* But he recognizes that the difference in temperature of sea and air is
* the decisive factor. He has observed carefully:
* "The occurrence of mirage during strong, or even fresh, winds, can be, I
* imagine, but seldom, particularly of that kind with elevated horizon. . . ."
* Despite the title, this is about mirages. This seems to be a verbatim
* reprint of his Nautical Magazine article, in response to Kelly.


K. B. Martin
“Mirage at Ramsgate,”
Nautical Mag. (London) 16, 457–459 (1847).

* A curious report, including claims of LATERAL MIRAGE
* ". . . the said light became perfectly distinct , and proved to be, (as
* in a former instance communicated to you, Calais Light , and in a
* position 2 3/4 points from its real bearing. . . . right over the middle
* of the North Sand."
* A Classical allusion: "The pilot of Ulysses was deceived, as Ithaca
* melted into mist . . . ."
* Cited by Lt. Raper.
* Capt. Martin is listed as "Harbour-Master, Royal Harbour, Ramsgate."
* Full title is "The Nautical Magazine and Naval Chronicle".
* Sept. issue.


R. Leighton
“Notes on a passage through the Grecian archipelago,”
Nautical Mag. (London) 18, 414–420 (1849).

* HEIGHT DEPENDENCE mentioned for BLACK SEA mirages
* In the section headed "Black Sea" (p. 418), Capt. Leighton says:
* ". . . I have found that dark overcast rainy weather occurs frequently,
* . . . and this weather sometimes clears off suddenly to beautiful clear
* weather, but leaves a miraged horizon. This, when it occurs at night is
* very deceptive, as it cannot then be seen, and may mislead you by false
* altitudes of stars. I have seen it several feet high all round the
* horizon during the day, appearing like broken water, or the tops of trees
* upon a low plain just rising above the horizon, that did not disappear
* until the eye was fifty feet above the sea. I have also observed the
* land to be affected by this mirage, particularly near Cape Fontane."


A. T. d'Abbadie
“Sur un météore peu observé jusqu'ici,”
Mem. Acad. Toulouse 5, 296–303 (1849).

* EARLIEST BLANK STRIP ?? Note references to "DRY FOG" throughout
* Many good descriptions and a DRAWING of black bars across the Sun!
* The "météore" is evidently a DUCT, which he says is known as "qobar"
* in the language of the Ethiopians. "Toutes les langues éthiopiennes
* ont un mot spécial pour le désigner et pour éviter les périphrases."
* (According to the E.B. (9th ed.), d'Abbadie compiled a catalog of
* existing Ethiopian manuscripts; see the article on Ethiopia.)
* "Vu de loin, aux limites de l'horizon, le qobar semble disposé par
* couches, le plus souvent horizontales, à tranches nettes, sans bavures,
* et tellement denses que le soleil s'y éclipse comme derrière l'écran
* le plus opaque. Ainsi, dans Ynarya nous vîmes, le 24 janvier 1844, le
* soleil disparaître complètement derrière un banc de qobar qui devint
* ainsi visible négativement. A mesure qu'il descendait, son disque
* paraissait, au-dessous de la limite inférieure du qobar, aussi net et
* exempt de déchirures que si l'on avait enlevé d'un trait de diamant la
* moitié supérieure d'un disque de verre rouge. Cette couche de vapeurs
* sèches avait une légère réfraction de lumière rouge sur sa surface
* supérieure pendent que l'astre était caché derrière, et nous pûmes
* voir ainsi que cette surface était tant soit peu plus déchiquetée que
* la surface inférieure."
* "Le caractère le plus frappant de notre météore, outre l'énorme
* sécheresse qui l'accompagne toujours, c'est sa faculté d'éteindre
* la lumière." N.B.: Drawing shows a VERTICAL COLUMN -- cf. Livesey, 1985.
* ". . . et toutes ces couches interceptaient totalement et sans
* déchiqueture la lumière du soleil."
* Many nice accounts of phenomena over a small lake (Tana).
* The comments following on pp.303-304 by the Commission of referees say
* that d'Abbadie was from a family of the Midi, and educated in Toulouse;
* he apparently inherited wealth, which he used to support scientific
* expeditions. This connection explains his presenting the paper here, and
* his final paragraph thanking the city fathers for their support of the
* Toulouse Observatory.


T. Milner
A Descriptive Atlas of Astronomy and of Physical and Political Geography
(William S.Orr & Co., London, 1850).

* THOMAS MILNER's "Atlas" -- mostly taken from his "Gallery of Nature"
* The "Icelanders" part has changed to: "The most usual effect is an
* increase in the vertical dimensions of the objects affected, so that
* low coasts appear elevated, what seamen call looming , and sites below
* the horizon are brought into view. The Icelanders, who are familiar
* with this effect of atmospherical refraction, call it upphillingar . . . .
*      "It is an old tradition, that Hvidsærk, a mountain in Greenland,
* and Sneefields, in Iceland, have both been visible at the same time
* from the middle of the intervening strait, which at the nearest point
* is about 300 miles wide. Though treated as a fable, it may be strictly
* true, owing to the effects of refraction. The last named mountain,
* Sneefields, though it is not seen under ordinary circumstances for
* more than 80 miles, has yet been often visible from the sea beyond
* the Westmanna Isles, a distance of more than 140 miles; and Scoresby
* relates having seen a part of the Greenland coast of inferior height,
* Home's Foreland 3500 feet high, when 160 miles distant." (p. 95).
*      Note: "upphillingar" seems to be the correct spelling.


J. B. Cherriman
“On the atmospheric phenomena of light,”
Canadian Journal 1, 6–8, 26–28 (1852).

* A very SUCCINCT SUMMARY of all of atmospheric optics
* J. Bradford Cherriman's review article deserves to be better known!
* He covers everything: refraction, mirages, scattering, absorption,
* rainbows halos, glories and coronae. He explains superior and inferior
* mirages, and says: "To this class of phenomena belong the well-known
* Fata Morgana , the appearances seen on the sandy plains of Egypt, and
* called by the French Mirage , and the Looming occasionally seen in
* parts of Great Britain."
* N.B.: The Roy. Soc. Cat. has this under "Bradford".
*      See Cherriman's entry in the  Dictionary of Canadian Biography  at
*
*      http://www.biographi.ca/en/bio/cherriman_john_bradford_13E.html
*


Mr. M`Farland
“On the Fata Morgana of Ireland,”
Report of the British Association for the Advancement of Science, Transactions of the Sections for 1852 22, 29–30 (1853).

* IRISH Fata Morganas, some with COLOR
* The first sentence is: "These singular illusions are termed in the
* Irish language Duna Feadhreagh , or Fairy Castles."
* After citing several rather fantastic reports, the author describes
* his own observation: ". . . in June, 1833, he himself and a party of
* friends, when standing on a rock at Portbalintrea, perceived a small
* roundish island as if in the act of emerging from the deep, at a distance
* of a mile from the shore; at first it appeared but as a green field,
* afterward it became fringed with red, yellow and blue; whilst the forms
* of trees, men and cattle rose from it slowly and successively; and these
* continued for about a quarter of an hour, distinct in their outlines,
* shape and colour; the figures, too, seemed to walk across it, or wandered
* among the trees, the ocean bathed it around, the sun shone upon it from
* above; and all was fresh, fair, and beautiful, till the sward assumed a
* shadowy form, and its various objects, mingling into one confused whole,
* passed away as strangely as they came."
*      Further instances are mentioned, but do not seem to be first-person
* accounts. A few references are offered for these later examples.
*      There seems to be no standard abbreviation for these Reports; see
*
*       http://www.scholarly-societies.org/history/1831baas.html
*
* The full title of the volume is: Report of the twenty-second meeting of
* the British Association for the Advancement of Science; held at Belfast
* in September 1852.
*      Note: these "Transactions of the Sections" are paginated separately
* from the rest of the Reports, though both are bound together. They
* are headed "Notices and Abstracts of Miscellaneous Communications to
* the Sections", and follow the first 355 pages of the volume. According
* to the Indexes that appear at the end of this section, the first part
* of the volume is "Reports on the State of Science", while the second
* is "Miscellaneous Communications to the Sections."
*      Following p. 144 of this section comes yet a third, separately
* paginated, section of the volume (again starting on p.1) that lists
* "those Members of the British Association . . . to whom Copies of this
* Volume [for 1852] are supplied gratuitously . . . ." -- with separate
* lists of "Honorary Members", "Life Members", and "Annual Subscribers".
* This is followed by several un-numbered pages listing the past volumes.
*      Note that the M of M`Farland is followed by a left single quote mark.
* He does not appear in any of the lists of members.


A. Ganot
Traité élémentaire de physique expérimentale et appliquée et de météorologie
(Chez l'Auteur, Paris, 1853).

* Adolphe Ganot's famous textbook
* This went through 18 editions under Ganot himself; Hachette continued to
* produce revised editions until 1931. It was distinguished by the
* introduction of numerous woodcuts, from the 2nd (1853) edition on.
*      The PALM-TREE diagram appears on p. 366: "Le mirage  est une illusion
* d'optique. . . .
*      "Ce phénomène a été observé dès la plus haute antiquité; mais c'est
* Monge, le premier, qui en a donné l'explication, lorsqu'il faisait
* partie de l'expédition d’Ègypte."
*      The 17th ed. is at Gallica; the figure is slightly more elaborate, and
* appears on p. 473 there.


A. Bravais
“Notice sur le mirage,”
Annuaire Météorologique de la France pour 1852 4, 227–280 (1853).

* BRAVAIS reviews mirages
* (This 53-page article is filed separately.)
*
* EARLY USE of "INFERIOR" and "SUPERIOR" mirage terminology:
* "Description du mirage ordinaire ou mirage inférieur" (p. 234)
* "Mirage inverse ou mirage supérieur" (p. 264)
*
* This is an outstanding review of the early literature, containing many
* results not re-discovered until much later. EXCELLENT INSIGHT into
* the problem, despite being confined to simple analytical cases.
* Very complete REFERENCES to the earlier literature, even mentioning
* Quintus Curtius (p.227). But he relies on secondary sources (like
* Gilbert), consistently calls Minasi "Minazi", and confuses Biot's
* publication date (1809) with the year of his observations at Dunkirk.
*
* He is very impressed with Wollaston's 1800 paper. (pp.231-232)
*
* Much discussion of the fact that the inferior mirage is usually smaller
* than the direct image (pp. 233, 241, etc.), and tentatively attributes
* it to the CURVE of the Earth: "J'ai remarqué que, lorsque l'oeil est
* près de la surface des eaux, à 1 mètre ou 2 mètres au plus de
* hauteur, les objets étant rapprochés, les deux images ne diffèrent
* pas beaucoup de l'égalité; mais que, si l'oeil est beaucoup plus
* élevé, par exemple à 10 ou 12 mètres d'elévation au-dessus du
* niveau de la couche liquide, le rétrécissement de l'image inférieure
* devient extrêmement sensible: d'après cela, il me paraît probable
* que la courbure de la terre joue un rôle assez actif dans ce
* phénomène." (p.241) [cf. Riccò et al., 1888.]
*      This idea was proposed earlier by Woltman (1800).
*
* CARE in observing: "Pour bien discerner le mirage, il faut
* non-seulement une vue longue et étendue, mais savoir observer des
* détails, et avoir l'habitude de l'horizon. Aux voyageurs, aux marins,
* aux météorologistes, cet exercice est devenu familier; le reste des
* hommes s'en doute à peine; vous leur montrerez le mirage et ils ne le
* verront pas, ou ils ne verront qu'un peu de brouillard et de fumée
* à l'extrême horizon." (p.235)
*
* EFFECT of INFERIOR MIRAGE on HORIZON (WAVES):
* "L'horizon sensible de l'eau paraîtra presque toujours offrir un
* léger tremblotemont: si le mirage est fort, il sera bordé par une
* crête dentelée dont les sinuosités paraîtront sans cesse monter et
* descendre, s'effacer et reparaître." (p.235)
* How to tell REFLECTION on water from inferior mirage, p.237.
* "En général, dans le cas du mirage, le raccordement d'une ligne
* oblique avec sa symétrique située au-dessous se fait, non par un angle
* à sommet net, mais par un arc de courbe ayant son principal élément
* vertical." (p.238) [cf. Wollaston, 1803; & Gilbert's 1806 transl., Fig.6 !]
*
* OPTIMAL HEIGHT of EYE: "Il est très-probable qu'il existe une certaine
* hauteur de l'oeil pour laquelle l'angle entre l'horizon apparent et la
* ligne de partage des objets situés à une distance donnée est un
* maximum. Ce maximum, dont la hauteur doit varier avec les circonstances
* météorologiques du mirage, paraît avoir lieu pour une élévation
* de l'oeil de 1m.5 à 2m . . . ." (p. 242)
*
* He seems to be the first to see that the whole TEMPERATURE PROFILE must
* be measured, and that the thermometer must be ventilated. (pp. 242-243)
*
* Effect of UNEVEN GROUND: ". . . le mirage des plaines ne pourra jamais
* offrir une régularité aussi parfaite que le mirage des mers ou des
* lacs." (p. 244)
*
* Notices "que le niveau de la caustique ne peut jamais s'élever . . .
* au-dessus de l'horizon apparent." (p. 250) -- a hint of The Theorem.
*
* LOOMING is explained on p. 256: the ray curvature can exceed the Earth's.
* He also finds hints of the CONCAVE SURFACE and the appearance of
* "high cliffs" in Woltmann and Biot (p.257) -- i.e., the Fata Morgana.
*
* An early EXPLANATION of NEGATIVE DIP (cf. Kimmfläche, and Biot):
* the space below the level where ray has constant height "est pour
* l'observateur comme s'il n'existait pas, c'est-à-dire comme si le sol
* ou la mer s'élevaient . . . ." (p. 262)
*
* He notes de Tessan's observations of "terres qui paraissaient bordées
* d'immenses falaises" (p. 263) in the estuary at Rio de Janeiro. And
* in discussing Woltmann's observations, he says: "souvent une strie
* d'air séparait l'image renversée des objets placés au-dessous; mais le
* plus souvent, l'image et l'objet se rencontraient et se pénétraient de
* telle sorte qu'il en résultait l'apparence d'une haute falaise avec des
* stries verticales." (p. 268) [translated from p. 430 of W., (1800).]
*
* His numerical difficulties (bottom of p. 272): ". . . j'ai été arrêté
* par la difficulté de cette analyse, et surtout par la complication
* des calculs numériques."
*
* He also emphasizes the parallels between inferior and superior mirages,
* and deals with the paradox of the missing 3rd image in inferior mirages:
* "le sol interceptera les trajectoires qui la forment et fera disparaître
* l'image directe secondaire qui devrait cette fois se montrer en dessous
* de l'image renversée." (p. 274)
* "Cette non-observation de la troisième image, dans le cas du mirage
* ordinaire, ne forme donc point une objection sérieuse contre la
* théorie que nous venons d'exposer." (p. 275) Yet Wollaston has seen
* it in the lab (p. 276).
*
* ADVICE to observers: ". . . il est très-utile d'être muni d'une longue
* vue, ou à son défaut, d'une lorgnette de spectacle groissant au moins
* deux à trois fois, et que certains détails échapperaient à l'oeil
* nu qui pourront être facilement saisis par une lunette . . . ." (p. 280)
*
* The first 3 volumes of this Annuaire were bound together, with a common
* table of contents. This 4th volume is separate, with its own Introduction
* that mentions Bravais's "Note" on p. VIII. The formation of the new
* Société Météorologique is reported on p. XIII. Bravais is one of the 5
* signers of the Letter announcing this event.
*
*      As usual, the Google Books scan is half useless because the plates are
* only shown folded up, and so mostly invisible.
*      Gallica tries to show the plates; but the lines are too fine for the
* scanner they used, and so again are nearly useless.
*      Note the Erratum on the last page, correcting the error on p. 256.
* No date is assigned to the manuscript; but as it comes toward the end of
* the collections of papers in this volume, I assume it was submitted
* late in 1852.


A. Bravais
“Notice sur le mirage,”
Annuaire de la Société Météorologique de France pour 1853, Vol. 1, 55–59 (1857).

* Bravais's follow-up comments on his "Notice" (above)
* He begins by explaining his strategy in dealing with the mirage problem.
* Notice that he seems to prefer his "direct/inverse" terminology to the
* "inferior/superior" alternative that won out.
*      After briefly summarizing his first mirage "Note", he gets into the
* horizontal-ray problem on p.56:
*      "Jusqu‘ici on a fait jouer au phénomène de la réflexion
* totale des objets un grand rôle dans la théorie du mirage. Le
* redressement des trajectoires lumineuses qui, après avoir été
* plongeantes vers le sol, deviennent horizontales pendant une courte
* portion de leur trajet, et vont ensuite en s‘éloignant du sol,
* paraissait à plusieurs physiciens ne pouvoir s’expliquer que par
* un phénomène de réflexion totale. Je montrerai que les conditions
* nécessaires pour produire cette réflexion ne peuvent exister, et que
* le mirage est un simple phénomène de réfraction. M. Biot a fait
* voir que le fait du redressement s‘expliquait très—bien, dans le
* système de l‘émission. On verra qu‘on l‘explique avec la même
* facilité dans le système des ondes lumineuses, en adoptant les idées
* de Fresnel sur la vitesse de la lumière dans les différents milieux.
* 0n arrive alors à cette conséquence remarquable. que lorsqu‘un rayon
* de lumière traverse un système de couches planes et parallèles, et,
* par exemple, horizontales, dont la densité varie suivant la normale
* commune aux couches, la courbure de la trajectoire est partout égale au
* quotient de la variation du logarithme de l‘indice de réfraction, par
* la variation correspondante dans la hauteur de la couche considérée. De
* là se déduisent facilement les équations qui peuvent ensuite servir
* à expliquer les circonstances du problème."
*
*      This is in the section called "Bulletin des Séances" -- the
* reports of the meetings. The date is 8 Mars 1853; Bravais presided.
* The report of this meeting begins on p. 34 and ends on p. 64.
*      The volume is in two sections, separately paginated.  The part with
* the meeting reports ends on p. 241; the Table of Contents is pp.239-241.


J. Abbott
“On the mirage of India,”
J. Asiatic Soc. of Bengal 23, No. 2, 163–169 (1854).

* Mostly superior mirages, with DRAWINGS; Fata Morgana mentioned
*      "Few have traversed the plains of central India without being struck
* by the appearance of distant cliffs --- sometimes also of towns and
* forests, seen shortly after the rising of the sun, but which they have
* vainly looked for later in the day. I first observed this phenomenon in
* October 1829, when marching with my company from Kurnaul to Mhow in Malwa.
* Several times on reaching camp, I found it pitched in a plain, walled
* apparently to westward by lofty (See Pl. VI.) cliffs which had an inviting
* aspect. Several times I promised myself that in the afternoon I would
* pay those cliffs a visit. But, whenever I would accomplish this design,
* I found that the cliffs had entirely disappeared, and I questioned whether
* I had not been suffering some illusion of the eye or mind: for I was not
* then aware that Mirage is known in India. A residence in Malwa, where
* it is common, made me familiar with some of its phases. . . ." (pp.163-4)
*      Major Abbott understands the appearances well, but not the physics
* behind them. He continues:
*      "The Mirage most commonly observed in India is the effect produced upon
* distant objects, by means of a mirror, suspended with its surface
* downwards at the distance of from 60 to 230 feet from the earth. . . .
* This mirror is a stratum of dense but transparent and scarcely visible
* vapor, evolved from the dewey earth by the action of the sun's rays,
* generally about an hour or two hours after sunrise. The refractive power
* of this vapor being greater than that of the atmosphere, acts precisely
* as would a mirror of glass . . . ."
*      So his "cliffs" are the striated zone of the Fata Morgana; and his
* timing is that of Angelucci's observation from Reggio. He fails to
* understand the atmospheric physics, either optically or dynamically.
*      "This reflecting canopy exhibits the images of distant objects alone,
* because its substance is not sufficiently dense to repel those rays
* of light which fall upon it at any sensible angle of incidence. It is
* only when the angle of incidence is extremely small, that the ray will
* rebound from the surface of the vapor. It follows that supposing the
* strength of the illumination sufficient, the image will be distinct in
* proportion to the distance of the object." (So, unlike Monge, he does not
* think this is total reflection.)
*      He does give us some further information: "The ordinary Mirage of India
* occurs at distances of from three to eight miles. But . . . the effect may
* be produced at distances so remote, as that the substance is completely
* hidden in the convexity of the earth, and only the reflected image is
* seen suspended in the air. Of such an effect the Fata Morgana are an
* instance. And the pictures of coming vessels, as seen from the Isle of
* France, are another."
*      "In India, the most general appearance is that of a long range of
* cliffs standing to westward of the spectator. . . . Trees are the objects
* most commonly pictured by the Mirage. . . . But sometimes the monotonous
* aspect of the cliff is diversified and enlivened by the presence of a
* white town or of moving objects. Every stump of a tree becomes a palm or
* a column. Every little bush becomes a tall mass of foliage." (p. 165)
*      "With respect to the Isle of France, the vapor hanging over the sea is
* probably more transparent and of higher elevation than that which
* overhangs the land. . . . the sails of a vessel brightly illuminated by the
* sun, might be seen at the distance of a hundred or more miles. . . . the
* reflecting canopy is not a perfect plane, but is a mirror slightly
* concave answering to the convexity of the earth. The image therefore
* would probably be magnified in the concave mirror . . . ." (p. 166)
*      "The effect of mirage is greatly enhanced by the use of a telescope
* which . . . greatly increases the beauty of the exhibition." (p. 167)
* He then briefly describes seeing "another variety" of mirage, "in which
* the reflecting surface lies below the object and the spectator's eye.
* . . . The effect was precisely that produced by water upon objects standing
* beyond it, excepting that the strong undules of the vapour [sic] did not
* much disturb the accuracy of the reflection." (p. 167; cf. Büsch, 1800)
* [So he saw inferior mirages more rarely than superior mirages! And on
* the next page, he says he had not been able to study the mirage of the
* desert, which "is commonest at night in India."]
*      "I have also observed upon the Nurbudda and other large rivers that,
* whereas the nearer current is too rapid and turbid to reflect the rocks
* upon its banks, the more distant current, equally rapid and equally
* turbid, presents a perfect reflection of the banks without any waving of
* outline. This may be attributable to the transparent vapour, ever hanging
* over streams, acting as a mirror to reflect surrounding objects." (But
* then he allows that it might be due to the combined reflections from wave
* crests -- cf. Budde (1885) and Venturi (1889).)
* EARLIEST WAVE-CREST THEORY?
*      On p. 169, he says he has "referred to Brewster's treatise on mirage,"
* and thinks that Brewster's attribution of superior mirages to "a denser
* stratum of atmosphere" is "a mistake." "It is undoubtedly a stratum
* of vapour which forms the mirror". So he thinks his own crank theory
* explains why "the phenomenon is only or chiefly visible from the 1st to
* the 2nd or 3rd hour after sunrise and when the nights are rather chilly
* and the skies clear."
*      So his observations are accurate and useful, but his theory is nonsense.
* Major James Abbott


Parès
“Note sur le mirage des côtes du département de l'Hérault,”
Mem. Acad. Sci. Lett. Montpellier 3, 1–11 (1855).

* Long verbal descriptions of inferior mirages; no drawings
* Remarks on effects of height of eye, etc.
* From 37 m height, "l'image inférieure était moindre de moitié."


Parès
“Sur le mirage,”
Annuaire de la Société Météorologique de France 3, 247–252 (1855).

* Possible FATA MORGANA with SUPERIOR MIRAGES with a fine fold-out plate.
* A very detailed account of observations from 37 m with 40x telescope.
* DIP VARIATIONS of 4' reported.
* "Abnormal" refraction is in fact normal:
* "Ces divers effets, je les ai observés si fréquemment, qu'on pourrait
* dire que c'est l'état normal de la contrée."
* A reasonable interpretation of "FOG":
* "Ce nuage est venu du côté de la haute mer. Sa largeur est faible, sa
* teinte et sa consistance sont celles d'un nimbus. It est probablement
* l'image du sol vu de profil." (p.248)
* "Il s'annonce par une vapeur générale qui couvre le ciel à l'horizon,
* sur une hauteur d'environ 3'." (p.251)
* A "BREATHING" MIRAGE:
* ". . . montant . . . et . . . redescendant renversées : one dirait qu'il les
* aspire à son passage."
* ". . . it n'eût ondulé, au point qu'il semblait danser , selon
* l'heureuse expression de M. Humboldt."
* At one point the inverted image disappeared, leaving 2 erect ones.
* (cited by Mascart)


(E.) Bigourdan
“Du mirage à Paris,”
C. R. Acad. Sci. 41, 541–542 (1855).

* EARLY MURAL MIRAGE
* "Le soubassement sud-ouest de la Bourse de Paris, que pour abréger
* j'appellerai le mur méridional, est formé d’un mur vertical en pierre
* de taille, parfaitement construit, et sans aucune partie saillante dans
* une étendue d’environ 78 mètres. Lorsque, entre midi et 3 ou 4 heures,
* ce mur est frappé parles rayons solaires, il présente le phénomène
* du mirage avec une assez grande intensité. . . .
*      "Le mirage se manifeste aussi très-bien sur les murs des
* fortifications de Paris, surtout du côté du sud. . . . si l’on observe
* les images réfléchies avec une lunette, on peut voir jusqu'à des arbres
* entiers avec leurs branches et leurs feuilles. Si le prolongement de
* la muraille rencontre une route fréquentée, on distingue très-bien
* à la lunette les images réfléchies des passants, des chevaux et
* des voitures, lorsqu'ils se présentent près du prolongement du mur.
* A un degré plus ou moins intense, ces phénomènes ont lieu tous les
* jours, ou du moins toutes les fois que le soleil éclaire les murs des
* fortifications, depuis deux ou trois heures.
*      "Au reste, comme il résulte des faits consignés dans ce Mémoire,
* le mirage se manifeste à Paris, dans beaucoup d’endroits, d’une
* manière permanente, l’hiver et l'été, la nuit et le jour. Lorsque le
* soleil brille avec un certain éclat, on peut l'observer très-facilement
* sur toutes les surfaces planes d’une certaine étendue exposées au
* soleil, sur les parapets des quais, sur les trottoirs, sur les marches
* des églises, etc.; mais c'est à la Bourse, je le répète, que le
* mirage se développe plus énergiquement et plus régulièrement que
* partout ailleurs."
*       This is NOT the well-known astronomer with the same last name.
* The initial "E" is listed in the volume's author index.


H. Emsmann
“Luftspiegelung an der Sonne; beobachtet von Prof. H. Emsmann,”
Pogg. Ann. Phys. Chem. , series 2, 98, 642–643 (1856).

* SUNSET MIRAGE
* "Auf einmal bemerkten wir, dass unsere Schatten, die wir vor uns liegen
* hatten, da wir ostwärts gingen, doppelt waren und zwar in der Weise,
* dass über unseren Köpfen im Schatten noch ein zweiter Kopf deutlich
* und scharf hervortrat. Ich sah mich um nach der Sonne, und
* es zeigten sich im Westen . . . zwei klare Sonnen vertikal
* übereinander. Der vertikale Abstand beider Sonnen von einander betrug
* etwas über einen Sonnendurchmesser."


Prof. C. W. Baur
“Ueber Erdrundung und Luftspiegelung auf dem Bodensee,”
Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg 13, 79–86 (1857).

* A good account of mirages seen on the Bodensee ( = Lake Constance)
* with many DRAWINGS and a good description of the DISTANCE EFFECT:
* "Ein in der Richtung nach Constanz fahrender Dampfer bot die bequemste
* Gelegenheit dar, die Erscheinung nach allen Modifikationen, welche die
* zunehmende Entfernung mit sich brachte, zu verfolgen."
* (The description is a whole page long -- too long to quote here.)
* He also notices the slight vertical compression of the inferior image,
* and mentions (but does not cite) a mural mirage "nach den Comptes rendus
* der Pariser Akademie . . . neuerdings an der südlichen sonnenerwärmten
* Aussenwand des Börsengebäudes in Paris . . . ."
* [This seems to refer to Bigourdan's report of 1855.]
*
* There is a good concluding EXPLANATION of the FANTASTIC SCENES often
* reported: "Wie ist es aber möglich, dass die Luftspiegelung Gegenstände
* darbietet, welche in der Wirklichkeit gar nicht vorhanden sind, Gebäude
* mit Kuppeln, Balkonen, Säulen, Palmenhaine, wo der enttäuschte Reisende
* nichts findet als Felsblöcke, Sandhügel und Gestrüpp? Bringen wir in
* Abzug, was auf Rechnung der Phantasie und der Vergrösserung durch die
* Fama beim Übergang der Beschreibung von Mund zu Mund, von Buch zu Buch
* kommen mag, so bleibt vielleicht folgende natürliche Auflösung des
* Zaubers. Ich sah hie und da eine rundliche Masse wie einen Baum,
* Steinhaufen oder dgl. mit ihren verkehrten Spiegelbild zu einem
* Doppelgebild zusammenfliessen, das an beiden Seiten den Anschein von
* senkrechten Wänden darbot. Hie und da zeigte sich am Seenufer ein
* steiler, senkrecht wie von Erdrissen durchstreifter Absturz, wo ich keinen
* solchen vermuthen konnte, und auch bei der nachfolgenden Betrachtung
* Nachmittags oder von einem höheren Standpunkte aus nur den schmalen Saum
* einer Kiesbank oder eines sonstigen unbewachsenen Bodens vorfand. Wie aus
* einem Felsblock dieser Art ein Gebäude, aus einem kurzen senkrechten
* Fleck eine Säule, aus Gestrüpp ein Wald werden kann, wenn der Wunsch und
* die Phantasie das ihrige dazuthun, mag einleuchten." (cf. Beauford, 1802)
*      This paper makes no sense until you know that the German "geogr. Meile"
* was 1/15 of a degree, or 4 nautical miles.
* This is the only place outside of America where I have seen ' used for
* feet and " used for inches!


Parès
“Deuxième note sur le mirage aux environs de Montpellier,”
Mém. Acad. Montpellier (Section des Sciences) 3, 493–504 (1855-57).

* A more direct account of the inferior and superior mirages than the
* following one. Good descriptions of FOG ("nuage").


Parès
“Deuxième note sur le mirage aux environs de Montpellier,”
Annuaire de la Société Météorologique de France 7, 125–132 (1859).

* A rather tedious account of inferior mirages seen at Montpellier
* FOG : "La mer la première se couvrait de la vapeur du mirage, vapeur
* blanchâtre qui le signalait toujours."
* TURBULENCE: ". . . un fort miroitement se prononçait dans le région du
* mirage, malgré le calme qui régnait dans toute la contrée; les images
* y flottaient, comme agitées par un vent violent . . . ."
* DEMAGNIFICATION: "Cette précision des images rendait encore un autre
* service: elle permettait de voir que l'image réfléchie était d'un tiers
* au moins plus petit que l'objet." (seen from 37 m height)
* (cited by Mascart)


P. A. Daguin
Traité élémentaire de physique théorique et expérimentale : avec les applications à la météorologie et aux arts industriels, Tome troisième
(Édouard Privat, Toulouse, 1860), pp. 368–378.

* Pierre-Adolphe Daguin's textbook
* A pretty thorough treatment, containing an early version of the
* "PALM-TREE" diagram -- complete with an 18th-Century French soldier
* as the observer (p. 372).      [Cf. A. Ganot (1853).]
*      This is the section on atmos. refr.
* The first volume appeared in 1855. A second edition came out in 1861;
* the third, in 1867; and the 4th, in 1878.
* Title page also lists Dezobry & E. Magdeleine, Paris, as publishers.


E. E. Kummer
“Über atmosphärische Strahlenbrechung,”
Monatsber. Kgl. Preuss. Akad. Wiss. Berlin 5, 405–420 (1860).

* KUMMER's paper on super-critical refraction in dense atmospheres:
* Multiple complete images of the whole sky and the whole surface of the
* planet, even for an outside observer.
*      Novel treatment of the problem from a mathematical point of view;
* Kummer has fun with PDE's. Note that he correctly describes the
* multiple horizons and the apparent horizon at the top of the duct,
* when the observer is inside the duct-producing inversion, as well as
* the distorted images:
* ". . . das erste Bild [der Sonne] welches . . . zu einer sehr schmalen
* Ellipse abgeplattet erscheinen müßte . . . ."
*      Available at last at
* http://bibliothek.bbaw.de/bibliothek-digital/digitalequellen/schriften#A9
*      The volume for 1860 was published in 1861.  Meeting date: 12. Juli
* [cf. Bouguer (1749), T. Young (1807) and J.de Graaff-Hunter (1913)]
*      See also the 1863 reprint and its English translation (below).


Verdet
“Mémoire sur la réfraction atmosphérique; par M. Kummer,”
Ann. Chim. Phys. , series 3, 61, 496–507 (1861).

* VERDET translates (?) Kummer's paper
* The section is headed "Mémoires sur la physique publiés a l'étranger.
* Extraits par M. Verdet." Verdet's presentation is somewhat more compact
* than Kummer's; it is not just a straight translation. In particular,
* note that Verdet defines the angle i as the local zenith distance of
* the ray, whereas Kummer uses the same symbol for its altitude (see the
* bottom of p. 498). Consequently, Verdet has sin i where Kummer has
* cos i . Similarly, Verdet's "I" is the complement of Kummer's.
*      There is a typo on p. 500, where Verdet says "I" when he means Kummer's
* small quantity ε. (He was thinking of the special value of i at the
* top of the duct, which he denotes by I a page or so later on.)
* (available from Gallica)


E. E. Kummer
“Über atmosphärische Strahlenbrechung,”
Journal für die reine und angewandte Mathematik 61, 263–275 (1863).

* An exact reprint of Kummer's original paper:
* (this is the version reprinted in Kummer's collected papers, edited by
* André Weil (Springer-Verlag, Berlin, 1975) pp.337ff.)
*      Mila Zinkova has discovered an English translation at
* http://www.neo-classical-physics.info/uploads/3/4/3/6/34363841/kummer_-_on_atmospheric_ray_refraction.pdf
* However, this translation is rather awkward, as the translator is not a
* physicist, and adopted peculiar terms instead of conventional terminology:
* thus we see "refraction exponent" instead of "refractive index"; "Kugel"
* is translated as "ball" rather than "sphere" or "globe"; "Luftspiegelung"
* is literally rendered as "air reflection" instead of "mirage"; and the
* niceties of German syntax sometimes become sheer nonsense in English.


E. B. Hunt
“Key West physical notes. 9. A water moonrise,”
American Journal of Science and Arts , series 2, 35, 395–396 (1863).

* Hunt's observation of an OMEGA MOONRISE in Key West
* "When becalmed in a beautiful evening between the Reef and the Key, the
* water being very tranquil, I saw the moon rise over the sea with some
* interesting appearances. The long reflection of the emergent disc on the
* water was well defined, and seemed to be a part of the moon itself. As
* the under semicircle of the disc began to rise above the water, there was
* an appearance of drawing in at the sides of the combined luminous figure.
* As this seeming contraction progressed, the outline showed a curved
* figure, like that made by water in raising a cohering disc from its
* surface. There was no cusp point between the disc and the
* disc-reflection, but a seemingly distinct curve, concave outwards. As
* the disc rose above the water, this curve opened, and a broad connecting
* column seemed to bind the disc and its reflection, just like a coherent
* water column between the lifted disc and the level water surface.
* Instantly this seeming column parted as if broken, when the moon was seen
* to be distinctly above the water by about a fourth of its diameter, as
* nearly as I could estimate. The sudden shock of rupture appeared
* perfectly distinct, and the semblance of a material connection between the
* disc and reflection was perfect, both before and at the instant of visible
* separation. This observation has interest in its relation to the contact
* phenomena of eclipses." So he mis-interpreted what he saw, in spite of
* very accurately recording the details.
* This is a short numbered section at the end of the longer paper called
* "Key West Physical Notes". Am.J.Sci. was also known as "Silliman's
* Journal".


J. Penn
“Chapter VI. South Coast, Banks, Currents, and Winds of the Rio de la Plata,” in The South American Pilot. Part I.
(J.D.Potter, London, 1864), p. 228.

* A paragraph on the mirages in the Rio de la Plata
*      This is a derivative work "compiled by Staff Commander James Penn, R.N."
* and "Published by order of the Lords Commissioners of the Admiralty"
* But the Advertisement that follows the title page is signed by "G.H.R,"
* at the Hydrographic Office, Admiralty, London. It says "The Rio de la
* Plata is from the surveys of Admirals FitzRoy and Suliva, Commander
* Sidney, the French charts of 1833, and the Spanish of 1837, with also
* many additions and corrections by M. Mouchez."
*      The actual paragraph, headed "Mirage or Refraction", says:
* "In the Rio de la Plata there is a great deal of refraction, and
* more so in the tributary rivers. It often happens that objects above
* the visible horizon disappear; others under the horizon rise and are
* clearly seen at great distances. At Buenos Ayres the cerros de San
* Juan, under the horizon, on the Oriental coast, a distance of 36 miles,
* are sometimes seen. When this is the case the atmosphere is extremely
* clear, and it is a most certain sign of bad weather."
* [Here a footnote adds: "Colonia lighthouse, and vessels at anchor there,
* were plainly seen by the naked eye, at a distance of 30 miles. ---
* R. Cook, master, H.M.S. Stromboli , July 1862."]
*      "This extraordinary refraction not only takes place near the horizon
* but also many degrees above it. E. Mouchez, capitaine de frégate,
* gives an instance of a fog rising during the time he was taking
* observations, which hid the sun but slightly, leaving the limbs clearly
* visible. In calculating the hour angles and comparing the different
* series, it was found that the refraction had regularly increased with
* the fog, and that at the last observation, when the altitude was 31°,
* it was higher by 1'25" than that given by the tables."
*      Obviously this is an error in the dip, not the refraction.
* Available at Google Books.


C. T. Ramage
“Fata Morgana in the Japygian peninsula,”
Notes and Queries , series 3, 12, 126 (Aug. 17, 1867).

* C. T. Ramage's report of FATA MORGANA in Apulia
* "In travelling over the Japygian peninsula, . . . I heard the natives
* speak of what they called “Mutate,” and on questioning them as to
* what they meant, I found that this was only another name for what is
* known as the “Fata Morgana.” At Nardo and Galateo, and more
* particularly at Manduria, they assured me that at dawn, when the
* atmosphere is perfectly calm, or when a “scirocco” is just beginning
* to blow, the appearances at times are very remarkable, exhibiting,
* if we can believe them, beautiful representations of castles, plains
* with cattle and flocks, men on horseback, and, what must be striking,
* the edges of the figures are often fringed with the prismatic colours."
*      The mention of DISPERSION in mirages is unusual; cf. Minasi.  But
* as the enumeration of details is close to Minasi's, I wonder if this
* may all be taken from his account. Ramage cites Antonio de Ferrariis
* Galatei De Situ Japygiae (1727). He then adds:
*      "I have observed in another part of Italy some approach to the
* “mirage” which is here described. At early dawn, on my way through
* the Caudine Forks towards Benevento, thick mists rested on the lower
* valleys; as the sun rose and the mist began to be dissipated, the villages
* seemed to be raised by the refracted light into the heavens." This
* may be an observation of the concave appearance of the surface.
*      Cited by Talman (1912).


J. Parnell
“On a mirage in the English Channel,”
Phil. Mag. , series 4, 37, No. 250, 400–401 (1869).

* John Parnell's MULTIPLE-IMAGE MIRAGES at Folkestone, 13 April (1869)
* FOG: "During the morning, and up to 2 o'clock P.M., a dense fog had hung
* over the sea; but apparently it was not very deep, as the sun's rays
* penetrated it pretty freely. At the hour above mentioned the fog opened
* towards the S.E., disclosing the cliffs on the French coast; and in the
* course of a few minutes the fog had disappeared, leaving the atmosphere in
* a state of unusual transparency. The French cliffs were apparently so
* lofty and with every indentation so clearly visible, that one might easily
* have imagined that they were but ten miles distant."
*      CONCAVE SURFACE: "The French coast could be seen from near Calais
* towards the E. to far away and many miles beyond Boulogne towards the
* S.W., the land in the latter direction being ordinarily invisible, as it
* is situated below the horizon. Immediately under the erect image of the
* coast was an inverted one, of about double the height of the former.
* The lighthouse at Cape Gris Nez gave five images in a vertical line: --
* the lowest erect but somewhat magnified; above that and separated from
* it a pair of images of the centre and highest portion of the building
* only, one erect and the other inverted; and over these another pair, the
* inverted image being like the former one, but the erect image showing the
* whole building."
* These are often supposed to be the first observations of more than 3
* images, though Kelly saw 5. However, Parnell reports seeing both 7 and
* 9 : ". . . some fishing-luggers were observed hull down, so that the
* position of the horizon could be ascertained . . . but over these were pairs
* of images of vessels which ordinarily would have been invisible. In some
* instances three and even four pairs could be observed placed in a vertical
* line, the lower image in each pair being inverted. With the exception of
* the uppermost pair, the images seemed to represent the maintopgallant
* sail only, and that considerably elongated; but the highest erect image
* showed the mizzen- and the fore masts and the jib, but in no instance
* could the hulls be seen. In all cases the inverted images were of about
* twice the height of the erect. Soon after 3 o'clock vessels between the
* observer and the horizon began to be affected. The Varne light-ship,
* which is about 8 1/2 miles from the English coast, had her mast-flagstaff
* and stanchions elongated to some three times their proper length: this
* effect lasted for about ten minutes, when they shrank to less than half
* their usual size, and the hull began to rise till it was nearly as high as
* it was long, and formed a most conspicuous object even to the naked eye.
* I then looked towards Dover: the pier seemed completely disorganized;
* it appeared to be divided in half longitudinally, with the sea in the
* midst, and the stone coping moved as if huge waves were agitating it. A
* steam-boat entering Dover harbour was shrunk to less than half her proper
* vertical dimensions, but elongated horizontally. Captain Paull, of the
* S.E.R. steam-boat 'Napoleon III.,' crossed the Channel between the hours
* of 2 and 4; and he told me that he saw Beachy Head during the passage, a
* circumstance which had never previously occurred during the many years
* that he has been on the Folkestone and Boulogne route."
*
* ". . . wind S.W., very light at 2 o'clock and dropping to a calm . . . ."
* "The place of observation was about 30 feet above high-water mark."
* Observations made "through a small telescope with a 25-power".
*
* Cited by Garbasso (1907). Cf. the similar report of Latham (1798).
* Available at Google Books


Janssen
“Extraits des séances de la Société Météorologique: Séance du 14 juin 1870; Communications,”
Nouvelles Météorologiques 3, 197 (1870).

* JANSSEN's first mirage report, followed by Silbermann's comment
* Janssen calls it "mirage inverse qu'il a eu occasion d'observer sur
* la mer Rouge, au moment du soleil levant. Ce phénomène est dû à
* l'influence des côtes élevées qui bordent la mer. Il résulte de
* cette situation qu'au moment où se produit le phénomène observé, la
* température maximum se trouve à une assez grande hauteur au-dessus des
* eaux ; c'est seulement à partir de ce niveau qu'elle décroît
* lorsqu'on s'élève. Ce mode de distribution des températures de l'air
* est très-différent de celui qui a lieu dans une plaine unie ; il
* explique nettement et dans tous ses détails la production du mirage
* inverse au lieu du mirage direct."
* Evidently, this is a superior mirage; unfortunately, no detail is given.
* (For more of his Red-Sea sunset observations, see his 1874 paper.)
* Août 1870, No. 8


Silbermann
“Extraits des séances de la Société Météorologique: Séance du 14 juin 1870; Communications,”
Nouvelles Météorologiques 3, 197 (1870).

* Silbermann's comment on Janssen's mirage report
* (This is the dog-like-a-fish report.)
* "M. Silbermann . . . signale certains phénomènes curieux que l'on peut
* observer à Paris même, dans tous les points où les couches d'air
* voisines du sol peuvent être échauffées exceptionnellement sur de
* grandes étendues. Ce cas se présente assez souvent en été sur la
* place de la Concorde pour un observateur qui place ses yeux tout près
* du sol."
* Then follows a direct quote from Silbermann:
*      «Si un chien passe sur le trottoir à une centaine de mètres, ses
* pattes plongeant au-dessous de la couche d'air qui produit le mirage,
* les parties supérieurs de l'animal sont réfléchies en dessous de
* cette couche. Elles offrent alors l'aspect d'une espèce de poisson
* fantastique qui semble nager à la surface du sol.»
* Août 1870, No. 8


C. Flammarion
in The Atmosphere , James Glaisher, ed.
(Harper Brothers, New York, 1873), pp. 149–150.

* FLAMMARION quotes DIODORUS SICULUS (but gives no detailed reference)
* "An extraordinary phenomenon occurs in Africa at certain periods,
* especially in calm weather; the air becomes filled with images of all
* sorts of animals, some motionless, others floating in the air; now they
* seem running away, now pursuing; they are all of enormous proportions, and
* this spectacle fills with terror and awe those who are not accustomed to
* it. . . . Strangers not used to this extraordinary phenomenon are seized
* with fear; but the inhabitants, who are in the habit of seeing it, take no
* particular notice of it." (p.149)
* "Certain physical philosophers attempt to explain the true causes of
* this phenomenon, which seems extraordinary and fabulous. They say that
* there is no wind, or scarcely any, in this country. The masses of
* condensed air produce in Libya what the clouds sometimes produce with us
* on rainy days, viz., images of all shapes rising on every side in the
* air."
* On the next page, he drops a tantalizing hint:
* "This same phenomenon (of which Quintus Curtius has also spoken) has
* long been remarked by the Arabs, and it is often discussed in the
* treatises of Oriental writers."
* Flammarion has found Büsch's work, but not Gruber's; so he thinks
* Monge was the first to explain it. [Thus, the source of that error.]


J. D. Everett
“On mirage,”
Nature 11, 49–52, 69–71 (1874).

* Joseph David Everett's review article in Nature
*      This appears to be an exact reprint of his Belfast lecture in the
* "MIRAGE THEORY" file.
* "Another class of appearances are known (especially among nautical men)
* under the name of looming . Distant objects are said to loom when they
* appear abnormally elevated above their true positions. This abnormal
* elevation not unfrequently brings into view objects which in ordinary
* circumstances are beyond the horizon. It is also frequently accompanied
* by an appearance of abnormal proximity (though this may perhaps be rather
* a subjective inference from the unusual elevation and clear visibility
* of the objects than a separate optical characteristic), and it is further
* accompanied in many, though not in all cases, by a vertical magnification,
* the heights of objects being many times magnified in comparison with
* their horizontal breadths, so as to produce an appearance resembling
* spires, pinnacles, columns, or basaltic cliffs."
*      "In rare instances, two or even three of these images are seen one
* above another, vertically over the real object; but these multiple images
* are usually too small to be seen without the aid of a telescope -- the
* objects whose images they are being so distant as to appear mere specks
* to the naked eye." (p. 49)
*      He then recommends Scoresby's accounts in his "Greenland" and
* "Arctic Regions"; and quotes from Latham's (1798) account of looming
* seen at Hastings.
*      "The circumstance which it is most important to know . . .  in order
* to predict the degree of curvature, is the rate at which the temperature
* changes with height." (p. 50)
*      "An increase of temperature upwards, at the rate of about
* one-sixteenth of a degree Fahr. per foot, would make the curvature of
* rays equal to that of the earth, so that a ray might encircle the globe.
* . . . The visible effect is precisely the same as if the convexity of the
* surface of the earth were diminished. And not only will objects which
* were previously beyond the horizon be brought into view, but objects
* which were previously visible near the horizon will become plainer,
* inasmuch as the rays by which they are seen will not pass so close to
* the intervening surface as before, but will traverse a higher portion
* of the air, which is less liable to be obscured by impurities." (p. 51)
*      He then considers a parabolic temperature profile, so that "A pencil
* of rays diverging . . . from a point . . . will thus converge accurately
* to another point. . . . Such a pair of points may be called principal
* conjugate foci." (p. 51)
*      ALTERNATION of erect/inverted images:
*      "As every point on the surface of an object will thus have its
* conjugates, we shall have a succession of images of the object. The first
* image will be upside down, the second erect, and so on alternately.
* They will be what are technically called `real' images . . . ." (p. 52)
* He ends this part by pointing out the astigmatism of the images.
*      On p. 69, he quotes (in translation) from Monge, and adds:
*      "The only objection which I think can be taken to this explanation
* of Monge, is that it seems to imply not a curvature, but an angle,
* in the course of the rays, just as in the case of what is called
* total internal reflection at the bounding surface of a piece of glass
* when the angle of incidence exceeds the critical angle.
*      "Now, the formation of an angle (even a very obtuse angle) in a ray
* would require a perfectly sharp transition from one degree of density to
* another, instead of the gradual transitions which are more in accordance
* with our knowledge of the properties of air."
*      "As to the propriety of applying the name reflection  to an action
* such as that . . . , it is perhaps just as proper as the application of
* the name refraction to the bending of rays which takes place in the
* atmosphere . . . ." (pp. 69-70)
*      On p. 71, he repeats Wollaston's experiment; but "a much finer
* effect is obtained in the arrangement . . . in which three liquids are
* employed, the middle one having the highest index of refraction, while
* its specific gravity is intermediate between those of the other two.
* The three liquids are -- (1) A strong solution of alum at the bottom;
* (2) pure water at the top; (3) Scotch whiskey mixed with enough sugar
* to make its specific gravity intermediate between those of the other
* two liquids. It is introduced last by means of a pipette."
*      "The arrangement of three liquids just described, which was suggested
* to me by Prof. Clerk-Maxwell, is extremely effective, but requires much
* delicacy in its preparation to ensure success."
*      "With the two-liquid arrangement I have obtained three spectra,
* the middle one inverted, by employing as object a horizontal slit in the
* shutter of a dark room; and very brilliant colour effects were obtained
* by bringing the eye to the conjugate focus of the slit."
*
* "a Paper read by Prof. J. D. Everett, M.A., D.C.L., before the
* Belfast Natural History and Philosophical Society"
* In the Nov. 19 and 26 issues.
* Cited by Humphreys (1919, et seq.) and Wood (1899).


J. Janssen
“On mirage at sea,”
Brit. Assoc. Adv. Sci., Reports of Sections , 26 (1875).

* The English version of Janssen's "mirage at sea" note
* As it is very short, I quote it completely here:
* "Many facts relating to the phenomena of mirages at sea are already
* known; but the author has paid great attention to these appearances in
* all his voyages since 1868, and has made some remarkable observations on
* mirage, especially at sunrise and sunset. He has established: -- 1.
* That the mirage is nearly constant at the surface of the sea. 2. That
* the appearances can be explained by assuming the existence of a plane of
* total reflection, situated at a certain height above the sea. 3. That
* the phenomena are due to the thermic and hygrometric action of the sea
* upon the neighbouring atmospheric strata. 4. That there exist at sea
* direct, inverse, lateral, and other mirages. 5. That these phenomena
* have a very general influence upon the apparent height of the
* sea-horizon, which is sometimes lowered, sometimes raised.
*      "This variation of the apparent horizon is very important to take
* into account, if we consider the use made of the horizon in nautical
* astronomy."
*
* Note the considerable differences between this and the French version.
* Here we have "a certain height" instead of a variable distance of the
* reflecting layer above the sea; here we have both thermal and
* hygrometric effects, there just thermal; here we have lateral mirage as
* well as direct and inverse. And here, the 1868 trip is made explicit.
*
* As this was given at the Bristol meeting in August, 1875, it seems to
* pre-date the French abstract -- which may explain the disappearance of
* "lateral mirage" in the latter (below).
* [Thanks to Madame Françoise Launay for information about the date.]


Janssen
“Du mirage en mer,”
Séances de la Société Française de Physique , 118 (1875).

* Jules Janssen's French summary of mirages at sea
* "D'après mes observations, qui embrassent plusieurs années déjà,
* le mirage en mer est très-fréquent, même dans les mers
* septentrionales. Dans le golfe de Siam et dans le mer Rouge
* [-- remember he observed the 1868 eclipse in India --], j'ai observé
* des cas très-remarquables de mirage direct et inverse . Les
* apparences observées, soit sur le Soleil levant et couchant [-- so no
* wonder Fisher was interested in this work! --], soit sur les objets
* situés à l'horizon, conduisent à admettre un plan de réflexion
* totale situé à une distance variable de la mer. La cause de ces
* effets de mirage et de réfractions anomales réside dans l'action
* thermique de la mer sur les couches atmosphériques voisines. Une des
* conséquences les plus importantes de ces études, c'est qu'elles
* conduisent à reconnaître que le niveau apparent de l'horizon de la mer
* est affecté d'une manière très-notable par ces effets optiques et
* qu'il y aura en tenir compte quand on prendra (pour des mesures
* soignées) la hauteur d'un astre par le moyen de l'horizon de la mer.
* Je construis un instrument pour donner la correction."
*
* It is almost inconceivable that Janssen had not also seen numerous
* green flashes on these trips, though he says nothing of them here. And
* it is said that Janssen was consulted by Jules Verne for technical
* information while Verne was writing "From the Earth to the Moon." Could
* Janssen be the source from which Verne learned about green flashes?
*
* I have no volume number for this.


J. Janssen
“Mission du Japon pour l'observation du passage de Vénus,”
Annuaire du Bureau des Longitudes pour l'an 1876, 572–588 (1876).

* very brief mention of Janssen's mirage-at-sea observations
* "En outre, . . . études sur le mirage en mer, études qui
* conduisent à l'explication des variations apparentes de la hauteur de
* l'horizon marin, et fourniront des bases plus sûres à l'Astronomie
* nautique." (p. 584)
* [followed by a detailed description of the Revolver photographique ,
* with detailed plates.]
*
* The Annuaire turns out to be a sort of French World Almanac ,
* rather than another Connaissance des Temps . There are tables
* of foreign exchange rates, conversions between decimeters and
* feet/inches/lines, densities and refractive indices of various
* materials, a list of the principal cities of the world, the areas
* and populations of the Arrondissements of France, etc., etc.
*
* Reprinted in Janssen's collected works, Tome I, pp.329-332; see p.332.


Prof. Prestel
“Meteorologische Bilder. VI. Die Luftspiegelung, die Kimmung und das Seegesicht,”
Leipziger Illustrirte Zeitung , Nr. 1826, 523–534 (29. Juni, 1878).

* Prof. PRESTEL's mirage review, with many ILLUSTRATIONS
* It includes his own observation of a superior mirage at Borkum.
* Fig. 9 shows superior mirages, and is captioned "Das Seegesicht".
* This is almost surely Michael August Friedrich Prestel (1809-1880),
* who was Prof. of Mathematics and Natural Science at the Gymnasium at
* Emden, and part-time instructor at the Trade- and Navigation School.
* He wrote numerous papers, primarily on meteorology and related
* matters, and many popular articles, according to Pogg.
* A note on the first page indicates that earlier installments were
* in Nr. 1760 and 1761, March, 1877.


P. G. Tait
“On mirage,”
Proc. Roy. Soc. Edinburgh 11, 354–361 (1882).

* abstract of the later Phil. Trans. paper, with comments by Everett
* O'C #136a


E. Sang
“A Critical Examination of two cases of unusual Atmospheric Refraction described by Professor Vince,”
Proc. Roy. Soc. Edinburgh 11, 581–594 (1882).

* vicious, nit-picking attack on Vince


P. G. Tait
“State of the atmosphere which produces the forms of mirage observed by Vince and by Scoresby,”
Nature 28, 84–88 (1883).

* USEFUL REVIEW of HISTORY, including BIOT's book, and WOLLASTON.
* TAIT explains that VINCE's drawings were only schematic;
* "Scoresby . . . has given numerous careful drawings of these most singular
* appearances. The explanatory text is also peculiarly full and clear,
* giving all that a careful observer could have been expected to record. It
* is otherwise with the descriptions and illustrations in Vince's paper . . . .
* In fact the latter are obviously not meant as drawings of what was seen;
* but as diagrams which exhibit merely the general features, . . . -- the
* details being filled in at the option of the engraver. That such was the
* view taken by Brewster, is obvious from the illustrations in his Optics
* . . . ."
* clearer account of his mirage theory than in the Trans.Roy.Soc.Edinburgh
* O'C #137


P. G. Tait
“On mirage,”
Trans. Roy. Soc. Edinburgh 30, 551–578 (1883).

* TAIT's full paper at last
* ". . . I do not think that Wollaston's square bottle with two
* inter-diffusing liquids presents a fair analogy." [p. 552]
* An implied DEFINITION: ". . . only one image: -- not, of course, in the
* true direction of the object: -- but erect, and therefore not properly
* coming under the designation of `mirage.'" [p. 559]
* He also notes that "although aqueous vapour diminishes the refractive
* index of air, the practical effect is so minute at its utmost that we
* neglect it." [p. 564]
* He observes directly a phenomenon closely related to GREEN FLASHes, but
* fails to make the connection: "The middle image . . . coincides with the
* upper image when the eye, gradually moved downwards, reaches the line DB.
* When they meet, both become blue and then disappear by moving the eye
* farther down." [p. 571]
* "It is much to be regretted that Vince's description, like his drawings,
* is of the very roughest character." [p. 576]
*      Tait foresees the multiply-LAYERED STRUCTURE that is so common with
* inversions: ". . . when a trough, in which brine has been diffusing for
* some time into water, is suddenly and roughly stirred for a short period,
* it settles in a few minutes into a large number of strata of different
* densities. Something similar must hold in the case of air irregularly
* heated . . . . In the absence of wind such strata, once formed, would last
* for a long time, in consequence of the very small thermal conductivity of
* air." Then he cites Tissandier's observation of a mirage from a balloon,
* mentioned in Glaisher's Travels in the Air , p.297. "This, of course,
* proves the existence, at a great elevation, of a stratum in which there
* was a comparatively rapid diminution of refractive index with increasing
* height." [pp. 576-577] Cf. Gossard et al. (1985).
*      Finally, he points out an essential difference between inferior and
* superior mirages [which an astronomer would call SEEING]. After quoting
* Scoresby's observation of his father's ship beyond the horizon, where the
* miraged image "was so extremely well defined, that when examined with a
* telescope by Dollond, I could distinguish every sail . . . ", Tait adds,
* "It seems hard to reconcile the clearness of definition in this case with
* any other than a stable state of equilibrium of a transition stratum. The
* mirage of the desert, where the equilibrium is essentially unstable, is
* always exceedingly unsteady."
*      At the very end, he admits that most of his results were already found
* by Biot, in his mirage monograph.
* O'Connell #136b


J. Janssen
“Note sur l'observation du passage de la planète Vénus sur le Soleil,”
C. R. Acad. Sci. 96, 288–292 (1883).

* Jules JANSSEN claims to photograph mirages in Algeria
* Possibly EARLIEST PHOTOGRAPH of mirages? (But not published.)
* Mostly about the transit of Venus; but in the last paragraph:
* "Enfin j'ai pu faire quelques études sur le mirage, dont les
* manifestations sont presque permanentes en ces régions. J'ai pu même
* faire photographier plusieurs de ces manifestations, et constater que
* les causes de ces phénomènes, dans les cas les plus nombreux, sont
* tout autres que celles admises généralement."


E. Sang
“On the impossibility of inverted images in the air,”
Proc. Roy. Soc. Edinburgh 12, 129–136 (1884).

* EARLIEST demonstration of "Fraser's THEOREM" by Edward Sang; he thought
* Vince had seen "a sloop floating on a calm sea with its shadow in the
* water" and imagined the rest.
* FLAT EARTH:
* FIRST derivation of flat-Earth model: "No sun, moon, or star could have
* been seen at a lower altitude than 1° 22'. All light reaching the
* eye from a lower elevation must have come from some terrestrial
* object. . . ." [But see Biot's 1809 monograph for the magic angle!]
* "Inverted images, then, can only be seen when the air is in an unusual
* condition; there must be unusually light air above. Now, in these, as in
* all investigations on the subject, the air is assumed to be disposed in
* horizontal layers, each of uniform density. . . . The absolute need for
* smoothness of arrangement may easily be illustrated: -- the sun's light is
* certainly reflected from the surface of the sea; yet we do not see an
* image of the sun in the water; we see only a confused brightness."


E. Budde
“Ueber eine Eigenthümlichkeit des Seehorizontes,”
Zs. der Österreichischen Gesellschaft für Meteorologie 20, 354–361 (1885).

* Earliest crude OMEGA drawing after Joule's? (cf. Fig. 7)
* An unclassifiable paper, but put here because it deals with the inferior
* mirage at sea. Like Maltézos, Budde discovers the mirage on his own;
* but, unaccountably, he discounts it as mirage because ``wenn über dem
* Meer eine spiegelnde Luftschicht vorhanden wäre, die bis a b Fig. 2
* reichte, so würde der Beobachter unter 5m Höhe unter ihr stehen, könnte
* also, wie leicht zu sehen, nicht das Bild Fig. 2 etc. erhalten." (p.358)
* (I.e., he assumes here that the angular difference between the apparent
* horizon and the vanishing line corresponds to the linear height of the
* mirage reflection above the sea surface.) Nevertheless, he recognizes
* that the inverted image is a "reflection", so he attributes it to the
* sea surface -- much like Venturi's 1889 wave-crest model. This leads
* him to the (correct) conclusion that the apparent horizon is depressed
* and nearer than the geometric one; but he then fails to see that this
* invalidates his reason for rejecting the mirage as the cause.
* I could as well have filed it in the Colton or Ricco files, or under Dip,
* or even with the Floor papers . . . .
* (reprinted in Naturwiss. Rundschau 1, 13 (1886).)


Anonymous
“Curieux mirage,”
l'Astronomie 7, 432 (1888).

* An implausible "distant city" mirage
* ". . . un curieux mirage qui . . . a rendu visible toute la ville de
* Saint-Pétersbourg, qui est située à 180 kilometres de Merexull."


Anonymous
“Mirages?. . . ,”
l'Astronomie 7, 392–393 (1888).

* Possible Biblical mirages: "AEROMANCIE" and aerial INFANTRY
* In the Hungarian plains, a mirage in which
* ". . . on voyait distinctement de nombreuses divisions d'infanterie . . . ."
* "La tradition nous offre des exemples nombreux de ces visions que les
* anciens appelaient l'aéromancie; le spectacle en devient général
* quand le système nerveux des populations se trouve modifié à la suite
* d'événements de la nature de ceux qui y avaient préparé les Hongrois."
*      "On trouve au Livre VII, Chapitre XII, de la Guerre des juifs , par
* Josephe:
*      « Pendant tout le cours de cette guerre, des armées qui manoeuvraient
* et formaient des sièges apparurent dans l'air. »
*      "Au Livre II des Macchabées , Chapitre VII:
*      « Avant que Jérusalem fût pillée une seconde fois par Antiochus,
* tous les habitants de cette ville purent voir dans l'air, pendant
* quarante jours, des chevaliers richement vêtus et des cohortes armées
* de piques; on voyait leurs mouvements, celui de leurs boucliers et une
* grêle de traits lancés de part et d'autre. »"
* [These citations are nonsense. The first may be Book VI, Ch. V, sect. 3;
* there is no Ch. XII in Book VII. See Whiston's translation of
* Flavius Josephus. The second is certainly Ch. V, not Ch. VII. ]
*      After citing some more recent examples of aerial infantry seen during
* or just before wars, he says:
* "L'énumération de faits similaires pourrait fournir la matière de
* plusiers volumes. . . .
*      "Ajoutons qu'il y faut faire beaucoup la part de l'imagination.  Mais
* peut-être, à notre époque surtout, l'imagination n'est-elle pas seule
* en jeu. Le mirage (?) observé cet été in Hongrie est bien bizarre."
* Cf. the final remarks of William Beauford (1802).
* [ Presumably, this is Flammarion. ]


W. Larden
“Mirage in the South American Pampas,”
Nature 41, 69–71 (1889).

* DARK BANDING, or SKY? DOUBLE SUPERIOR MIRAGE
* "The land seen just above the lines (α) and (β) was paler than
* that seen just below these lines."


J. Macé de Lépinay and A. Perot
“Sur une reproduction artificielle du mirage et les franges d'interférences qui peuvent accompagner ce phénomène,”
C. R. 108, 1043–1046 (1889).

* Fringes shown experimentally in mirages -- cf. Raman's papers


C.-H. Martin
“Mirage de la Tour Eiffel,”
l'Astronomie 9, 41–42 (1890).

* The Eiffel tower reflection (cf. Tissandier's 1890 review)
* Letter from Charles-Henri Martin to Flammarion, referring to his book
* "l'Atmosphere". The engraving is evidently from the description, not
* from observation. Probably not a mirage. In the Feb.,1890, issue.


J. Janssen
“Note sur des travaux récents exécutées en Algérie,”
C. R. Acad. Sci. 110, 1047–1049 (1890).

* Janssen's mirage photography in Algeria (continued); cf. his 1883 note
* "Un autre objet intéressant a été l'obtention, par la Photographie,
* des images des phénomènes si varie's et si curieux du mirage dans les
* régions des grands chotts qui se trouvent entre le Souf et Biskra, le
* chott Melrir, Merouan, etc. La Photographie permettra de discuter, sur
* documents certains et mesurables, les conditions qui président à la
* production de ces singuliers phénomènes dont les apparences et les
* causes sont beaucoup plus multiples qu'on ne le croit."
* (Cf. his 1892 paper for more details.)
* This is reprinted in Janssen's collected works, Tome II, pp.187-188;
* but the initial page is given incorrectly there as 1067.
* It is the same expedition on which the "Janssen bands" were
* investigated.
*      Unfortunately, the photographs appear to have been lost; neither
* the Academy of Sciences nor the Institute has them today.


A. E. Brown
“Mirages,”
Nature 41, 225 (1890).

* "The mirage of the reflection of the sun in the sea was, when seen
* through a glass, especially beautiful. It resembled a glorious cataract
* of golden water." (cf. Pekka's photo!)


W. M. Davis
“Mirage on a wall,”
Amer. Met. J. 8, 525–526 (1892).

* W. M. Davis's Harvard mural mirage
* On a NNW-SSE brick wall about 3 pm, Feb.10
*      [This is evidently the same William Morris Davis whose paper on
* rainfall appears in the proceedings of the New England Meteorological
* Society on p. 493. He is given as "Prof. W. M. Davis" on p. 481.]
* ". . . the sunshine was strong enough by noon to melt the snow and ice on
* the streets."
* "On looking closely, I found that when my eye approached within about
* an inch of the plane of the wall, the further extension of the wall
* disappeared, and was replaced by a reflection of distant objects a little
* to the west of its line. . . .      The reflection repeated all the familiar
* forms seen over the surface of the sea, when cold winds blow from the
* land over its warmer waters. . . .      Effects of this kind must be common,
* for on the day in question, all the conditions were such as might easily
* occur again."
* Available at Google Books.
*      The volume spans 1891-1892.  This is No. 11, dated March, 1892.
* The journal was published in Ann Arbor, Mich.


J. Janssen
“Les observatoires du montagne. Un observatoire au Mont Blanc,”
Annuaire du Bureau des Longitudes pour l'année 1892, D.1–D.33 (1892).

* Janssen's mirages in some detail! A good OMEGA described
* The first (p. D.9) is a good description of a sunrise of Fisher's type A
* seen in the Gulf of Siam in 1874, en route to Japan for the Venus
* transit. There is no mention of a green flash: "Le lever a débuté par
* un point brillant, lequel, circonstance remarquable, se montrait non pas
* sur la ligne d'horizon de la mer, mais à quelques minutes d'arc
* au-dessus." Then comes the Omega stage: "Puis l'image solaire
* présente, à la hauteur où tout à l'heure le Soleil commençait à
* poindre, un étranglement qui va en ce rétrécissant de plus en plus,
* et l'image ronde ordinaire se dégage enfin.
*      "Mais cette image est toujours accompagnée au-dessous d'elle d'une
* portion de disque qui s'en sépare et s'enfonce de plus en plus dans la
* mer pour disparaître enfin, laissant le disque supérieur dans les
* conditions ordinaires." (But he thinks it is due more to water vapor
* than to temperature.)
*      This is evidently the observation Fisher (1921) tried to find, but
* without success.
*      The mirage photographed in Algeria is also described (p. D.10):
* "En regardant cette photographie, on dirait qu'on a sous les yeux la
* vue d'une plage de la Manche avec ses dunes, ses eaux basses et son
* horizon de mer. Quand j'étais en face du chott, l'illusion était si
* complète que, malgré ma connaissance de la véritable nature du
* phénomène, des doutes traversaient encore mon esprit. Il était alors
* 5h du soir, le Soleil allait se coucher; toute cette plage avait une
* belle couleur bleue et un petit tremblement, qui faisait comme
* frissonner ces eaux, ajoutait encore à l'illusion.
*      "Tout à coup, quand le Soleil eut disparu derrière l'horizon, la
* scène changea brusquement, et, à cette scène d'une belle plage
* maritime succéda celle d'une solitude glacée. Le tableau riant d'une
* rive méditerranéenne avait été subitement remplacé par celui d'un
* paysage d'hiver en Sibérie.
*      "J'ai analysé les causes de ce curieux phénomène, mais cette
* discussion serait déplacée ici . . . ."
* His contribution is Appendix D of this volume, which also contains a
* report by rear-admiral Mouchez on the progress of the Carte du Ciel.
*
* The passage of interest here appears on pp. 265-266 of Tome II of
* Janssen's collected works. It says there that parts of the paper were
* also reprinted in pp. 92-111 of Janssen's Lectures Académiques (1903)
* but this seems not to include the interesting mirage observations.


A. Perot Macé de Lépinay
“Contribution a l'étude du mirage,”
Ann. Chim. Phys. , series 6, 27, 94–138 (1892).

* Applications of mirage theory to study interdiffusion of liquids,
* and corresponding laboratory simulations of mirages


A. L. Colton
“A mirage in Washington,”
Amer. Met. J. 9, 239 (1892).

* COLTON's street mirage in D.C.
* "On June 25, at about 4 P.M. . . . "
* "I infer that the mirage may not infrequently be seen over pavements
* or other surfaces of sufficient heat-absorbing capacity."
*      Useless; but noted because of Colton's 1895 sunset observations.
* Available at Google Books.
* No.5, Sept. 1892; now published in Boston, Mass. -- see Editorial, p. 98


A. Delebecque
“Note sur les Fata Morgana,”
Arch. Sci. Phys. Nat. , series 3, 27, 358–360 (1892).

* DELEBECQUE's first Fata Morgana note
* Cited and partly quoted by Forel (1895), p. 557
* The BNF says the date is 15 Mars 1892; I have not seen it yet.
* According to Rev. Sci., this was reprinted by Ciel et Terre in 16 Sept. 1892.
* Their copy, titled "La « fata morgana », is on p. 478 of the 1892 volume.


O. Wiener
“Darstellung gekrümmter Lichtstrahlen und Verwerthung derselben zur Untersuchung von Diffusion und Wärmeleitung,”
Wied. Ann. Physik u. Chemie 49, 105–149 (1893).

* GOOD REVIEW of earlier mirage simulations and theory [FILED SEPARATELY]
* "Die Darstellung dieser Sachlage ist in keiner Weise neu,
* doch wohl wenig bekannt."


J. Macé de Lépinay
“Quelques remarques relatives a la théorie du mirage de Biot,”
J. Physique , series 3, 2, 320–327 (1893).

* Comments on Biot's theory


Ch.-Ed. Guillaume
“Les rayons lumineux curvilignes,”
BSAF 8, 226–227 (1894).

* EARLY mention of modeling the SETTING SUN
* Metrologist Charles-Edouard Guillaume was the inventor of Invar, and
* received the Nobel Prize in physics in 1920 for his work.
* He says Kummer first predicted a ray encircling a planet.
* [No mention of Bouguer, though.]
* "L'étude de la marche curviligne des rayons, fort intéressant en
* elle-même, devient très importante lorsqu'on l'applique aux phénomènes
* naturels. La reproduction des formes du soleil couchant offre un exemple
* d'une imitation de cette sorte. Nous pouvons, à volonté, imiter le
* phénomène normal que l'on observe chaque soir en plaine ou au bord de la
* mer, ou bien ces apparences exagérées, qui témoignent d'un équilibre
* particulier des couches d'air, ou même produire des déformations plus
* grandes que celles observées."
* This is the last volume of the old BSAF before it merged with
* l'Astronomie.


F. Koerber
“Atmosphärische Lichterscheinungen,”
Himmel und Erde 7, 127–140 (1894).

* A general introductory discussion of atmospheric optics, including
* rainbows, halos, scintillation, blue sky, refraction, (including mirages).
* The figure from Müller's "Kosmische Physik" was recently reproduced in
* *color* by Vollmer & Tammer (Appl.Opt.37,1557 (1998)).
* Note that volumes and years of H&E don't match up.


W. Upham
The Glacial Lake Agassiz (USGS Monograph 25)
(Government Printing Office, Washington, DC, 1895), pp. 21–22.

* Warren Upham's mirages on the Minnesota/North Dakota border
*      "In crossing the vast plain of the Red River Valley on clear days the
* higher land at its sides and the groves along its rivers are first seen
* in the distance as if their upper edges were raised a little above the
* horizon, with a very narrow strip of sky below. The first appearance
* of the tree tops thus somewhat resembles that of dense flocks of birds
* flying very low several miles away. By rising a few feet, as from the
* ground to a wagon, or by nearer approach, the outlines become clearly
* defined as a grove, with a mere line of sky beneath it. This mirage is
* more or less observable on the valley plain nearly every sunshiny day of
* the spring, summer, and autumn months, especially during the forenoon,
* when the lowest stratum of the air, touching the surface of the ground,
* becomes heated sooner than the strata above it.
*      "A more complex and astonishing effect of mirage is often seen
* from the somewhat higher land that forms the slopes on either side of
* the plain. There, in looking across the flat valley a half hour to two
* hours after sunrise of a hot day following a cool night, the groves and
* houses, villages and grain elevators, loom up to twice or thrice their
* true height, and places ordinarily hidden from sight by the earth's
* curvature are brought into view. Occasionally, too, these objects,
* as trees and houses, are seen double, being repeated in an inverted
* position close above their real places, from which they are separated
* by a very narrow, fog-like belt. In its most perfect development the
* mirage shows the true upper and topsy-turvy portion of the view quite
* as distinctly as the lower and true portion; and the two are separated,
* when seen from land about a hundred feet above the plain, by an apparent
* vertical distance of 75 or 100 feet for objects at a distance of 6
* or 8 miles, and 300 to 500 feet if the view is 15 to 20 miles away.
* Immediately above the inverted images there runs a level false horizon,
* which rises slightly as the view grows less distinct, until, as it fades
* and vanishes, the inverted groves, lone trees, church spires, elevators,
* and houses at last resemble rags and tatters hung along a taut line."
* So, here we have first a nice account of the HEIGHT and DISTANCE
* dependences of the inferior mirage; then a FOG report connected with
* the superior mirage.
* Quoted (but not cited) in Frazer (1929).


A. Delebecque
“Sur les réfractions extraordinaires observées au bord des lacs et connus sous le nom de Fata Morgana,”
C. R. 123, 387–389 (1896).

* More FATA MORGANA studies, following FOREL
* His telescopic observations indicate that the F.M. is not a simple
* vertical elongation, but a stack of direct and reversed images: "J'en ai
* compté jusqu'à cinq. Comme ces images sont, en général, très
* rapprochées; que parfois même elles empiètent l'une sur l'autre, il est
* très difficile de les séparer à l'œil nu, et elles donnent l'illusion
* d'un objet agrandi." However, there is useful seasonal information:
* "Je ne les ai observées sur le Léman que par des temps calmes, et
* lorsque la température de l'air est notablement plus chaude que celle
* du lac; mars, avril et mai sont les mois où elles sont les plus belles."
*      Reprinted, with a faked "mirage photograph," in "La Nature" 25:1 (1897).
* Cited by C.Abbe in the next item.


(editorial -- presumably written by Cleveland Abbe)
“Atmospheric refractions at the surface of water,”
Mon. Weather Rev. 24, 371–373 (1896).

* Good review article with some references
* Leans heavily on the papers of Charles Dufour and F.-A.Forel;
* follows the latter's classification, and discusses the Fata Morgana.
* He thinks everything is explained in Mascart's Traité d'Optique .
* [Cleveland Abbe edited MWR from 1872 to 1909; later his son, C.A.Jr.
* took over.]


C. Maltézos
“Sur le phénomène de suspension et de subdivision des iles dans le golfe de Phalère,”
Ann. Obs. Nat. Athènes 1, 223–225 (1896).

* A novice discovers mirages
* This seems to be the first of Constantin Maltézos's "tunnels" papers


A. M.
“The mirage [letter 41505],”
English Mechanic 68, 116 (1898).

* A disappearing city; Lord Rayleigh invoked in favor of "total reflection"
* quoted from the "Echo" on 9 Sept.
* "I believe that Lord Rayleigh some time since suggested total reflection
* as affording at least a partial solution of some of these phenomena, in
* preference, or, in addition, to the refraction and simple reflection of
* the older theory."
* No. 1747, Sept.16,1898


R. W. Wood
“Mirage on city pavements,”
Nature 58, 596 (1898).

* ROBERT W. WOOD's excellent EARLY MIRAGE PHOTOGRAPH in San Francisco
* This seems to be the FIRST PUBLISHED MIRAGE PHOTOGRAPH, preceding Alfred
* Wegener's 1907 photograph, published in 1911, by about a decade.
* "The refracting layer is probably only a thin skin of warm air, which
* adheres as it were to the surface of the flagstones, for the mirage is
* unaffected by the strong winds which frequently sweep the top of the
* hill." [cf. McNair, 1920.]
* Oct.20, 1898 issue


A. W. S.
[Query 94348] Photographing a mirage
English Mechanic 68, 244 (1898).

* E.M. 68 series started by Query 94348
* No. 1752, Oct.21, 1898


Glatton
[Reply to Query 94348] Photographing a mirage
English Mechanic 68, 375 (1898).

* Reply to Query 94348 -- EARLIEST MIRAGE PHOTOGRAPH CLAIMED
* ". . . I possess a photograph of a church spire in Tenby, halfway up which
* appears an inverted image of what was afterwards identified as the gunboat
* Gadfly , then being launched at Pembroke Dock, 12 miles distant. Though
* it was taken so long ago as May 5, 1879, it is possible that copies can
* still be procured if the photographer, Robert Symons, St. Julian-street,
* Tenby -- is still in business. The editor of the Photographic News , and
* chief of the photographic department at Woolwich, said: -- `Mr. Symons
* must be congratulated: he is the first to photograph that most romantic
* phenomenon, the mirage.'"
*      According to Eric Hutton, "Glatton" was the pen-name of Mr. Clement
* Stretton [ref. No. 3105 p327]
* No. 1758, Dec. 2, 1898


anonymous
“Useful and Scientific Notes: mirage,”
English Mechanic 68, 584 (1899).

* RESTRICTED HEIGHT of visibility; nice BEACH MIRAGE
* (Report of a talk by Major MacMahon to the Camera Club)
* "One very curious thing about mirage is that it depends very much upon
* the position of the eye: a few inches in the height of the eye may make
* all the difference. On one occasion on the plains of India he observed a
* mirage which was only evident when he was at a particular height; there
* was only a vertical space of two or three inches in which the effect could
* be seen, so that these phenomena may easily escape notice. A singular
* effect may sometimes be observed at a particular spot on the south coast,
* and very likely at other places, when the waves come in on to a very hot
* beach; if you place the eye about a foot from the ground and look parallel
* to the wave fronts you can see an image of the wave two or three feet
* above the real wave."
* No. 1767, Feb. 3, 1899


E. K. [Ernst Krause]
“Luftspiegelung auf den Strassen,”
Prometheus 10, 431–432 (1899).

* STREET and LATERAL (MURAL) MIRAGES
* Report of R. W. Wood's mirage photography on San Francisco streets
* (not cited, but obviously refers to the 1898 paper in Nature).
* Also, a reference to mural mirages with both direct and reversed images,
* which certainly predates Hillers's report!
* Nr. 495, 5.April


R. W. Wood
“Some experiments on artificial mirages and tornadoes,”
Phil. Mag. , series 5, 47, 349–353 (1899).

* R.W.WOOD's mirage demo essentially repeats Gruber's experiment
* Note that he admits Wiener's writeup (1893) is better
* Cites Everett's 1874 paper.
* [I forgot to copy Plate III but it is only moderately interesting.]


(anonymous)
“Mirage over Lake Michigan,”
Mon. Weather Rev. 28, 544 (1900).

* DARK STREAK
* Eastern shore seen from Chicago, Dec. 20, 1900: "The view was elevated
* above the horizon and was enveloped in a pale blue light. It formed
* the lower lining of a maze of darkness that hung over the lake shortly
* after noon and was visible for more than an hour.
* "There was a dark streak between it and the horizon."


C. E. Borchgrevink
First on the Antarctic Continent
(McGill-Queen's Univ.Press, Montreal, 1980), pp. 126–128.

* BORCHGREVINK's Antarctic mirages and Novaya Zemlya observation
*      "On May 15th we had the last greeting from the departing sun.
* The refraction of it appeared as a large red elliptical glowing
* body to the north-west, changing gradually into a cornered square. . . .
* The promising effect of that evening . . . lasted until the returning sun
* again made the peaks and crevasses shine on the 27th July.
*      "Both during the time the sun was low in its descent and when
* it rose again, a strong mirage effect was observed towards the west,
* showing images of icebergs far below our horizon, and Antarctic scenery
* only visible to us through this phenomenon. This strong mirage remained
* after the sun's return late in the summer, and the opening of the ice was
* prophesied to us in the mirage long before the ice-fields near Victoria
* Land broke.
*      "It was very interesting to see the picture of far-away broken
* ice-fields, with their dark channels and towering icebergs, in the
* north-western sky; and on several occasions towards the time when the
* vessel was expected back, members of my staff returned to the camp in
* enthusiasm, thinking to have discovered the masts of the Southern Cross
* in the mirage, so strongly did their hopes confirm the impression made
* by the wonderful creations in the air."
* (Nice to see the WISHFUL THINKING factor made explicit.)
* Mentioned but not cited by Frazer (1929).
* This is the reprint edition; the original was published by George
* Newnes, Ltd., London, 1901.


C. Maltézos
“Phénomènes de mirage dans le golfe du Phalère,”
Bull. Soc. Astron. Fr. (l'Astronomie) 15, 282–284 (1901).

* SUSPENSION of islands; "TUNNELS"
* "FOG": "Parfois, l'île paraît suspendue tout entière, une bande
* laiteuse, brillant, s'interposant entre elle et la surface de l'eau."
* The "tunnels" are the reflected images of dips in the miraged terrain.
* Some data are given on the HEIGHT effect (changes in 40 cm, 2 m).
* He seems a novice at the mirage game, but the observations are good
* and the SKETCHES are accurate.
* Here he quotes Aristotle and Theophrastus.
* cited in Maltézos's 1912 paper


V. E. Boccara
“La Fata Morgana,”
Mem. Soc. Spett. Ital. 31, 199–218 (1902).

* A useful review of the FATA MORGANA in the Strait of Messina!
* Boccara claims to have read everything published on the subject!
* There is a half-page footnote quoting Minasi's etymology of the term
* "Fata Morgana"; it seems far-fetched.
* Unfortunately, so does his explanation of the phenomenon; the paper is
* most valuable for his own observations, and the references.
* He confines his attention to the Strait of Messina (whose local
* geography, he thinks, is responsible); so Forel, etc. are ignored.
*      He dismisses Kircher's explanation, saying: "And with him are put
* together Giardina, [and a host of others], all of whom, not having seen
* the phenomenon, as they say explicitly or make clear by their arguments,
* can only be repetitive, both in the invented descriptions and in the
* puerile explanations." (p. 201)
*      But there are some serious errors: he believes the F.M. is not  a
* mirage, because "the images are erect". He accepts the idea of multiple
* images displaced sideways (i.e., "lateral mirages").
*       A copy of Willem Fortuyn's engraving for Minasi is Fig. 1 (p. 203)
* There is an extensive annotated bibliography at the end.
*      For a summary in English, see Nature 67, 393-394 (Feb.26, 1903).
*
* Available from Google Books (with OCR text, but a badly aliased version
* of Fortuyn's engraving), and from ADS (no text, but much better figure):
* http://adsabs.harvard.edu/abs/1902MmSSI..31..199B
*      See Talman (1912) for a good summary in English.


J. Fényi
“Ueber Luftspiegelungen in Ungarn,”
Met. Z. 19, 507–509 (1902).

* QUANTITATIVE MEASUREMENTS of inferior mirages, showing vertical stretching
* N.B.: Pernter was the publisher of Met.Z.!
* J Fenyi, S.J. (note accent over e: "Fényi")


A. Hofmann
“Eine optische Täuschung,”
Prometheus 13, 700–701 (1902).

* Despite the title, this is not an optical illusion, but a fine
* LATERAL MIRAGE at the surface of a hot smokestack.
* The author's attempt to explain differences between naked-eye and
* telescopic views led to his optical-illusion notion.
* [Cf. Nölke (1917) for the image-location problem.]


G. H. B.
“The Fata Morgana of the Straits of Messina,”
Nature 67, 393–394 (Feb. 26, 1903).

* A Fata Morgana review in Nature, prompted by Boccara's 1902 paper
* in Mem. Soc. Spett. 31, 10. Reproduces Boccara's drawings (see P&E).
*      Is "G.H.B." the "G.H.Baines" who wrote a GF note in 1910?
* Probably not. A more likely choice is George Hartley Bryan, FRS,
* who wrote many items for Nature around this time. Whoever he was,
* "G.H.B." reviewed some more Italian works on mirages in 1908.
* Number 1739


H. E. Wimperis
“A mirage at Putney,”
Nature 68, 368 (1903).

* Early modern observation of road mirage


V. E. Boccara
“La Fata Morgana,”
Bull. Soc. Belge d'Astronomie 8, 143–152, 347–353 (1903).

* FINE REVIEW article on FATA MORGANA in Strait of Messina
* This is a French translation of Boccara's original in Mem.Soc.Spett.
* There is a half-page footnote quoting Minasi's etymology of the term
* "Fata Morgana"; it seems far-fetched.
*      Boccara claims to have read everything  published on the subject!
* Plate VI, mentioned in the second part, appears in the first one.
*      However, some errors have crept into the translation, such as the
* statement in §7 that Capozzo made no additions to Saffiotti's letter.
* Both parts are available at ADS.


G. Costanzo
“La Fata Morgana: Memoria Prima,”
Memorie della Pontificia Accademia Romana dei Nuovi Lincei 21, 101–128 (1903).

* Another great REVIEW ARTICLE on Fata Morganas: GIOVANNI COSTANZO
* Cites everybody (Agrippa, Facellus, Carnevale, Politi, Reina, Kircher,
* Gaspari Schott, Minasi, Pindemonte, Houel, Ribaud, Saffiotti, Boccara).
* He skipped Giovene, and has de Ferrariis only in an addendum. There
* are extensive quotations from unpublished letters, and from newspapers.
*      Costanzo cites the Amsterdam reprint of Kircher's Ars Magna , quoting
* Angelucci's letter -- but with the "Salome" typo corrected -- and
* mentions the Roman editions of 1645 and 1647.
*      A table (p. 123) compares the various observations.
* The dateline at the end says "Napoli, marzo, 1903".


G. Costanzo
“La Fata Morgana: Memoria Prima,”
Atti della R. Accademia Peloritana 18, 1–35 (1904).

* Costanzo's revised version
* Here a few more observations are added to both the text and the table.
* The addendum "SULLE MUTATE DI TERRA D'OTRANTO" has been removed.
* The dateline at the end says "Napoli, Maggio, 1903".


C. Maltézos
“Phénomènes de mirage dans la mer et plaques de calme,”
Bull. Soc. Astron. Fr. (l'Astronomie) 17, 450–452 (1903).

* Maltézos discovers the oil slick???
* This starts out with a mirage report, and then refutes Lazzaro's
* criticisms that the mirages reported earlier were only optical illusions.
* Then he goes off on a tangent:
* "Tandis que la surface de la mer présentait une agitation due à une
* multitude d'ondulations différents, coexistant, la surface des plaques ne
* présentait qu'une seule espèce d'ondulations, de plus grande longeur
* d'onde."
* ". . . le phénomène est dû, pour les uns à des souillures de l'eau par
* diverses matières étrangères . . . ."


W. Krebs
“Atmosphärische Sprungflächen und Spiegelungserscheinungen,”
Das Weltall 4, 181–184 (1904).

* "BLACK LINE" (der schwarze Strich) discussed (cf. his distorted-sunrise
* paper in Met.Z. earlier in 1904; this issue is No.10, but dated Feb.15)
* Wilhelm Krebs argues that the horizontal black line seen in the mountain
* sky is due to reflections at an inversion layer, not an aerosol
* boundary. (cf. his distorted-sunrise paper in Met.Z. earlier in 1904;
* this issue is No.10, but dated Feb.15)
* He also argues that multiple features in the rising Sun could be due to
* WAVES on an inversion, thus prefiguring Fraser's 1975 suggestion;
* (cf. Garnier, 1899, for a less definite, but similar, suggestion).
* Citing von Wrangell's observation: "Bei Beginn der Morgendämmerung sah
* er am östlichen Horizont den schwarzen Strich in der scheinbaren Form
* einer grauen Wolkenbank von etwa 1° Höhe." (cf. FOG file)


P. Gast
“Ueber Luftspiegelungen im Simplon-Tunnel,”
Zs. f. Vermessungswesen 33, 241–271 (1904).

* Detailed study of mirages and refraction in tunnel


E. F. Bigelow
“A mirage,”
St. Nicholas 32, 1038 (1905).

* The importance of FIELD-GLASSES in a first-hand report
* In response to a boy's letter reporting "a ship upside down in the sky",
* the writer (editor?) says:
* "Not long after I received this letter I was riding in a fast
* express-train across the sandy plains of New Mexico, where the only
* vegetation was a few low scattered shrubs and some tufts of coarse
* grass. On the nearer parts of the lake there were beautiful islands
* with trees and shrubs . . . and I remarked to a fellow-passenger: `. . .
* Perhaps there may be interesting water-birds that have nests among those
* tall grasses and shrubs. It seems to be a better home for the pelicans
* than on those muddy banks by that small river a few miles back.'
*      "He smiled.  He had been over the road half a dozen times, he told
* me, while this was my first trip.
*      "`Try your field-glass,' he merely remarked.
*      "I did; and, like a beautiful dream that is lost on waking, the lake
* disappeared when viewed only through the glass. Later, as the train
* came nearer, I saw that it was only sand and scattered shrubs and
* grass."
* Edward F. Bigelow's "Nature and Science for Young Folks" column runs
* from p. 1032 to 1039; only the "mirage" section is cited here.


v. S.
“Luftspiegelung und Strahlenbrechung auf See,”
Ann. Hydrog. Maritim. Met. 36, 86–87 (1908).

* Two separate reports from different ships
* The first reports "SURF" all around the horizon, after a
* water-temperature drop of 3 C with constant air temp., near 41 N, 54 W.
* The captain changed course from WNW to SW.
* "Ich glaube, daß dieses Phänomen eine Fata Morgana
* (Seeluftspiegelung) gewesen ist. Wahrscheinlich haben wir die Küste
* von Neufundland etwas nördlich von Kap Race gesehen."
* The second reports "land" ahead and on both sides: "Deutlich vermochte
* man Höhenzüge, sogar einzelne Bäume zu unterscheiden, und so
* überzeugend was die Erscheinung, daß Kapitän Bodmann das Schiff über
* den anderen Bug auf östlichen Kurs legte, um vorläufig, der Sicherheit
* halber, von diesem verwirrenden Phänomen wegzuliegen. Da nun aber nach
* der ziemlich gut festgestellten Position des Schiffes wirkliches Land gar
* nicht in Sicht kommen konnte und die Erscheinung nach und nach auch am
* östlichen Horizont auftrat, überzeugte sich der Kapitän von der Bramrah
* aus, daß es sich nur um eine Luftspiegelung handelte. Daraufhin wurde
* der westliche Kurs wieder aufgenommen." (near 56 S, 66 W)
* "v.S." is probably von Schrötter. (Feb. issue)


G. H. B.
“Theory of the mirage,”
Nature 77, 356 (Feb. 13, 1908).

* "G.H.B." on Italian mirages again
* This time he reviews Garbasso's papers, and Rolla's lab simulation
* of Parnell's observations.
* Number 1998


W. Parr
“Coloured optical phenomenon,”
Q. J. Roy. Met. Soc. 37, 274 (1911).

* Claimed mirage of a rainbow, but impossible at 45° altitude
* (Some halo arc is a more likely explanation.)


C. F. Talman
“The Real Fata Morgana,”
Scientific American 106, No. 15, pp.335, 345–349 (April 13, 1912).

* C. Fitzhugh Talman's Fata Morgana article, summarizing Boccara and
* Costanzo, and citing Forel and Ramage as well. A good summary of the
* observations, with a decent copy of Fortuyn's engraving for Minasi.
* (Thanks to Eric Frappa for a good PDF copy!)


D. Manning
“A St. Lawrence River mirage,”
Mon. Wea. Rev. 40, 1757 (1912).

* Typical mirages on St. Lawrence River, seen from Alexandria Bay, N.Y.
* ". . . seen during the spring and autumn months . . . when cloudy skies
* prevail, and soon after northerly winds have set in and the weather
* is growing colder . . .      several small islands, about 2 miles away, . . .
* appear as though they were situated on a snow-covered ice field with the
* trees standing out in strong relief, giving the appearance of a dead
* calm . . . . in reality the wind is strong and the water quite rough,
* for north winds blow against the river current.
*      "The most interesting feature is that if one ascends a nearby bluff
* about 25 feet high, the illusion disappears entirely, and the islands,
* surrounded by the rough, blue waters, and the trees take on their
* natural look."
* (Cf. Büsch, 1800; Abbot, 1854; and Forel, 1895.)
* Nov. issue


C. Maltézos
“Les phénomènes optiques en mer,”
BSAF 26, 514–515 (1912).

* Maltézos summarizes his mirage studies, and quotes Aristotle again
* The quotations from Aristotle turn out to be:
* "Problems" XXVI. 53: "Why, when the east wind blows, do all the things
* seem larger?" and
* "Meteorologica" III. IV (p.253 of the Loeb Library edition):
* "Distant and dense air does of course normally act as a mirror . . . ,
* which is why when there is an east wind promontories on the sea appear to
* be elevated above it and everything appears abnormally large;. . . "
* and unfortunately Aristotle then drags in the Moon illusion.


V. Stefánsson
My Life with the Eskimo
(Macmillan, New York, 1913), pp. 72–73.

* VILHJÁLMUR STEFÁNSSON's astute remarks on "suggestion" in the Arctic
* After a brief description of the deceptive-appearing mirages, he says:
* "I think it is David Hanbury who tells of mistaking a lemming for a
* musk-ox, and Lieutenant Gotfred Hansen speaks of being astounded by
* the courage with which his dogs attacked a polar bear, and of being
* dumbfounded not only at seeing them killing the bear but more especially
* at one of the dogs bringing the bear back in his mouth. It turned out,
* of course, that the polar bear had been an Arctic fox. In things of
* this sort there is always a certain amount of suggestion; Hanbury had his
* mind centered on musk-oxen, and Hansen was expecting to see a polar bear."
* He then tells of seeing a grizzly bear that turned out to be a marmot.
*      "The main reason for such cases of self-deception is that one sees
* things under circumstances that give one no idea of the distance, and
* consequently one has no scale for comparison. The marmot at twenty
* yards occupies as large a visual angle as a grizzly bear at several
* hundred, and if you suppose the marmot to be several hundred yards away
* you naturally take him for a bear. There is, under certain conditions
* of hazy Arctic light, nothing to give you a measure of the distance,
* nothing to furnish a scale to determine size by comparison."
* (available on Google Books)


W. Hillers
“Ueber eine leicht beobachtbare Luftspiegelung bei Hamburg und die Erklärung solcher Erscheinungen,”
Unterrichtsblätter Math. Naturwiss. 19, 21–38 (1913).

* WILHELM HILLERS -- MURAL MIRAGE PHOTOGRAPHED


W. Hillers
“Die erste photographische Aufnahme einer ständigen Luftspiegelung bei Blankenese,”
Kosmos (Stuttgart) 10, 37–39 (1913).


E. Wiedemann
“Über die Fata Morgana nach arabischen Quellen,”
Met. Z. 30, 246–248 (1913).

* Eilhard Wiedemann's additional Arab mirage refs. to supplement Erdmann
* Unfortunately, he uses "Fata Morgana" for inferior mirages here.
*      Eilhard was a son of Gustav Heinrich Wiedemann, who assumed the
* editorship of Ann. Phys. after Poggendorff's death.


W. Hillers
“Bemerkung über die Abhängigkeit der dreifachen Luftspiegelung nach Vince von der Temperaturverteilung,”
Physik. Zeitschr. 14, 719–723 (1913).

* Hillers applies his model to Vince's observations
* He shows that an inflection point in the temperature profile is required


W. Hillers
“Nachtrag zu einer Bemerkung über die Abhängigkeit der dreifachen Luftspiegelung nach Vince von der Temperaturverteilung,”
Physik. Zeitschr. 15, 303–304 (1914).

* Hillers generalizes his model, removing a restriction to small T changes
* Note that he comes up with the "magic number" of 1° 20'


W. Hillers
“Einige experimentelle Beiträge zum Phänomen der dreifachen Luftspiegelung nach Vince,”
Physik. Zeitschr. 15, 304–308 (1914).

* Hillers compares theory with observation in nature as well as in his
* laboratory simulation.
* He discovers the interference fringes later seen by Raman (1959).
* [see also J.Macé de Lépinay and A.Perot (1889).]
* This is a fine piece of work!


W. Hillers
Theoretische und experimentelle Beiträge zur Aufklärung des dreifachen Bildes einer Luftspiegelung = Abhandlungen aus dem Gebiete der Naturwissenschaften 20, No.2, 1-55 (1914)
(L.Friedrichsen & Co., Hamburg, 1914), pp. 1–55.

* This is Hillers's complete, detailed work
*      "Wie es scheint, liegt aber noch nirgends ein Vergleich der Theorie
* mit der Erfahrung vor; noch niemals ist es bisher geglückt, die zur
* dreifachen Bildentwickelung notwendige anormale Dichteänderung der
* Atmosphäre gleichzeitig mit der Beobachtung der Luftspiegelung
* durchzumessen." (p. 3)
*      "Ferner muß nach theoretischen Erwägungen die Winkelgröße des
* Gesamtbildes stets recht klein bleiben, es wird bei normaler Entwicklung
* niemals über 20 Bogenminuten hinausgehen können. Eine gewöhnliche
* photographische Aufnahme wird deshalb von dem Schauspiel auch kaum
* etwas zeigen. Handzeichnungen, denen man öfter begegnet, sind stets
* nach Fernrohrbeobachtungen ausgeführt und lassen leicht die Größe
* und die »Bildmäßigkeit« überschätzen." (pp. 3 - 4)
*      On carrying out the desired comparison, he finds that "der ganze
* Vorgang der Abbildung sich in überraschend dünnen Schichten abspielt."
*      He discusses the ASTIGMATISM of the image, pp. 42-44.


G. Isely
“Optique atmosphérique,”
BSAF 28, 270–271 (1914).

* THREE SUNS, one above the other, about 2 degrees apart (cf. Hevelius!)
* This short paragraph precedes his GF report.
* O'C #223


E. Kleinen
“Luftspiegelung in Straßen,”
Z. physik. chem. Unterricht 27, 339–340 (1914).

* Pedagogical treatment of street mirage
* Mirages appear DARK:
* ". . . dann findet man bald eine Stelle, die ganz dunkel erscheint."
* ". . . erscheint es einem ganz sonderbar, daß man diese Strasse
* jahrelang zu jeder Tageszeit begangen hat, ohne diese Luftspiegelung zu
* bemerken."


G. E. Hubbard
From the Gulf to Ararat
(William Blackwood and Sons, Edinburgh and London, 1916), pp. 60–61.

* Hubbard was a participant in the Mesopotamian campaign
* There are two parts here: the eyewitness account on p. 60:
*      "Our caravan . . .  straggled over two or three miles of country,
* and to anyone riding somewhere near the middle the head and tail of
* the procession seemed always to be marching through a smooth, shallow
* lake; occasionally, for some unfathomable cause, the mules and men would
* execute a bewildering feat of `levitation' and continue their progress
* in the sky. Often we saw a lake spread out on the horizon, stretching
* a long arm towards us to within a few hundred yards; at other times
* a clump of palms or a group of mounted men appeared in the distance,
* only to resolve themselves, as we approached nearer, into bushes of low
* desert scrub or a grazing flock of goats."
*      Here there is a footnote on the "curious incident . . .  reported to have
* happened . . . at the beginning of the Mesopotamian campaign:
*      "Our men, after a particularly courageous attack across the open
* desert (which at the time was such a sea of mud that they had to advance
* at the walk), reached the Turkish trenches and put the Turks to flight.
* The enemy were now in the same predicament as the British had been in
* just before, and provided a splendid target for our artillery as they
* floundered through the mire. A gunboat was lying in the river, and the
* men in the tops were watching the proceedings when they were surprised to
* see our guns suddenly stop firing, although the Turks were still easily
* within range. It transpired later that, to the eyes of the gunners on
* the desert level, the target had disappeared into the mirage ."
*      Quoted by Hurd (in the 1937 Pilot Chart article)


A. O. Holcroft
“A strange sunset,”
English Mechanic 104, 389 (1916).

* "houses and trees with writing underneath" at sunset
* "People living in the Karroo are accustomed to see mirages in the veldt,
* but not at sunset nor during wet weather, as far as my own experience
* goes."
* might be a cloud miraged?


Anonymous
“Turks lured into a trap. Successful move in Mesopotamia.,”
Times (London) , p.8 (16 April, 1917).

* This seems to be the original account of the battle stopped by mirage
* "Fighting had temporarily to be suspended owing to the mirage, but
* upon this lifting our offensive continued." [on April 11, 1917.]
* Presumably this is the dispatch from Lt.-Gen. Sir Stanley Maude.


R. de C. Ward
“Weather controls over the fighting in Mesopotamia, in Palestine, and near the Suez Canal,”
Scientific Monthly 6, 289–304 (1918).

* quotes but does not cite the previous item, mis-dating it the 10th
* (April issue; See p. 294 for the quote.)


R. de C. Ward
“Weather controls over the fighting during the summer of 1918,”
Scientific Monthly 7, 289–298 (1918).

* Story of Turkish retreat caused by mirage "in the early days of the
* Mesopotamian campaign."
* Seems to be taken from Mrs. Eleanor Franklin Egan's stories in the
* Saturday Evening Post .
* (Oct. issue; see pp. 295-296.)


C. P. Du Shane
“The road mirage,”
Scientific American 119, 335 (Oct. 26, 1918).

* ROAD MIRAGE between Canton and Alliance, Ohio: SMOOTH SURFACE required
* Two letters from a resident of New Castle, Pa., with the Editor's
* explanation between them. The first reports: "On July 24th, while
* traveling in an easterly direction between Canton and Alliance, Ohio, I
* noticed a car about half a mile ahead apparently perfectly reflected in
* the roadbed, as if the latter was flooded with water. . . . the road in
* front was straight almost to the horizon and an exceptionally fine
* cemented brick surface. When I came up to the `given point' I found the
* road perfectly dry and the car ahead again showing a reflection in a
* perfectly mirror-like surface about the level of the bottom of the spare
* tire. I called the attention of the rest of the party to the
* reflection, they seeing it very plainly, then and several times later
* when similar stretches of roadway offered, but each time only above the
* heated brick surface.
*      "I have traveled the roads in this section since the high wheel days
* of 1885 but have never been favored with any such phenomena."
* The second letter says, "Since receiving your reply . . . , I have been
* out mirage hunting with some friends and have been successful in bagging
* some beauties as well as establishing a list of requirements . . . .
*      "The requirements are a very hot, dry, clear day, and a smooth hard
* road (brick gave the best reflections) . . . ." He adds sketches that
* illustrate the need for the observer's eyes to be "just above the level
* of the level piece ahead." This usually requires the observer to be in a
* slight dip. "The best point of observation I have found is the stretch
* between Canton and Alliance, but any similar road should give equally
* clear reflections."
* [NOTE: When I was a small boy, I remember this part of the Lincoln
* Highway was still paved with bricks.]
* This was when Sci.Am. was "bedsheet" size -- hard to copy!


M. S. Harloe
“Note on a mirage at sea,”
Mon. Wea. Rev. 47, 453 (1919).

* Looming and mirage at sea
* "with air at 63° F and sea surface at 53° F, "Strong mirages
* noted all around. Four other ships . . . appeared at times to be steaming
* along at the top of a hugh [sic] wall of ice; at other times the bodies
* of the ships seemed to rise out of the water at least twice their height.
* Horizon had all the appearance of a long, rugged coast line.''
* July issue


A. A. Knowlton
“An unusual mirage,”
Science 50, 328 (1919).

* Inferior mirage seen over a road "just after dusk"
* Oct. 3 issue


W. M. Davis
“A wall-side mirage,”
Science 50, 372 (1919).

* A mural mirage reported in Garden St., Cambridge!
* Cf. his 1892 note in Am. Met. J.
* cites Knowlton (above)


F. W. McNair
“A sidewalk mirage,”
Science 52, 201 (1920).

* ought to mention R.W.Wood, but doesn't


H. H. Platt
“Mirages?,”
Science 52, 290–291 (1920).

* Two responses to McNair:
* Platt mistakenly thinks it is a grazing-incidence reflection . . .


F. F. Burr
“Mirages?,”
Science 52, 291 (1920).

* . . . but Burr suggests these mirages "may serve in part to account for
* ideas of temporary disappearance, or dematerialization, of solid
* objects, and for occasional accounts of apparent hallucination."


S. R. Williams
“Mirages?,”
Science 52, 291 (1920).

* A report of large lateral displacement that needs detailed
* investigation: 6 degrees -- probably a misidentification.


P.-L. Mercanton
“"Les Phénomènes d'optique atmosphérique" in "Ergebnisse der Schweizerischen Grönlandexpedition, 1912-1913", A. de Quervain & P.-L. Mercanton, eds.,”
Neue Denkschriften der Schweizerischen Naturforschenden Gesellschaft 53, 192–198 (1920).

* Mercanton's mirage DRAWINGS and HEIGHT EFFECTS in Greenland, in 1912:
*       [actually FILED with green flashes]
* The mirage observations are on pp. 196-197.
* 1. On 15 April 1912 in the Davis Strait, "un beau mirage d'«eau chaude»"
* 2. On 27 May, a superior mirage of icebergs; "vent faible"
* 3. On 2 June "nombreux isbergs visibles au loin apparaissaient tous
* étirés verticalement et surmontés de leur image renversée et
* ratatinée. Une fine ligne sombre courait parallèlement à l'horizon
* marin, représentant, sans doute possible, [!] l'image réfléchie de
* la nappe liquide." (So, he's not always reliable.) He took a telephoto
* picture, but it wasn't good enough to reproduce.
* 4. On 10 Sept., "j'ai vue sur quelque trente kilomètres de côte
* se développer une fatamorgana très belle. Elle se présentait sous
* l'aspect d'un ruban horizontal, strié de lignes verticales floues
* correspondant aux linéaments du paysage recouvert par le dit ruban.
* Celui-ci était nettement limité en haut et en bas. Son bord inférieur
* se découpait sur la mer, sa lisière supérieure sur le paysage côtier.
* Devant de Hjortetakken il marquait le 1/6 de la hauteur apparente de
* cette montagne, soit les 200 m inférieurs. . . .      Quelques isbergs . . .
* apparaissaient très nets et dans leur position normale mais étirés
* et coiffés dès le tiers supérieur de leur image renversée, limitée
* par ailleurs strictement au bord supérieur de la zône floue.
*      "La largeur verticale de la dite zône variait d'ailleurs en sens
* inverse de la hauteur de l'œil au-dessus des flots."
*      The title pages are given in both German and French; I give only the
* German here, as de Quervain (despite his name) writes only in German
* and was the expedition's leader; and this was published in Zürich.
* Dated 1. Dezember 1920; abstracted by Brooks in MWR, 1923.


Anonymous
“Royal Meteorological Society,”
Obs. 43, 420–421 (1920).

* Account of a meeting of the Roy. Met. Soc.
* "A paper on the Mirage, by Dr. W.H.Steavenson . . . . The visibility
* of the mirage was found to be dependent solely on the distribution of
* temperature near the ground . . . not necessarily associated with hot
* weather, and had, in fact, been well seen when the shade temperature
* was below 50° Fahrenheit. Investigations had shown that the old
* reflection theory was untenable, and that the phenomenon was purely a
* refraction effect. . . . The paper was illustrated by actual photographs
* of the mirage, taken by Dr. Steavenson with a telephoto lens." (p.421)
* [The published paper is the next item (1921).]
* Dated Dec. 1920. Available from ADS.


W. H. Steavenson
“Note on the mirage, as observed in Egypt,”
Q. J. Roy. Met. Soc. 47, 15–21 (1921).

* HEIGHT EFFECTS + PHOTOS


R. Forbes
The Secret of the Sahara: Kufara
(George H. Doran Co., New York, 1921).

* Use of mirage for DESERT NAVIGATION (cf. Hassanein Bey, 1925)
* Rosita Forbes (1893-1967) nearly died in the North African desert.
* "On clear mornings, about an hour after dawn, when the desert is
* very flat, a mirage of the country about a day's journey distant
* appears on the horizon. For a few minutes one sees a picture of
* what is some 50 kilometres farther on. The Arabs call it `the
* country turning upside down.'" (p.135)


C. P. Du Shane
“The sidewalk mirage,”
Science 53, 236 (11 March, 1921).

* Another note by Du Shane, commenting on McNair (1920)
* He mentions but does not cite his earlier observation.


(anonymous report from H. M. S. "Cleopatra")
“Mirage on the Gulf of Finland, May 1st, 1919,”
Met. Mag. 56, 40 (1921).

* Fine example of LOOMING
* accompanied by detailed temperature and wind data
* "sea 1 . . . air 43 F, sea 39 F"
* "The ice presented a curious mirage effect, being reflected upwards.
* When first sighted with the sun on it, it looked very like a continuous
* line of chalk cliffs in a slight haze; with the sun behind it, small
* detached pieces appeared as dark blurred objects which might be anything,
* and might be mistaken for land. On closing, it was found to be floating
* not more than a foot or so above water."
* LOOMING and STOOPING of other ships reported as well.


D. C. Bates
“Mirage across the Bay of Plenty,”
Met. Mag. 56, 41 (1921).

* Fine example of LOOMING and "FOG"
* originally cited as "Bay of Plenty Times" of Dec.6, 1920
* "All this time there was a dark grey-blue band on the horizon . . . .
* Soon after 4:30 this bank appeared to condense from the surface of the
* sea towards its upper margin, till it resembled a thick dark-coloured
* cable stretched from island to island."
* Note the Editor's WRONG explanation of the "black band", which confuses
* radiance and irradiance !!


A. F. Odell
“Sidewalk mirages,”
Science 54, 357 (14 Oct., 1921).

* More comments on the previous letters to Science


V. Stefansson
The Friendly Arctic
(Macmillan, New York, 1922), p. 490.

* Arctic "CLIFFS" mirage that sets like a heavenly body
* Vilhjalmur Stefansson is following Storkerson's trail:
* "Beyond Cape Grassy we found that Storkerson had struck away from the
* land in a direction 22 degrees west of north which is the proper course
* for Cape Murray . . . . But four miles from Cape Grassy we found a place
* where the sledges had stopped briefly by the way, to judge by the tracks
* of men and dogs. After this the trail led for eleven miles in a
* direction 20 degrees east of north. . . . But after eleven miles of this
* course the party had turned back to their previous one, heading again
* for Cape Murray. I learned later that the reason had been one of the
* remarkable mirages or `appearances of land' that have deceived so many
* arctic explorers. Storkerson told me later that the fog had suddenly
* lifted, showing a land with bold cliffs apparently only fifteen or
* twenty miles away. This surprised him, but after consulting his
* companions, both Eskimo and white, and studying the land carefully
* through the glasses he made up his mind that they could probably reach
* it that day and that he might as well strike it first at this cape and
* follow it westward. But for two or three hours as they advanced the
* land kept receding and getting lower, until finally without becoming
* obscured by any fog or mist it sank beneath the horizon as if it had
* been some heavenly body setting."


(editorial news item)
“An Exceptional Mirage,”
Met. Mag. 57, 337 (1923).

* Met.Mag.'s brief account of the next item


D. Brunt
“A double vertical reflection mirage at Cape Wrath,”
Nature 111, 222–223 (1923).

* TRIPLE SUPERIOR MIRAGE


K. Sinclair
“Mirages and similar phenomena,”
John O'Groat Journal , (26 Jan., 1923).

* Several mirages and other phenomena (Kenneth Sinclair, Maughold Head
* Lighthouse, I.O.M.) "ORKNEY WITCH" original report
* ". . . I remember the remark of a Highland fisherman made to his fellow
* boatman after directing his attention by a sweep of his massive hand to
* the northern sky. . . . `there's Margaret, the Orkney witch, going to meet
* the sun.' and there, sure, hung, as if suspended by invisible threads, a
* stretch of the Orkneys mapped in the sky. I remember the sea was smooth
* and the sun glaring."


[K. Sinclair]
“Surging mirage,”
Met. Mag. 58, 12–13 (1923).

* PERIODIC MIRAGE and the ORKNEY WITCH
* ". . . in the Pentland Firth the superior mirage is sometimes referred to
* by the name of `Margaret, the Orkney Witch'. . . ."
* ". . . as sure as the timely rise and fall of a fountain ball, so did this
* strange sight rise and fall as if governed by the movement of some sighing
* bosom."
* "Such direct evidence for Helmholtz waves in the transition layer
* between a warm current and the cold air beneath it is valuable."


A. Réthly
“Fata Morgana on the Nagyhortobágy,”
Mon. Wea. Rev. 51, 312–313 (1923).

* NOT a FATA MORGANA (according to Bonnelance, 1929) but an inferior mirage
* decent photograph reproduced


J. H. Gordon
“Mirage in Lower California,”
Mon. Wea. Rev. 51, 313–314 (1923).

* pretty standard mirage story (stapled with the previous paper)


Val. Thomas
“Mirage sur la Manche,”
BSAF 37, 314–315 (1923).

* "absolutely characteristic" FATA MORGANA (according to Bonnelance, 1929)


Anon.
“Travaux astronomiques récents,”
BSAF 37, 487–489 (1923).

* NOT a FATA MORGANA (according to Bonnelance, 1929) but an inferior mirage
* This is a repeat of one published in Mon.Wea.Rev. for June 1923 (above)


P. Neame
“An Alpine mirage,”
Times (London) , p.10, col.6 (May 11, 1923).

* Report in the Times by "P. Neame, Lieutenant-Colonel, Royal Engineers"
* [quoted in full in the QJRMS report, so not copied.]
* "Mr. F. S. Smythe and I were climbing the Finsteraarhorn in the Bernese
* Oberland on May 2. . . .      Suddenly at 11.55 a.m. the image of a ship
* appeared in the sky just to the east of the Eiger peak, floating in
* a blue shimmer just beyond the visible horizon. This lasted for a
* minute or so, and then vanished. Very soon after a line of five ships
* appeared farther east, funnels and masts clearly distinguishable. This
* image lasted for some fifteen minutes, and varied in its clearness from
* time to time. The ships appeared of course greatly exaggerated in size,
* and were right way up, not inverted."
* "On reference to an atlas, this brings their position on the nearest sea to
* approximately the eastern exit of the English Channel into the North Sea, a
* distance of some 400 miles."


E. V. Newnham and F. J. W. Whipple
“Correspondence and Notes: An Alpine Mirage,”
Q. J. R. Met. Soc. 49, No. 208, 278–281 (Oct., 1923).

* ILLUSION of ships in SUPERIOR MIRAGE
* This is hard to classify: first, Neame's report in the Times is quoted;
* then comments on it by Newnham and Whipple. I'll isolate Neame's item
* as a separate entry (above), and attribute just the comments here.
*      However, note that in April, 1924, MWR indexed this under "Neame".
* Newnham just gives the synoptic situation. But Whipple says:
*      "The illusion of distant ships would seem to be explicable by the
* presence of an inversion of temperature. . . .      The illusion of the ship's
* masts is comparable with that of reeds growing by the edge of water in the
* 'inferior' mirage of the desert. A similar drawing out of a small object
* can often be observed through a windowpane of poor glass." (p. 281)
* Saved as "AlpineMirage1923.pdf"


N. Korzenewsky
“Ein seltener Fall abnormer Strahlenbrechung,”
Met. Z. 40, 374–375 (1923).

* EXTREME LOOMING
* Hard to believe they saw mountains 750 km away,
* ". . . jedoch ließen sich die mächtigen Schneegipfel und ihre von
* Klüften zerfurchten Abhänge überaus deutlich wahrnehmen."
* The feet of the mountains couldn't be made out, so maybe the long
* path is explicable by the great height (4560 m) of the peaks.
*      A garbled footnote refers to Jessen's (1914) mistaken observation.
* Cf. Garner (1933).


A. M. Hassanein Bey
The Lost Oases
(Century Co., New York, 1925), pp. 124–125.

* Use of mirage for DESERT NAVIGATION (cf. Rosita Forbes, 1921)
* On p. 124, after mentioning the ordinary (inferior) mirage, he says:
* "Another kind of mirage comes sometimes in the early morning. Then the
* country far ahead of one appears in the sky at the horizon, as the
* Bedouins say, `upside down.' This is not, as the other variety of
* mirage is, entirely an illusion. It is really the reversed reflection
* of the country thirty or forty kilometers ahead of where the observer
* stands." He also says, "Sometimes . . . a small pebble the size of a
* cricket-ball seen from a mile away might assume the appearance of a big
* rock, standing like a landmark. The skeleton or part of the skeleton of
* a camel or a human being may take on the most fantastic shapes on the
* horizon, but the Bedouins know it well."
* and: "The seasoned desert traveler knows a mirage when he sees one. It
* is entirely possible indeed that the `upside down' variety may be a
* positive assistance, since it can suggest what kind of country lies ahead."


C. Maltézos
“Observation de la Fata Morgana en Grèce,”
BSAF 39, 202 (1925).

* FATA MORGANA with LATERAL MIRAGE (according to Bonnelance, 1929)


C. F. Brooks
“Looming and multiple horizons,”
Mon. Wea. Rev. 53, 313 (1925).

* textbook example of MULTIPLE HORIZON due to INVERSION
* Seen at Hampton Beach, Mass., June 17, 1925.
* Sounds like Forel's "FATA MORGANA" displays. 8' HEIGHT.
* "The Isle of Shoals looked like a city of skyscrapers of uniform
* height. . . . The loomed horizon joined with the other farther and farther
* northward in the course of the hour from 10 to 11 a.m. The extending
* upper line of the loomed horizon became visible first in rather regularly
* spaced spots (marking air waves?) which developed columnar connections
* with the lower sea level as the top line became continuous. A rough
* angular measurement indicated the looming to be about eight minutes
* of arc.
*      "Over the ocean there was the normal cool cushion of air, represented
* by the moderate sea breeze at 59° F. blowing in from the ocean (shore
* water 54.5° F.), over which was beginning to run a warm southwesterly
* wind, which became strong by mid-afternoon at points a few miles inland."
*      [The islands are about 20 km from the beach.]


E. Oddone
“Sulla fotografia di un miraggio,”
Boll. Bimens. Soc. Met. Ital. 44, 51–54 (1925).

* A mirage photograph discussed, not very informatively


A. Wegener
“Die prognostische Bedeutung der Luftspiegelung nach oben,”
Ann. Hydrog. u. Maritimem Met., Köppen-Heft , 93–95 (1926).

* WEGENER's statistical support for superior mirage predicting warmer
* weather


P. A. Bonnelance
“Note sur les réfractions anormales,”
Bull. Obs. Lyon 8, 17–20 (1926).

* MIRAGE CLASSIFICATION (preliminary version; see his 1929 paper in BSAF)
* This is on the first leaf of No.2; the title says "Tome IX" but that
* must be an error, as the title page of the *volume* says Tome VIII (1926)


A. R. Hassard
[account of meeting]
JRASC 20, 102–104 (1926).

* Mirages across Lake Ontario; random reports in discussion
* Available from ADS.


N. Ivanov
“A propos de la `Note sur les réfractions anormales' de M. P. A. Bonnelance,”
Bull. Obs. Lyon 8, 218–219 (1926).

* Ivanov reports miraged sunsets from Anapa (Northern Caucasian coast of
* the Black Sea) and cites Wright's experiments with colored filters.
* He shows crude MIRAGE DRAWINGS of setting Sun (all Omega type)


C. Maltézos
“Les réfractions anormales,”
Bull. Obs. Lyon 8, 218–220 (1926).

* Maltézos reports his work as well, in response to Bonnelance's note
* The page numbers overlap with the previous item, as Ivanov's drawing
* is placed on p.219, in the middle of Maltézos's letter.


A. Wegener
“Photographien von Luftspiegelungen an der Alpenkette,”
Met. Zs. 43, 207–209 (1926).

* PHOTOGRAPHS of SUPERIOR MIRAGES in the Alps, by A. Vaupel
* Commentary by Alfred Wegener (June issue)


B. M. Varney
“A striking case of looming over the sea,”
Bull. Amer. Met. Soc. 7, 109–110 (1926).

* Nice observation of HEIGHT effect, and "SURF"
* "From a rowboat, the low, rocky coast of one of the outlying islands was
* seen to alternate rapidly between its normal shape and that of splendid
* `cliffs.' The alternations synchronized with the rising and falling,
* respectively, of the boat over the slight swells of a glassy sea. So thin
* was the refracting layer of air, that when the boat was on top of a swell,
* the distant coast appeared in its true character to a person sitting in
* the boat. When the boat was in the trough, up popped the `cliffs' to form
* a fine palisade along the whole visible length of the island. From the
* deeper troughs the looming very nearly went over into full mirage, the
* normal form of the island shore then shooting out horizontally bottom up,
* over the true shore. . . .      The most spectacular feature of the display was
* the magnificent `surf' made by the very moderate swell when its breaking
* coincided with the dips of the boat into troughs. The spray would at such
* times shoot upward in a brilliant white column as high as the `cliffs'
* produced by the momentary looming."
* Aug.-Sept. issue


E. A. Mills
Romance of Geology
(Doubleday, Page & Co., Garden City, NY, 1926), pp. 1–31.

* Lengthy but fanciful descriptions of mirages in the manner of James Gordon
* Mentions "FOG" on p.7. Also:
* "A mirage is the reflection of something; sometimes the mixed
* reflection of several things. It appears that an object or a landscape
* is lifted, perhaps by reflection, projected afar, and then set down in
* another place as a mirage. . . . It may be photographically clear, or
* vague and cloudy, or a confused mixture. This confusion may be due to
* several reflections mingling in the same picture . . . ." (pp. 7, 8)
*      "The mirage shows many ambiguous images.  Desire often insists we are
* seeing the thing we want." (p. 9)
*      "The turning of my field glass upon a mirage often changed it into
* nothing -- or formless light and shadow." (p. 12)
*      There is a nice description of how a mirage made a couple of stalks
* of grass appear to be distant spruce trees in snow (pp. 16-17): "Before
* me, two slender grass stalks stood above the snow. I circled back to
* where I had first seen the spruces. They were in view again, but this
* time they were upon a snowy rim of a cañon -- the magnified
* overlapping snowshoe tracks that I had made by the grass stalks."
*      There is a good description of a "breathing" or waving mirage on
* p. 18: "Up and down they rose and sank, teetering as though upon an
* invisible support laid across the peninsula. Sometimes they balanced or
* swung back and forth slightly as they seesawed."
*      Peary's "Crocker Land" is on pp. 21-22.
* "During the Franco-Prussian War a number of scattered and independent
* observers in northern Sweden and Norway saw mirage armies marching
* through the air, equipped like the real ones that were fighting a few
* hundred miles to the south." (p. 23) [but no references!]
* "A vague or confused mirage . . . often reveals something in the mind of
* the onlooker." (p. 25)
* "Generally, the image shown is not moved to one side, but just
* uplifted above the horizon's rim. That these mirages often are directly
* above the real, I have proved with islands in the Pacific by taking a
* compass course and sailing directly to the real island." (p. 27)


P.-A. Bonnelance
“Etude sur les réfractions anormales,”
Bull. Obs. Lyon 9, 143A–155A (1927).

* Bonnelance's detailed statistical study of the frequency of different
* forms of refraction during the year and their relations to temperature
* gradients. He finds a rough relation to temperature difference between
* air and water, but not to humidity or barometric pressure. Comments on
* the importance of a trained eye.


W. G. Emmett
“A sideways mirage,”
Met. Mag. 63, 15–16 (1928).

* Dubious lateral mirage of mountains
* The explanation proposed by R.Corless does not seem plausible.


H. E. Wimperis
“Road mirages,”
Met. Mag. 63, 16 (1928).

* Wimperis calls attention to his 1903 note in Nature:


H. L. Pace
“Mirage at sea,”
Met. Mag. 63, 16–17 (1928).

* "The shapes of these ships are distorted when the temperature of the sea
* is higher than the temperature of the air . . . wind force makes no
* difference . . . ."


H. A. Rogers
“Sea and road mirage,”
Met. Mag. 63, 138 (1928).

* Comments from an unobservant reader:
* "I have not observed any road mirage in my time and am an octogenarian . . . ."


W. H. Bigg
“Road mirages,”
Met. Mag. 63, 138–139 (1928).

* Report of persistant inferior mirage on a tarred road at airport
* ". . . it was visible both in winter and summer (although less intense in
* the former season) under most conditions of wind, weather and temperature.
* . . . Even with a damp road and drizzle falling one was considerably
* surprised to find that, on approaching what appeared from a distance to
* be a puddle of water, the puddle vanished." (Cf. Ashmore, 1955)


A. Mallock
“Mirage: natural and artificial,”
Nature 122, 94–95 (1928).

* Describes LABORATORY DEMONSTRATION of mirages (syrup + water; hot-plate)
* Curious terminology: "hot" and "cold" mirages, as the surface layer is
* (compared to those higher up). He also makes a hot-wire refraction,
* with no mirage counterpart: a shadow zone around the wire, with
* "brightly coloured interference bands."
* July 21 issue.


P. M. Millman
“Two optical phenomena observed. I. A mirage seen near Victoria, B.C.,”
J. R. A. S. C. 22, 94 (1928).

* STANDARD TRIPLE IMAGE with drawing of SUPERIOR MIRAGE
* "The day was hot and clear with a temperature of about 65°."
* Available from ADS.


L. G. Vedy
“Sand mirages,”
Met. Mag. 63, 249–253 (1928).

* Mirages studied on sandy beaches
* Notable for observations in the LAMINAR layer.


T. H. Applegate
“Sun pillar,”
Met. Mag. 64, 67 (1929).

* DOUBLE SUN, compared by F.J.W.Whipple in the following comment (p.68)
* to Hevelius's observation in 1682. He points out that it does not
* appear to be 2 images of the Sun separated by a blank strip; I am not so
* sure. This is the observation invoked by Botley (1935).
* "In the path of the pillar there was an image alike in all respects to
* the sun, the distance between the two balls being equal to the diameter of
* either. It was quite impossible at that time to say which was the object
* and which the image but this was decided when, two minutes later, the
* upper `sun' quite suddenly faded."
* cf. Emsmann, 1856, as well as S&T, 1980.


C. Frazer
“Ups and downs of the horizon,”
Popular Mechanics 52, 242–246 (Aug., 1929).

* Calvin Frazer's mirage article
* Despite the title, this is about mirages, not variable dip. Contains
* several interesting references (but not citations) to Bonnefont (1837);
* Warren Upham (1895); Lt. Wilkes; Borchgrevink; Bottineau. Alas, the
* "accompanying illustration" by Arctowski was not published.


P.-A. Bonnelance
“Les réfractions anormales,”
BSAF 43, 489–501 (1929).

* SUPERB treatment of mirages observationally; much improved classification
* scheme compared to his 1926 paper. Schiele's review missed this.
* Many comments on FOREL's work; good FATA MORGANA discussion:
* "La Fata-Morgana . . . atteint et déforme des objets plus ou moins hauts
* et donne continuellement l’impression que l’on regarde le paysage à
* travers la longueur d’uneplaque de verre qui en donnerait une image
* confuse, étirée ou multiple." (p. 497)
* Useful comments about "FOG", which he seems to equate to the Fata-Brumosa.
* Useful comments on earlier reports in BSAF, too; see notes elsewhere here.
* EXCELLENT ADVICE to observers (cf. Nijland's list for GFs)
* He also notes the unexplained nature of "lateral mirage" reports.


H. T. Smith
“Abnormal refraction and mirage at sea,”
Marine Obs. 7, 133–135 (1930).

* Interesting review of mirages at sea, with many examples


H. Jameson
“Inferior mirage at Sunrise?,”
Met. Mag. 65, 138 (1930).

* badly drawn OMEGA sketch


A. A. Justice
“The passing of the mirage locally,”
Mon. Wea. Rev. 58, 414–416 (1930).

* Claims that mirages in Kansas are less frequent than before farming of
* the plains, due to the effects of more plant cover. Several anecdotal
* accounts of mirages there.
* (cf. Fingado, 1932)


J. Reger
“Spiegelung an einer Diskontinuitätsfläche,”
Beitr. Physik d. freien Atmos. 18, 190–195 (1932).

* impossible balloon sounding explained by abnormal refraction at inversion


C. L. Garner
“Seeing things at a distance,”
The Scientific Monthly 36, 71–74 (1933).

* LOOMING and cases of LONG VISUAL RANGE due to refraction
* Cites examples of long triangulation baselines: 192 miles [309 km]
* from Mt. Shasta to Mt. St. Helena, and 183 miles [295 km] in Utah.
* Then, on p. 73, there are examples of seeing great distances: the
* Explorer , in 1911, is said to have seen the Fairweather Mountains
* at 330 miles [531 km]. Other examples of looming on land are given.
* Cf. Korzenewsky (1923).


C. F. Talman
“The magic called mirage,”
Yachting (NY) 50, pp.47–49, 100, 102, 106 (April, 1932).

* CHARLES FITZHUGH TALMAN's article in Yachting
* An EXCELLENT popular review! Mentions Justice's note in MWR, 1930; the
* mirages of Mt. Canigou seen from Marseille; mirages near Chicago on Lake
* Michigan; Thomas Jefferson's "canoe" mirage; and many classical examples.
* Very clear on terminology -- a specialty of his, according to the obit.
* Explicitly says: "When abnormal refraction increases the apparent
* elevation of distant objects -- often lifting above the horizon things
* normally below it -- the process is described as `looming.' Because we
* associate a certain apparent altitude with a certain distance, this
* phenomenon generally makes the objects seem nearer than they really are."
*      Excellent advice: "The yachtsman who wishes to become better
* acquainted with mirage . . . if he knows enough German, . . . will read the
* appropriate sections of Pernter and Exner's Meteorologische Optik , and
* his best guide in English will be W. J. Humphreys' Physics of the Air .
* . . . A good pair of binoculars or other optical aid will be found necessary
* for making out details, especially in the observation of superior mirage,
* as great distances are usually involved . . . ."
* Much of the wording is borrowed from his earlier works.
*      This mag has had a varied history.  Founded in 1907 by Yachting
* Publishing Inc., it made its way to Z-D, then to CBS Magazines, who sold
* to Diamandis Communications, bought by Hachette Magazines c. 1987; then
* they sold it to Times Mirror Magazines, Inc.. In 2000, they sold it to
* Time, Inc. In 2008 it was acquired by Bonnier Magazine Group. It is
* still publishing 2 volumes/year in an unbroken series.
* I have a *very* poor photocopy -- can anyone provide a good one?


H. L. Page
“Mirage,”
Met. Mag. 68, 167 (1933).

* Mirage of Isle of Man from Holyhead, with looming


J. Pinkhof
“Fata Morgana te Zandvoort,”
Hemel en Dampkring 31, 252–254 (1933).

* SKETCHES of mirages, reproduced in Minnaert's book
* The drawings are about as reduced as is tolerable, here; but they were
* reduced still further, to illegibility, in Minnaert's book.
* [For larger versions, see ten Kate (1951).]
* Fig. 6 is a nice superior mirage of a ship beyond the horizon, like
* the drawing with the Sun in M.O. 37, 18 (1967).
* I don't think Pinkhof's argument against the supposed mirage of the
* cliffs of Dover holds water; he forgets that towering can magnify the
* image -- cf. Met. Mag. 56, 40 (1921), where again "chalk cliffs" were
* imagined. But he may well be right that this interpretation was wrong.


W. H. Hobbs
“Visibility and the discovery of polar lands,”
Geografiska Annaler 15, 217–224 (1933).

* Nice REVIEW of mirages and looming in mistaken claims of polar discoveries
* See some other of his papers in the "Lehn/Novaya Zemlya" file, esp. the
* 1937 paper for an update of this topic.


J. Boyer
“Curieuses apparences du mirage,”
La Nature 62:1, 385–387 (1934).

* GOOD PHOTOGRAPHS of mirages


W. Findeisen
“Über Beobachtungen von Luftspiegelung auf dem Neuwerker Watt,”
Ann. Hydrog. u. Maritimem Met. 62, 423–426 (1934).

* Good PHOTOGRAPHS of mirages (Tafel 46)
* Okt. 1934


H. C. Freiesleben
“Luftspiegelung nach oben,”
Ann. Hydrog. u. Maritimem Met. 62, 426 (1934).

* DOUBLE HORIZON; DEVELOPMENT of the superior mirage above 3 boats in 5
* minutes, from masts downward.


E. W. Barlow
“Deceptions of vision due to atmospheric conditions at sea,”
Marine Observer 12, 14–19 (1935).

* GOOD REVIEW of mirage phenomena, with discussion of terminology, and a
* mention of Diodorus Siculus at the end (probably via Flammarion).


W.-E. Schiele
“Zur Theorie der Luftspiegelungen, insbesondere des elliptischen Falles,”
Veröff. Geophys. Inst. d. Univ. Leipzig , series 2, 7, 101–188 (1935).

* Thesis -- good references
*      This is a good guide to the mirage literature.  There is a good
* review of the classical treatments -- particularly, a fine appreciation
* of Biot's monograph, Wegener's theory, etc.
*      The second part develops the ellipsoidal case in series, using
* perturbation theory. Today, it would be easier to just do the
* numerical integrations, as van der Werf has done.
*      Cited by Humphreys (1940) in connection with the mention of Japanese
* Fata Morganas on p. 107; however, the ellipsoidal theory is never really
* applied to that situation.


R. Meyer
“Die Entstehung optischer Bilder durch Brechung und Spiegelung in der Atmosphäre,”
Meteorologische Zeitschrift 52, 405–408 (1935).

* Rudolf Meyer FIRST DISCOVERED the Mock Mirage ("intermediate mirage")
* too many good quotes to give here!
* Rudolf Hans Wilhelm Meyer (1880-195x?) was educated in Warsaw and
* Berlin, after being a student at Dorpat Meteorol. Obs. He was born in a
* suburb of Riga, and often contributed to the Korrespondenz-Blatt there.
* O'C #88


W. G. Burt and H. D. Pim
“Mirage. Portuguese waters.,”
Marine Obs. 13, 92 (1936).

* Good DRAWINGS showing a DOUBLED image with one part TILTED
* July issue


L. W. Wilson
“Mirage. Gulf of Mexico.,”
Marine Obs. 14, 11 (1937).

* Good DRAWINGS and FOG description
* "The appearance of a fog bank lay on the horizon, the angular height of
* which was 2° 10'." This complex display needs work.
* Jan. issue


G. van den Bergh
“Fata Morgana in de Wieringermeer,”
Hemel en Dampkring 38, 259–260 (1940).

* Not a Fata Morgana, but a spectacular case of LOOMING,
* in which a farm appears (and a town is reported to have appeared)
* at "less than 10% of the real distance." Not even a drawing.
* Observed on 20 May.


W. J. Humphreys
“How Moses crossed the Red Sea,”
Scientific Monthly 63, 82 (1946).

* Humphreys was probably the inspiration for Fraser's "Theological Optics"
* This note also mentions the incident of April 11, 1917 reported by
* General Maude. [see London Times for April 16.]


K. Class
“Beobachtung einer seltenen Luftspiegelung,”
Zeitschrift für Meteorologie 1, 152 (1947).

* GOOD CASE for a MOCK MIRAGE in MOUNTAINS
* From Donnersberg (835m) mirages described in abstract as "Fata Morgana"
* were seen of Fichtelberg (1214m) and Keilberg (1244m), 71 km away.
* "Fichtelberg und Keilberg sowie sämtliche Bergkuppen bis herüber zum
* Wieselstein (Entfernung = 26 km NW, h = 856 m NN) standen auf sich selbst
* Kopf, nach oben begrenzt durch eine messerscharfe, waagrechte Linie."
* "Sämtliche Berge verloren ihre ursprüngliche Form. Vor allem der
* Oedschloß-Berg im Duppauer Gebirge (Entfernung = 70 km SWzW, h = 925 m
* NN) machte alle Stadien von Klumpen, feinst zugespitztem Kegel bis zu
* einem sonderbar geformten Zylinderhut durch. Auch das Riesengebirge
* (Entfernung 130 km E, h = 1400 bis 1600 m NN) zeigte, wenn auch nicht in
* so deutlich wahrnehmbarer Form, die im Westen so ungewöhnlich stark
* auftretenden Luftspiegelungen."
* Mountains were about 15 C warmer than valleys; "Der Temperatur- und vor
* allem der Feuchtigkeitssprung (Donnersberg nur 3% rel. Feuchte!) lag bei
* rund 750 m NN."


R. L. Ives
“Meteorological conditions accompanying mirages in the Salt Lake desert,”
J. Franklin Inst. 245, 457–473 (1948).

* GOOD REVIEW OF DESERT MIRAGES (ALL KINDS)
* Ives had degrees in geography and geology, but had a minor interest
* in meteorology, which led to a few publications on mirages.
*      This paper is particularly interesting in describing some rare mirage
* phenomena, esp. on pp. 468-469. The inversion of 15°F in one inch of
* height reported on p. 468 exceeds the 1°C in 5 cm inversion of Balsley
* et al. (2003) by an order of magnitude.
*      Superior mirages are discussed on pp. 469-471, including association
* with inferior mirages. Miraged nocturnal lights are treated on p. 470.
*      Fata Morgana mirages are on pp. 471-472.  They "not infrequently have
* peripheral color fringes" -- cf. Minasi! -- and are complicated "in many
* instances" by "wisps of steam fog".


R. L. Ives
“Climate of the Sonoran Desert region,”
Ann. Association of American Geographers 39, 143–187 (1949).

* More remarks on mirages by Ives, with climatology
* The brief mirage discussion is just pp. 175-176. After mentioning
* the common inferior mirages (and accompanying turbulence), he says:
* "Less common in this area are superior and multiple mirages, occurring
* when the lower layers of air are thermally stratified. These are
* particularly common over the Gulf of California, and on the west side of
* Baja California, where the California Current (Fig. 17) chills the lowest
* stratum of air, producing great stability, and leading to stratification.
*      "Near the sea, particularly in areas where high mountains are quite
* close to shore, Fata Morgana mirages are not unknown, and lead to annoying
* or serious misobservations by navigators and pilots."
* [no hard copy filed.]


G. E. Mitchell
“Mirage, Gulf of Cadiz,”
Marine Obs. 21, 81 (1951).

* GOOD DRAWINGS showing the change in mirage with DISTANCE of ship


R. L. Ives
“Recurrent mirages at Puerto Peñasco, Sonora,”
J. Franklin Institute 252, No. 4, 285–295 (Oct., 1951).

* Ronald L. Ives describes mirages in the Gulf of California
* while working as an engineer at Cornell Aeronautical Laboratory.
*      This is a VERY THOROUGH OBSERVATIONAL REVIEW of many kinds of mirage,
* with clear drawings of 3-image and other superior mirages, looming,
* and descriptions of CONCAVE appearance of the sea, truncated images and
* false horizons, etc.; "False sea horizons, due to refraction, are a
* standard midday condition . . . . Fata Morgana is a common occurrence
* when cold air drainages from high mountains reach the warm waters of
* the Gulf of California." (from Abstract!)
*      The section on "False Sea Horizons" is on p. 287:
* "On hot clear days, which are frequent near the Gulf of California, the
* sea horizon acquires a peculiar appearance in midmorning, the visible
* horizon being 10' to 15' of arc higher than its sunrise position.
* This condition persists until very late afternoon, at which time the
* "upper horizon" dissolves, not always regularly. Onset of this false sea
* horizon is contemporaneous with the development of a thin warm surface
* stratum of water. Neither the warm surface stratum nor the false sea
* horizon develops when the wind speed is much more than 5 mph.
*      ". . .  inferior mirages commonly develop over flat land areas 15
* minutes to two hours before formation of the false sea horizon. On very
* hot summer afternoons, the inferior mirages over land may merge with
* the false horizons over water.
*      "Although deceptive to the unaided eye, so that its presence
* complicates accurate marine navigation, the false sea horizon can be
* distinguished from the true horizon by use of a deep red viewing filter,
* such as a Wratten "A" or "F."
*      "When winds of small areal extent blow over the sea surface, they
* remove the false sea horizon locally and temporarily, in much the same
* manner that dust devils "eat holes" in inferior mirages on land.
*      "In a great majority of observed instances, objects at sea
* considerably nearer the observer than the apparent horizon have an
* entirely normal appearance during the middle hours of the day, whether
* or not a false horizon is present. As these objects recede from the
* observer, they will cross the horizon and disappear below it in a normal
* manner if no false horizon is present; but will sail off into the sky,
* undergo great vertical distortion, or partake of more complicated visual
* transfigurations when a false sea horizon is present."
*      On the next page: "The shallow northern part of the Gulf of
* California, roughly from Latitude 27° north to the mouth of the Colorado
* River, is noted for its mirages, which, in one form or another, are of
* almost daily occurrence at all seasons." Fig. 2 (p. 288) shows the
* progressive changes in appearance of a ship steaming away from the
* observer as it crosses the horizon. "If . . . mirage conditions exist,
* as is usually evidenced by a false horizon at sea, and by inferior mirages
* over adjacent lands, the appearance of the vessel will not remain normal
* after it reaches the apparent horizon." (p. 289)
*      "Never reported from Puerto Peñasco, but common in the narrow
* channels between islands farther south, is the Fata Morgana , a weird
* mélange of diffuse and ever-changing images, perhaps magnified and
* distorted views of objects on the shore. These annoyances to mariners . . .
* are most commonly seen in the early morning, when the air is very cold
* relative to the water, and are usually accompanied by steam fogs."
*      "Where study of air conditions has been possible during Fata Morgana
* displays, a thin layer of relatively cold air, in turbulent motion, has
* been present over the surface of relatively warm water. Above the
* thin cold air stratum, which usually results from local air drainage,
* is a layer of much warmer air. Other stratifications aloft are sometimes
* present.
*      "Observed colors in the main body of the mirage are always
* degradations of those present in the local environment. Occasionally
* spectral hues are present, as "rainbow glints," adjacent to steam fogs
* associated with the Fata Morgana ." (p. 290) [Cf. Minasi!]
*      Next comes a discussion of "looming" of distant mountains:
* "On any ordinary clear day, when air temperatures are substantially
* normal for the season, and wind speed is below about 15 miles per hour,
* dim shapes, that might be distant mountains shrouded in desert haze,
* appear on the western horizon at about noon . . . [A]bout an hour before
* sunset, . . . the images sharpen . . . . A few minutes before sunset, the
* images tower and sharpen still more, . . . This image lasts for about
* half an hour, until very shortly after sunset, at which time it darkens,
* and rapidly falls below the horizon.
*      "After an abnormally hot still day, the image towers to a much
* greater height, and the sea appears to have a concave surface from the
* observer to the base of the range, with "embayments" of mirage extending
* up valleys in the distant mountains." (p. 291)
*      On p. 292 he describes loomed images of distant islands to the south,
* as seen from a height of 250 ft. (76 m). They appear in midmorning or
* later, "snapping into view" about a minute of arc above the horizon.
* [This means the images appear at the inferior-mirage fold line.] "The
* images slowly rise as the day progresses," -- or, more likely, the dip
* of the apparent sea horizon increases as the mirage grows stronger.
* "Appearance of the upper images changes with each minor change in
* the position of the observer, and the actual changes in appearance
* with changes in the height of the observer's eye above sea level are
* disproportionate to the change of elevation." So, here again,
* we have an inferior mirage at the surface, with inversion (superior)
* mirages above. The similarity to Forel's account is striking.
*      Thanks to Eric Frappa for an excellent PDF of this!


H. ten Kate
“Luchtspiegelingen,”
Hemel en Dampkring 49, 91–94 (1951).

* Big reproductions of Pinkhof's (1933) drawings
* GOOD DEFINITION: "What is a mirage? One should be able to define this
* as the phenomenon whereby we see objects at a sufficient distance in the
* open air not singly, but double or sometimes multiple, from which it is
* obvious that the light rays that leave an object come to our eyes along
* different paths. Then the light rays are not all propagated
* rectilinearly but sometimes also along curved paths . . . . The question
* is now more how it is possible that the rays become bent."
* He is one of very few writers who contrasts the astronomical and
* terrestrial refractions; but he supposes that straight rays are possible,
* or even common; and that superior mirages are rarely seen because the
* thermal gradients there tend to be weaker, not because of the restricted
* height from which they are perceptible. However, he does emphasize the
* importance of eye height.


H. ten Kate
“Fata Morgana,”
Hemel en Dampkring 50, 32–34 (1952).

* FATA MORGANA discussed
* Cites his mirage article in the previous volume: "The Fata Morgana are
* also mirages, but of a much more complex form than we have described in
* the cited article."
* He correctly connects the phenomenon with air-water temperature
* differences, and especially those near land; but thinks the F.M. is due to
* CURVATURE of the isopycnic surfaces.


J. C. Goverde
“Over het waarnemen van luchtspiegelingen,”
Hemel en Dampkring 50, 34 (1952).

* a nice SKETCH of MURAL MIRAGE
* on the last page of the previous item.


W. Weigel
“Beobachtung von Luftspiegelungen auf dem Fichtelberg im Erzgebirge,”
Zs. f. Met. 6, 94 (1952).

* MOUNTAIN MIRAGES and nocturnal inversion data
* Comments on inadequate resolution of soundings (200 - 300 m)
* Werner Weigel, Met. Station auf dem Fichtelberg i. Erzgebirge


G. Kohl
“Erklärung einer Luftspiegelung nach oben aus Radiosondierungen,”
Zs. f. Met. 6, 344–348 (1952).

* Gerhard Kohl tries to explain Weigel's observation
* Notable as the FIRST paper to consider the MOCK-MIRAGE geometry
* explicitly: "Einmal handelt es sich um eine Luftspiegelung eines weit
* entfernten Objektes (rund 165 km), zum anderen lag der Beobachtungspunkt
* einwandfrei oberhalb, aber nicht unterhalb der Grenzfläche zwischen
* Bodenkaltluft und der darüberliegenden, bedeutend wärmeren Luftmasse."
* -- though he tries to force Wegener's model onto it, and
* mistakenly asserts that "die Lichtstrahlen [werden] von der totalen
* Reflexion betroffen." But at least the radiosonde profile shows an
* 8-degree inversion close to the peak-to-peak line of sight.
* Many other circumstantial details are given, as well as a tell-tale
* drawing of the mirage (Abb. 4) supplied by Weigel.


P. W. Kidd and A. D. Terras
“Mirage and temperature fluctuations, Mediterranean Sea,”
Marine Obs. 23, 77 (1953).

* a series of M.O. mirage reports -- NOT ALL indexed here!
* HOT, DRY GUSTS -- cf. M.O.24,13(1954).
* "In one of these gusts (at 0820) the dry bulb rose to 89 F and the wet
* bulb fell to 71 . . . ." "Sea temperature remained 76 throughout . . . ."


P. P. Ainsworth
“Abnormal refraction, Cabot Strait, Gulf of St. Lawrence,”
Marine Obs. 23, 77–78 (1953).

* Fine DRAWINGS of 3-image mirages


J. D. MacMillan
“Abnormal refraction, off Cape Town,”
Marine Obs. 23, 78–79 (1953).

* NOVAYA ZEMLYA (leaky-duct) display of great duration
* Surface-based DUCT phenomena (cf. ATY's April 23, 1995 ducted sunset)
* "The upper limb of the sun appeared elongated and remained above the
* horizon for approximately two minutes." [This is the flattened image
* above the duct.] "Three minutes later a bright red light appeared,
* intermittently, in the sea about two-thirds of the distance to the
* horizon. The light was rectangular in shape, 40' of arc in length and 3'
* wide, and lasted for eight minutes." [This is the Sun seen through the
* duct. Note the long visibility -- a fine Novaya Zemlya display!]
* Evidently the observer mistook the top of the duct for the horizon
* (cf. Le Gentil's "whale" remark). The Editors were completely baffled
* by this report: "It is not possible to give any simple explanation of it. . . "


P. W. Hodges
“Abnormal refraction, North Atlantic Ocean,”
Marine Obs. 23, 202–203 (1953).

* MULTIPLE IMAGES OF VENUS and "VERTICAL WHITE STREAK" --> GF
* "Before finally setting the planet appeared elongated to a vertical
* white streak which immediately turned a bright green. All these changes
* were visible to the naked eye."
* [cf. Biot's "petite colonne de feu", and M.O.24,13(1954)]


J. Y. Kerr and D. K. Bhattacharya
“Abnormal refraction, Off Port Okha (West coast of India),”
Marine Obs. 23, 203 (1953).

* DRAWINGS of distorted sunrise
* (belongs in "DISTORTED" file but on same page as above)


S. Keenan and G. Griffiths
“Abnormal refraction with gusts of dry air, Western Australian waters,”
Marine Obs. 24, 13 (1954).

* Seems to be a CREPUSCULAR RAY from VENUS
* ". . . gusts of hot, dry breezes were encountered, readings of the dry and
* wet bulbs then noted were 88 and 64 F . . . " [cf. M.O.23,77(1953).]
* "During the phenomena Venus was observed setting. Just before setting
* a column as of fire shot up from it to a height of a few degrees and
* remained visible for 30 sec while the planet set."
* [cf. Biot's "petite colonne de feü!]


W. Weigel
“Luftspiegelungen auf dem Brocken,”
Zs. f. Met. 9, 58 (1955).

* MOUNTAIN MIRAGES - identified as superior mirages
* Strong inversions (15 C in 540m)
* Werner Weigel, Brocken


S. E. Ashmore
“A North Wales road-mirage,”
Weather 10, 336–342 (1955).

* ASHMORE's road-mirage observations: almost unaffected by clouds
* Ashmore's by-line reads "Hon. Meteorologist to Wrexham Borough".
*      Observations made by an observer sitting on the "kerb" at Wrexham,
* and using binoculars. No info on the road surface!
*      Visibility in RAIN:
* "It became evident that the mirage can be formed during favourable
* conditions at any time the sun's altitude exceeds 24½° and that it is
* almost always present, whatever the conditions, with a solar altitude
* of 29° or more. . . . cloudiness may have a slight effect, but in
* general, the only conditions which prevent it are snow lying, rain heavy
* enough to produce considerable splash, or visibility less than about
* 150 yards . . . ." (p. 338) [cf. Woltman 1796, 1798, 1800, and Bigg, 1928.]
*      By measuring the ray curvature (using Vedy's method), ". . .  it
* appears that the temperature gradient lies mainly in a layer of air
* about ¾ in. thick, and since even the strongest winds do not upset the
* gradient, it is probable that most of it is confined to a portion much
* shallower even than that." (p. 341)
*      At the end, he comments: "This work was not always easy ; the road is
* often busy, chiefly with pedestrian traffic. Naturally the activities of
* the observers, involving prone lying in the roadway, aroused curiosity;
* occasionally expressions of commiseration were overheard as passers-by
* receded from the scene."
*      Cites Vedy's 1928 paper, and Miss Botley's in Weather  (1952).
* (kept only as a PDF)


C. S. Durst and G. A. Bull
“An unusual refraction phenomenon seen from a high-flying aircraft,”
Met. Mag. 85, 237–242 (1956).

* SUPERIOR MIRAGE of cumulus cloudtop from airplane
* "Such phenomena as described in this paper do not appear to have been
* previously reported from aircraft in flight, unless some of the reports
* of 'flying saucers' may have been due to this effect."


H. Gäbler
“Beobachtung einer Luftspiegelung nach oben,”
Zs. F. Met. 12, 219–221 (1958).

* MOUNTAIN MIRAGE - identified as superior mirage; but the stretched zone
* looks like Wegener's Nachspiegelung (viewed from above).
* The mirror image is drawn equal in size to the erect one.
* Milleschauer (835m) seen from Fichtelberg (1214m) above "Nebelmeer" at 750m.


(anonymous)
“Luchtspiegelingen,”
[newspaper clipping, dated in ink] , (1 July, 1958).

* A 1958 Dutch newspaper clipping found by R. H. van Gent in a copy of
* Flammarion's "l'Atmosphère":
* Besides giving the wrong date ("1708" !) for Monge's observations, and
* exaggerating the French army's reactions to the desert mirages ("the
* men thought the end of the world had come"), there are a couple of
* tantalizing hints of mirages seen from AIRPLANES:
* "The pilot Martin flew into a mountain peak 30 years ago [this is dated
* 1958] when he tried to evade a mirage. Lindbergh himself said that he
* had seen strange shores in the middle of the Atlantic Ocean."


J. H. Gordon
“Mirages,” in in Annual Report of the Smithsonian Institution, (1959)
(U.S. Government Printing Office, Washington, 1960), pp. 327–346.

* James H. Gordon's mirage summary
* Useful remarks on the difference between ASPHALT and DIRT surfaces,
* despite his ignorance of the literature and optics. Cf. his 1923 paper.
* Good line: "Mirages are definitely not photogenic."
* Penny Porter tells me James Gordon was Janet Gordon's father.


E. Trautmann
“Über Luftspiegelungen der Alpen, gesehen vom Bayerischen Wald,”
Mitt. Deutsch. Wetterdienstes 3, Nr. 21 , (1960).

* Trautmann's attempt to interpret mirages of the Alps
* This is a useful but problematic report. The mirages are merely
* described (no drawings). But the observations are accompanied by
* balloon soundings from Munich, roughly on a line between the observers
* on Gr. Falkenstein and the miraged mountains. Unfortunately, only
* Wegener's simplified theory is used, so the comparison of theory with
* experiment is not exact (although he does demonstrate that ducting
* conditions existed in 2 of 3 superior mirages). Worse, he supposes that
* "reflections" can occur at the inversion layers seen below eye level;
* so the attempts to interpret these supposedly "inferior" mirages are
* nonsense. The resulting disagreements are "explained" by some
* hand-waving arguments of little merit.
* Obviously, this needs to be re-done properly.
* [Cited by Löw in his "Luftspiegelungen" book.]


N. P. Austin and M. Edward
“Abnormal refraction, North Pacific Ocean,”
Marine Observer 32, 22 (1962).

* DISTORTED MOONRISE with INFERIOR MIRAGE (textbook example)
* good drawings


M. J. Downie
“Abnormal refraction, North Atlantic Ocean,”
Marine Observer 32, 182–183 (1962).

* DISTORTED MOONRISE with multiple MOCK MIRAGES (Filed in GF file!)
* good drawings


C. M. Botley
“Mirages — What's in a name?,”
Weather 20, 22–24 (1965).

* BOTLEY mixes up mirages and other phenomena


J. H. Gordon
“It's only a mirage,”
Ford Times , 16–17 (July, 1966).

* James H. Gordon's short note
* "These road mirages are a comparatively modern development, almost
* unknown on the old dirt roads, and rarely seen today over dirt surfaces."
* Ford Times was a travel mag put out by Ford Motor Co.
* Thanks to Penny Porter for providing a copy!


R. L. Ives
“The mirages of La Encantada,”
Weather 23, 55–60 (1968).

* REGULAR MIRAGES IN BAJA


H. Ramforth
“Abnormal visibility at sea,”
Mariners Weather Log 17, 300–301 (1973).

* Visual and radar looming compared; "FOG" observed
* During the "fog" episode, the air was 2.5 deg. warmer than the water;
* apparently the inversion then lifted and became inaccessible.
* "A star fix taken by two officers from seven stars came out with useless
* results, although stars and horizon appeared good visually. While
* searching for the error that might have caused the useless results, it
* was found that if 10 min were added to the height of each observation,
* the results would have been correct." [Cf. Koss's footnote, 1901]
*      [Note observation of CONCAVE surface:]
* A lighthouse with normal range 15 miles was seen at 75 miles.
* This appears to be a clear case of NEGATIVE DIP (cf. Hasse's
* "Kimmfläche") caused by a strong inversion overhead. The editor's
* comments are mostly wrong and should be disregarded.
* N.B.: There is no apostrophe in the title of this publication.


J. Collins and A. J. Bairstow
“Abnormal refraction, Mediterranean Sea,”
Marine Observer 49, 23 (1979).

* TRIPLE-IMAGE mirage within "yellow band . . . thought to be dust or haze.
* The yellow colour was very distinct and it may have been significant
* that the sun was setting over mountains around the coast at the time."
* A miraged ship was seen at 12 n. mile radar range; "the effects
* persisted until each observed target came within seven nautical miles . . .
* On two occasions the inverted image was observed before the true
* object." Air temp. 17.1 C, water 15.2, wind force 2.


A. B. Fraser
“Simple solution for obtaining a temperature profile from the inferior mirage,”
Appl. Opt. 18, 1724–1731 (1979).

* Fraser's parabolic profile
* He mentions the more correct logarithmic profile, but does not use it.


R. Brownbill, R. Owen, and M. Harris
“Abnormal refraction, Mediterranean Sea,”
Marine Observer 50, 23–24 (1980).

* Interesting DRAWINGS of superior mirages, with ships towering
* Radar distances of targets given.


K. W. D. Shears
“Abnormal refraction, North Sea,”
Marine Observer 50, 74–75 (1980).

* Inferior (?) mirage effects on HORIZON, 4 April 1979
* A vessel "was observed fine on the port bow. At a range of 8 n. mile it
* was seen to be in a normal position on the visible horizon, but when at a
* range of 12 n. mile it appeared in very clear detail to be in a position
* above the visible horizon.
*      "At the same time a small fishing vessel, at a range of 9 n. mile and
* approximately 4 points on the port bow, was producing a wake on the
* horizon which appeared to the observer as a mountainous sea, see . . .
* sketch. This phenomenon persisted until the range had decreased to 7 n.
* mile." Air 5.5° C, sea 6.3; wind calm.


W. A. Murison, M. J. Power, and D. J. Izzard
“Abnormal refraction, Tasman Sea,”
Marine Observer 50, 115 (1980).

* LOOMING of trees on shore, despite inf.-mir. temps.
* ". . . there appeared to be a layer of shimmering haze above the land
* . . . the trees were estimated to be 7 n. mile distant from the vessel."
* The DRAWING shows 2 separate layers at least.
* "HAZE" is drawn dark, despite Sun's altitude of 30-40°.
* Air 11.7° C, sea 14.1. A complex and puzzling observation!


I. O. Williams
“Abnormal refraction, Little Minch,”
Marine Observer 51, 117–118 (1981).

* Interesting DRAWINGS of superior mirages, with SMOKE MIRAGED
* The measured altitude of the boundary at 51' is unusually large.


R. Fullagar and J. L. Meade
“Abnormal refraction, North Atlantic Ocean,”
Marine Observer 51, 183 (1981).

* WAVY HORIZON DRAWING
* An otherwise undistinguished inferior-mirage observation, which calls
* attention to the irregular waves on the apparent horizon. At 11.5 n.
* mile range, a vessel appeared miraged (usual drawing). "As the vessel
* drew closer the fo'c'sle, masts and accommodation appeared to hover above
* the horizon, seemingly separated from the rest of the vessel, which could
* not be observed at the time. Although the sea was calm with only small
* ripples, the waves at the horizon appeared magnified." Air 10.8 C, sea
* 13.2; wind, light airs. Position 39 20 N, 73 18 W (i.e., probably in
* Gulf Stream).


P. Day, P. C. Dyer, and R. P. Swinney
“Abnormal refraction, Tasman Sea,”
Marine Obs. 52, 26–27 (1982).

* DRAWING of multiple beach images
* "Initially an apparent line of haze or mist was observed, extending from
* the horizon to an altitude of 0° 10' - 0° 13' and presenting a false
* horizon. The ship's funnel smoke was then observed trapped on a level
* with this, indicating an inversion . . . . As the vessel closed with the
* coast the land was noticed to be apparently sitting on top of the
* inversion level, with the line of beach repeated two or three times in the
* shimmering air below (Figure 2). Sometimes water could be seen between
* the layers of the beach . . . . The top layer did not remain solid-looking.
* At intervals sections would dissolve into narrow vertical blocks that
* resembled single trees before disappearing altogether (see Figure 3); this
* resembled a wave-like motion, with the top layer gradually dissolving from
* right to left, then re-forming from left to right with waves of varying
* thickness forming in the top layer, and ripples moving along the top."
* Air temp 21.0° C; sea 19.5; wind force 2.


D. N. Roberts and J. G. Pearce
“Abnormal refraction and mirage, South Atlantic Ocean,”
Marine Obs. 52, 27–28 (1982).

* DRAWINGS of superior mirages and miraged ship
* "Shortly after departure from Cape Town a superior mirage was observed
* to extend around two-thirds of the visible horizon. Throughout the
* following 2 1/2 hours very vivid inverted images could be seen. It
* was noted at 1300 GMT and again at 1630 that there were quite marked
* discontinuities of the reflected horizon. The two most distant images
* were observed at 1300 and 1400 GMT, the first being Dassen Island, which
* at the time of observation lay 13 n. mile to the north (the visible
* horizon being 7.85 n. mile distant); the height of Dassen Island is 19
* metres." Air temp. 22.9° C, sea 18.1, wind force 3 increasing to 4.


P. D. Cullen and I. Buckley
“Abnormal refraction, Straits of Labrador,”
Marine Obs. 52, 78–80 (1982).

* Many interesting DRAWINGS of superior mirages, with radar ranges
* "As the Strait of Belle Isle was approached a thick, low band of
* refraction was observed to stretch across the entrance to the Strait."
* Air, 5.9; sea, 4.1 C.


A. H. White and R. E. Lough
“Abnormal refraction, South Atlantic Ocean,”
Marine Obs. 52, 78–80 (1982).

* Drawings of looming of a ship.
* Enlargement of image claimed with no distortion.


K. Lenggenhager
“Luftspiegelungen über unsern Seen (Fata Morgana),”
Z. Meteorol. 32, 187–190 (1982).

* Nice photos. This guy had a whole series of interesting papers for
* several years in Z.Met., all nicely illustrated, on halos, subsuns, the
* shapes of icicles, etc.
* This paper has beautiful illustrations of inferior mirages over lakes.
* The author doesn't understand Fraser & Mach's paper in Scientific
* American, though; he insists on "reflection" without refraction.


E. E. Gossard
“Formation of elevated refractive layers in the oceanic boundary layer by modification of land air flowing offshore,”
Radio Sci. 17, 385–398 (1982).

* NICE SUPERIOR MIRAGE PHOTO (triple image)
* This really belongs in BLM file, but is in my mirage file because of photo
* ". . . conditions such as these are common in southern California, as
* evidenced by the well-known distortions of the solar limb as the sun sets."
* [Cf. O'Connell's book.]


N. R. Pryke, C. M. Billington, I. Foster, M. O'Gorman, and T. Rowland
“Abnormal refraction, Strait of Belle Isle,”
Marine Observer 53, 128–129 (1983).

* Interesting DRAWINGS of towering and superior mirages of icebergs
* at 38 - 43 nautical mile range
* ". . . all the bergs observed at a distance of 18 n. mile and over were
* seen to be abnormally refracted."


R. Spencer and M. G. Welsh
“Abnormal refraction, Bass Strait,”
Marine Observer 53, 203–204 (1983).

* Strong SUPERIOR MIRAGE produces "A SOLID WALL OF WATER" (see DRAWING)
* ". . . what appeared to be land features were observed on the horizon; at
* the same time the horizon ahead of the vessel became distorted and gave
* the impression that the vessel was approaching a solid wall of water. . . .
* The nearest land at this time was 85 n. mile away."
* Air varied from 25.6 to 21.6 C, sea temp. 18.8 C; wind force 2, sea
* slight. "Exceptional radar detection" to 45 n. miles.


J. G. Reeve, C. P. R. Clarke, and C. Purser
“Abnormal refraction, South African coastal waters,”
Marine Observer 54, 79–81 (1984).

* Many SUPERIOR and TRIPLE-IMAGE MIRAGE DRAWINGS in "mist"
* radar ranges from 8.0 to 17.5 n.miles; dry bulb 22.0 C, sea 15.8,
* wind force 1


J. P. Ayling
“Abnormal refraction, South-west Australian waters,”
Marine Observer 54, 126–127 (1984).

* Mirage of coasts described, but the sketch "cannot be reproduced"!
* Many interesting details; a puzzling report.


M. Sams and B. W. Watson
“Abnormal refraction, North-west Australian waters,”
Marine Observer 54, 127–128 (1984).

* GOOD DRAWINGS of superior mirages with vertically stretched zone
* Air temp. 30 C, water 26; wind force 3.


J. C. S. Yeo and J. A. C. Pearce
“Abnormal refraction, Gulf of Mexico,”
Marine Observer 56, 193–194 (1986).

* Strong inferior-mirage near Grand Bahama Island, with DRAWING
* Ship at 16 n. miles ahead seen miraged. "Slowly, this effect diminished
* until . . . at a range of 12 n. mile, the ship's hull touched the horizon."
* Air 21.2 C, sea 27.0; wind force 3. "The sea state was slight, with no
* swell." The background land was also miraged.


A. D. Matthias and N. Ferguson
“Superior-mirage photographs: evidence of complex air temperature profiles in Sonoran Desert valleys,”
Bull. Amer. Meteorol. Soc. 67, 1266–1271 (1986).

* SUPERIOR MIRAGE PHOTOS


A. von Chamisso
A voyage around the world with the Romanzov exploring expedition in the years 1815-1818
(U. of Hawaii Press, Honolulu, 1986), pp. 83–84.

* Adelbert von Chamisso's 1816 mirages in translation
* A very clear explanation of both the appearances and their causes:
* "I saw a surface of water before me in which a low hill was reflected
* that extended along the opposite shore. I went toward this water. It
* disappeared before me, and I reached the hill with dry feet. When I had
* covered about half the distance, I seemed to Eschscholtz, who had remained
* behind, to have been submerged up to my neck in the reflecting layer of
* air, and, shortened the way I was, he said I looked more like a dog than a
* human being. As I strode onward, toward the hill, I emerged more and more
* from the layer of air, and I appeared to him, lengthened by my reflection,
* to get taller and taller, gigantic, slender."
* "When land rises above the horizon, as seamen are wont to express it,
* the line that is taken to be the horizon is the edge of a reflecting
* surface formed by the lower layer of air and closer to the eye; a line
* that really lies below the visible horizon. I believe that this illusion
* in some cases can have an influence on astronomical observations and can
* cause an error in these of five and perhaps more minutes."
* He also mentions Flinders, Ross, and Scoresby.
*
* NOTE: Johann Friedrich Eschscholtz was the physician and naturalist who
* accompanied Kotzebue's expedition, along with writer/botanist Chamisso
* and the artist L. A. Choris. Chamisso produced the first scientific
* description of California's golden poppy (now the state flower) on this
* expedition, and named it in honor of his friend Eschscholtz.
* The best biography of Chamisso I have seen is in the DSB.


K. H. Milne and R. Duff
“Abnormal refraction, Mediterranean Sea,”
Marine Observer 57, 112 (1987).

* Good DRAWINGS of towering of ship; another "yellow band" within 1 hr.
* of sunset; cf. Marine Observer 49, 23 (1979).
* ". . . a low, yellow-coloured sand layer was observed, originally thought
* to be haze or fog." Air temp. 25.5 C; sea decreased from 20 to 15,
* then increased to 18 C.


R. G. Greenler
“Laboratory simulation of inferior and superior mirages,”
JOSA A 4, 589–590 (1987).


K. R. Lown
“Mirage over Thames estuary,”
Weather 42, 393 (1987).

* drawing of triple-image mirage
* with standard commentary by Ken Bignell


A. Mayor
“Marine mirages,”
Sea Frontiers 34, 8–15 (1988).

* Adrienne Mayor's fair popular review: Tape, Greenler & Fraser are cited
* Besides the standard examples, several less-common ones are mentioned:
* accounts from Giraldus Cambrensis's Topography of Ireland (1187),
* literary passages supposedly inspired by mirages (Wordsworth;
* Coleridge); Wilkes and J.C.Ross; Borchgrevink.
* Jan.-Feb. issue


C. Sturcke and G. R. Jackson
“Abnormal refraction, Western North Atlantic,”
Marine Observer 58, 68–69 (1988).

* SUPERIOR MIRAGE DRAWINGS and descriptions, including land seen
* inverted beyond horizon (25 n. mile range). The mirage of land at 18
* miles was slightly magnified. Wind: force 4.


W. G. Rees
“Reconstruction of an atmospheric temperature profile from a 166-year old polar mirage,”
Polar Record 24, 325–327 (1988).

* INVERSION of SCORESBY's drawings
* See Lehn & Rees (1990) for correction.


C. Bohren
“Simple experiments in atmospheric physics: Highway mirages,”
Weatherwise 42, 224–227 (1989).

* REALLY GOOD piece on inferior mirages by CRAIG BOHREN!
* (with 3 fine color photographs of hot-road mirages.)
* First sub-head is: A Mirage Is Not an Illusion (Thanks, Craig!)
* "I shudder when I see or hear mirages referred to as optical illusions.
* . . . these optical phenomena are no more illusions than are images
* in a mirror." (He offers the Moon Illusion as a real example: "An
* enlarged moon is a creation of the mind; a mirage is a creation of the
* atmosphere.")
*      "When images formed by the refracting atmosphere depart markedly from
* what they would be in its absence, they are called mirages."
*      "Before considering the consequences of atmospheric refractive
* gradients, I must dispose of the notion that water vapor plays an
* essential role in the formation of mirages. This misconception dates to
* antiquity and persists today, evidence that no misconception ever dies."
*      But, alas, he equates inferior mirages with images below the geometric
* position. Despite this single flaw, a fine article.


P. R. Barker, P. R. M. Crofts, and M. Gal
“Apparatus Notes: A superior "superior" mirage,”
Am. J. Phys. 57, 953–954 (1989).

* Nice Wollaston-style demo using HEAT LAMPS and water
* "When the lamps are switched on, the beam immediately begins to deflect
* . . . . After 30 s a deflection of 6 cm is observed on the screen. . . .
* The deflection rapidly returns to zero when the lamps are switched off."
* Unfortunately they define inferior and superior mirages in terms of
* image displacement, blaming this on Greenler's 1986 OSA abstract. But
* at least they say mirages "are caused by gradients in the temperature"
* and not temperature differences -- still, no second derivatives.


W. G. Rees
“Mirages with linear image diagrams,”
JOSA A 7, 1351–1354 (1990).

* Rees never read Biot's book, though it is his first reference!
* ". . . inverted mirages . . . are not included in Biot's analysis . . . ."


W. H. Lehn and W. G. Rees
“The Scoresby ship mirage of 1822,”
Polar Record 26, no. 158, 181–186 (1990).

* Lehn corrects the old Rees (1988) inversion
* This deals with the UNIQUENESS problem, in part.


W. G. Rees, C. M. Roach, and C. H. F. Glover
“Inversion of atmospheric refraction data,”
J. Opt. Soc. Am. A 8, No. 2, 330–338 (February, 1991).

* Rees et al. introduce the Runga-Kutta forward model


J. F. Davis and T. B. Greenslade , Jr.
“Computer modeling of mirage formation,”
Physics Teacher 29, 47–48 (1991).

* A worse-than-average account by ignorant physicists
* "Monge . . . was the first to give an explanation . . . . The coordinates at
* which zero slope is reached can be approximated . . . ." A crude empirical
* approximation for the temperature profile over a hot surface is used (with
* no physical basis); the index of refraction "must approach a constant" (!)
* at heights "greater than about 2 m"; and of course the Earth is flat.
* They touch on the horizontal-ray paradox. Pretty dismal.
* 5 papers, all in Am. J. Phys., are cited from 1974 to 1982.


S. Mak
“Showing the light path of a mirage,”
Physics Teacher 31, 476–477 (1993).

* A glorified version of Wollaston's demo
* The use of a pinch of Coffee-Mate to make the beam visible is a nice
* contemporary touch. And as "alcohol is not benign to most transparent
* plastic containers," he recommends a strong (0.5g/ml) sugar solution.


A. T. Young, G. W. Kattawar, and P. Parviainen
“Sunset Science. I. The Mock Mirage,”
Appl. Opt. 36, 2689–2700 (1997).

* our MOCK MIRAGE paper (Paper I)


G. Horváth, J. Gál, and R. Wehner
“Why are water-seeking insects not attracted by mirages? The polarization pattern of mirages,”
Naturwissenschaften 84, 300–303 (1997).

* Mirages, polarization, and insect vision
* Shows a photograph of a Tunisian mirage
* Thanks to Gábor Horváth for supplying a PDF copy!


G. Horváth, J. Gál, and R. Wehner
“Erratum: Why are water-seeking insects not attracted by mirages? The polarization pattern of mirages,”
Naturwissenschaften 85, 90 (1998).

* Mirages, polarization, and insect vision (erratum)
* This shows a corrected version of Fig.1
* Thanks to Gábor Horváth for supplying a PDF copy!


C. H. Tape
“Aquarium, computer, and Alaska Range mirages,”
Physics Teacher 38, 308–311 (2000).

* All qualitative, but good photographs


T. Kosa and P. Palffy-Muhoray
“Mirage mirror on the wall,”
Am. J. Phys. 68, 1120–1122 (2000).

* MURAL MIRAGE well photographed
* But much of the discussion is confused: the erect image is described as
* "real"; Hillers is wrongly credited as being the "first" to study "the
* wall mirage"; the ray trajectory is assumed to be parabolic, or circular;
* the refractive-index and temperature profiles are arbitrarily assumed,
* with no reference to the relevant boundary-layer literature; etc.
* Dec. issue


P. Porter
“Mirages: Heaven in the sky and other sightings,”
Arizona Highways 77, No. 7, 22–25 (July, 2001).

* Penny Porter's Fata Morgana Arizona observation, plus quotes from Gordon
* The observation was made at 7 am in April 1981
* "A city afloat on a vast blue ocean . . . . doorways on dwellings framed
* in timber and ladders stretching from the ground up to occasional arched
* windows of the upper levels -- suggesting the architecture of the
* pueblo-builders of Arizona or Mexico. Garden plots on upper terraces
* blazed with fiery flowers. Chickens scuttled around courtyards. Two
* heavily laden burros tied to hitching posts were clearly visible, and
* people strolled down quiet, peaceful streets. . . .
* "Finally it broke into sections. Huge fragments collapsed, and in
* slow motion they sank one by one into the sea."


J. D. Pettigrew
“The Min Min light and the Fata Morgana,”
Clinical and Experimental Optometry 86, No. 2, 109–120 (2003).

* distant lights seen at night via inversions -- fine MIRAGE PHOTOS in color
* Notable for a good section ("Animation and human factors") that
* discusses the perceptual issues. The colors reported remind me of
* the Biot-Arago observations. Cites my mirage page.
*      Formerly available on the Web at
* http://www.optometrists.asn.au/ceo/backissues/vol86/no2/2043
*      Presently available on the Web at
* http://onlinelibrary.wiley.com/doi/10.1111/j.1444-0938.2003.tb03069.x/pdf


E. Darack
“Unlocking the atmospheric secrets of the Marfa Mystery Lights,”
Weatherwise 61, No. 3, 36–43 (May/June, 2008).

* Ed Darack's article on MARFA LIGHTS featured on cover
* Nice COLOR PHOTOS of inferior and superior mirages of lights, including
* Fata Morganas. Cites my mirage page.


M. Zinkova
“Fata Morgana in coastal California,”
Weather 64, 287 (2009).

* Mila Zinkova's good Fata Morgana picture of glitter (see cover!)
* Contains comments by ATY. Nice mock-mirage GF shown, too.
* No. 11 (Nov. issue)


S. Y. van der Werf
“Noninverted images in inferior mirages,”
Appl. Opt. 50, no. 28, F12–F15 (2011).

* Siebren's 2011 paper on inferior-mirage wiggles
* He understands the cause of the alternation, but uses a bad temperature
* profile.


J. Blanco-García and F. A. Ribas-Pérez
“Mirages above the sea waters,”
J. Phys. : Conf. Ser. 274, 012001 (2011).

* Nice COLLECTION of MIRAGE PHOTOGRAPHS from Spain
* Good examples of the main types, including FM; shows effects of height.
* But: "Although there are descriptions of mirages since the Classical
* Antiquity, the first scientific explanation was given by Gaspard
* Monge, who accompanied Napoleon Bonaparte in the Egypt campaign . . . ."
* doi:10.1088/1742-6596/274/1/012001


J. Blanco-García, B. V. Dorrío, and F. A. Ribas-Pérez
“Photographing mirages above the sea surface,” in Proc. 8th International Conference on Hands-on Science,Focus on multimedia , M. F. M. Costa and S. Divjak, eds.
(Copissauro Repro, Portugal, 2011), pp. 78–85.

* Nice COLLECTION of MIRAGE PHOTOGRAPHS from Spain
* Good examples of the main types, including FM; shows effects of height.
* ISBN 978-989-95095-7-3


D. M. Farmer, L. Armi, and A. T. Young
“Mirages across the Salish Sea,”
Weather 69, No. 8, 215–220 (Aug., 2014).

* DAVID FARMER's excellent mirage of Mt. Rainier, with my ray-traces


S. Y. van der Werf
“Hafgerðingar and giant waves,”
Appl. Opt. 56, No. 19, G51–G58 (July 1, 2017).

* Siebren van der Werf's nice paper on "sea fences", with waves and animations
* This is a close match to the next item; read both together with the
* Lehn & Schroeder papers (1981 and 2003).
* https://doi.org/10.1364/AO.56.000G51


A. T. Young and E. Frappa
“Mirages at Lake Geneva: the Fata Morgana,”
Appl. Opt. 56, No. 19, G59–G68 (July 1, 2017).

* my paper with Eric Frappa
* Explains the FM with valley-circulation model (thick inversion)
* many photographs, and a real-time video
* Should be read together with Siebren's paper, just above.
* [Note observation of CONCAVE surface.]
* https://doi.org/10.1364/AO.56.000G59


M. Zinkova
“Sunset mirages involving ducts,”
Weather 72, No. 12, 372–375 (2017).

* Mila ZINKOVA's "Sunset mirages" paper in "Weather"
* http://dx.doi.org/10.1002/wea.3056


N. Idris and T. N. Usmawanda,A. M. Sari Maswati
“Effect of temperature and humidity on the visibility of mirage on the runway of Sultan Iskandar Muda Airport, Aceh, Indonesia,”
Journal of Physics and Its Applications 2, No. 1, 67–71 (2019).

* VISIBILITY in RAIN; temperature and humidity data; no profiles
*      "It was observed that mirage has shown up from morning to afternoon,
* from 07.00 AMuntil 18.00 PM, even until sunset. Mirage is also still
* visible when the weather is cloudy or drizzling, but disappeared when
* heavy rain." [Cf. Ashmore (1955), above]
*      "When the air temperature is high and the humidity is low, the mirage
* appears with high visibility (very thick), so that it can be observed
* clearly visually. Conversely, when the temperature of air is low and
* the humidity is high, mirage appears with low visibility (very thin)
* or almost non-existent or completely gone. [Abstract]
*      "Mirage is an optical illusion. . . ."  [first sentence!]  "The light
* undergoes refraction and total internal reflection . . . ." [first para.]
*      "Mercury thermometers are installed at an altitude of 1.5 km from
* ground level." These seem to be naked-eye observations. The broken
* English does not help: ". . . no mirage can be seen on the second morning
* of the day" seems to mean the second observation of the day. They were
* surprised to see no mirage at daybreak on a hot day, and attribute this
* to the effect of humidity. Not useful.
*      Nasrullah Idris, Maswati, T. N. Usmawanda,Arlin Maya Sari



*** ALEXANDER von HUMBOLDT FILE ***

A. de Humboldt
Relation historique du Voyage aux Régions équinoxiales du Nouveau Continent
(Dufour, Paris, 1814).

*
* This also has the title:
* Voyage de Humboldt et Bonpland. Première partie. Relation Historique.
* The various editions and many translations divide the "books" into
* volumes in various different ways.
* MIRAGES and TERRESTRIAL REFRACTION are mentioned occasionally; one needs
* an edition with an index to find them.
* Note the flowery dedication: "A L'Illustre Auteur de la Mécanique
* céleste, P. S. De La Place, comme un faible hommage d'admiration et de
* reconnoissance."


A. de Humboldt
Personal Narrative of Travels to the Equinoctial Regions of the New Continent
(Longman, Hurst, Rees, Orme, and Brown, London, 1818).

* Helen Maria Williams's translation, often reprinted. Lacks an index.
* This is a rather crude, literal translation, but at least it is
* unabridged. I have found mirages mentioned in Vol. 1, p.187;
* Vol. 2, p.189 (the footnote citing Hooke); Vol. 3, pp. 542-554
* (the famous Note D); Vol. 4, p. 292; Vol. 4, pp. 299, 325, 327-329.
* The last of these is the passage referring to the Sanskrit phrase, and
* to "the Indian, Persian, and Arabic poets".
*      On p. 542 is a reference to "Gruber, (Ueber Stralenbrechung und
* Abprallung des Lichts, 1793)." This may be a later offprint of his
* 1786 work?
*      The translator has the quirk of invariably writing "it's" for "its".


Al. de Humboldt and A. Bonpland
Voyage aux Régions Équinoxiales du Nouveau Continent, fait en 1799, 1800, 1801, 1802, 1803 et 1804, par Al. de Humboldt et A. Bonpland; rédigé par Alexandre de Humboldt. Tome Premier
(Chez F.Schoell, Paris, 1814).

* Humboldt's detailed mirage report (see Note D, p. 625)
* This is the original, now available from Gallica.bnf.fr


A. von Humboldt
Relation historique du Voyage aux Régions équinoxiales du Nouveau Continent
(Brockhaus, Stuttgart, 1970).

* This is the republication sponsored by the Humboldt Foundation:
* "Neudruck des 1814-1825 in Paris erschienenen vollständigen Originals,
* besorgt, eingeleitet un um ein Register vermehrt von Hanno Beck"
*
* By far the most interesting passage is Note D on pp.625-631 of Band I.
* It contains quantitative measurements of zenith distance (though
* mostly on the scale of his quadrant, which contained 96 degrees, each of
* which corresponds to 56' 15") of several fixed points on islands, and of
* the sea horizon. He thus was able to observe the VARIABLE DIP and its
* relation to air and water temperatures, and to the color of the sea (p.
* 628). He cites Aristotle, Theophrastus, Büsch, Gruber, Monge, Brandes,
* Wollaston, Tralles, Woltmann, Biot. He mentions the Sanskrit phrase
* "mriga-trichná". He cites his own demonstration that, in the tropics,
* the water is nearly always 1 to 1.5 degrees warmer than the air, as the
* cause of the miraging. Most impressive!
* The Hooke citation is on p. 296 here.



*** GASTON TISSANDIER and JAMES GLAISHER (balloon) FILE ***

J. Glaisher
“An account of meteorological and physical observations in three balloon ascents made in the years 1865 and 1866,”
Report of the Thirty-Sixth Meeting of the British Association for the Advancement of Science , 367–401 (1867).

*
* Glaisher's 1865 Oct. 2 ascent, confirming NOCTURNAL INVERSIONS
*      [Cf. Brandes (1806), who may have been the first to notice them.]
* ". . . an accidental descent just at the time of sunset showed very
* little or no difference of temperature for a height of nearly half a mile.
* The question then arose as to whether it was possible that at night the
* temperature might increase with elevation, and not decrease as always
* heretofore had been considered . . . ." (pp. 367-368)
*      "The results of this first night experiment are very valuable; and,
* so far as one experiment can give, indicate that, on a clear night,
* the temperature, up to a certain elevation, increases with increase
* of elevation."      (p. 370)
* Comment on REFRACTION:
*      "Certain it is, from the very remarkable results obtained from the
* night ascents, which might, with sufficient number of observations,
* have important bearing both on the theory of astronomic refraction and
* on the theory of heat, that nocturnal observations deserve repetition
* and extension."      (p. 373)
*
* These remarks are repeated, without the tabular data, in his part of
* "Travels in the Air"
*      Google Books has several scans of this, but only the Harvard one
* is complete.


J. Glaisher, C. Flammarion, W. de Fonvielle, and G. Tissandier
Voyages Aérienes
(L.Hachette et Cie., Paris, 1870).

* Tissandier's part of this 19th-Century ``coffee-table'' book contains
* his brother's woodcut of the mirage over the English Channel, facing
* p.408, in "Troisième Partie: Voyages de MM. de Fonvielle et Tissandier":
* "Nous cherchons les falaises de Douvres et nous nous étonnone bientôt
* de ne pas voir les côtes de l'Angleterre qui ne sont pas bien distantes
* de notre aérostat; elles sont cachées par un immense rideau de vapeurs
* plombées, qui s'étend vers ce côté de l'horizon. Je lève la tête
* pour chercher la limite de cette muraille de nuages, et quelle n'est pas
* ma stupéfaction quand j'aperçois dans le ciel une nappe verdâtre qui
* ressemble à l'image de l'océan; bientôt un petit point semble se
* mouvoir dans cette plage céleste, c'est un bateau, gros comme une
* coquille de noix, et en y fixant avec soin mes regards, je ne tarde pas à
* constater qu'il navigue à l'envers sur cet océan retourné; ses mâts
* sont en bas et sa quille en haut. Un moment après je vois l'image du
* bateau à vapeur qui vient de partir de Calais pour l'Angleterre, et, avec
* ma lunette, je distingue la fumée qui s'échappe de son tuyau. Voici
* bientôt deux ou trois autres barques qui apparaissent au milieu de cette
* mer magique, tableau vraiment saisissant, d'une éblouissante
* fantasmagorie du mirage."


G. Tissandier
Histoire de mes ascensions
(Maurice Dreyfous, Paris, 1878).

* The popular summary of Gaston Tissandier's 24 balloon flights
* The first chapter (pp.119-127) contains a textbook example of the
* SEA-BREEZE circulation (see diagram, p.125) with a capping inversion at
* 600 m. It alludes to the mirage over the English Channel, but says the
* first 7 flights were described more fully in Hachette's "Voyages
* aériens" (1870).
* Drawings of distorted Sun- and Moon-rises are on pp. 260 & 261.
* There is a 2-page bibliography of aeronautics at the end.


G. Tissandier
“Le mirage de la Tour Eiffel,”
La Nature 18:1, 195–198 (1890).

* Tissandier's review of "mirages" -- some may be snowflake reflections?
* (The Eiffel-tower reflection is from l'Astronomie 9, 41-42 (1890), q.v.)
* Here is where he quotes extensively from his earlier work, but
* mis-attributes it to "Histoire de mes ascensions". The illustration by
* his brother Albert, showing the inverted images of ships on the North Sea,
* accompanies this article. As this illustration was based on his
* "crude sketch" made after the flight, it can hardly be regarded as an
* accurate observation.
*      NOTE: Gaston Tissandier was the founder, in 1873, of "La Nature".
* Eric Frappa tells me this is "Semestre 1".



*** ADMIRAL W. H. SMYTH FILE ***

W. H. Smyth
Sketch of the Present State of the Island of Sardinia
(John Murray, London, 1828), p. 80.

*
* (mostly minor references to mirage phenomena)
* N.B.: Admiral Smyth was the father of Charles Piazzi Smyth, q.v.
*
* "The deceitful phenomenon so well known in Barbary by the name of
* `sarab ,' is very frequent in the lower grounds of Sardinia; and while
* at Villa-Cidro, I one morning saw the whole Campidano appearing like a
* vast lake, with the hills of Cagliari in the distance resembling islands."


W. H. Smyth
The Mediterranean, a Memoir Physical Historical and Nautical
(J.W.Parker and Son, London, 1854).

* Discussion of mirages, pp. 288-291
* The Fata Morgana "is said to occur in sultry, calm weather, when the
* tides, or streamed-up waters, are at their highest, and when the sun
* shines from that point whence its incident rays form an angle of about
* 45° on the water. At such times, they tell us, multiplied images of
* all the objects existing on the two lines of coast -- as castles, arches,
* towers, houses, trees, animals, and mountains -- are presented in the air
* with wonderful precision and magnificence. Padre Minasi assures us that,
* in addition to obvious appearances, numberless series of pilasters,
* superb palaces with balconies, armies of men on foot and horseback, and
* many other strange figures, are seen in their natural colours and proper
* action, as in a catoptric theatre; and there exist paintings and
* engravings of the wonderful phenomenon. Still, on the whole, I cannot but
* repeat the conviction to which inquiry led me, and which I published as
* far back as 1824 ( Sicily and its Islands, page 109): -- `I much doubt,
* however, the accuracy of the descriptions I have heard and read, as I
* cannot help thinking that the imagination strongly assists these dioptric
* appearances, having never met with a Sicilian who had actually seen
* anything more than the loom or mirage, consequent on a peculiar state of
* the atmosphere; but which, I must say, I have here observed many times to
* be unusually strong.'"


W. H. Smyth
The Sailor's Word-Book
(Blackie and Son, London, 1867).

* Here is his famous "What's in a word?" discussion



*** SOLAR AFTERIMAGE FILE ***

Joh. Georg Sulzer
Johann Jacob Scheuchzers . . . Natur-Geschichte des Schweitzerlandes, Zweyter Theil
(David Geßner, Gbdr., Zürich, 1746), pp. 338–343.

*
* See also Kritzinger (1914), Vogel (1940) in Green Flash file.
*
* Johann Jacob Scheuchzer is sometimes regarded as the "father of
* paleobotany" because of his early work on plant fossils.
* Sulzer edited Scheuchzer's works and translated them from the Latin
* edition published at Leyden by Peter van der Aa in 1723, adding later
* material from Scheuchzer's contributions to Breßlauer Sammlung as well
* as some of his own speculations on the origins of the Alps (he thought
* they were produced by the Earth's center of gravity having shifted!) and
* the fossils in their sedimentary rocks (which he explained by Noah's
* Flood). He attempts to combine the physical evidence with a literal
* interpretation of Scripture.
*
* There are many amusing bits in this work, from the editor's railing
* against people who only buy books for the pictures ["Viele Leute lieben
* die Kupferstiche weit mehr, als eine Beschreibung der Sachen; ja einige
* kauffen die Bücher nur deßwegen. Diesen verständigen Liebhabern zu
* gefallen, hat der dienstfertige Verleger der Holländischen Ausgabe eine
* Menge Kupfer beygelegt, welche aus Merians Topographie genommen sind.
* Stücke, davon oft in dem Texte kein einiges Wort stehet. Diese hat man
* hier weggelassen, und vielleicht in eben der Absicht, in welcher sie Hr.
* van der Aa dazu gethan hat. Wer diesen Abgang nicht vertragen kan, der
* hat die Freyheit, die Holländische Ausgabe oder Merians Werck zu
* kauffen."] to the description on p. 238 (the wrong page number happily
* supplied by "M" in Gilberts Annalen) on how to tell real dragons from mere
* snakes: "Bochart . . . unterscheidet . . . die Drachen von den Schlangen durch
* nachfolgende Kennzeichnen: 1) Die Grösse. 2) Den Bart unter dem Kinn.
* 3) Eine dreyfache Ordnung der Zähnen. 4) Eine schwarze, feuer-rothe oder
* aschenfarbe. 5) Eine sehr grosse Oeffnung des Mundes. 6) Daß sie durch
* das Anziehen der Luft nicht diese allein, sondern auch vorbey fliegende
* Vögel an sich ziehen. 7) Ein erschreckliches und auf gewisse Weise
* trauriges Zischen, daher sie im Hebraischen Tannin genennt werden."
* (Some 20 pages are devoted to these supposedly real creatures.)
*
* Of more interest here is his observation (p. 42) of a "Phænomenon an
* der Sonne": ". . . da sie einen gantz neuen Habit angezogen, (zum wenigsten
* habe ich sie in solchem noch niemal gesehen). Abends um 5. Uhr ist bey
* neblichtem Himmel dieses sonst so hellglänzende Gestirn, zum wenigsten
* einige Augenblicke, in Mitten dem Nebel, in einer angenehmen purpur-blauen
* Farbe erschienen." As this is seen through "fog", I take it to be a
* "BLUE SUN" and not a bluish sunset flash, despite the "few moments"; as
* the date was July 29, 1703, this would be several hours before sunset.
*
* The solar after-images are nicely described under the heading "Von
* ungewöhnlichen in der Schweiz A. 1719. im Heumonat aus der Luft
* gefallenen Bläßgen oder Bullis " with a footnote: "Sihe gedachte
* Breßl. Sam~lung im Julio 1719, Class.IV. Art.IV." The classical
* particulars are there: a hazy sky, in which people could look at the Sun
* without discomfort; a series of images drifting across the sky; a variety
* of colors seen; the "bubbles" vanish into insubstantiality on falling to
* the ground; etc. "Es ist dieses völlig die gleiche Luft-Geschicht von
* Bläßgens oder Bullis , die A. 1553 den 21. Brachm. zu Sculs im
* Engadin ist angemerckt, und in unsrer Meteorol. Helv. p.96 beschrieben
* worden . . . ." Pfarrer Judas Uttiger in Lichtensteig sends him a detailed
* account, of which he writes that "er seye um dieser sehr seltsamen
* Luft-Geschichte willen zum drittenmal spazieren gegangen, und habe sich
* nicht genug verwundern können, daß die bey ihme stehende ihme gleichsam
* mit dem Finger die fliegenden und fallenden Luft-Kugeln gezeiget, deren
* er doch keine mit seinen eignen Augen sehen können." But those who lived
* on higher hills above the fog had seen nothing; "daraus sich schliessen
* läßt, die unterste Gegend der Athmosphaer seye sonderheitlich mit
* dicken Dünsten angefüllet gewesen, da hingegen die obere hell geblieben.
* Diese ganze Luft-Geschicht endlich scheinet es, könne als ein optisches
* Gesichtspiel, oder als ein Betrug unserer Augen, angesehen, und mit
* demjenigen verglichen werden, da einer, der die Sonne mit starren Augen
* anschauet, hernach, ob er die Augen gleich zuschliesset, das Bild der
* annoch scheinenden Sonne siehet oder zu sehen vermeynt, und sie zwaren
* siehet durch verschiedne Farben als roth, blau und so ferner, untergehen,
* bis sie völlig verschwindet."
* This is followed by two more very similar reports, in the last of which
* Scheuchzer himself finally gets to see the "Bläßgen" and confirms his
* opinion: ". . . so wie nemlich das dem Aug eingedruckte Bild der Sonne,
* welches eine Zeitlang, wann man auch gleich die Augen von der Sonne
* abwendete, bliebe, eine mehr oder minder stärckere Bewegung in den
* Augen-Nerven verursachte."
*
* The whole book is printed in old-style Fraktur, with little e's over
* the letters for umlauts. The Courier-like Roman type used is a poor
* match to the Fraktur. A much wider, different face is used for display
* type (still a Fraktur face). It's amazing that anyone would actually
* send this treasure out to another library; perhaps the dowdy 19th-Century
* re-binding deceived them into thinking it worthless.


Weise
“Notizen aus dem 17ten Jahrhundert von einigen merkwürdigen Meteoren,”
Gilb. Ann. Physik 30, 105–112 (1808).

* A collection of 17th-Century oddities, collected by "Landmesser Weise"
* taken from the Theatro Europaeo .
* Pp. 106-107 relate a double-Moon crescent of 15 July 1633.
* The SOLAR AFTERIMAGES are on pp. 107-108 and 109-110.


E. Acharius
“Besynnerligt Meteor-phenomén,”
Stockholm Acad. Handl. 29, 215–218 (1808).

* Erik Acharius's second-hand solar afterimage reports
* As Gilbert's German translation appears to be complete and satisfactory,
* see the next item for it.


E. Acharius
“Beschreibung eines besondern Meteors,”
Gilb. Ann. Phys. 52, 235–239 (1816).

* An early SOLAR AFTERIMAGE report (see next item for explanation)
* Also a good example of "mass hysteria" or mutual brainwashing by
* the inhabitants of a village: everybody came to believe "eine Menge
* Kugeln oder sphärische Körper nach einander mit Geschwindigkeit
* aufsteigen, die dem blossen Auge von der Grösse eines Hutkopfes
* erschienen, und eine dunkelbraune Farbe hatten." The mysterious
* "balls" vanished soon after falling to earth. One person saw them
* first, "und als es so lange dauerte, wurden nach und nach alle
* Dorfbewohner darauf aufmerksam, so dass es keine Täuschung seyn konnte,
* die bloss bei einem und dem andern Individuum hätte möglich seyn
* können." The Sun had been dimmed by a haze so "dass man ohne
* Unbequemlichkeit mit blossen Augen in sie hinein sehen konnte."


"M."
“Eine Bemerkung über das besondere, von Herrn Acharius beschriebene Meteor, welches vor einigen Jahren in Schweden gesehen worden ist,”
Gilb. Ann. Phys. 52, 342–343 (1816).

* The above phenomenon explained: ". . . der Grund der Erscheinung in einer
* Blendung der Augen durch die Sonne liege." The anonymous correspondent
* in Göttingen points out some earlier examples: "Dasselbe Phänomen
* erwähnen frühere Schriftsteller beinahe mit denselben Worten."
* Certainly true; but he gives the wrong page number (238 for 338) in
* Scheuchzer's Natur-Geschichte.


K. P. Jessen
“Neobyknovennoe yavlenie refraktsii, nablyudennoe v Yaponskom morye,”
Izvestiya Imperatovskogo Geograficheskogo Obshchestva 50, 95–100 (1914).

* Admiral K. P. Jessen's odd account: afterimage or bleached areas?
* After establishing himself as an experienced observer of phenomena at
* sea in "my numerous navigations, carried out in all nearly 40 years,"
* with a brief account of mirages and looming seen in the Baltic in June,
* 1895, he gets to his main theme: an observation made at sunrise on 25
* Feb., 1902, 12 miles off "Cape Boltin, on the eastern coast of Korea."
*      "Standing on the command bridge together with the senior and junior
* navigating officers and the officer of the watch, I observed the rising
* sun: the horizon was perfectly clean, free of clouds and the rising
* sun appeared to us, as always, in the form of a continually increasing
* bright segment. Suddenly I, and behind me also the aforesaid officers,
* noticed on the perfectly clean disk of the sun a dark spot, continually
* increasing just like the rising sun above the horizon and little by
* little taking on the obvious form of a high mountain. In a few seconds
* a new spot appeared on the left beside this peak, gradually changing into
* another such summit, but lower, separated from the first by a deep pass.
* Finally, the entire disk of the sun was covered from limb to limb by
* a whole mountain massif, reaching to the very lowest limb of the sun as
* it rose. Just as the whole solar sphere separated from the water horizon,
* the whole phenomenon instantly vanished."
*      The accompanying drawings, based on sketches made as soon as he
* returned to his cabin, show two steep mountains appearing to rise together
* with the Sun, so that their image remains fixed with respect to its disk.
* (Considering the latitude of over 40°, this is impossible.) The
* Sun's disk is shown round, with no distortions.
*      "Obviously, those mountains which we saw so clearly on the solar
* disk had to be on a line between us and the rising sun. And, indeed,
* by constructing on a chart the aforementioned azimuth of the sun at the
* moment of its rising, it turned out that this line passed just through
* the high mountain Tonvumi-yama , located on the north-western part of the
* Japanese island of Nippon [sic -- he means Honshu], at north latitude
* 39° 5' and east longitude 140° 10', not far from the city of Akita.
* The distance from the cruiser to that mountain was 480 sea miles."
* An accurate calculation gives 897 km or 490 nautical miles.
*      He later gives the height of the mountain as 7130 feet.  The only
* mountain of this height near this location is Chokai-San; I cannot find
* any place in Japan with the peculiar name of "Tonvumi-yama" (which he
* repeats later); it might be a mistake for the lower peak Tokami-Yama.
* Photographs of Chokai-San show it has shallow slopes, like Mt. Fuji,
* quite unlike the "mountain" in the drawings. (As the Sun appears
* undistorted, the mountain should, too -- if it were real.)
*      His sunrise azimuth of 77° 40' E from S (or 102.3° by the usual
* astronomical convention) agrees well with calculation for the stated
* date and coordinates. He gives the time of sunrise as 6h 4m but fails
* to state whether this was LCT or zone time; predicted sunrise for the
* ship's position is indeed 6:04 zone time, however. As "The state of
* the weather was most ordinary: a light breeze and calm sea" and the
* accompanying table of meteorological data shows the water and air to
* have the same temperature within a few tenths of a degree, the most
* reasonable conclusion is that there was no mirage at all, and that the
* "mountain" was illusory. His drawings show the *lower* limb of the Sun,
* even where it should be occulted by the "mountain" if it were real!
*      I conclude that the "dark spots" were either afterimages or bleached
* areas on the observers' retinas. We have no direct accounts from the
* other officers present; they would be unlikely to contradict their
* commanding officer, I suspect.
*      Note that Korzenewsky (1923) says the distance claimed here was 1177 km
* but the actual value is just under 900 km.
*
* The title translates as:
*
* "Unusual phenomena of refraction observed in the Japanese Sea."
* "Read at the I.R.G.O. session for the sections of mathematical and
*                               physical geography, March 11, 1914"
*             Reports of the Imperial Russian Geographical Society
*
*      Of course the pre-Revolutionary alphabet and spelling are used:
*
*      К. П. Іессенъ
*      Необыкновенное явления рефракціи, наблюденное въ Японскомъ морѣ
*      Известія Императорскаго Русскаго Географическаго Общества
*



*** CROCKER LAND FILE ***

Anonymous
“The Peary expedition to the North Pole,”
Times (Lond.) , p.6 (20 July, 1908).

*
* Early mention of "Crocker Land" in the London Times
* "Crocker Land" appears 5 times, in passing.
* Dateline is "from our correspondent", New York, July 7 (1908)


Anonymous
“The Crocker Land Expedition under the auspices of the American Museum of Natural History and the American Geographical Society,”
Science 35, 404–408 (1912).

* Plans for the "Crocker Land Expedition"
* "It is estimated that not less than fifty thousand dollars ($50,000)
* must be provided for the absolute needs of the expedition, in order to
* enable it to accomplish the valuable results that have been outlined
* above . . . . Subscriptions to the fund are invited."
* At this point, the expedition was to have been led by George Borup,
* then only 5 years out of Yale, with Donald B. MacMillan.


Anonymous
“The Crocker Land Expedition,”
Science 38, 120–121 (1913).

* The start: it is now "George Borup Memorial" with MacMillan leader
* "The original program of work for the expedition contemplated two
* years or three summer seasons in the Arctic, but supplies have been
* taken north which will enable the party to remain three years or even
* longer . . . ."


Anonymous
“Crocker Land eludes explorers,”
New York Tribune , pp.1, 4 (Nov. 25, 1914).

* The New York Tribune announcement that "Crocker Land" was a mirage
* "The news that the land was not seen . . . where Peary sighted it eight
* years ago, was received yesterday by the American Museum of Natural
* History. The news was relayed . . . through the courtesy of Knud
* Rasmussen" who is quoted from an interview. The word was received
* second-hand from Ekblaw, who met Rasmussen's men while hunting.
* MacMillan's full report "will wait until spring at Upernavik for the
* first Danish boat to convey it to Copenhagen. The report will then be
* cabled to the Tribune . . .      probably in April or May. . . ."


Anonymous
“The Crocker Land Expedition,”
Scientific American 111, 489 (Dec. 12, 1914).

* Scientific American reports that the N.Y.Tribune is the "mouthpiece"
* of the Expedition, and reports that the news that "Crocker Land does
* not exist" was in the Nov. 25 issue of the Tribune .


D. B. MacMillan
“In search of a new land,”
Harper's Mag. 131, 651–665, 921–930 (1915).

* Donald B. MacMillan's report on the expedition, in HARPER'S
* Contains the first-hand MIRAGE reports.
*
* There's not much of interest in the first installment, except for a
* discussion on p. 654 in which he mentions that he made a point of
* getting rid of "the older and more influential Eskimos, who seemed to
* be very much afraid of walking home in case their dogs should die. In
* a discussion of this kind as to what they should do, the younger men of
* the party listen respectfully to the opinion of their elders and do as
* they advise. Young Eskimos on a long and dangerous trip are much to be
* preferred, for they are fond of adventure and willing to take a chance,
* while the older men wish to make certain of getting home." He then
* says, "From the sixteen Eskimos I picked out seven who appeared to me
* to be of the right stuff and who, I thought, would go the limit."
*
* The second installment tells of reaching "Crocker Land" and contains
* the various well-known (but usually uncited) quotations. Page 924:
* "April 21st was a beautiful day; all mist was gone, the clear blue of
* the sky extending down to the very horizon. Green was no sooner out of
* the igloo than he came running back, calling in the door, `We have it!'
* Following Green, we ran to the top of the highest mound. There could be
* no doubt about it. Great heavens, what a land! Hills, valleys,
* snow-capped peaks extending through at least 120 degrees of the horizon.
* Anxiously I turned to Pee-ah-wah-to, asking him toward which point we
* had better lay our course. After critically examining it for a few
* minutes, he astounded me by replying that he thought it was `poo-jok'
* (mist). Ee-took-ah-shoo offered no encouragement, saying, `Perhaps it
* is.' Green was still convinced that it must be land. At any rate, it
* was worth watching. As we proceeded it gradually changed its appearance
* and varied in extent with the swinging around of the sun, finally at
* night disappearing altogether. As we drank our hot tea and gnawed the
* pemmican we did a good deal of thinking. Could Peary with all his
* experience have been mistaken? Was this mirage which had deceived us
* the very thing which deceived him eight years ago? If he did see
* Crocker Land, then it was considerably more than one hundred and twenty
* miles away . . . ." On the next page he mentions "our almost constant
* traveling companion, the mirage. We were convinced that we were in
* pursuit of a will-o'-the-wisp, ever receding, ever changing, ever
* beckoning." He then quotes from Peary's "Nearest the Pole" book (but
* gives no page reference.)
*
* On the return trip (p. 927): "Throughout the day the mirage of the sea
* ice, resembling in every particular an immense land, seemed to be
* mocking us. It seemed so near and so easily attainable if we would
* only turn back." On p. 928, he is standing on "the very spot" where
* Peary "saw what resembled land. The day was exceptionally clear, not a
* trace of a cloud or mist; if land could ever be seen, it could be now.
* Yes, there it was! It could even be seen without a glass extending
* from southwest true to north-northeast. Our powerful glasses, however,
* brought out more clearly the dark background in contrast with the
* white, the whole resembling hills, valleys, and snow-capped peaks to
* such a degree that, had we not been out there for one hundred and fifty
* miles, we would have staked our lives upon it. Our judgment then as
* now is that this was a mirage or loom of the sea ice."
* Oct. & Nov. issues


C. A. Reeds
“A perplexing phenomenon — Mirage,”
American Museum Journal 16, 512–524 (1916).

* a MIRAGE review article
* A popular and not very critical review, prompted by the article in
* Harper's Magazine debunking Peary's "Crocker Land". The images are
* drawn in both inferior and superior mirages at exactly the same
* distance from the observer as the object. He thinks the intermediate
* images in multiple mirages are all inverted, with only the top and
* bottom ones erect. (p. 519)
*      The striations of the Fata Morgana are supposedly "parallel with the
* axes of cylindrical air fields." [sic!] (p. 520)


Anonymous
“The Crocker Land Expedition,”
Science 45, 609–610 (1917).

* The rescue (3rd attempt!)
* Dr. Hunt has made it back, but MacMillan et al. are still isolated in
* northern Greenland. "Direct news" from MacMillan said "that he and
* his companions had only enough supplies to last them until August of
* this year" and that "both relief vessels sent to his aid, the
* George B. Cluett and the Danmark , have failed to reach him and urges
* that a third be sent . . . . This third effort to reach the party will
* cost at least $40,000, provided that the Neptune is able to reach the
* base at Etah . . . . The Committee hopes that in view of the extraordinary
* expenses it will receive substantial financial aid from the public."
* June 15 issue


Anonymous
“The Crocker Land Expedition,”
Science 45, 655–656 (1917).

* Further reports from Dr. Hunt
* The Danmark is stuck in 6 feet of ice and low on coal.
* June 29 issue


D. B. MacMillan
Four years in the white North
(Harper & Brothers, New York, 1918).

* Donald B. MacMillan's book
* This is the full text of the manuscript excerpted by Harper's in 1915.
* Some editor has now tidied up the prose a bit, restraining the somewhat
* breathless pace of the magazine version.


H. J. Hunt and R. H. Thompson
North to the Horizon: Searching for Peary's Crocker Land
(Down East Books, Camden, Maine, 1980).

* Dr. Harrison Hunt's story, assembled by his daughter, Ruth Hunt Thompson
* Apparently, the Expedition came near mutiny because MacMillan traded
* necessary supplies to the Eskimos for furs; see p. 71.
* According to Dr. Hunt, MacMillan was irresponsible and had
* "hoodwinked" the Museum. His view was shared by Captain Comer [of the
* Neptune ], who told Hunt's wife that "The whole expedition was founded
* on selfishness. Peary reached a little too far, wished to see land,
* thought he did, and claimed it, resulting in the Crocker Land fiasco . . .
* MacMillan used the expedition as his plaything . . . Dr. Hovey was
* penny-wise and pound-foolish . . . The Cluett was a sailing vessel, not
* fit for a relief ship, and not properly prepared . . . The last two years
* were the hardest, and they were unnecessary." (p.107)



*** STRANGE PHENOMENA FILE (MULTIPLE IMAGES, illusions, etc.) ***

Laugier
“Observation faite a l'île d'Ouessant sur le coucher du soleil du 22 juillet 1854,”
C. R. Acad. Sci. (Paris) 39, 409–410 (1854).

*
* See also p. 207 of T.Forster (1824) for a double lunar crescent
*
* Probably an early BLEACHING observation
* "La journée avait été superbe, le ciel était sans nuages et
* la mer tranquille comme un lac. Le soleil, fort près de l'horizon,
* était rougeâtre comme dans les couchers ordinaires, et son disque
* paraissait à l'oeil nu parfaitement bien terminé. Le bord inférieur
* toucha d'abord l'horizon de la mer, puis le disque s'y enfonc,a peu à
* peu sans se déformer et en conservant sa netteté. Au moment où le
* centre de l'astre atteignait la ligne parfaitement définie qui limitait
* l'horizon de la mer, la partie supérieure du disque, la seule qui fût
* encore visible, se teinta subitement en bleu. Cette teinte nous sembla
* uniforme; elle rappelait exactement le bleu des liquides renferme's dans
* les bocaux que l'on voit ordinairement sur les devantures des pharmacies.
* Ce phénomène persista tout le temps qu'on vit la partie supérieure
* du soleil. Aussitòt après le coucher, l'horizon présenta son aspect
* ordinaire. On distinguait encore, à quatre ou cinq degrés au-dessus
* du point où le soleil avait disparu, trois petits nuages sous-tendant
* chacun un angle d'un ou deux degrés : encore éclairés par le soleil,
* leur lumière était, comme avant le coucher, d'un rouge cuivre très-vif.
* Je n'était pas seul à observer ce curieux spectacle . . . . A quelques
* détails près, nous avons tous été d'accord quand nous avons rassemblé
* nos souvenirs."
* Thanks to Luc Dettwiller for finding this!


Prof. Dr. Reimann
“Spiegelungen der Mondsichel,”
Met. Zs. 4, 144–145 (1887).

* This is the MULTIPLE LUNAR CRESCENT mirage reproduced by Minnaert!
* cf. Clark et al., M.O.1964, and Fultz, 1951.


J. Mintern
“A kaleidoscopic Sun,”
Met. Mag. 58, 10–11 (1923).

* Iridescent corona? Or what?


A. Hofmann
“Interessante Beobachtung einer Sonnenspiegelung,”
Met. Z. 49, 439–440 (1932).

* A curious observation -- not exactly a mirage, though.


D. Fultz
“An unusual double-refraction at high levels in the tropics,”
Bull. AMS 32, 102 (1951).

* MULTIPLE IMAGE SPLITTING


P. J. E. Marshall
“Abnormal refraction, North Atlantic Ocean,”
Marine Obs. 22, 125 (1952).

* Probably not "abnormal refraction" at all, but an AFTERIMAGE report
* "The sun was setting, and about one minute after the sun's upper limb
* had completely disappeared below the horizon five completely circular
* images of the sun were seen to shoot up into the sky at about five
* second intervals."
* The Editor's comment that "it is obviously due to some peculiar form of
* abnormal refraction" is obviously wrong.


R. Richard
“Phénomène optique remarquable,”
La Météorologie , series 4, 32, 301–302 (1953).

* MULTIPLE IMAGES OF THE SUN


E. Vassy
“Quelques remarques sur un phénomène de mirage du disque solaire,”
La Météorologie , series 4, 32, 302–303 (1953).

* ?? Off-base comment on the preceding report


E. G. O'Driscoll and F. G. Gurney
“Abnormal refraction, Van Diemen Strait, Japanese waters,”
Marine Obs. 24, 210 (1954).

* Would be an ordinary inf.-mir. sunrise, but 1st drawing makes no sense.
* N.B.: later drawings use circles; so drawings may not be accurate.


A. E. Williams
“Abnormal refraction, North Atlantic Ocean,”
Marine Obs. 24, 210 (1954).

* ANOMALOUS COLOR CHANGES of MOON
* "The moon also appeared to be changing colour from the normal yellow to
* green and deep red, and then back again, with a frequency of about 5 sec
* for the complete cycle."
* Otherwise, this would simply be a distorted moonrise.


O. Springett and G. Lowery
“Double Moon, South Pacific Ocean,”
Marine Obs. 25, 34 (1955).

* DOUBLE IMAGE of MOON
* The colors seen here suggest a grating image. There had been heavy
* rain; could this be a wet grating on a window?


L. Poncelet
“Un curieux phenomene de refraction atmospherique,”
Ciet et Terre 71, 350–351 (1955).

* DOUBLE (??) IMAGE OF SUN
* Surely this can't be right! Because it was taken with a short (45mm)
* lens, and the photo shows cloud strips, I suspect this is simply an
* overexposed image divided by a strip of cloud. It seems impossible to be
* a refraction effect as claimed, at 7 deg. 20 min. above the horizon!


J. K. Currie and J. Isbester
“Double Moon, Indian Ocean,”
Marine Obs. 26, 9 (1956).

* another fishy-sounding report:
* ". . . disappeared when viewed through a telescope . . . "


C. Rowntree
“Abnormal refraction, North Atlantic Ocean,”
Marine Observer 27, 84–85 (1957).

* DOUBLE SUN
* "The image was to the right of the true sun, there being no distortion
* of either. This phenomenon persisted for 2 min, after which the image
* gradually elongated in the direction of the true sun, eventually merging
* with it within 1/2 min."
* I think the editor's remarks are off the mark ("lateral mirage").


S. Gordon
“A green sun after sunset,”
Met. Mag. 87, 277–278 (1958).

* Certainly NOT a GF report; the colors sound like mother-of-pearl clouds,
* but the sharp outline is a puzzle.
* The editor's comments, which continue on p.278, are certainly off the mark.


G. W. B. Lloyd
“Abnormal refraction, South Atlantic Ocean,”
Marine Obs. 29, 177–178 (1959).

* MULTIPLE LUNAR CRESCENTS


L. G. Williamson
“Abnormal refraction, South Pacific Ocean,”
Marine Obs. 29, 178 (1959).

* MULTIPLE LUNAR CRESCENTS


D. H. Clark, P. J. Morgan, and P. Dawson
“Abnormal refraction, Eastern Mediterranean,”
Marine Obs. 35, 122 (1965).

* MULTIPLE LUNAR CRESCENTS
* The drawing is impossible -- something fishy here.
* (A crescent Moon cannot be seen when line of cusps is vertical.)


M. Minnaert
“Unusual or neglected optical phenomena in the landscape,”
JOSA 58, 297–303 (1968).

* Minnaert's review in JOSA
* Minnaert accepts the multiple images as real, largely because of
* Richard's photograph.


J. Richmond, W. Downing, R. Jones, R. C. Corbett, and R. Bush
“Abnormal refraction, South Pacific Ocean,”
Marine Observer 46, 172–173 (1976).

* PHONY MULTIPLE LUNAR CRESCENTS
* These multiple images appear to be caused by reflections between glasses
* and eyeball? They are CERTAINLY SPURIOUS, as "This phenomenon could not
* be observed through binoculars or a telescope, it was, however, seen
* through `Polaroid' sunglasses. The phenomenon was also observed, though
* to a lesser degree, on the next five nights."
* The appearance also changed with position of the head, etc.


Anonymous
“Moonfleet,”
New Scientist 173, no. 2334, p.ibc (16 March, 2002).

* MULTIPLE MOONS
* Several disparate phenomena are reported, but treated as if they
* were identical. The original report sounds like a reflection, but too
* few details are provided to identify it. The "answer" provided by John
* Richfield "explains" the report as a mirage, which it cannot be (because
* of the duration of over an hour). Richfield also seems to confuse
* inferior and superior mirages, and understands neither. The second
* "answer", supplied by Hector McDonnell, is clearly a sundog report;
* but he attributes it to "reflection of the Moon and Sun at particular
* angles off the water droplets", which is bizarre nonsense.
* Thanks to Storm Dunlop for the reference!


H. Gudiksen
“Moonfleet,”
New Scientist 173, no. 2336, p.ibc (30 March, 2002).

* MULTIPLE MOONS
* A photograph that most likely shows a ghost image in the camera;
* certainly *not* an atmospheric phenomenon.
* Thanks to Storm Dunlop for a scan of the image!



*** "FOG" / DARK BAND --> this is the FOG FILE ***

C. N. Brown
“Mirage after sunset,”
Mon. Weather Rev. 33, 323 (1905).

* cf. photo in Gossard & Strauch book
* For early mentions of "fog", see Marra (1775?), Dickenson (1793),
* Mureau (1798, 1799), Beauford (1802). Kelly (1832), Parnell (1869),
* and Upham (1895).
* also: Schnippel; Bonnelance 1929; P&E pp.184-186 give a bad discussion.
*
* Many lights seen (looming?) from Staten Island at 8 pm, Aug.16
* "All this was seen right side up, and you can imagine how keenly we
* enjoyed it all and longed to reproduce it with a camera. After ten
* minutes during which time we went down to the beach (fourteen feet to
* sea-level), the vision passed suddenly away. At that moment the mirage
* cloud, which was before invisible, was seen. Then we saw in the usual
* place the real lights of Coney Island. This cloud was entirely
* horizontal, very narrow, black, and stationary."


F. J. W. W(hipple)
“The false horizon,”
Met. Mag. 55, 256 (1920).

* "The objects of this note are two: the first is to inquire whether there
* is any popular name for the phenomenon, which is, I am told, well known to
* sailors; the second is to ask for references to any measurements of sea
* and air temperatures in conjunction with observations of this character."


R. H. Jenkins
“Mirage at Skegness,”
Met. Mag. 56, 290 (1921).

* "At about mid-day peculiar cloud effects were noticed on the horizon,
* giving the appearance of a well-wooded tropical coast line. This became
* somewhat indistinct until 16 h. 30 m., when a faint darkness appeared on
* the horizon, increasing in density and in its liquid appearance until
* objects were noticed in an inverted position at an altitude of about two
* degrees [!] above the horizon."


W. Ullrich
“Starke Luftspiegelung im Golf von Tschili,”
Ann. Hydrog. Maritim. Met. 55, 352–353 (1927).

* "FOG" and STRIPES and mirages; TEMPERATURE of air about 4 deg. above water
* ". . . über dem ganzen Horizont ein mehr oder weniger starker
* Dunstschleier,. . . " followed by mirages of ships and looming of lights.
* "Gegen Abend bildeten sich in geringer Höhe über der Kimm die bei
* Luftspiegelungen gewöhnlich auftretenden Streifen, besonders am
* westlichen Horizont, also gegen die Sonne . . . ."
* N.B.: The Gulf of Chihli is the NW arm of the Yellow Sea, usually
* denoted as Bo Hai today, where the Yellow River has its mouth.
* November issue


J. R. Sherwood
“Mirage off Newfoundland,”
Met. Mag. 67, 259 (1932).

* Might be REAL FOG in the Straits of Belle Isle?
*      "At 8h. on August 17th, . . .  although it was perfectly clear and
* sunny where I stood on the shore, there was an extensive layer of fog
* at the scene of operations, about three miles out, and only the smoke
* of the Empress was visible above the layer. . . . I was startled to
* see the Empress above the fog completely upside down with her hull
* pointing skywards and her masts apparently resting on the layer of fog.
* The illusion lasted for about one minute and was perfectly clear in
* every detail when it finally disappeared and the ship came out of the
* fog in its normal position.
*      "On a previous occasion I saw three mountains on the Newfoundland
* coast, fifteen miles distant; their summits appeared to be resting on
* the water while the bases were pointing skywards."
* Dec. issue; cited in Hurd's review


W. E. Hurd
Refraction and mirage (on reverse of Pilot Chart of the North Atlantic Ocean)
(Hydrographic Office, Washington, DC, 1937).

* Willis Edwin Hurd's mirage review speaks of "MOCK FOG"
*       [Filed separately, because of bulk]
* A review of observations, mostly from the later 1920s and a few from
* the early 1930s; most taken from Marine Observer, but a few "from the
* Hydrographic Bulletin, published by the U.S. Hydrographic Office."
* There is a clear explanation of the terminology, but the observations
* are sometimes misinterpreted, and he seems to count looming in with
* mirages. He unfortunately also says the visibility of objects above
* the horizon when they are geometrically below "is of course an optical
* illusion." [middle of 4th paragraph]
*      In the middle of col. 3, he first says ". . .  along the line of
* sharpest density change . . . " and then later ". . . a further line of
* density discontinuity." Could this be where O'Connell got the notion
* of "surfaces of discontinuity"?
*      The lower part of Col.4 discusses the effects of height of eye, and
* distance to the miraged objects.
*      The end of col. 5 discusses "mock fog and haze bands".  The "fog"
* aspect is emphasized throughout the paper. He also uses the phrases
* "simulation of fog" and "optical haze".
*      The bottom of col. 6 mentions "waterfalls" that are apparently
* either discontinuities in the "horizon", or Lehn's "sea fences".
*
* Cites Barlow (1935, in "Mirage File"), as well as several other
* sources. Because of the large size, this is printed in 8 columns.
* This is known to have appeared on the backs of many Pilot Charts;
* I have seen references to ". . . of the Central American Waters" as
* late as 1944.
*
* THANKS to many people for finding this elusive item! Brenda Corbin
* was instrumental in getting in touch with the NIMA people, who
* eventually came up with it. I had references in the 1930s and '40s;
* but the last paragraph is a post-script saying that Barlow's article
* had appeared "Since preparation of the present . . . article". So the
* writing was evidently done by early 1935. According to Howard J. Cohen
* at NIMA, this was actually published in 1937. Finally, the chart was
* found in a *bound* volume by Albert E. "Skip" Theberge, Jr., at NOAA!
* But, as the format was about 3 ft by 4 ft (that's 75 x 100 cm for the
* metric part of the world), it was too big to photocopy. . . .
* He finally managed to get it photographed and scanned (as a 214 MB
* TIFF file!) Thanks to all these people for their Herculean efforts!


W. S. Skelton
“Nebraska mirages,”
Nature Mag. 34, 479 (1941).

* "When a gray, rather smoky and unnatural-appearing cloud lies along the
* horizon in the early morning, it is generally mirage material. Such a
* cloud will usually form into a clear cut mirage before the morning passes."
* "One fresh morning last autumn . . . a smoky, unnatural cloud graced the
* horizon to the southwest."
* "In the atmosphere at each end of the display the scenery feathered out
* into a misty cloud, which in turn extended ever dimmer into the clear
* sky."


R. Leeds
“Mirage, Spanish coast,”
Marine Obs. 17, 12–13 (1947).

* "The apparent bank of fog was probably an effect of mirage of the horizon."
* Air was 4 F warmer than sea.
* Note: this is shortly after M.O. resumed publication after WW II.


H. L. Holland and C. R. Kelso
“Abnormal refraction, Bay of Fundy,”
Marine Observer 22, 125 (1952).

* "From afar, it appeared as if the whole coastline was engulfed in a belt
* of fog with the higher land showing clear."
* "Air temperature 60 F, wet bulb 57, sea 55. The wind was light and
* variable."


S. L. Hoare, J. L. Blanch, and J. L. Chapman
“Abnormal refraction, South African Waters,”
Marine Observer 22, 125–126 (1952).

* "Approaching Cape St. Francis, a white mist appeared to creep under the
* land and apparently divided it from the sea." See Plate 2, facing p.128


J. McP. Pratt
“Abnormal refraction, Gulf of Aden,”
Marine Observer 24, 142 (1954).

* Here the band is described as a "DUST STORM"
* DOUBLE IMAGES appear in the "dust" band (with its "sharp top outline"!)


K. D. Billinghurst
“Abnormal refraction, South African waters,”
Marine Observer 25, 100–101 (1955).

* EXCELLENT detailed account of "FOG"
* flanked by rather ordinary mirage reports.
* ". . . what at first appeared to be a fog bank proved to be a mirage.
* With the coastline on the starboard side, distant 15 miles, a dark-blue
* mass, having every appearance of land with undulations as of hills, was
* seen on the port bow from about 4 points to 1 point off the bow where it
* faded into a white band above the horizon."
* ". . . the smoke from these whalers and from our own ship did not rise
* above mast height, but flattened out and hung in the atmosphere in a great
* band about 100 ft above sea level."
* Many nice details of observation, including the effect of eye height.


A. S. M. Jamieson and D. G. Whiteley
“Abnormal refraction, Tasmanian waters,”
Marine Observer 27, 83 (1957).

* ". . . a greenish fog or smoke bank . . . "


D. G. Whiteley
“Abnormal refraction, Strait of Gubal,”
Marine Observer 27, 83 (1957).

* ". . . a heavy whitish mist . . . "


B. P. Telfer
“Abnormal refraction, South Pacific Ocean,”
Marine Observer 27, 83–84 (1957).

* RED LINE MOONRISE (filed in wrong file here; on same page as previous)
* Seems to be also an example with a dark strip of sky at horizon (false hor.)
* ". . . was obviously in, not on, the water. . . . The moon then rose and the
* red, flame-like light disappeared, to be replaced by two half-moon shaped
* glows in the water."
* Probably belongs in "distorted" file?


B. G. Turner
“Abnormal refraction, Marguerite Bay, Antarctica,”
Marine Observer 30, 16–17 (1960).

* NICE SKETCH
* ". . . the lower ridges were obscured by a grey haze in which appeared
* many inverted icebergs. . . ."


R. J. Craddock
“Abnormal refraction, off Cape Finisterre,”
Marine Observer 30, 65 (1960).

* "All round on the seaward side, there was what looked like a high thick
* bank of fog, which at times resembled a mountainous coastline. This was
* found to have no real existence as it continued to recede as the ship
* advanced."


J. B. James
“Abnormal refraction, South Atlantic Ocean,”
Marine Observer 30, 66 (1960).

* NICE DRAWINGS
* ". . . towards sunset, when the sun's upper limb was still well above the
* horizon, an inverted image of this limb, but smaller in area, appeared
* beneath a narrow band of Sc lying very low on the western horizon."
* (Dwg. says "layer of stratocumulus not formed by the spreading of cumulus"
* and it is drawn absolutely flat -- blank strip?)


C. H. P. Brown and A. H. Hodgson
“Abnormal refraction, Australian waters,”
Marine Observer 30, 66 (1960).

* NICE DRAWINGS
* "The presence of a heavy grey-brown mist for much of the day gave rise
* to the impression that there was a double horizon. . . .      Cliffy Island
* and other small islands appeared very clearly on the `upper' horizon while,
* projecting downwards from them, was a mass of wavy-looking grey-green mist
* and haze." (triple images, a pair between the horizons)
* "Air temp. 81 F, sea 69."


J. M. Connoly and A. D. Fraser
“Abnormal refraction, South African waters,”
Marine Observer 30, 133–134 (1960).

* NICE DRAWINGS of DISTORTED MOONRISE
* (belongs elsewhere, but is filed here because of the next item)


D. A. Hunt, A. O. Proudfoot, and B. G. Gouldthorpe
“Abnormal refraction, Australian waters,”
Marine Observer 30, 134 (1960).

* NEGATIVE DIP
* "During the afternoon the horizon was elevated by between 7 and 10
* minutes of arc above what appeared to be the normal sea horizon.
* All round the horizon there was a band of what looked like fog or mist
* but, on approaching the land, this mistiness disappeared."
* [Note observation of CONCAVE surface.]


J. Ratcliffe, T. V. Kinley, and R. J. Carty
“Abnormal refraction, Great Bank, Newfoundland,”
Marine Observer 32, 62 (1962).

* DOUBLE DARK BAND sketched -- just sup. mirages of the ocean?
*      ??? This seems to call for a weak duct inside a stronger one.
* "Around the horizon there appeared to be a large bank of fog, topped by
* two thin layers of low stratus. Beneath each layer of cloud there was an
* inverted image of the tanker. . . ."


J. Pilling and D. L. Smith
“Abnormal refraction, South Australian waters,”
Marine Observer 34, 18–19 (1964).

* ENLARGED DRAWING OF STRUCTURE
* ". . . the horizon appeared to become raised above the sea and separated
* from it by an indistinct misty band. . . . (opposite to the sun) the
* appearance was that of a bank of fog."


J. J. Gomez
“Abnormal refraction, Western North Atlantic,”
Marine Observer 35, 122 (1964).

* ". . . a layer of haze, dark grey in colour and with a clearly defined
* upper surface, was seen all round the horizon. One ship appeared to be
* completely inverted and an iceberg which was not visible to the naked eye,
* seemed to be hanging upside down from the top of the layer."


D. H. Clark, P. J. Morgan, and P. Dawson
“Abnormal refraction, Eastern Mediterranean,”
Marine Observer 35, 122 (1964).

* DOUBLED CRESCENT MOON like the one shown in Minnaert (Reimann, 1887)
* (same page as above; belongs in STRANGE PHENOMENA file)



*** LAPLACE, EXTINCTION, and AIRMASS FILE (see also LINK, below) ***

de Mairan
“Memoir sur la Cause generale du Froid en Hiver, & de la Chaleur en Eté,”
Mem. Acad. Roy. Sci. 1719, 104–135 (1721).

*
* JEAN JACQUES D'ORTOUS DE MAIRAN's first paper on extinction
* He supposes the temperature difference between summer and winter is
* partly due to absorption of the Sun's heat in the atmosphere.
* Curiously, he invokes what is essentially Lambert's [1760] cosine law,
* by introducing the sines of the angles of "incidence" [by which he
* clearly means the altitudes, not the usual angle]; but then decides
* the factor of 3 between the noontime illuminances ought to be squared
* to allow for shadowing by irregularities (pp. 106-107).
*      Then he worries about the reflection loss at the upper surface of the
* atmosphere, which he argues might increase with obliquity, as does the
* reflection from water into air as the angle of total internal reflection
* is approached (p. 110). [There is an interesting quote from an earlier
* author about this surface.] But he decides that this is not what happens;
* on p. 111 he argues that the disappearance of the refracted light is
* abrupt. So he thinks the winter attenuation is due to the longer path.
* "Chaque rayon prêt à entrer dans l'Atmosphere, peut être consideré
* comme une balle de Mousquet tirée contre la surface de l'eau d'un
* Bassin, laquelle aura d'autant plus de chemin à faire dans l'eau,
* avant que d'en toucher le fond, qu'elle y fera tirée plus obliquement."
* So he argues that the path is inversely proportional to the sine of
* the angle of incidence, and that the intensity should therefore (!) be
* reduced by this factor yet again. (p. 112)
*      But then he has doubts, and wonders about an atmosphere "chargée
* de vapeurs & d'exhalations, telle qu'elle est ordinairement dans toute
* sa partie inferieure, lorsque le Soleil est proche de l'Horison, &
* sur-tout en Hiver." (p. 113).
*      He then makes the interesting observation that, at solar eclipses,
* one hardly notices the diminution of the light until the Sun is almost
* completely covered: ". . . j'aurois cru qu'au moins le tiers ou le quart
* de son disque venoit de se découvrir, & ce n'en étoit pas peut-etre
* la milliéme partie." (p. 115)
*      On p. 118 he considers the length of the day as a factor.  On pp.
* 127-128, he notes that refraction lengthens the day a little; but this
* "est de peu de consequence." [But he thinks it might be important
* near the Poles; and adduces (p. 129) the observations of Bilberg, and
* the Dutch "dans la Nouvelle Zemble."]
*      The rest of the paper is an attempt to square his numbers with
* actual temperature measurements. Really, a rather muddle-headed
* attempt all around.


de Mairan
“Eclaircissement sur le Memoire de la cause generale du froid en hiver, & de la chaleur en eté. Mem. 1719. page 104.,”
Mem. Acad. Roy. Sci. (Paris) 1721, 8–17 (1723).

* DE MAIRAN's "Clarification"
* Here he realizes that the extra-atmospheric light of the Sun
* can be extrapolated from two measurements inside the atmosphere.
* Unfortunately, he assumes the light lost is proportional to the
* path length in the atmosphere -- wrong, but not bad near the zenith.
* [But at the horizon, the setting Sun disappears in his model!]
* He assumes a plane-parallel atmosphere (p. 10). He neglects refraction.
* The path lengths are, of course, inversely proportional to the sines of
* the altitudes.
*      In section II (p. 12) he considers the curvature of the atmosphere.
* However, he takes the height of the atmosphere to be 15 leagues of
* 2000 toises each, which is much too large; and consequently finds the
* horizontal path to be only 15 times the vertical one. (p. 13)
* "J'ai supposé AT de 20000 toises ou de 15 lieuës, qui est la
* hauteur qu'on donne aujourd'hui le plus communément à l'Atmosphere.
* . . . en faisant AT de 20000 toises ou de 10 lieuës, on trouve AH plus
* de 18 fois aussi grande que AT , . . . & en ne donnant que 1000 toises,
* ou environ demi-lieuë à AT , AH devient environ 74 fois aussi grande
* que AT . D'où il resulte . . . Que lorsque le Soleil est à l'horison,
* les vapeurs doivent nous intercepter une beaucoup plus grande partie de
* la lumiere que ne fait l'Atmosphere, non seulement parce qu'elles sont
* composées de parties plus denses, & peut-être moins transparentes que
* l'air, mais encore que se trouvant d'ordinaire fort près de la surface
* de la Terre, la ligne horisontale qui les travers a un beaucoup plus
* grand rapport avec leur hauteur. . . . Donc des vapeurs qui ne sont point
* du tout sensibles à la vûë, dans le cas des rayons perpendiculaires
* ou peu obliques, doivent affoiblir sensiblement la lumiere du Soleil
* cans le ca de la grande obliquité, & lorsqu'il approche de l'horison:
* ce qui s'accorde parfaitement avec l'experience . . . ." (p. 16)
*      On p. 17, he suggests that this obliquity to the vapors might explain
* the variations in the refraction near the horizon as well: "D'où il
* suite que des vapeurs de même nature & de même densité doivent
* donner une refraction horisontale d'autant plus grande, qu'elles sont
* moins élevées, ou que la couche qu'elles forment sur la surface de la
* Terre est moins épaisse."


Anonymous
“Diverses observations de physique générale. II.,”
Hist. Acad. Roy. Sci. , 11–13 (1726).

* PIERRE BOUGUER's first photometric measurements, inspired by de Mairan
* Evidently written by the secretary, rather than Bouguer himself:
* "M. Bouguer, . . . dont nous avons déja parlé en 1721, ayant lû les
* Mémoires donne's par M. de Mairan en 1719 & 1721 . . . , chercha les moyens
* de découvrir par expérience le rapport des diférens degrés de lumiere
* du soleil à différentes élevations . . . ."
* Bouguer's measurements of extinction, and of the ratio of Sun and Moon,
* are reported here. The first date reported is 23 Nov. 1725.
* The copy on Gallica shows 1753 as the publication date on the title
* page; that must be a reprint, as Bouguer corrects a typo on p. 12
* of it in his 1729 "Essai" (below). There are other typos here, too:
* e.g., "lamiere" on p. 11.


[P. ] Bouguer
Essai d'Optique sur la Gradation de la Lumiere
(Claude Jombert, Paris, 1729).

* PIERRE BOUGUER's "Essai" (1729)
* Bouguer corrects de Mairan's faulty assumptions, and publishes his own
* airmass table. Only 164 pages are numbered.
*      In the Preface, one reads that "C'est Snellius qui a le premier
* découvert la loi de ces réfractions; mais M. Descartes la considérant
* de plus près, en a poussé l'application extrêmement loin." He cites
* de Mairan's 1721 memoir, which inspired his own investigation.
* He also corrects a typo from his 1726 entry in the Histoire .
*      de Mairan is cited again on p. 21.  He then describes his observations
* of the Moon, and its attenuation at the horizon, "sujet à de très-grande
* varietez;" -- ascribed to "vapeurs", of course. He then endorses de
* Mairan's notion that this is connected with the variations of refraction
* at low altitudes. (p. 25)
*      In paragraph VII, p. 28, he compares the Sun with the full Moon, finding
* a ratio of about 300 000.
*      His detailed discussion of atmospheric transmission begins on p. 146.
* Here is the origin of the term "air mass". The "Table des masses d'air"
* appears on p. 160. See Bemporad's criticism of Bouguer's derivation.
*      The curious remarks about refraction (see next entry) are on p. 151
* here. Most of this atmospheric discussion is reprinted unchanged in the
* 1760 Traité (below).


[P. ] Bouguer
De la Méthode d'Observer Exactement sur Mer la Hauteur des Astres
(Claude Jombert, Paris, 1729).

* PIERRE BOUGUER's "Prize Essay" (1729)
*      The first part discusses instruments and their use; the second, the
* necessary corrections to the observations, for both refraction and dip.
* Our concern here is in the corrections, which begin on p.35 [image 46
* of the PDF cited below.]
*      Bouguer immediately points out that the angles made by the rays with
* the spherical surfaces of the atmospheric layers are changing with
* distance, and that "cette diversité d'angles d'incidence . . . vient
* principalement de la courbure des couches . . . ." This is why one can
* not apply the famous theorem promoted by Newton in his Opticks to
* the atmosphere. However, on pp. 41-42 a similar invariant for
* the curved atmosphere appears: ". . . les perpendiculaires tirées
* du centre de la terre sur les tangentes de cette courbe, seront
* continuellement proportionelles aux . . . des dilatations . . . ." (This is
* all done in geometric terms, using proportions; but basically he has
* the refractive invariant here.) In the process, he has developed the
* differentials of refraction at each level in the atmosphere.
*      Bouguer calls the curved path of the ray "le Solaire", and is
* concerned to find its shape. By taking account of the curvature of the
* Earth and its atmosphere, he assumes that the ray makes the same angle
* at each spherical surface, so that the ray paths are logarithmic spirals
* [p. 43].
*      On p. 44, he does the inverse problem, and introduces the sine of the
* apparent zenith distance at the observer, calling it c . This angle is
* the complement of the apparent altitude of the star. [Two decades later,
* he develops this theory more clearly, in his "Second Memoir" published
* in 1753.]
*      On p. 47 he writes down an integral for the astronomical refraction.
* His ignorance of the gas laws leads him to believe that the refractions
* are caused by a "refractive material" different from air. [p. 48].
* (His problem is that he expects the refractive index to be the same
* thing as the "refractive power " -- i.e., the refractivity.) So he
* assumes that the sines of the angles are some power of the dilations
* of the air, and that these are proportional to some power of the
* distance from the center of the Earth. But these "dilations" are (in
* modern terms) just inversely proportional to the refractive indices.
*      So in fact, this amounts to an assumption that the refractivity is a
* power of the radius, which is equivalent [we now know] to assuming the
* density to be a power of the pressure: he has accidentally adopted a
* polytropic model! So, luckily, he finds his model gives a refraction
* that is a constant fraction of the horizontal arc traversed by the ray
* -- "which is very remarkable!" [p. 49]
*      As his Fig. 11 is already too cluttered with about 30 labelled points,
* he removes some of them to make room for more labels, in Fig. 12. Here
* again (p. 50) we have the complement of the apparent altitude of a star.
*      So [p. 52] he can construct his refraction table geometrically from
* his logarithmic spiral, given the exponent in the power law. In §.L.
* [p. 53] he explains the details of this process, which requires finding
* the exponent m and the height of the atmosphere. "But nothing is
* easier than to discover these two quantities," says Bouguer [p. 54]
* (though Cassini had a much harder time to do so in a simpler model).
* He has only to fit his model to exact observations of the refraction at
* two different apparent altitudes. He assumes the horizontal refraction
* is one of the known values, and derives an expression for the refraction
* at some other altitude. He then develops an iterative solution for the
* two parameters; this involves the ratio of the sine and cosine of the
* apparent altitude.
*      In fact, he calls the sine of the apparent altitude q  and the sine of
* its complement (i.e., the zenith distance at the observer) p . (P.54)
*      In §.LII. [p. 56] he then shows how to calculate refraction for any
* given altitude -- i.e., how to build a refraction table. He adopts
* 33' for the horizontal refraction, and 2' 12" for 26° altitude.
* These values allow him to compute a new refraction table; he does the
* calculation using 7-place log tables. His new table of astronomical
* refractions is on p. 59 [PDF image 66]. The values are about 10% too
* high, but they do increase steadily near the horizon.
*      In §.LVI. [p. 61] he compares his results with the works of Tycho and
* Cassini II.
*      On the next page (and Chapter), he discusses the dip of the horizon.
* His dip table [p. 65] is for heights in feet and inches, as the metric
* system had not yet been invented. But on the next page, he points out
* that the ray curvature should decrease the dip slightly. And on the
* next page, he begins the investigation of this correction. And on
* p. 70, he gives a revised dip table.
*      Unfortunately, on p. 72 he blames the irregularities of refraction on
* the "vapeurs qui se soutiennent dans la partie basse de l'Atmosphere,"
* and so excuses any discrepancies between his tables and observations.
*      Available at  https://www.e-rara.ch/zut/content/titleinfo/746433
* NOTE: the text is often obscured by wrinkles in the paper.
* DOI: http://dx.doi.org/10.3931/e-rara-2231
*      A MUCH better scan is available at
*            https://bvpb.mcu.es/es/consulta/registro.do?id=576360
* Thanks to Luc Dettwiller for this link!


P. Bouguer
Traité d'Optique sur la Gradation de la Lumiere
(H.L.Guerin & L.F.Delatour, Paris, 1760).

* PIERRE BOUGUER's posthumous "Traité" (1760)
*      There is an interesting Preface ("Avertissement") by the Abbé de la
* Caille, who edited Bouguer's work and saw it through the press.
*      Bouguer has some curious remarks about refraction (pp. 326-327):
* "Il faut remarquer, que nous négligeons ici la courbure que
* la réfraction fait souffrir aux rayons de lumiere, quoique cette
* courbure les rende un peu plus longs. Il est certain que la réfraction
* astronomique est trop petite , pour que le rapport des sinus d'incidence
* & de réfraction soit conforme à celui des densités de l'air.
* La réfraction suit certainement un autre rapport ; & peut-être
* aussi qu'elle est causée par une matiere particuliere répandue dans
* l'Atmosphere, comme l'ont déja soupçonné quelques Auteurs."
* He then shows how the problem is more complicated if refraction is
* included, so "qu'il est très-difficile de découvrir la relation que
* suivent entr'elles les condensations u de la matiere réfractive; &
* d'ailleurs comme la plus grande réfraction astronomique n'est pas même
* de deux tiers d'un dégré, nous ne rendrions pas notre calcul beaucoup
* plus exact. C'est pourquoi nous négligerons la réfraction . . . ."
*      The airmass table is on p. 332.  This is available at Gallica!
* Note the English translation by W. E. Knowles Middleton (Toronto, 1961).


P. S. Laplace
Traité de Mécanique Céleste, tome 4, liv. X, Ch. III
(J.B.M.Duprat, Paris, 1805).

* LAPLACE
* Ch. I begins the treatment of refraction; Ch. III is the extinction theorem
* See fuller treatment under "General refraction references".


J. D. Forbes
“On the transparency of the atmosphere and the law of extinction of the solar rays in passing through it,”
Phil. Trans. 132, 225–273 (1842).

* FORBES EFFECT -- Forbes's Bakerian Lecture
* See the interesting discussion of Laplace's theorem, and airmass
* generally, in section III, pp. 233-241.
* Forbes says (p.234) that Lambert derived the sec z formula as an
* approximation to the path length in the uniform model, citing p. 393
* of Lambert's Photometria . He has some criticism of L. on p.235.
*      Note his treatment of the refraction law on p.237:
* after stating the ratio of sines, he says, "This optical principle
* is derived from experience." [So much for Descartes!]


M. J. Maurer
Die Extinction des Fixsternlichtes in der Atmosphäre in ihrer Beziehung zur astronomischen Refraction
(David Bürkli, Zürich, 1882).

* Maximil. Julius Maurer's feeble effort
* The historical part is weak, depending mostly on Bruhns for the
* refraction. He shows how little had been done in extinction; this makes
* Bemporad's later remarks about neglect more comprehensible.
*      See pp. 21-22 for some snide remarks about Lambert, who thought sec z
* was adequate to 80°. Maurer denotes the airmass function as \Sigma.
*      On p.22, he introduces Laplace's theorem, though without understanding
* well the importance of the isothermal assumption.
*      On p. 34, there is a curious digression into the arguments of Cheseaux
* and Olbers, and then W. Struve (p. 35) for the absorption of light by
* dust ("fein zertheilter ponderabler Materie im Weltraume") in space. (p.1)
*      The more interesting attempt to calculate airmass begins on p. 41;
* but, alas! he adopts an effective height of the atmosphere of 65 km
* (p. 51) and so greatly overestimates the curvature effects. So his
* airmass table (p. 53) gives only 14.961 at the horizon!
*      Interestingly, he already (p. 55) points out that the use of
* time and spherical astronomy to calculate ZD gives "die w a h r e n
* Zenithdistanzen der beobachteten Sterne" in Seidel's work.
* This is Maurer's 58-page Inaugural-Dissertation, done under Rudolf Wolf.


F. Hausdorff
“Ueber die Absorption des Lichtes in der Atmosphäre,”
Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig, Mathematisch-Physische Classe 47, 401–482 (1895).

* FELIX HAUSDORFF's Habilitationsschrift
* Yes, this is the famous topologist; he started out as a student of
* Heinrich Bruns, writing a thesis on refraction in 1891.
*      The style (and notation) is similar to Bruns's: clear, explicit, and
* original. Following Bruns (1891), he immediately notices the important
* product r⋅μ, which he denotes by ν (p.402). He notes (p. 403)
* (cf. Bruns's p.169 footnote) that the refractivity can be proportional
* to [(almost any power of the refractive index) - 1], so that we can
* choose the power to make the integrals easy --- noting that T. Young had
* already made the choice (as he does here) of the first power, in his
* Nautical Almanac tables.
*      P.407: he notes there is a formal relationship between the power
* series for refraction and extinction (in terms of powers of tan Z); but
* "Es wäre zwecklos, diese sehr complicirten Ausdrücke aufzustellen,
* da eine Ermittlung . . . aus den Beobachtungen direct . . . wegen der
* Unsicherheit der Messungen im Horizont ganz illusorisch wäre."
*      P.408: He describes the airmass "als reducirte Weglänge  des
* Strahles" and shows how the extinction can be expressed in magnitudes.
*      P.412: He notes that Laplace's approximations have neglected an
* appreciable term, so that the ratio of extinction to refraction contains
* a factor of 1/10 in the zenith, but 1/7 at the horizon. ". . . die
* Laplace'sche Formel . . . die hier dem Gliede erster Ordnung entspricht,
* ist also entschieden unvollständig. Dass sie trotzdem . . . nahezu
* dieselben Resultate ergiebt wie die strengere Formel . . . , liegt daran,
* dass die . . . Coefficienten . . . bis zu hohen Zenithdistanzen einander
* nahezu proportional laufen . . . ."
*      P. 417: he recommends a ZD near 87° as a fitting point, in fitting
* 3 parameters (the other two being at Zenith and Horizon).
*      P. 420:  He notes that twice the path, where the ray is horizontal,
* gives values needed for the theory of lunar eclipses.
*      P. 421: note remark on semiconvergent series for Kramp's function.
*
* In Section II (p. 422), he takes a more general approach to resolving
* the discrepancy between theory and observation, by abandoning Laplace's
* proportionality between density (i.e., refractivity) and extinction.
* He notes (p. 423) that this assumption leads neither to closed-form
* expressions nor to a good agreement of theory and observation; while
* taking the absorption as an arbitrary function of height allows a test
* of assumptions about the atmosphere, while operating with closed-form
* expressions instead of series expansions. Here he takes the (nR)
* product as the independent variable!
*      This leads (p. 427) to a more general relationship between refraction
* and extinction than Laplace's formula, and one which has "den viel
* weiteren Sinn einer Functionalbeziehung, eines »heuristischen Princips«
* . . . ." (There is still the form of Laplace's relation, though.)
*      Semiconvergent series again appear on pp. 431 and 433, as ways to
* evaluate Kramp's (and related) function(s).
*      On p. 439, he derives a generalized form of Lambert's extinction
* formula, attributing the simple sec Z form to Pouillet.
*      With his decomposition of the extinction into component terms, he
* can represent the observations tolerably exactly -- indeed, I must say
* this is greatly over-analyzing the (rather shaky) data (pp. 440-441).
* On p. 442, he admits as much, pointing out that the result is not
* physically possible: ". . . also die Darstellung der Müller'schen Zahlen
* auf diesem Wege illusorisch ist." (The absorptions become negative.)
*      Consequently, in section III (pp. 445 ff.) he investigates what is
* physically possible (i.e., sets limits on the possible extinction
* corrections to the zenith, assuming a positive absorption coefficient
* throughout the atmosphere.) This is done very elegantly by investigating
* the mathematical properties of the extinction integral. The result
* (p.451) is that Müller's values up to 70° ZD cannot represent a
* physically possible run of the absorption coefficient in the atmosphere:
* ". . . die Potsdamer Zahlen wären also in den mittleren Zenithdistanzen
* erheblich zu gross." [So here we see that rara avis , a theoretician
* who actually can detect bad observations!] He tries a more complicated
* (2-term) fit, with similar results: "Diese Zahlen lehren, dass der
* Müller'sche Werth für θ = 75° um mindestens 8 Einheiten der
* letzten Stelle zu gross ist; wollte man ihn beibehalten, so käme man auf
* enorme Widersprüche in den nächsthöheren Zenithdistanzen, z. B. für
* θ = 85° auf eine Mindestabweichung von 0.160."
*      Adding more terms to fit more points makes matters worse (p. 452); so
* "Wir schliessen . . . dass eine absolute Darstellung der Müller'sche
* Zahlen durch einen zulässigen Werthverlauf . . . unmöglich ist. . . .
* Auf eine Fehleranhäufung zwischen 60° und 80° liess auch der Gang
* der Widersprüche zwischen M und Laplace schliessen." [ M = Müller ]
*      On p. 454, he shows that a fair fit to Müller's data can be obtained
* with a simple rational formula; however, it allows no significant
* improvement. On the next few pages (455-457), he shows that a
* considerably better fit can be obtained by adding a thin absorbing layer
* to the normal atmosphere. This layer turns out to have a height between
* 50 and 170 km; he suggests it could be meteoric dust. [Perhaps it's
* an alias of the ozone layer?] In the subsequent discussion (p. 458),
* he remarks that two acceptable formulae can give quite different zenith
* transmissions; "dies errinnert uns daran, dass Beobachtungen einer
* Station in verschiedenen Zenithdistanzen noch nicht genügen, einen
* Schluss auf die Constitution der Atmosphäre zu begründen, sondern durch
* Beobachtungen auf Stationen verschiedender Meereshöhe zu ergänzen sind."
* He even considers formulae that allow absorption in space, wherein the
* excess of the horizontal over the vertical extinction would be due to the
* one-Earth-Radius longer path length at the horizon! "Derartige Curiosa
* sind bei Formeln mit unendlicher Atmosphäre, die sich der Beobachtung
* einigermassen anschliessen, zwar nicht zu befürchten, wohl aber, dass
* sie den Transmissionscoefficienten zu klein ergeben." (Variants on this
* theme, in which the infinitely thin absorbing layer is replaced by some
* formula with a maximum high in the atmosphere, are also explored.)
*      In comparing a number of these variants with observation, he finds
* (p. 463) that there is a tradeoff between the deviations between 60 and
* 80°, and those between 85 and 87.5°: one increases while the other
* decreases. So all these models are so similar that one can only
* conclude "dass die absorbirende Kraft der Atmosphäre zwar zuerst
* mit wachsender Höhe abnimmt, in grösseren Höhen aber (50 bis 200 km)
* wieder merkliche Werthe besitzt."
*      In the next section (pp. 464 ff.) he considers additional data, which
* help limit the possibilities. One is the run of the data near the
* horizon: "Für die Horizontalabsorption finden sich aus unseren Formeln
* alle möglichen Werthe bis zu ∞ . . . ." But more important is the
* comparison of data from different heights above sea level. For this,
* he uses Müller's observations from Säntis. These allow some of the
* worst models to be rejected.
*      Note: on p. 469, he points out that both Müller's tables and Seidel's
* use true rather than refracted zenith distances as arguments.
*      P. 472: at last he comes to Langley's objections (i.e., the Forbes
* effect). He develops this theory in general terms, introducing a
* function s that is the base-10 equivalent of sinh(x)/x. He then
* finds (p. 478) that introducing this effect greatly improves the
* agreement with observation, but without greatly changing the zenithal
* transmission value for integrated light. (Unfortunately, he does not
* cite Forbes's paper.)
*      P. 480: "Diese Rechnungen mögen genügen, um zu zeigen, dass man
* mit der Langley'schen Bemerkung in der That einen weit besseren Anschluss
* an die Beobachtungen erzielen kann als durch die Laplace'sche Formel."
* But (p. 481) the zenith transmission for integrated light is always
* close to 0.8, not Langley's 0.6.
*      The conclusions of the paper are summarized on p. 481.
* NOTE: This volume is available at Google Books.


A. Bemporad
“Zur Theorie der Extinktion des Lichtes in der Erdatmosphäre,”
Mitt. Grossherzogl. Sternwarte Heidelberg , Nr. 4, 1–78 (1904).

* AZEGLIO BEMPORAD's AIRMASS TABLE
* ``Ein mit der astronomischen Strahlenbrechung sehr verwandtes Problem
* ist das der Extinktion des Lichtes in der Erdatmosphäre. Während wir
* aber von Kepler bis Radau eine grosse Zahl von Theorien der Refraktion
* verzeichnen können, fehlt es bis jetzt überhaupt an einer Theorie der
* Extinktion des Fixsternlichtes, welche mit ähnlicher Strenge und
* Vollständigkeit wie die ersteren entwickelt ist. Dies kann Überraschen,
* wenn man die Wichtigkeit und das immer mehr sich steigernde Interesse
* bedenkt, welches die photometrischen Beobachtungen seit Jahrzehnten
* geniessen, und noch mehr, wenn wir die bis jetzt entwickelten Theorien der
* Extinktion mit den umfangreichen Beobachtungsarbeiten auf demselben
* Gebiete vergleichen.'' [1st para. of Intro.!]
*      Bemporad, like Forbes, criticizes Lambert (p.8) for his empiricism.
* The historical review is mostly devoted to the isothermal model and
* Laplace's theorem. However, B. shows that the homogeneous model has
* a series expansion in which the second term already has half the size
* of that for the isothermal model (p. 11); thus there is no equivalent
* of Oriani's theorem for extinction.
*
* B. adopts gradient of 6.22 deg/km to at least 9 km (maybe all the way?)
* (n-1)2 = 1.0005864 for 0 C and 760 mmHg
* R = 6377.36 km; g=9.8052m/sec2; p=1013.168 = 760 mm
* finds M(87)=15.364; 88: 19.787; 89: 26.959; 89.5: 32.332; 90: 39.651
* adopts gradient of 6.21 deg/km in summary table (?).
* finds M(87)=15.365; 88: 19.787; 89: 26.959 in F(z) table.
*      Published by "W. Valentiner" (Karl Wilhelm Valentiner, says Wikipedia.)


K. Rohlfs
Tools of Radio Astronomy
(Springer-Verlag, Berlin, 1986), pp. 165–168.

* ROHLFS mentions Bemp. and Schoenberg, calling airmass X(z)
* He gives the airmass integral, and then: "Bemporad [no citation] and
* Schönberg (see Schönberg (1929)) have done extensive investigations
* of X(z), and a Chebyshev-fit to these data up to X = 5.2 with an error
* of less than 6.4 ⋅ 10-4 is given by" a cubic polynomial in sec z.
* "Such a formula should indeed be used in radio astronomy because
* measurements are often made at zenith distances up to 80° (or even
* more!)" [p. 166]
* On p. 168, he gives an expression for the radio refractivity,
* and suggests that an error of 15% would be acceptable, so that "mean
* refraction can be used and this closely resembles the optical refraction.
* Therefore for z < 80°
*
*            Δ z = β tan z ,            β = 1.'50 .
*
* The ratio of radio to optical refraction is . . . 1.56; thus for larger
* zenith distances, optical refraction tables can be used, provided the
* result is correspondingly multiplied." Tsk, tsk.


A. T. Young
“Air mass and refraction,”
Appl. Opt. 33, 1108–1110 (1994).

* My Airmass approximations for geometric ZD
*      Eq.(6) is faulty, and should be ignored.  And I misspelled Abalakin's
* name.


L. K. Kristensen
“Astronomical refraction and airmass,”
AN 319, no. 3, 193–198 (1998).

* L. Kahl Kristensen rediscovers Laplace's theorem and the rational approx.
* with comments on Wittmann's refraction paper. He shows the constancy of
* the ratio r(z)/(M(z)*sin z) for the std. and isothermal models.
*      He cites Newcomb's unreliable text for the refractive invariant, and
* uses the old ICAO atmosphere -- which he apparently does not realize is
* different from Bemporad's model.
*      Unfortunately, he only fits the Pulkovo table for mean refraction, so
* the claimed high accuracy of the fit is of little practical use.
*      Thanks to ADS for making this available!  Their scan is better than
* the Wiley one; but Wiley's has OCR'd text, and ADS does not.


K. C. Chambers
“Astrometry with Pan-STARRS and PS1: Pushing the limits of atmospheric refraction, dispersion, and extinction corrections for wide field imaging,” in Astrometry in the Age of the Next Generation of Large Telescopes , P. K. Seidelmann and A. K. B. Monet, eds., (ASP Conference Series, Vol. 338)
(ASP, Provo UT, 2005), pp. 134–144.

* Chambers knows about Laplace's theorem, but . . .
* . . . proposes to use it to calculate airmass for photometric reductions,
* via the Saastamoinen method for calculating the refraction! (pp.142-143)
* There are also some other scary bits, like giving a CO2 refractivity to
* 3 sig. figs. without a dispersion term, and the use of a scale height
* that assumes a fixed water-vapor mixing ratio, and "the local radius of
* the reference ellipsoid" for the radius in calculating h/R . . . .
* [This group's use of square-sided passbands also does not increase
* confidence that they know what they are getting into.]


S. N. Kivalov
“Improved ray tracing air mass numbers model,”
Applied Optics 46, 7091–7098 (2007).

* Sergey Kivalov's new method of calculating airmass


Siebren Y. van der Werf
“Comment on "Improved ray tracing air mass numbers model",”
Appl. Opt. 47, 153–156 (2008).

* Siebren's comment on Sergey's paper
* "Ray tracing by path length is shown to avoid singularities both at
* the horizon and in the zenith. A fourth-order Runge-Kutta numerical
* integration scheme is presented, which treats refraction and air mass
* as path integrals."
* Interesting comparison of choices of independent variables.


Ígor Rapp-Arrarás and Juan M. Domingo-Santos
“Extinction, refraction, and delay in the atmosphere,”
J. Geophys. Res. 113, D20116 (27 Oct., 2008).

* These guys took up my suggestion to show that the "mapping function"
* of the radio scientists is essentially the airmass function.
*      Available at:  https://doi.org/10.1029/2008JD010176


Ígor Rapp-Arrarás and Juan M. Domingo-Santos
“Functional forms for approximating the relative optical air mass,”
JGR: Atmospheres 116, D24308 (27 Dec., 2011).

* Fine REVIEW of 26 airmass approximation formulae


J. G. Mangum and P. Wallace
“Atmospheric refractive electromagnetic wave bending and propagation delay,”
PASP 127, 74–91, 500–501 (2015).

* Jeffrey G. Mangum and Patrick Wallace review refraction and airmass
* for radio astronomers. There is much emphasis on water-vapor effects
* at microwave frequencies.
*      They cite my 2004 AJ paper but not the 2006 tutorial paper in Obsy.,
* or the 2008 and 2011 papers by Ígor Rapp-Arrarás and Juan M. Domingo-Santos
* cited above.
*      Don't overlook their 2-page Erratum on pp. 500-501, which corrects some
* serious errors in the original paper.


C. Qiu, X. Wang, Z. Li, S. Zhang, H. Li, J. Zhang, and H. Yuan
“The performance of different mapping functions and gradient models in the determination of slant tropospheric delay,”
Remote Sens. 12, 130 (2020).

* Cong Qiu and many co-authors compare "mapping functions"
*      Here the tilt effect appears as "atmospheric gradients" or "atmospheric
* azimuthal asymmetry" in "gradient models". (See references 49-51 and 61.)
*
*      Full list of authors:
* Cong Qiu, Xiaoming Wang, Zishen Li, Shaotian Zhang, Haobo Li, Jinglei Zhang,
* and Hong Yuan
*      Available at  www.mdpi.com/journal/remotesensing
* DOI: doi:10.3390/rs12010130



*** LINK FILE ***

F. Link
“Théorie photométrique des éclipses de Lune,”
Bull. Astron. 8, 77–108 (1933).

*
*
* Logically belongs with the AIRMASS file because of Link's work on both.
*
* Link's thesis on lunar-eclipse photometry: he invents a Biot-like scheme
* He shows very clearly the relation between REFRACTION and AIRMASS:
* refraction is proportional to the integral of a function with respect
* to ρ , but airmass is the same function integrated with ρ dh.
* He shows a graph of his refraction integrand at the horizon.
*      The part about refraction is on pp. 89-92.  He does the integrals
* graphically!


F. Link
“Nouvelles Tables de masses d'air,”
J. Obs. 17, No. 3, 41–48 (1934).

* Link's "new airmass table" denotes airmass as M
* He uses his graphical method to do the numerical quadratures. The
* atmospheric data are from Humphreys's book.
* Remarkably, there is no mention of Bemporad!
* Available from ADS.


F. Link
“Masses d'air et réfractions sous diférentes latitudes et en diférentes saisons de l'année,”
J. Obs. 20, 165–171 (1937).

* Link repeats his exposition here, and clearly explains the refr./airmass
* relationship. Fig. 1 shows his airmass integrand for 90 and 84° ZD.
* "La forme générale des courbes . . . montre que la valeur
* des intégrales correspondantes dépend surtout des conditions
* météorologiques dans la basse atmosphère. L'importance des couches
* élevées décroit assez vite pour qu'on puisse les négliger ou mieux
* les remplacer par leurs valeurs moyennes." (p. 166)
*      He also suggests that, as a complete atmospheric sounding is needed
* to determine the refraction and airmass near the horizon, "Le procédé
* inverse ne paraît pas impossible à première vue . . . ."
*      Cites Tikhov (1936) for large (2°) refractions in winter.
* Again, no mention of Bemporad!
* Available from ADS.



*** GENERAL BOOK FILE (TEXTBOOKS, review articles, and reference works) ***

I. Newton
Opticks
(Dover, New York, 1952), pp. 271–273.

*
* NEWTON
* Book Two, Part III, Prop. X contains the result that in plane-parallel
* media, "the Sum of all the Refractions will be equal to the single
* Refraction which it would have suffer'd in passing immediately out of the
* first Medium into the last." He uses this to derive the "Refraction
* of the Air" from "that of the Atmosphere observed by Astronomers."
*      "Based on the Fourth Edition London 1730"; the same passages occur on
* pp. 73-74 of the first edition (1704), which is available at
*
* https://www.google.com/books/edition/Opticks/Oqd3OUaKY0UC?hl=en&gbpv=1
*
* The 1704 edition ends with Query 16 of Book 3, Part I, which is on p.347
* of the Dover edition, and p. 137 of the 1704 edition. After that, the
* first edition contains two mathematical treatises in Latin on third
* order curves, and the quadrature of curves.


Delambre
Histoire de l'Astronomie au Dix-Huitième Siècle
(Bachelier, Paris, 1827).

* DELAMBRE/Mathieu "Histoire"
* Mathieu edited Delambre's manuscipt for publication, adding extensive
* footnotes and comments of his own, and analysing many old observations
* in the light of current understanding c. 1825.
*      Of importance here are the extensive discussions of astronomical
* refraction (indexed on p. xlvi = image 54 of the Gallica PDF); the
* discussion of mirage observations by both Le Gentil and by Mathieu and
* Biot in Mathieu's long footnote on pp. 695-697 (Gallica images 756-758);
* and Mathieu's special "Note" on pp. 774- 796 (images 835-857) discussing
* refraction. The main text ends with Ivory's 1823 work, which was very
* fresh when this was published. The Note refers to Plana's 1823 paper;
* unfortunately, the "Histoire" was published just a year before Plana's
* even more thorough 1828 paper.
*      In the mirage discussion (p. 696), Mathieu says: "Ces apparences
* singulières ne sont pas rares dans nos climats, car, pendant
* l'hiver de 1808. je me trouvais à Dunkerque avec M. Biot, et nous
* avons eu ocoasion de voir des effets très variés de réfraction
* extraordinaire. Nous étions presque sûrs de les retrouver quand nous
* nous rendions au bord de la mer, après un abaissement brusque dans la
* température de l'air." On the next page he adds: ". . . et il parait
* bien constant que, quand il a lieu, l'air est toujours plus froid que le
* sol. Les doubles images qui produisent les phénomènes du mirage et de
* la simple suspension peuvent même se former quand les rayons visuels
* rasent de la glace ou de la neige, pourvu que ces corps soient à une
* température plus élevée que celle de l'air."
*      Mathieu accepts Arago's spurious "disproof" of Bouguer's observation
* of solar limb-darkening.
*      The title page says "Publiée par M. Mathieu", which should technically
* make him the publisher; but in fact he was the editor (as well as a
* co-author!).
*      Available from Gallica; the PDF image numbers are larger than the page
* numbers by 61. Gallica's PDF contains the Figures at the end.


D. Brewster
A Treatise on Optics
(Longman, Rees, Orme, Brown, and Green, London, 1831).

* David BREWSTER's "Treatise on Optics"
*      Widely cited by later authors; but not entirely reliable.  Mirages are
* treated in Chapter XXXI, "On Unusual Refraction", pp. 255-264. He mixes
* in some optical illusions and the Brocken specter; mentions the classic
* examples (Latham, Vince, Monge, Scoresby, Wollaston) without actually
* citing them, and accepts the phony Jurine & Soret "lateral mirage". The
* fata morgana gets a brief summary of Nicholson's translation of Minasi,
* but no citation. He thinks horizontal magnification is "quite possible"
* in mirages, and accepts Monge's "reflecting surface". On p. 263 he says:
*      "That some of the phenomena ascribed to unusual refraction are owing to
* unusual reflexion arising from difference of density, cannot, we think,
* admit of a doubt."


[Anonymous]
“Del fenomeno detto Miramento , Miraggio , Miraglio ,Fata Morgana,”
Teatro Universale 6, No. 264, 233–236 (1839).

* Article in TEATRO UNIVERSALE on mirages, etc.
*      Notable for attempts to explain these terms.
*      This weekly publication was written for educated general readers,
* bringing them up to date on diverse matters; see the Prefazione
* on p. VII. As the subtitle "RACCOLTA ENCICLOPEDICA E SCENOGRAFICÄ
* indicates, it was profusely illustrated. It ran from 1834-48. The
* printing equipment is described in the Prefazione to Vol. 1, which is
* available at Wikimedia.
*      Its publisher was Giuseppe Pomba, who set up the first rotary press
* in Italy. He produced several weekly journals, with the common theme
* of educating the general public.
*      The title page says it was published by "una societá di librai
* italiani" (association of Italian booksellers). The Prefazione in
* vol. 5, dated 31 Dec. 1838, is signed by Davide Bertolotti. But Vol. 5
* also shows that Pomba had turned this publication over to Baglione
* in 1838. Bertolotti also signed poems in the Dec.1, 1838 issue,
* and in some 1839 issues. But by 1840, another publisher had taken
* over, and Bertolotti had disappeared from its pages.
*      Bertolotti mentioned (in his Preface to vol. 5) that "the illustrious
* Prof. Brugnatelli" had contributed many articles on "physical geography"
* to the Teatro ; so perhaps this item is one of them?
*      Google Books has vols. 5 (1838) and 6 (1839) bound as one volume.
* This is the 27 Luglio issue. This article is illustrated with a large
* wood engraving of "Fenomeno del Miraglio nelle pianure del Messico."
*      Thanks to Marcella Pace for pointing out this article!


R. Clausius
“Die Lichterscheinungen der Atmosphäre,” in Beiträge zur meteorologischen Optik und zu Verwandten Wissenschaften
(E.B.Schwickert, Leipzig, 1850), p. 367–462.

* GRUNERT/CLAUSIUS review
*      Good explanation of German terms (Kimmung = looming; Seegesicht =
* inferior mirage) and sloppy usage.
*      In the third number, a few pages earlier, Grunert himself comments on
* Gergonne's theory of mirages (p. 308), which he extends; and on
* Biot's monograph. In particular, in section 24 (pp. 348-357), he
* discusses the elliptical locus of the vertices of the rays, and the
* relations [later rediscovered by Tait!] between them and the nature
* of the images. This 3rd number is dated 1849; it begins on p. 267.
*      The 4th number (1850) is by Rudolf Clausius.  He begins with the
* apparent shape of the sky; evidently this was the model for Pernter &
* Exner's discussion. Then comes extinction, and the light of the sky,
* followed by a long discussion of twilight.
*      Refraction begins on p. 399.  He discusses the horizontal refraction,
* and the flattening of the Sun and Moon there. The interesting part
* begins on p. 401, with "Ungewöhnliche Senkung und Hebung des
* Horizontes." He mentions "sinking" observed in the Gulf Stream, and
* cites Latham's observations in the English Channel. "Man hat für das
* ungewöhnliche Sichtbarwerden ferner Gegenstände auch im Volke eigene
* Ausdrücke. Bei den englischen Schiffern heisst es looming , und bei
* uns      K i m m u n g  ,      welche Namen freilich auch oft für andere
* verwandte Erscheinungen gebraucht werden." (p. 404)
*      Then come mirages.  Of Minasi's account of the Fata Morgana, he says:
* ". . . hat seiner Beschreibung, die aus mehrfacher eigener Anschauung
* geschöpft sein soll, offenbar Manches aus seiner Phantasie beigemischt."
* Then he brings in Monge. He notes that inferior mirages were long known
* to sailors as "Seegesicht". He cites Büsch's "Tractatus duo". (p. 407)
* and Woltmann's observations, too. "Aber vollständig entwickelt ist sie
* erst von Biot".
*      Then comes the passage referred to by Möbius (1925): ". . .  dem
* beschriebenen Vorgange eine gewisse Aehnlichkeit mit der
*  R e f l e x i o n      des Lichtes giebt, obwohl er von dieser seinem
* Wesen nach ganz verschieden ist, und nur auf Brechung beruht." Here,
* he adds a footnote that mentions total reflection. (p. 409)
*      Vince and Scoresby then appear.  The mirage discussion ends on p. 419,
* where he goes on to discuss the twinkling of the stars.
*      This is "Erster Theil, Viertes Heft" of "Beiträge zur meteorologischen
* Optik und zu verwandten Wissenschaften. In zwanglosen Heften
* herausgegeben von Johann August Grunert"
* = Beiträge z. meteorol. Optik. I. 4.
*      available at https://archive.org/details/beitrgezurmeteo00claugoog
* (but of course the plates are suppressed).


A. R. Clarke
Geodesy
(Clarendon Press, Oxford, 1880).

* CLARKE's important "Geodesy" text (1880)
* Colonel Alexander Ross Clarke, C.B.
*      The first page of the Preface says:
*      "The Essay entitled 'Figure of the Earth,' by Sir G. B. Airy,
* in the Encyclopedia Metropolitana, is the only adequate treatise on
* Geodetic Surveys which has been published in the English language, and
* though now scarce, it will ever remain valuable both on account of the
* historic research it contains, and the simple and lucid exposition of the
* mechanical theory there given. Since the date of its publication however
* have appeared many important volumes, --- scientific, descriptive,
* official, --- such as Bessel's Gradmessung in Ostpreussen; Colonel
* Everest's Account (1847) of his Great Arc; Struve's two splendid volumes
* descriptive of the trigonometrical chain connecting the Black Sea with
* the North Cape; the Account of the Triangulation of the British Isles;
* the Publications of the International Geodetic Association; recent vo1umes
* of the Mémorial du Dépôt Général de la Guerre; the Yearly Reports
* of the United States Coast and Geodetic Survey; the current volumes by
* General Ibañez, descriptive of the Spanish Triangulation, so remarkable
* for precision; and last, though not least, the five volumes recently
* published by General Walker, containing the details of Indian Geodesy."
*      The first chapter is a fine HISTORICAL REVIEW, starting with Snellius
* and Picard. Ch. II is Spherical Trigonometry; III is Least Squares.
* The radius of the (assumed) spherical Earth appears first; dip is in
* the fourth sentence, and the Mount Edgecombe observation is cited as an
* early attempt to measure it. [According to Airy's article "Figure of
* the Earth" in vol. 5, pp. 175-240 of "Encyclopedia Metropolitana" (1845),
* this was measured by Edward Wright, and published by Richard Norwood in
* "The Seaman's Practice, contayning a fundamentall Probleme in Navigation
* experimentally verified, namely touching the Compasse of the Earth and
* Sea, and the Quantity of a Degree in our English Measures, &c." (1637).
* Airy gives the location as "Mount Edgecumbe".]
*      A nice feature of the historical introductory chapter is that it
* provides the geodetical connection among the works of the Cassinis,
* the French surveys in Peru and Lapland, and later workers, and thus
* puts into context the works of people like Bouguer, de La Condamine,
* Maupertuis, General Roy, Von Zach, Delambre, Mechain, Legendre, and
* later workers like Tobias Mayer, Struve, Biot and Arago, and Bessel,
* and instrument makers like Ramsden. Finally, on p.27, Colonel Everest
* appears. So, all the scattered studies that seem like isolated details
* in this bibliography are brought together in a grand historical narrative.
*      Talcott's Method is discussed on pp. 186-187.
*      Refraction is mentioned on p. 2, as "a phenomenon of variable and
* uncertain amount", but is not examined until Ch. XI, "Heights of Stations"
* (p. 280), where Bauernfeind's 1866 papers are cited. Here we find:
* "The amount of terrestrial refraction is very variable and not to be
* expressed by any simple law: the path of a ray of light, inasmuch as it
* depends on the refractive power of the atmosphere at every point through
* which it passes, is necessarily very irregular. This irregularity is
* very marked when the stations are low and the ray grazes the surface of
* the ground. In the plains of India it has been observed that the ground
* intervening between the observer and the distant signal, from being
* apparently convex in the early part of the day, changes gradually its
* appearance as the day advances, to a concavity --- so that at sunset
* the ground seems to slope up to the base of the signal tower which in
* the early morning was entirely below the horizon."
*      Here (p. 281) are cited the "Great Trigonometrical Survey of India"
* and Hossard's paper in Mém. du Dépôt Gén. de la Guerre, vol. ix, p. 451
* (1853). Unfortunately this seems to be where the mistaken notion that
* the refraction is least in the afternoon came from. Note that his
* "coefficient of refraction" is about 1/14. not 1/7.
*       On the next page are some British measurements, of which the most
* discrepant was made at Ben Nevis, where "for a fortnight --- when
* the greater part of the observations were made --- the state of the
* atmosphere at the top of the hill was most unusually calm, so much so,
* that a lighted candle could often be carried from the tents of the men
* to the observatory, whilst at the foot of the hill the weather was wild
* and stormy."
*      On p. 283 a distinction is drawn "between rays which cross the sea and
* those which do not." (A larger coefficient of refraction is found across
* water.)


F. R. Helmert
Die Mathematischen und Physikalischen Theorieen der Höheren Geodäsie. II. Theil: Die physikalischen Theorieen
(B.G.Teubner, Leipzig, 1884).

* HELMERT's "Geodesy" text
*      The refraction details are all in Part 2 here; Part I was called
* "Einleitung und I. Teil: Die mathematischen Theorieen". (Notice the
* curious change in spelling; the body of the text wavers between keeping
* and dropping the "h" in both volumes.)
*      In the Vorwort, Helmert says: "Bei der Theorie der Refraktion
* im achten Kapitel habe ich mich darauf beschränkt, solche Formeln
* abzuleiten, welche voraussetzen, daß das Gesetz für die Änderung der
* Temperatur mit der Höhe durch eine stark konvergente Reihe nach Taylor
* darstellbar ist. Für diesen Fall sind die Formeln allgemein gültig,
* so daß man die Konstanten aus zweckmäßig angeordneten Beobachtungen
* bestimmen kann. Ein Zahlenbeispiel ist den von v. Bauernfeind
* publizierten Messungen entnommen." (p. VIII)
*      The refraction discussion really begins about p.502; but is sparse
* until after p. 550, where "Lateralrefraktion" is mentioned. (This is the
* skewness effect due to the polar flattening of the ellipsoid.) And
* refraction in altitude begins on p. 553, where the familiar expression
* (dn/n) tan z appears. The invariant is on p. 554. But this good start
* is derailed by replacing cot z with sqrt(1 - sin2 z). "Von dieser
* Gleichung, welche schon Laplace kannte, ausgehend, . . . " (But of course
* Newton and several others had it before Laplace.) Then comes the
* Reihenentwicklung. . . .
*      P.555: here, kappa is the symbol for -(r/n)(dn/dr), and I hoped he
* would go on to pre-empt Auer & Standish; but no. On the next pages we
* find the surveyors' refraction coefficient k derived. But this all
* assumes that the expansion of κ in terms of its height-derivatives
* converges sufficiently rapidly. On p.556, he says: "Selbstredend ist
* zur praktischen Brauchbarkeit der Formel (7) eine so rasche Konvergenz
* erforderlich, daß zum mindesten die nicht angesetzten Glieder unerheblich
* sind. Inwieweit dieses für einen thatsächlichen Luftzustand der Fall
* ist, kann aber nur die Erfahrung zeigen." [Modern high-resolution
* observations of boundary-layer fine structure do not support this.]
* TILT discussion:
*      The skewness effects are discussed on pp. 564 ff.; see references
* cited on p. 565. Of more interest is the discussion of deviations of the
* surfaces of constant density from the "Normalform" due to irregularities
* in the distribution of heat and pressure in the air (p. 566), especially
* those due to sloping ground. If the isopycnic surfaces are inclined, the
* differential of refraction must have the angle between the ray and the
* local normal to these surfaces instead of the zenith distance. (p. 567)
* He denotes the tilt angle as ν, which he imagines might be as big as
* several degrees. (p. 568) But he notes (p. 569) that abnormal lateral
* refractions rarely exceed a few arc seconds, so the actual tilts must
* be small.


W. Chauvenet
Manual of Spherical and Practical Astronomy, Vol.I
(J.B.Lippincott, London, 1891).

* WILLIAM CHAUVENET's treatment
* This used to be the standard textbook of astronomical refraction; it's
* now completely obsolete. Likewise, the treatment of Least Squares in
* Vol. II (especially "Chauvenet's criterion" for the rejection of data)
* is frowned on today, now that we have better methods of "robust
* estimation". However, he does provide an early description of Talcott's
* Method for measuring latitude; cf. Clarke (1880).


E. von Oppolzer
“Strahlenbrechung,” in Handwörterbuch der Astronomie , W. Valentiner, ed.
(Verlag von Eduard Trewendt, Breslau, 1901), Vol. IIIb, pp. 548–601.

* VALENTINER/OPPOLZER
* Oppolzer appreciates the height distribution; see p. 562, where he cites
* Fabritius. There is a good section on TILT of layers, pp. 577-580.
* He also discusses nocturnal inversions (pp. 588-589) and dispersion, and
* has a section on pavilion refraction. Very good!
*      The series is "Encyklopædie der Naturwissenschaften"; this is
* "III. Abtheilung. II. Theil: Handwörterbuch der Astronomie".
*      Google Books has a good scan of this volume.


S. Newcomb
A Compendium of Spherical Astronomy
(Macmillan, New York, 1906), Ch.\ 8.

* NEWCOMB
* Surprisingly full of errors.      The numerical error I found here in my
* 2004 AJ paper is on pp. 217-219. In any case, his treatment, based on
* Radau's series expansions, is completely obsolete today.
*      The clarity is not helped by the typography.  The publisher chose to
* use a printer in Glasgow (!) -- presumably to save cost in printing.
* That printer used fonts in which the Greek α is very similar to the
* Italic a . In addition, Newcomb used a local constant factor denoted
* by a Roman "a" in some of the equations for refraction.
*      The start of each signature is marked by "N.S.A." at the foot of the
* page, which presumably meant "Newcomb's Spherical Astronomy" to the
* binder. It's a bit distracting, as this footer is not separated from
* the body type by leading, but is just the last line printed.
*      The scan of this volume in Google Books duplicates some of the later
* pages: pp.356-391 appear twice; next come pp. 392-395, which are then
* followed by an additional copy of pp. 326-444 (the end of the book).
* So pp.356-391 appear three times altogether, and 326-355, twice.
*      W.W.Campbell's 20-page biography of Newcomb is in Mem.N.A.S. 17 (1924)


A. Bemporad
“Besondere Behandlung des Einflusses der Atmosphäre (Refraktion und Extinktion),” in Encyklopädie der Mathematischen Wissenschaften mit Einschluss ihrer Anwendungen, Band VI, Teil 2, Astronomie, Erste Hälfte , K. Schwarzschild and S. Oppenheim, eds.
(B.G.Teubner, Leipzig, 1907), pp. 287–334.

* BEMPORAD's Encyclopädie der Mathematischen Wissenschaften article
*      This review begins with a table of contents, followed by the bibliography.
* Bemp. explicitly refers to Bruhns, saying that his list extends and
* continues that of Bruhns. The references are blessedly complete!
* Unfortunately, because of the reliance on Bruhns, Ivory's warnings
* about convergence are ignored here. So the development uses the old
* expansions in odd powers of tan Z.
*      The super-adiabatic lapse rate of Laplace's model is mentioned in note
* 24 on pp. 305/6. The paragraph suggesting plain mechanical quadrature
* would be better is in the middle of p. 313; cf. n.4, p.294.
*      The publication date is uncertain; the title page of this volume says
* "1905-1923". Bemporad's contribution is dated December 1907, so
* the actual publication date might have been 1908.
*      [See the review article about the Enzyklopädie by W. van Dyck
* in Jahresbericht der Deutschen Mathematiker-Vereinigung 17, 213-227
* (1908) for an overview -- available from Digizeitschriften, at
*      http://digizeitschriften.de/home/zeitschriften/  ]
* A digital version is available at SUB Göttingen. Its Inhaltsverzeichnis
* shows that in section A (Sphärische Astronomie), chapter 3 (Geographische
* Ortsbestimmung, nautische Astronomie) by C.W.Wirtz has a section V.,
* Nautische Astronomie, with subsection 38. "Die Kimm und ihr Verhalten"
* (p. 139) that might also be of interest. These PDFs have high-quality
* page images, but are not searchable; but tesseract handles them well.
*      Bemporad's chapter is number 6.


A. Bemporad and P. Puiseux
“VII. 2. Réfraction et Extinction,” in Encyclopédie des Sciences Mathématiques Pures et Appliquées
(Gauthier-Villars, Paris, 1913), pp. 14–67.

* BEMPORAD's German Encyclopedia article translated into French
* The sub-title says "Exposé, d'après l'article allemand de A. Bemporad
* (Catane) par P. Puiseux (Paris)"; I give both, but it's mostly Bemporad.
*      The very first footnote gives 5 references on atmospheric dispersion.
* And (pp. 15-16): "A nos yeux il est beaucoup moins important d'insister
* sur les artifices de développement que de bien caractériser les
* différentes hypothèses. Il y a en effet une méthode (la quadrature
* mécanique), qui, dans toutes les hypothèses, conduit également vite
* au but, c'est-à-dire à la connaissance de la réfraction théorique."
*      There is a succinct discussion (pp. 16-17) of the different formulae
* linking the density to the refractivity, pointing out who has used which
* ones, and concluding that the simple Gladstone-Dale formula is as good
* as any. "On devra donc, dans les théories de la réfraction et de
* l'extinction, choisir la formule la plus avantageuse au point de vue
* analytique . . . ."
*      Pp. 23-37 have a nice historical summary of the models of Cassini,
* Tobias Mayer, etc. On p. 28 is pointed out that Laplace's formula gives
* a slightly super-adiabatic lapse rate at the surface. This is a much
* clearer review of the various theories than Bruhns's, with the further
* advantage that the works of Bessel and Radau are included. Bauernfeind,
* Schmidt, Gyldén, Oppolzer, and Bruns are given rather short shrift.
* At the end of this review section (p. 37) is the punch line:
*      "Quand on réfléchit à la peine qu'ont demandée les developpements
* analytiques des théories de la réfraction, et notamment les plus
* complets de ces développements élaborées par H.Gyldén et R. Radau ,
* on a le droit de penser que la réfraction astronomique s'obtiendra plus
* aisément par un simple calcul numérique (quadrature mécanique), qui
* tiendra compte directement des donées de la physique de l'atmosphère."
*      On pp. 37-50 the refraction integral is developed according to the
* more important theories. The extinction is treated on pp. 58-67.
*      The title page says "Publiée sous les auspices des académies
* des sciences de Göttigue, de Leipzig, de Munich et de Vienne avec
* la collaboration de nombreux savants. Édition française rédigée
* et publiée d'après l'édition allemande sous la direction de Jules
* Molk, Professeur à l'Université de Nancy. Et pour ce qui concerne
* l'astronomie sous la direction scientifique de H. Andoyer Professeur à
* l'Université de Paris. Tome VII (premier volume), Astronomie Sphérique.
* Rédigé dans l'Édition allemande sous la direction de K. Schwarzschild
* à Potsdam." The original German edition appears to be:
* Besondere Behandlung des Einflusses der Atmosphäre (Refraktion und
* Extinktion), Enz. der math. Wiss. 6, part 2, (Teubner, Leipzig, 1907)
* My photocopy lacks pp. 21, 51-57.


R. Ball
A Treatise on Spherical Astronomy
(Cambridge Univ.Press, Cambridge, 1915).

* Sir ROBERT BALL
* Very readable treatment; derives the usual approx. from Cassini's model
* on pp. 125-128. Unfortunately, an excessive number of approximations
* is used, so the result is not very accurate. However, there is a neat
* proof of Oriani's theorem on pp. 123-124 (though Oriani is not mentioned).


W. Möbius
“Optik der Atmosphäre,” in Encyklopädie der Mathematischen Wissenschaften, Band VI, Teil 1: Geodäsie und Geophysik , Ph. Furtwängler and E. Wiechert, eds.
(Teubner, Leipzig, 1925), pp. 497–540.

* Theoretical treatment of atmospheric optics; no GF coverage
* There are some useful remarks on mirages:
* "Da plötzliche Übergänge von n , wie zu festen order flüssigen
* Mitteln, hier nicht anzunehmen sind, dürfte man wohl, streng genommen,
* nicht, wie es oft geschieht, von Totalreflexion und Luftspiegelungen
* sprechen, wenn auch eine Analogie zweifellos besteht." (p. 500)
* (Here he cites Claudius [sic; he means Rudolf Clausius, in Grunerts
* Beiträge zur Met. Optik ], 1850, for similar remarks.)
* This is the only work to cite Brandes's article in Gehlers
* Physikalisches Wörterbuch , so far as I know.
* THANKS to Shaun Hardy for supplying a copy of this!
*      After much searching, I found that this author is Alfred Willy Möbius
* = Wilfried Möbius (1879 - 1964). See
*
* https://de.wikipedia.org/wiki/Willy_M%C3%B6bius
*
* He published a few papers on the theory of the rainbow, some of which are
* cited in his Encyclopedia article, which seems to be his last publication.
* Most were published by Teubner, beginning with "Einführung in die Optik
* der Atmosphäre" (1907).


P. de Vanssay
“On refraction and refraction tables,”
Hydrographic Review 21, 17–36 (1944).

* Review article in 1944 "International Hydrographic Review"
*      This covers both REFRACTION and DIP, and cites many obscure tables.
* It is available at the University of New Brunswick library website:
*
*            https://journals.lib.unb.ca/index.php/ihr/issue/archive/2
*
*      The coverage is much more complete (up to 1944) than the recent
* review article by François Mignard in C.R.-Physique (2022). On the
* other hand, this review contains some typos, such as "Bompard" for
* Bemporad, and "Delamare" for Delambre, so that one wonders about the
* accuracy of the discussion.
* On the title page of this article, the author is "Ingénieur Hydrographe
* Général P. de VANSSAY de BLAVOUS, Director". He is just "P. de Vanssay"
* in the IHR archives. On the front matter, he is listed as one of the
* two Directors of the International Hydrographic Bureau (which is now
* the International Hydrographic Organization, whose website is at
*
*        https://ihr.iho.int/ .
*
*      This issue is No. 39 in the series published by the IHB in Monte-Carlo,
* Monaco, and dated August, 1944. The title page simply says "Hydrographic
* Review".


H. Neuberger
“General Meteorological Optics,” in Compendium of Meteorology , T. F. Malone, ed.
(American Meteorological Society, Boston, 1951), pp. 61–78.

* GENERAL REFERENCES before 1951


A. Danjon
Astronomie Générale: Astronomie Sphérique et Éléments de Mécanique Céleste
(J. & R. Sennac, Paris, 1952-53).

* DANJON
* Chapitre IX is devoted to refraction, including DIP and MIRAGES.
* Dispersion and chromatic scintillation are mentioned, but not green flashes.
* Thanks to Fred Talbert for reminding me of this!


É. Vassy
Physique de l'Atmosphère. Tome II: Phénomènes de Réfraction
(Gauthier-Villars, Paris, 1959), pp. 14–16.

* VASSY
* Étienne Vassy was primarily interested in the upper atmosphere, which
* explains the chapters here on the ionosphere and sound propagation.
* He is mostly remembered today for his work on ozone in the 1930s.
*      Section 4 of Ch. I is "Influence de la dispersion; le rayon vert."
* Even at this late date, he says Julius's anomalous-dispersion theory is
* one of two possible explanations; though he points out that Danjon &
* Rougier's work refutes it.
*      Having seen the phenomenon repeatedly at a single location during one
* week(!), he thinks it is a result of thermal inversions. He also has
* the Byrd story wrong ("le premier jour de l'apparition du Soleil après
* la nuit polaire. . . "). (p. 15)
*      On p. 16, he worries about the variable (and overly long) duration.
* But he thinks this can be explained by the effects of "fluctuations
* notables d'indice le long des rayons . . . si l'obstacle derrière lequel
* disparaît le Soleil est surmonté d'une couche d'air dont l'indice
* commence par croître avec l'altitude."
*      He also worries about the sudden change of color, which he attributes
* to the rain-band of water vapor.
*      On p. 40, he attributes the distortions of the low Sun to variations
* of index along the trajectory. Much of his mirage discussion is based
* on Flammarion.
*      Hardly half a dozen references are cited in the whole book!
* [Tome I was on emission phenomena.]


W. M. Smart
Text-Book on Spherical Astronomy
(Cambridge Univ. Press, Cambridge, 1962), Ch.~3.

* SMART
* The classical textbook on traditional spherical astronomy.


R. G. Fleagle and J. A. Businger
An introduction to atmospheric physics
(Academic Press, New York, 1963).

* Robert G. FLEAGLE and Joost A. BUSINGER
* Shows a simplified PALM-TREE diagram, with the usual error (p. 296)
* (Ironic, in view of Businger's later importance for inferior mirages!)
* Mirages get only a page here; GF gets one sentence (p. 358, 2nd ed.).
* The Second (1980) edition is on a Ukrainian Website or Scribd; see p. 356


E. W. Woolard and G. M. Clemence
Spherical Astronomy
(Academic Press, New York, 1966).

* WOOLARD & CLEMENCE
*      General: Chapter 5;  DIP, SUNSET in Chapter 10,
* "Determinations of position in the local reference system"
*      Specific: a very superficial mention of refraction near the horizon on
* p. 88, listed in the index; but citing few references, and neglecting
* the works of Fletcher, Sugawa, and many others.


I. G. Kolchinskii
Refraktsiya Sveta v Zemnoi Atmosfere
(Naukova Dumka, Kiev, 1967).

* KOLCHINSKII emphasizes issues omitted from the regular texts
* After pointing out the need for refraction of objects within and near
* the limits of the atmosphere, he briefly reviews the literature.
* There are several interesting items in his bibliography, especially
* dealing with refraction near the horizon, in the polar regions, etc.
*      Pp. 11-12 have a clear summary of Emden's polytropic model, and give
* his series-expansion terms.
*      Pp. 13-14: after describing the tables of Link & Neuzil in BAC (1958),
* he notices that their extreme values at the horizon strongly violate
* the usual refractivity scaling (from T and p values). Then (p. 14):
* "Thus, the dispersion between the refraction at the horizon, calculated
* by [refractivity scaling] and obtained by numerical integration, proves
* to be highly significant. It indicates that in this case the upper layers
* of the Earth's atmosphere influence the value of the refraction integral."
*      Pp. 14-15 describe Fuss's observations at Pulkovo, which he attributed
* to a low-lying inversion; but K. says that Bauschinger, and also
* Banakhevich, showed this was insufficient. The discussion of large
* refraction near the horizon continues on pp. 16-17; he seems to consider
* this normal phenomenon "anomalous" simply because it is not in the
* standard tables.
*      On pp. 18-19, he discusses TILT of the layers, with several references.
*      At the end of the Conclusion, p. 40, he raises the issue of using
* terrestrial refraction to estimate temperature gradients, as suggested
* by Fesenkov -- cf. Faye!


M. Hotine
Mathematical Geodesy
(Department of Commerce, Washington, D.C., 1969).

* Martin Hotine's "Mathematical Geodesy" reference (1969)
*
*      This work introduces the use of tensor calculus to geodesy; see the
* Preface, starting on p. x. TERMINOLOGY and notation are discussed on
* p. xiii. He does not clearly explain his use of ambiguous terms; it
* appears from context that he uses "altitude" to mean height above sea
* level most of the time, but does refer to "altitude and azimuth" on
* p. 251. He uses "height" to mean "height above the reference surface"
* (which is usually the geoid); see p. 233 for "geodetic heights", and
* also the discussion of sign conventions on p. 70.
*      Users of GPS will be amused at the remark on p. 147: ". . .  relativistic
* effects . . . are unlikely ever to be significant in the case of near-Earth
* satellites."
*      Chapter 24 (pp.209-) is "Atmospheric Refraction".  Here the refractive
* index is µ. The refractive invariant for the spherical case is derived
* on p. 211. The discussion is basically in terms of geometrical optics:
* he assumes rays, point sources, and the like.
*      A notable comment on p. 214 says: "One possible assumption is that the
* model atmosphere is in static equilibrium , which might be approximately
* so in settled weather conditions during the afternoon. This would mean
* that the isopycnics --- or surfaces of equal density --- which are nearly
* the same as the surfaces of equal refractive index, are gravitational
* equipotentials; the gradient of (In µ) is accordingly in the direction
* of the astronomical nadir." But he then assumes the isopycnics are
* all surfaces of constant gravitational potential, "so that the zenith
* distances are all unrefracted." So tilt is neglected. Then the gradient
* of refractivity "will not usually differ from an exact gravitational model
* by more than a few minutes of arc."
*      On p.215 we see that geodesists call vertical angles "elevation"
* (corresponding to the astronomer's "altitude".) Footnote 4 there
* discusses the surveyors' "coefficient of refraction". We also have the
* circular-ray approximation. Then the elegant mathematical formalism is
* wasted, and we are back to Helmert.
*      Fortunately, this oversimplification is relaxed on the next page, where
* the equation of state is modified to include the water-vapor partial
* pressure. Here the old "3/8" becomes 0.37803. The refractivity of air
* is taken from Edlén's 1966 formula and Barrell & Sears. The group
* velocity finally appears on p. 217. The radio refractivity is the old
* Essen & Froome value with no dispersion.
*      The discussion of lapse rates is quite primitive.  On p. 221 he does
* find that the rays are straight in dry air for a lapse rate of 0.0334 °C.
* per meter. On the next page, he says the adiabatic lapse rate is "almost
* double what is usually found during the period of minimum refraction from
* reciprocal vertical angle measurements." [Monin and Obukhov published
* their paper in 1954, 15 years before this was published.]
*      Astronomical refraction begins on p.223.  "A good historical summary
* is given by Newcomb." [ouch!] Garfinkel's works are cited, too. The
* refraction integral is given with d(ln µ) as the variable of integration;
* but no details are offered. Parallactic refraction is treated crudely
* in section 69. Early attempts to measure terrestrial refraction with the
* two-wavelength method conclude the chapter.
*      This is ESSA Monograph 2.  Its analyses (but not its obsolete numbers)
* are still widely cited by geodesists.


F. Link
Eclipse Phenomena in Astronomy
(Springer-Verlag, New York, 1969).

* for DISTORTED SUN, see Fig. 1.2.23, p.49


F. Link and L. Neuzil
Tables of Light Trajectories in the Terrestrial Atmosphere
(Hermann, Paris, 1969).

* AIRMASS & REFRACTION TABLES for std.atmospheres


R. A. R. Tricker
Introduction to Meteorological Optics
(American Elsevier, New York, 1970).

* ``Temperature inversions . . . occasionally give rise to abnormal effects of
* refraction. . . . The effects are transient and variable, and there is little
* point in attempting to work out an exact theory for them. . . .'' (p.19)


A. P. Norton
Norton's Star Atlas, Sixteenth Edition
(Gall & Inglis, Edinburgh, 1973), p. 2.

* NORTON'S STAR ATLAS
* The 17th edition (1986) is the same as here.
* A longer but less accurate account is on p. 38 of the 15th ed. (1966).


A. V. Alexeev, M. V. Kabanov, I. F. Kushtin, and N. F. Nelyubin
Opticheskaya refraktsiya v zemnoi atmosferye
(Nauka, Novosibirsk, 1983), p. 58.

* Cassini's "formula" given


C. A. Murray
Vectorial Astronomy
(Adam Hilger, Ltd., Bristol, 1983).

* AIRMASS & REFRACTION in Chapter 7, "Astrometry through the atmosphere"


R. M. Green
Spherical Astronomy
(Cambridge University Press, Cambridge, 1985).

* GREEN -- Ch. 4, esp. pp. 87-93
* Table 4.1 (p. 91) "gives approximately the amount of refraction taking
* place above the level in question, for a source at zenith distance
* 45°."


P. K. Seidelmann
Explanatory Supplement to the Astronomical Almanac
(University Science Books, Mill Valley, CA, 1992).

* 2nd EXPLANATORY SUPPLEMENT
* Recommends the Auer-Standish method to calculate refraction, using the
* Hohenkerk-Sinclair (1985) computational scheme.


A. T. Young
“Understanding astronomical refraction,”
Obs. 126, 82–115 (2006).

* not a book, but a textbook-style tutorial article; so placed here
*      Caution: fails to mention the tilt effect, so is incomplete.


C. F. Bohren and E. E. Clothiaux
Fundamentals of Atmospheric Radiation: An Introduction with 400 Problems
(Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 2006).

* Craig F. Bohren and Eugene E. Clothiaux's textbook on RT
* Chapter 4 on Radiometry and Photometry is a nice review of these
* quantities and their units, with an introduction to color science as
* well. But Ch. 8 on Meteorological Optics (p. 397) is our main interest
* here. especially §8.3 on atmospheric refraction (pp.418-426), which
* touches on mirages and GFs.
*      The treatment is quite limited: only the flat-Earth mirage model is
* treated, and only Cassini's uniform model is used for astronomical
* refraction. Because dip is ignored, "Fraser's Theorem" is taken to
* imply that the serrated Sun at the horizon must be due to "horizontal
* variations of the refractive index" (p. 425).
*      Unfortunately, the uniform model leads to large errors in the
* flattening of objects at the horizon and the width of the green rim.
* No mention of Biot, who did better.
*      §8.3.3 (pp.425-426) treats green flashes, pointing out that the
* atmosphere can magnify the green rim. But the various forms are not
* mentioned. Overall, good on the fundamentals, but lacking in depth.


L. Dettwiller, P. Léna, and D. Gratias
“Astronomy, Atmospheres and Refraction: Foreword,”
Comptes Rendus. Physique 23, No. S1, 5–11 (2022).

* The Special Issue of C.R.-Physique on atmospheric refraction
*
*      Published online at
*
* https://comptes-rendus.academie-sciences.fr/physique/item/CRPHYS_2022__23_S1/
*
*      That link shows the Contents of the whole issue.  Its Foreword is at
*
* https://comptes-rendus.academie-sciences.fr/physique/item/10.5802/crphys.132.pdf
*
* or      https://doi.org/10.5802/crphys.132
*
*      This Foreword briefly enumerates the articles in the Special Issue.
* The emphasis is mainly pedagogical and historical, so the articles are
* reviews rather than technical advances. The Foreward is in both French
* and English; most of the articles are in French, with English abstracts.
*      I list here some of the more general articles.  The more technical ones
* are distributed in this bibliography to their most relevant positions.
* Also, I omit several contributions that deal primarily with "seeing" and
* other effects of turbulence.
*      Although the date of the issue is 2022, most of the papers were not
* actually published until 2023.


F. Mignard
“Les tables de réfraction astronomique,”
Comptes Rendus. Physique 23, No. S1, 133–178 (2022).

* François Mignard's review of refraction tables (and how to compute them)
* This starts out looking like a more expanded version of my own paper
* (see below); but it has considerably more numerical detail. There are
* some interesting variations on Cassini's model.
*      However, there is also much emphasis on the tangent series; and some
* peculiar omissions: no mention of Flamsteed's connection to Newton's
* table; considerable discussion of how to evaluate integrals, but no
* mention of S.Y. van der Werf's papers; considerable use of polytropic
* layers, but no mention of Emden; etc. In discussing Newcomb's book, he
* notices that the numbers don't agree with the analysis, but fails to
* identify the exact error in Newcomb's numerical work -- which is pointed
* out in my AJ paper, which he cites. He also has the title of Newcomb's
* "Compendium" wrong in the text (but right in the Références).
*      On the other hand, he uses Ciddor's dispersion formula, and points out
* the unrealistic nature of the Standard Atmosphere. And Fig. 22 shows an
* actual sunrise sequence (affected visibly by the nocturnal inversion).
* So, a mixed bag. Read with caution; refraction is not his specialty.
*      Published online: 25 May 2023  at: https://doi.org/10.5802/crphys.123
* DOI: doi:10.5802/crphys.123


L. Dettwiller
“Phénomènes de réfraction atmosphérique terrestre,”
Comptes Rendus. Physique 23, No. S1, 103–132 (2022).

* Luc Dettwiller's classification of refraction phenomena in CR-Phys.
*      Largely a descriptive summary of terrestrial refraction phenomena,
* like a shortened French version of Humphreys (1940) brought up to date
* with recent references.
*      There is a nice discussion of the virtual images percieved by the eye,
* and their apparent positions (even when the physical position of the
* real astigmatic image lies behind the eye).
*      Luc makes good use of several ray-trace diagrams taken from my website.
*      [The discussion is mostly in terms of Lambert's model, which is
* appropriate for beginners; but its unreality tends to mislead them, as
* mirages are due to changes in lapse rate.]
*      Published online: 21 February 2023  at:  https://doi.org/10.5802/crphys.114
* DOI: doi : 10.5802/crphys.114
* Part of the special issue: Astronomy, Atmospheres and Refraction
* Also avaliable at
* https://comptes-rendus.academie-sciences.fr/physique/item/10.5802/crphys.114.pdf
*


A. T. Young
“Did Monge really explain inferior mirages?,”
Comptes Rendus. Physique 23, No. S1, 467–481 (2022).

* Review of inf.-mir. history, Monge's error, and reactions to it.
*      The origin of the word "mirage" is examined in detail.
* I should also have cited Möbius (1925), and perhaps Garbasso's second
* (1907) paper.
*      Published online at:      https://doi.org/10.5802/crphys.106
* on 20 Dec. 2022
* DOI: doi : 10.5802/crphys.106
* Part of the special issue: Astronomy, Atmospheres and Refraction


A. T. Young
“Relations among atmospheric structure, refraction, and extinction,”
Comptes Rendus. Physique 23, No. S1, 179–212 (2022).

* Review of astronomical refraction and extinction (airmass), and their
* relation to atmospheric structure. Shows that the Standard Atmosphere
* is unsuitable; that Cassini's model is adequate, except near the horizon;
* and that the Auer-Standish recipe fails near the top of a duct.
* Largely historical.
*      Published online at:      https://doi.org/10.5802/crphys.125
* on 21 Feb. 2023
* DOI: doi : 10.5802/crphys.125
* Part of the special issue: Astronomy, Atmospheres and Refraction



*** POPULAR BOOKS FILE ***

E. Hawks
Stars Shown to the Children
(T.C. & E.C.Jack, London, 1911?), p. 60.

*
* ELLISON HAWKS's book
* ". . . you must watch carefully, for, as the minutes go by, the sun
* will get lower and lower until there is only a tiny tip left. Then,
* just before it finally disappears, you will perhaps see a little green
* flame shoot up, and the tip of the sun itself will turn green. I do not
* say that you will always be able to see this Flash, but only on certain
* occasions. I have known people only see it once out of a dozen times,
* but it is very interesting to watch the sun disappear over the horizon,
* and to look for the green Flash." (p. 60)
*      So far, so good.  But then, the sun ". . .  will also seem a great deal
* larger than it does when seen high in the sky. This is because of the
* extra thickness of atmosphere near the horizon, which acts as a sort of
* magnifying glass and enlarges the sun, when it is low down. The moon may
* also be seen enlarged in the same way, as it rises in the east, when it is
* full." Ouch! (Well, you can't win them all.)
*
* Thanks to Charles Campbell, of Cranleigh, Surrey (UK) for the reference!
* He says it was published in 1912, but the copy I borrowed from Case,
* while undated, has "October 1910" at the end of the preface; and the
* last page of the index has a footer naming the printer (Ballantyne,
* Hanson & Co.) and the notation "5/11"; so I believe it was printed in
* 1911. This is the ninth volume in the "Shown to the Children" series.
* According to the L.C. catalog, Hawks wrote other books in that series.
* The British Library catalog credits 120 popular books to him, and dates
* this one 1910.
* Case's copy showed up with the frayed black register bookmark ribbon
* lying between pages 60 and 61 -- right at the GF entry!
* Note the GF observation by Hawks in 1909, shortly before this was written.


A. Turpain
La Lumière, Deuxième Édition
(Librairie Delagrave, Paris, 1923), Ch.XI.

* TURPAIN's book on light, illustrated with photos by Rudaux
* A nice chapter on atmospheric optics, including twilight phenomena,
* zodiacal light, aurorae as well as the usual halos, rainbows, and
* mirages. Mirages and distorted sunsets are illustrated with photos from
* Rudaux; GF is illustrated with his drawings of the 1904 flash.
* Libert's "green Sun" observations are also mentioned.
* Thanks to Luc Dettwiller for a copy of this!


C. F. Talman
Our Weather -- What Makes It and How to Watch It
(Reynolds Publishing Co., New York, 1925).

* CHARLES FITZHUGH TALMAN's books
* Talman is listed on the title page as "Chairman Committee on Public
* Information, American Meteorological Society"
* Crepuscular rays are treated on p. 169, ending with mountain shadows.
* Pp. 170-171 describe textbook green flashes, and red flashes. He
* seems to give a little credence to the "after image" explanation.
* Pp. 171-174 treat mirages, described as "some of the most bizarre of
* optical illusions." General Maude is mentioned on p. 173, as is
* Scoresby, and "Crocker Land".


C. F. Talman
The Realm of the Air
(Bobbs-Merrill, Indianapolis, 1931).

* TALMAN's later book
* In "The Author's Apology", Talman says he "has enjoyed for a number
* of years the exceptional privilege of being the custodian of a nearly
* exhaustive collection of literature on the subject . . . ." [The obit
* on NOAA's Web pages, taken from Weather Bureau Topics and Personnel,
* July 1936, says he had been in charge of the Weather Bureau Library at
* the Central Office since 1908.]
*      Facing p. 21 is a picture of "the most famous cloud in the world":
* the "tablecloth" on Table Mountain, near Cape Town.
* The treatment of mirage (pp. 114-118) is much fuller and better
* here than in the 1925 book. Looming and "lateral mirage" are briefly
* mentioned. He suggests the Flying Dutchman probably arose from
* mirages at sea. On p. 116 appears a garbled account of the New Haven
* ghost ship, here transferred to New York, and mistaken for a mirage of
* a real ship. Wilkes Land and Crocker Land are mentioned; Hubbard's book
* is named, and quoted, but without a page reference (p. 117).
* Pp. 136-137 mention sunset distortions; GF on 137-138. The Lick
* sunset photographs are mentioned (p. 137). There is now no mention of
* after images.
*
* The author says these are edited articles from Nature Magazine, Popular
* Mechanics, NY Times, etc.
* No copyright date is given for the book, only for its sources;
* L.C. says "c1931".


W. E. Harper
“Radio talks over CFCF. LX—Mirages,”
JRASC 27, 59–61 (1933).

* W.E.Harper's Canadian radio talks -- not a book, but belongs here anyway
* This is the lead article in the Feb. 1933 issue, beginning on p.49.
* Available from ADS.


C. M. Botley
The Air and its Mysteries
(G.Bell and Sons, London, 1938).

* BOTLEY -- a popularization of meteorology
* The Manx GF legends mentioned on pp. 152 and 206 are both taken from
* the same letter to The Times (M.Douglas, 1929). Botley exaggerates:
* Manx folklore does not "contain much" about it; it was barely known in
* 1929, and nobody there seems to have heard of it today. The reference
* to Rex Clements's story is also overblown. And the purported "superior
* mirage" in Plate XI (facing p.210) is almost certainly a fake.
* Yet the Italian translation of this book is O'Connell's ref. #10.


C. D. Neal
Exploring Light and Color
(Childrens Press, Chicago, 1964), p. 18.

* Dr. Charles D. Neal's book for juveniles
* "When there is, near the earth, a layer of air that is warmer and
* denser [sic!] than the air above it . . . ."
* [Well, it isn't the *air* that's denser here . . . .]


F. M. Branley
Sun Dogs and Shooting Stars: A Skywatcher's Calendar
(Houghton Mifflin, Boston, 1980), pp. 73–75.

* Franklyn M. Branley's treatment for juveniles
* ". . . the green flash, a bright green strip of light that appears just
* above the setting sun. Usually it is seen close to the horizon an
* instant after the sun itself has disappeared . . . . Because of its longer
* wavelength red is bent the least." (The diagram is equally poor.)
* Branley wrote many books on astronomy for children; he died in 2002.


W. R. Corliss
Rare Halos, Mirages, Anomalous Rainbows and Related Electromagnetic Phenomena
(Sourcebook Project, Glen Arm, MD, 1984).

* Compendium of reports, as in Mulder's book: this put me on to
* Starr's (1930) paper, so Corliss is accomplishing his aim here.
* Like Mulder, he quotes items and adds short comments:
* "The green flash and the crepuscular rays . . . have long been considered
* as fully explained. The stock explanations, however, seem simplistic
* when the full ranges of these phenomena are considered."
* Of "the appearance . . . of multiple green rays of light ascending from
* the point of the sun's disappearance", he astutely says, "This phenomenon
* may be related to the crepuscular rays."
* Corliss's list of 42 references contains no errors, which speaks well
* for the care he has exercised -- especially considering that the
* ``standard'' references typically have 10% to 20% errors!


H. Miles
“Rare Haloes, Mirages, Anomalous Rainbows and related electromagnetic phenomena,”
JBAA 95, No. 4, 188–189 (1985).

* Corliss's book reviewed in JBAA
* GF is mentioned. Available from ADS.


R. A. Gallant
Rainbows, Mirages, and Sundogs
(Macmillan, New York, 1987).

* A juvenile book illustrated in b/w, with the usual mistakes
* Mirages are treated on pp. 14-22. Looming is treated as a mirage:
* "Looming mirages are the only mirages that appear to be nearby. They
* may also greatly magnify the real object."
* "Our first glimpse of the Sun at sunrise is a mirage."
* An interesting variation is the suggestion to observe variations in dip.


Q. L. Pearce
Amazing Science. Lightning and other wonders of the sky
(Julian Messner, Englewood Cliffs, NJ, 1989), p. 17.

* Another juvenile book, full of strange stuff
* ". . . at sea . . . the air layer closest to the water is usually colder
* than the air layer above it. As a result, sea mirages . . . are right
* side up and above the object . . . ." (even worse about Fata Morgana)
* Acknowledgment thanks "William A. Selby, Professor of Geography/Earth
* Sciences, Santa Monica City College . . . for his critical reading of the
* manuscript."


D. K. Lynch and W. C. Livingston
Color and Light in Nature
(Cambridge Univ. Press, Cambridge, 1995).

* much misinformation, but some great photographs
* The second edition, published in 2001, is greatly improved, and RECOMMENDED.
* [Although they propagate the "fata bromosa" error.]


F. Suagher and J.-P. Parisot
Jeux de Lumière
(éditions Cêtre, Besançon, 1995).

* This is a beautiful book, similar to the Lynch/Livingston book;
* it contains the best mirage photos I have seen. The GF pictures are
* poor, but the advice on how to obtain them is good. Unfortunately,
* the multiple inferior mirage (due to uneven ground) on p.60 is
* mis-identified as a Fata Morgana; and the price is a bit high (FF 240).
* See pp. 49-56 for the GF, and 56-60 for mirages.


K. Schlegel
Vom Regenbogen zum Polarlicht - Leuchterscheinungen in der Atmosphäre
(Spektrum Akademischer Verlag, Heidelberg, 1995), pp. 24–25.

* Clear presentation of the textbook story, with one of Pekka's GFs.
* Note that the wrong colors were printed on Abb.1.6 on p.24.
* Thanks to Dr. Kristian Schlegel for a copy of his book! It turns out
* to contain many fine pictures of natural phenomena, including one of
* ball lightning. The author tells me a revised edition is in the works.


P. Murphy and P. Doherty
The Color of Nature
(Chronicle Books, San Francisco, 1996).

* All sorts of pretty pictures, not just atmospheric optics
* Pekka's multiple-mock-mirage flash sequence is on pp. 131-133, with
* the final stage on a double-page spread. "The conditions for seeing
* the green flash, or green ray, with an unaided human eye occur only a
* few times out of every ten sunsets over a distant unobstructed horizon."


P. Simons
Weird Weather
(Little, Brown & Co., London, 1996).

* a journalist's attempt to cover science?
* Paul Simons's book is full of errors, but has some decent coverage --
* it seems to fall somewhere between Corliss and the National Enquirer .
* The author has believed everything he's read, and has sorted out the
* most sensational accounts. So he asserts, in the introduction, that
* "The Föhn wind in Germany sends people mad," and other nonsense.
* Speculation is presented as fact; there is no index; and the "Select
* Bibliography" at the end is already secondary and tertiary sources, some
* not too reliable themselves. The book is clearly pitched at an English
* readership (British spellings throughout).
* The photographs (some by Pekka Parviainen, some by Alistair Fraser;
* some strangely reproduced with moiré stripes through them) are mixed
* with engravings from Flammarion (!)
* One of Pekka's pile-of-plates clouds is captioned ". . . lenticular
* clouds created on waves of turbulent air." And the adjacent text says
* ". . . called rotor clouds or lenticular clouds." [p. 60]
* The story of Ross mentions his "Croker Mountains" on p. 58.
* "Green Flash" is on pp.85-86: ". . . it sometimes hurls a shaft of vivid
* green light across the sky . . . ." The usual "prism" is invoked.
* While there are hints of interesting reports to pursue, the lack of
* detailed references makes most of them useless. The unwary should
* steer well clear of this confused and unreliable book.


J. Naylor
Out of the Blue: A 24-hour Skywatcher's Guide
(Cambridge Univ.Press, Cambridge, 2002).

* John Naylor's mixed bag: great photographs, some good (and some misleading)
* diagrams, some good (and some wrong) information. Many of the topics
* of interest here are covered: refraction & mirages (Ch.3, pp. 50-63);
* flattened sunsets (pp. 64-67); crepuscular rays (pp. 77-79); distorted
* sunsets (pp. 80-84); Green Flashes (pp. 84-86). All non-mathematical.
*      Pekka's pictures are great.  But there are some howlers: Naylor claims
* Monge made up the word "mirage" (p. 51), though he gives the correct
* etymology. He thinks mirages are due to temperature gradient, not the
* curvature of the temperature profile (p. 55). "If your eye is too high,
* it will not intercept the rays that produce the inverted image, and you
* will not see a mirage." (p. 57) [Pekka's over-sized Omega is on p. 56.]
*      Ch. 4 (pp. 64-87) deals with low-Sun and twilight phenomena; GFs are
* on pp. 84-86; ". . . blue flashes have been seen . . . only from altitudes
* of several kilometres." The pictured mock-mirage flash (Fig. 4.15,
* p. 85) is mis-identified as "Green segment." Many minor errors.
*      There are a number of wrong-word errors that show the manuscript was
* spell-checked but not carefully proof-read.
*      The selection of references is also haphazard, including minor works
* while omitting more important ones. He has the date wrong (as 1968!)
* for O'Connell's book.


M. Vollmer
Lichtspiele in der Luft: Atmosphärische Optik für Einsteiger
(Spektrum/Elsevier, München, 2006).

* MICHAEL VOLLMER's new book on atmospheric optics for beginners
* SUPERB photographs in the color-plates section. This is a more
* technical book than most of the ones in this section -- it's almost a
* textbook rather than a popular work. (He's not afraid to use calculus
* occasionally.) Section 11.2 (pp. 315-322) covers green flashes; there
* are also good sections on refraction in general, and mirages. Each
* chapter has a good list of references.
*      Springer issued a slightly revised second edition in paperback (2019).


M. Maunder
Lights in the sky: Identifying and Understanding Astronomical and Meteorological Phenomena
(Springer, London, 2007).

* MICHAEL MAUNDER's book
* GF treatments are on pp. 72-74 for morning, and 115-118 (evening).
* But he starts off with "The scientific basis for the green flash had
* to wait until 1960 [sic] when D.K.J. [sic] O'Connell of the Vatican
* Observatory produced the first [sic] authenticated color photographs
* of the phenomenon, but he [sic] took those at sunset . . . ."
*      Well, it isn't all that bad, but it isn't good.  "The green flash
* occurs when light is refracted through an atmospheric layer and thereby
* seems to come from this higher layer." (All this from the top third
* of the first page! He does manage to connect flashes with mirages,
* but clearly doesn't understand either one.)
*      On p. 74, we get: "Blues should never be possible and it is difficult
* to give an explanation." [Especially if you don't understand GFs.]
*      The mirage discussions on pp. 101 ff. aren't much better; he confuses
* inferior mirages with looming and normal refraction: "The interface
* acts very much as a mirror with light reflected back from the much
* denser air above. . . . this mirage is described as an 'Inferior' mirage,
* from the reflection back from above." (p. 101)
* Like O'Connell, he takes the gaps between multiple mock mirages as
* "blind strips": "These multiple mirages often lead to a whole series of
* green flashes, often seen underneath as well as above, as each layer pass
* through the boundary layers in the atmosphere." (p. 103, strictly sic .)
* Pretty awful. Too bad Patrick Moore's name is on this series.


Marcello Séstito
Fata Morgana o la città riflessa
(Rubbettino Editore, Soveria Mannelli, 2011).

* MARCELLO SÉSTITO's peculiar "Fata Morgana" book
*      A beautifully produced "coffee-table" book, which plays with the
* idea of reflections in its design and illustrations. The author is an
* architect who seems enchanted with the idea of mirror images and symmetry,
* and the architectural theme in the historical accounts of these mirages.
* The first 31 pages provide a brief sketch of the myth of Morgana and
* the literature of the mirages, followed by two pages of more detailed
* references to some sources of information. I was glad to see Boccara's
* paper cited; but Costanzo's is not. And the author has unfortunately
* ignored Boccara's advice about the unreliability of many old works.
*      Then come several sections: "Quaderni" ["Exercises"], of colored
* sketches and art studies inspired by the stories connected with Morgana;
* and then other, more formal paintings devoted to Morgana herself, the
* Strait, and Kircher's "Catoptic Theater". Many of these echo motifs
* seen in Fortuyn's engraving, which is well reproduced on p. 128, just
* before the beginning of the second half of the book.
*      This second half is a series of Appendices that reproduce several
* well-known works devoted to the mirages, beginning with Minasi's classic
* Dissertation of 1773. Unfortunately, it is followed by some of the most
* unreliable essays ever published on this subject: those of Capozzo
* (1840), Saffiotti (1837), Giardina (1758), etc. Minasi's text and
* Capozzo's are printed in two-column format, with a vertical rule that
* separates the columns; but Saffiotti's and Giardina's are reproduced
* in a peculiar 4-up format that retains the 2-column arrangement, so that
* each photocopied page image at bottom of a book page follows the image
* immediately above it; the reader must envision an invisible 2-column
* format, instead of reading pairs of page images side by side.
* Fortunately, the page images bear the original page numbers. As in
* Consolo (1993), Minasi's notes are re-numbered by section instead of
* by pages, and some copying errors in Consolo's version, including his
* errors in re-numbering Minasi's footnotes, are exactly reproduced
* here; so it seems that this is a third-hand copy of Minasi.
*      Minasi's text and Capozzo's are separated by a double-page spread
* that reproduces a widely-reprinted wood engraving from 1865 that falsely
* depicts some imaginary superior mirages, with the upper images shown
* impossibly enlarged in azimuth as well as unrealistically elevated
* in altitude. The misleading text of Giardina, with Gallo's notes and
* Allegranza's garbled commentary, are followed by another pair of phony
* "mirage" images from the 19th Century, including the frequently reproduced
* fantastic image "Mirage in the Desert" from Hartwig's 1875 "The Aerial
* World"; here, Hartwig is mis-identified as "Hartwing". Caveat lector!
*      However, the photocopied texts are followed by the little-known but
* influential discussions led by Johann Reinecke in the pages of Allgemeine
* Geographische Ephemeriden in 1800, which have been capably translated
* from German to Italian by Mario Izzi. The copperplate engravings
* (Tafeln I & II) from Reinecke's initial discussion, which are hard to
* obtain, are usefully reproduced on (unnumbered) pages 206 and 208.
*      Incredibly, this Italian translation of Reinecke's comments actually
* includes an Italian translation of Reinecke's German translation of
* Nicholson's English translation of Minasi's original Italian description,
* even though this book has already reprinted Minasi's original Italian
* text a few dozen pages earlier. So we get to read the third-generation
* version: "Quando il Sole al mattino raggiunge un'altezza tale che i suoi
* raggi formano col mare di Reggio un angolo di incidenza di circa 45
* gradi, . . . " instead of the original "Quando il nascente Sole splende
* in punto, onde l'incidente suo raggio formar possa sul mare di Reggio
* l'angolo di gradi 45 circa, . . . ". Well, maybe it's useful to show the
* modern Italian reader what the 19th-Century German reader read about
* what the 18th-Century Italian writer really wrote; but maybe not.
*      Then come more than four pages of annotated bibliography, containing
* many other little-known and obscure references on Fata Morganas. They
* contain some valuable citations to the recondite literature; but they
* also contain many obvious errors. For example, Humphreys' middle
* initial is given as "L" rather than "J", and the title of his textbook is
* printed as "Phisics" of the Air instead of "Physics"; furthermore, only
* its 1929 edition is mentioned, although the 1940 revision contains
* additional information about mirages. Only the abridged 1671 edition
* of Kircher's Ars Magna (the one with the typo that fooled Marina
* Warner) is cited for Angelucci's letter, rather than the more correct
* text of the original 1646 edition; and the heading of the section is
* cited with "sine" in place of "siue". Similarly, only Pernter's 1902
* edition of Meteorologische Optik is cited, rather than the expanded
* 1910 revision by Exner, let alone the 1922 second revision. Another
* example of carelessness is the misspelling of Marina Warner's last name
* as "Worner", which caused her unreliable book "Phantasmagoria" to be
* placed after Elizabeth Werner's 1896 work. This shows the error to be
* the author's, not that of the printer or proofreader.
*      Strangely, the references cited in the bibliography section do not
* include several other useful references that appear in the Notes on
* pp. 32-33, such as Boccara's fine review of the literature before 1900;
* so it is necessary to consult the Notes as well as the Bibliography
* to discover all of Séstito's sources. His omission of important works
* like Costanzo's review and the later editions of both Humphreys and
* Pernter & Exner reveal his unfamiliarity with the mirage literature.
*      As is usual with the Fata Morgana literature, one needs considerable
* experience with the field to separate the wheat from the chaff; this
* book contains an abundance of both.
*      I was pleased to see the woodcut, or wood engraving, on the
* penultimate page of the book, which illustrates the classical
* demonstration of refraction described by Euclid and Cleomedes.
* It would be nice to know what 19th-Century textbook was its source.
*      Special thanks to Marcella Giulia Pace for bringing this attractive
* and useful work to my attention, and for providing a copy!



*** MINNAERT's BOOK FILE ***

M. Minnaert
De natuurkunde van't vrije veld. Deel I. Licht en kleur in het landschap
(Thieme, Zutphen, 1937).

*
* original edition of Part I of Minnaert's book;
* note that there are three parts to this monograph.
* They are now available on the Web at:
*
*       http://www.dbnl.org/tekst/minn004natu01_01/minn004natu01_01.pdf
*
* He introduces verdwijnlijn and grenslijn on p. 47.
* The "Groene Straal" is introduced with a quote from Verne, and a
* reference to Mulder's book; then comes "Volgens een oude Schotse
* legende . . . ." (p. 58)


M. Minnaert
Light and Colour in the Open Air
(G. Bell and sons, London, 1940).

* first English translation of Part I:
* The term "vanishing line" appears for the first time here, on p. 48


A. D. T.
“Light and Colour in the Open Air,”
Obs. 63, 241–243 (1940).

* REVIEW of the 1940 edition; mentions "the green ray".
* I suppose the reviewer is Thackeray.


C. E. P. B[rooks]
Light and Colour in the Open Air, by M. Minnaert,”
Met. Mag. 76, 67–68 (1947).

* REVIEW of the 1940 edition; mentions "the green ray"; and calls
* Hillers's mural-mirage photo "one of the oddest" in the book.


M. Minnaert
The Nature of Light & Colour in the Open Air
(Dover Publications, New York, 1954).

* This should be the same as the 1940 edition
* "According to an old Scotch legend, . . . "
* He has "Continho" for Coutinho
* Note that he endorses Forel's explanation for the Fata Morgana (p.53)
*      The Dover edition brought Minnaert's work to a much wider public.
* Even so, his term "vanishing line" does not appear in the technical
* literature until 1960.
* O'C #91


M. Minnaert
Light and Color in the Outdoors
(Springer-Verlag, New York, 1993).

* new translation of Minnaert



*** MIRAGE DEFINITIONS FILE -- various handbook accounts of mirages ***

(no author listed)
in Encyclopædia Americana, vol. VIII , F. Lieber, ed.
(B.B.Mussey & Co., Boston, 1851), pp. 525–526.

*                                                             and refraction terminology
*
*       NOTE: This file is mainly the "mirage" articles from a number of
*                    encyclopedias, dictionaries, and similar reference works.
*
* "MIRAGE; an optical phenomenon, produced by refraction. The unusual
* elevation or apparent approximation of coasts, mountains, ships, and other
* objects, has long been known under the name of looming ; and, if the same
* phenomenon is accompanied by inverted images, it is called a mirage ."
*      N.B.: "A popular dictionary of arts, sciences, literature, history,
* politics and biography, . . . on the basis of the seventh edition of the
* German Conversations-Lexicon." [see below for a later edition of that]


(no author listed)
Chambers's Encyclopædia , vol. VI
(J.B.Lippincott & Co., Philadelphia, 1868), p. 485.

* "Under it are classed the appearance of distant objects as double,
* or as if suspended in the air, erect or inverted, etc."
*      But there are some errors:  "In particular states of the atmosphere,
* reflection of a portion only of the rays takes place at the surface of
* the dense medium, and thus double images are formed, one by reflection,
* and the other by refraction -- the first inverted, and the second erect."
* And: "The Spectre of the Brocken , in Hanover, is another celebrated
* instance of mirage."


G. P. Quackenbos
A Natural Philosophy
(D.Appleton & Company, New York, 1870), p. 248.

* "Mirage is the appearance in the air of an erect or inverted image of
* some distant object which is itself invisible." (Garbage.)


(no author given)
Meyers Konversations-Lexikon, Fünfte, gänzlich neubearbeitete Auflage, Elfter Band
(Bibliographisches Institut, Leipzig und Wien, 1896), pp. 587–588.

* "Luftspiegelung . . .  bewirkt, daß Gegenstände, die sich      u n t e r
* dem Horizont befinden, deutlich sichtbar, also gewissermaßen gehoben
* werden . . . , oder daß ü b e r dem Horizont befindliche Gegenstände
* doppelt, vergrößert oder umgekehrt in der Luft schwebend erscheinen."
*      There is a fine laundry list of TERMINOLOGY here:  "Die deutschen
* Seeleute nennen diese Erscheinung K i m m u n g , die englischen
* L o o m i n g , die holländischen U p p d r a c h t , die
* französischen  M i r a g e .      In Indien nennt man die L.
* C h i l t r a m , » Bild « , oder S i k o t a , » Schlösser der
* kalten Zeit « ; bei den Arabern heißt sie S e h r a b ,
* » geheimnisvolles Wasser « , auch Bacher el Alfrid, » Sohn des
* Teufels « , oder Bacher el Gazal."


J. G. Albright
Physical Meteorology
(Prentice-Hall, New York, 1939), pp. 355–359.

* Albright's treatment of the green flash is straightforward and accurate.
* But his section 6 on "Mirages" in Chapter XX leaves much to be desired:
* "The mirage is an optical illusion due to the refraction of light as
* it passes through nonhomogeneous layers of the atmosphere. Distant
* objects are seen in an unnatural position, sometimes elevated, sometimes
* depressed, and often inverted." (p. 355)
*      He also seems to think that any images in excess of 2 must be due to
* reflection on water; in discussing the superior mirage, he says (p.357):
* "If the mirage occurs at sea, the image of a distant ship and of its
* reflection in the water also may appear in the sky, the image of the ship
* inverted and the image of the reflection erect, as shown in Fig. 231."
* [N.B.: This spurious suggestion was already made in 1806 by Kries.]
* His description of looming confuses it with ordinary terrestrial
* refraction; his illustration on p. 358 shows a flat Earth!


A. H. Thiessen
Weather Glossary
(U.S.Government Printing Office, Washington, D.C., 1949).

* Thiessen's Glossary cites Albright's text (above), but omits its
* worst errors. Here looming is succinctly described as "An optical
* phenomenon in which objects below and beyond the horizon appear to
* the view of the observer, and even the horizon itself is extended."
* (I think he is saved by also referring to Humphreys.) Unfortunately,
* for "mirage", he simply quotes the first passage from Albright (see
* above). Here again, he cites Humphreys as well. (p. 188)
* Note that this is "W. B. No. 1445 Issued August 1, 1946" and "Reprinted
* May 1949".


H. Neuberger
“General Meteorological Optics,” in Compendium of Meteorology , T. F. Malone, ed.
(American Meteorological Society, Boston, 1951), pp. 61–78.

* Hans Neuberger (Penn. State) cites 59 references.
* He gives the standard textbook explanation of the green flash, but adds:
* ". . . most observations seem to be associated with refractions in excess
* of the normal," citing Meyer (1939) and Visser & Verstelle (1934).
* He correctly describes looming, sinking, towering and stooping, and
* attributes the mathematical theory of these to Exner (in P&E II).
*      His description of mirages as "one or more images of the object"
* clearly means extra images; he seems to fall into the error of
* assuming that one image is "the object" itself.


World Meteorological Organization
International Cloud Atlas, Volume I
(W.M.O., Geneva, 1956), p. 74.

* A definition that tries to be all things; or at least to cover all
* mirages -- to its detriment:
* "MIRAGE: An optical phenomenon consisting mainly of steady or wavering,
* single or multiple, upright or inverted, vertically enlarged or reduced,
* images of distant objects."
* About all that is useful here is "distant objects"; though "mainly"
* is a nice touch, in light of the rest of the arm-waving! Furthermore:
* "Objects seen in a mirage sometimes appear appreciably higher or lower
* above the horizon than they really are; the difference may amount to as
* much as 10 degrees." So this is all nonsense.
*      In addition, they use the curious non-standard terms "lower mirage"
* and "upper mirage" (in place of "inferior" and "superior", respectively.)


R. E. Huschke
Glossary of Meteorology
(American Meteorological Society, Boston, 1959), p. 373.

* Another completely wrong-headed attempt:
* "mirage -- A refraction phenomenon wherein an image of some object is
* made to appear displaced from its true position."
*      On the other hand, looming, towering, etc. are described correctly
* on p. 349, though described as a "mirage effect".


World Meteorological Organization
International Meteorological Vocabulary
(W.M.O., Geneva, 1966), pp. 117–118.

* The WMO is still confused:
* "Mirage: Optical phenomenon consisting essentially of steady or
* wavering, single or multiple, upright or inverted, vertically enlarged
* or reduced, images of distant objects." (p. 117) [Note that "mainly"
* has now become "essentially"; otherwise, their folly goes on unchanged.]
*      Worse yet, they now think there is a distinction between an "image"
* and "the actual object":
* "Superior mirage: Special case of mirage , . . . in which the virtual
* image is above the actual object." And:
* "Inferior mirage: Particular case of mirage , . . . in which the virtual
* image is found below the actual object." (both on p. 118)
* (Note that what they call a "virtual image" is in fact a real image, not
* a virtual one.)


R. W. Fairbridge
The Encyclopedia of Atmospheric Sciences and Astrogeology (Encyclopedia of Earth Sciences series, Vol. II)
(Reinhold, New York, 1967), pp. 605–606.

* Fairbridge has the same problem:
* "MIRAGE, FATA MORGANA: The mirage is a general category of atmospheric
* optical phenomena involving refraction of light rays bent by differential
* heating of a land or water surface, which results in the distortion or
* displacement of some object viewed, sometimes leading to a misleading
* optical illusion. . . .
*      "Three major types of mirage are recognized:
*      "The  inferior mirage , where the false image is seen below the true
* position of the object viewed."
*      Note that the diagram on p. 606 is reproduced from Hutchinson's book
* on limnology. Fairbridge cites all the right references, but seems to
* have misunderstood them. This article is signed by Fairbridge himself.


D. H. McIntosh
Meteorological Glossary
(Chemical Publishing, New York, 1972), pp. 181–182.

* . . . and so does McIntosh:
* "Two main classes of mirage occur, (i) `inferior' and (ii) `superior',
* in which the virtual image is below and above the object, respectively."
* (Of course all this nonsense about "virtual images" is quite wrong:
* it is the erect images that are virtual and the inverted ones that
* are real!) Worse yet, after discussing the superior mirage:
* "In such physical conditions multiple reflections may give rise to
* various images, some displaced laterally with respect to the object,
* as in FATA MORGANA."


T. S. Glickman
Glossary of Meteorology, Second Edition
(American Meteorological Society, Boston, 2000).

* Fortunately, the Second Edition is far better -- both more complete
* and more accurate -- than the First. Green flashes are connected with
* mirages; mirages are explicitly stated to be all images, not an "object"
* plus (supposedly spurious) "images". "Lateral mirages" in the
* wrong-headed sense are refuted: "the rare reports of such sightings
* undoubtedly arose from misinterpretations of observations." The lifted
* inversions responsible for superior mirages "are common over, but hardly
* confined to, enclosed bodies of water on warm afternoons when the warmer
* air from the surrounding land flows over the colder water." And the
* initial definition of "mirage" as "An image formed when the atmosphere
* behaves as a lens" is succinct and accurate.
*      On the other hand, there are still a few points I'd quibble with.
* Looming and sinking, stooping and towering are all called "mirages".
* Multiple images are attributed to periodic thermal inhomogeneities.
* Inferior and superior mirages are distinguished according to the
* direction of "displacement" of the image. And the Fata Brumosa is
* mistakenly called "Fata Bromosa". Alas, no references are cited.
*      Still, this must be regarded as about the best modern  summary of
* refraction phenomena available.



*** GF TEXTBOOK FILE -- various didactic accounts of green flashes ***

J. M. Pernter
Meteorologische Optik
(Wilhelm Braumüller, Wien und Leipzig, 1902).

*
* Pernter's original 1902 edition, before Exner got involved
* This edition treats only mirages; there is no mention of green flashes.
* It contains only 212 pages, and does not reach halos and rainbows.
*      However, there is much material on the Moon Illusion and its possible
* explanations (pp. 42 ff.) that was removed by Exner in later editions;
* notably the references to Ptolemy's "Optics", and the reference (note 1
* on p.42) to Ptolemy's belief in the Almagest that the "vapors at the
* horizon" are involved.


S. Arrhenius
Lehrbuch der kosmischen Physik
(S.Hirzel, Leipzig, 1903), pp. 856–857.

* Dr. Svante August Arrhenius may have the first textbook account
* The "textbook" story appears here: "Da die roten Strahlen die geringste
* Brechung erleiden, verschwindet zuerst das rote Bild der Sonne unter dem
* Horizont, zuletzt das blaue."
* There is also good coverage of mirages, including a reference to Budde
* (but no citation) on pp.832-835.
* Refraction begins on p.827; dispersion appears on p. 829.
* As the organization and title of the chapter on "Meteorologische Optik"
* are exactly the same as in Pernter's book, that was evidently the model
* for this.
* (Cited by Mulder)


J. M. Pernter and F. M. Exner
Meteorologische Optik
(Wilhelm Braumüller, Wien und Leipzig, 1910).

* Here Exner adds a great deal of material, including GF on pp.798-799
* at the very end of the volume. He accepts Julius's 1/10 second and so
* must reject Henry's 1 sec., but can't swallow the anomalous dispersion;
* so "Einfacher scheint es, . . . die selective Absorption des Wasserdampfes
* zu berücksichtigen." Though there is no mention of either Abbe or
* Tyndall, I suspect this notion came from Abbe's 1905 editorial in MWR.
* Thanks to Günter Können for a copy of this!


J. Moore
Meteorology: Practical and Applied. Second revised and enlarged edition
(Rebman Co., New York, 1910), pp. 459–460.

* Sir John William Moore's curious book on meteorology
* The author was a professional physician, and an amateur meteorologist.
* His book is full of speculations about the effects of the weather and
* climate on disease. This 2nd edition contains a two-page Appendix on
* green flashes (listed in the Contents as "The Green Flash at Sunrise
* and Sunset", and on p. 459 both as just "GREEN FLASH" (below the word
* "Appendix") and "The Green Flash on the Horizon at Sunset" (in italics).
* It contains a brief review of the subject, concentrating on the 1906
* discussions in Symons's Met. Mag., and especially on Rambaut's refutation
* of Lippincott. No further mention of refraction phenomena.


W. Trabert
Lehrbuch der Kosmischen Physik
(B.G.Teubner, Leipzig, 1911), p. 420.

* A very brief exposition of the textbook model


R. Börnstein
Leitfaden der Wetterkunde (3rd edition)
(Friedr.Vieweg & Sohn, Braunschweig, 1913), p. 100.

* Börnstein mentions only Julius's anomalous-dispersion explanation
* -- which I hardly think qualifies as "Gemeinverständlich"!
* (Full title is "Leitfaden der Wetterkunde -- gemeinverständlich
* bearbeitet von Dr. R. Börnstein, Geh.Regierungsrat" etc.)
* Dritte umgearbeitete und vermehrte Auflage
* ". . . der `grüne Strahl' . . . nennt man das ganz kurz dauernde
* Aufleuchten eines smaragdgrünen Flämmchens an derjenigen Stelle des
* Horizontes, wo die untergehende Sonne gerade verschwunden ist. . . ."
* Thanks to Steve Williams for getting this. (cited by Mulder)


A. Berget
Les problèmes de l'Atmosphère
(E.Flammarion, Paris, 1914), pp. 84–87.

* Author at least reports a couple of GFs he saw himself, as well as both
* inferior and superior mirages (p.82). Good clear presentation of the
* standard model at an elementary level, with clear diagrams.


J. M. Pernter and F. M. Exner
Meteorologische Optik
(Wilhelm Braumüller, Wien und Leipzig, 1922).

* A standard textbook account, often cited
* Wegener's mirage theory is reproduced on pp. 151-155.
*      Unfortunately, the French literature is shortchanged here: though
* Biot's mirage monograph is cited, and we have a few mentions of standard
* reference works like Mascart's "Traité", Bouguer and Bravais are cited
* only in connection with Halos, and astronomical refraction is mentioned
* mostly in vague gestures toward "astronomical textbooks."
*      Green flashes are mentioned only in the last 3 pages (901-903).  The
* colored plate at the end of the book shows Wegener's Nachspiegelung.
*      Available at the HathiTrust.
* O'C #101


A. Berget
L'air -- Une nouvelle conquête de l'homme
(Librairie Larousse, Paris, 1927), p. 26.

* Alphonse Berget's interesting book, illustrated by Lucien Rudaux
* Chapt. 3 (pp. 20-27) covers refraction phenomena, and contains many of
* Rudaux's monochrome photographs of low-sun phenomena. Fig. 14 on
* p. 24 is noteworthy. P. 25 shows a mirage photograph and drawings.
* There is a nice COLOR PLATE facing p. 24 that shows some of Rudaux's
* drawings of sunsets and green flashes.
* Thanks to Eric Frappa for pointing this out!


R. W. Wood
Physical Optics, 3rd Ed
(Macmillan, New York, 1934), p. 84.

* R.W.WOOD
* "It has frequently been contended that the phenomenon is an illusion due
* to contrast, the green spot being an `after-image.' This however is sheer
* nonsense, as any trained observer can testify."
* BUT: ". . . the case of mirage . . . would be unfavorable for the occurrence
* of the green flash" (assuming super-refraction is the cause).
* N.B.: Reprinted by Dover, 1967.


W. J. Humphreys
Physics of the Air, Third Edition
(McGraw-Hill, New York, 1940).

* HUMPHREYS's book
* Pp. 466-467 give the "textbook" GF description; no numbers or diagrams.
*      The section on atmospheric optics is a slightly updated version of
* his 1919 J. Franklin Inst. paper; the 2nd ed. (1920), on Google Books,
* says "Pub. for the Franklin Institute . . . by J.B. Lippincott Company".
*      The Fata Morgana section is the last 2 pages (pp. 474-475) of the
* mirage discussion. In the 3rd ed., he adds a reference to Schiele's
* thesis, calling it "an elaborate mathematical treatment of" the F.M.,
* and including the Japanese (Geophys. J.) refs. from Schiele.
*      Although this is a standard textbook, I have found that some people
* with no background in physics or optics have difficulty in following it.
* In particular, the brief description of "looming" is too terse -- and
* confusing, because of his mentioning the older broad use of that term
* for all sorts of refraction effects at the horizon.
*      probably O'C #54 is a garbled version of this book.


J. Q. Stewart and N. L. Pierce
Marine and Air Navigation
(Ginn and Co., Boston, 1944), p. 279.

* Standard textbook story
* [Newton Lacy Pierce has a prize named after him, awarded by the AAS.]


N. Bowditch
American Practical Navigator (H.O. Pub. No. 9)
(Government Printing Office, Washington, 1958), pp. 811–812.

* BOWDITCH
* Apparently Bowditch acquired the GF paragraph 3821 in 1958;
* the 1943 edition of H.O. 9 lacks it, but it's there in the 1958 one.
* The Decennial Indices to U.S.Govt. pubs. list no edition between.
* Gives the standard Rambaut-Rayleigh story, but with a nice simile:
* "The effect is similar to that of imperfect color printing in which the
* various colors are slightly out of register."
* ". . . the greatest difference, which occurs between violet at one end of
* the spectrum and red at the other, is about ten seconds of arc."
* ". . . under suitable conditions is far more common than generally
* supposed. . . . With a sharp sea horizon and clear atmosphere, an
* attentive observer may see the green flash at as many as 50 percent of
* sunsets and sunrises, although a telescope may be needed for some of
* the observations."
* "Usually it lasts for a period of about half a second to two and
* one-half seconds with about one and a quarter seconds being average."
* ??? WHERE DID THESE NUMBERS COME FROM ???
*      This same treatment occurs on p. 500 of the 1995 edition, available
* on-line at
*
*             http://www.irbs.com/bowditch/
*
* Full title is:
* The American Practical Navigator, an Epitome of Navigation
* originally by Nathaniel Bowditch, LL.D. [honorary degree from Harvard]
* published by the U.S.Navy Hydrographic Office . . . .


S. W. Visser
Optische verschijnselen aan de hemel (KNMI verspreide opstellen, 3)
(Staatsuitgeverij, 's-Gravenhage, 1957), pp. 23–24.

* S.W.VISSER
* Gives the std. textbook story, but then admits it isn't adequate, and
* that "irregular refraction" is certainly necessary for a good display.


??
“Green Flash,” in Encyclopaedic Dictionary of Physics
(Pergamon, New York, 1961).

* Fairly good short account; cites only O'Connell
* BUT: "It occurs when refraction in the atmosphere close to the Earth's
* surface is abnormally great . . . ."


K. Mütze, L. Foitzik, W. Krug, and G. Schreiber
ABC der Optik
(Verlag Werner Dausien, Hanau/Main, 1961).

* Good "Handbuch" treatment of optical subjects
* "Grüner Strahl", pp.352-353, cites only Meyer's article in Hb.d.Geophys.
* and shows a sketch of Lagaaij's green ray (without attribution). The
* explanation of the phenomenon is a bit muddled, but mostly follows the
* textbook story; however, following Meyer's lead, "Treten nun infolge
* außergewöhnlicher Temperaturschichtung -- insbesondere wahrscheinlich
* durch das Vorhandensein tiefliegenden kräftigen Inversion -- zusätzlich
* Luftspiegelungen und damit in Verbindung wohl auch anormale Verhältnisse
* der atmosphärischen Dispersion in diesen Schichten auf, dann können
* Zerrbilde des oberen Sonnenteiles als Erklärung für den grünen Strahl
* angenommen werden. Es wird auch vermutet, daß die Absorptionsbanden des
* Ozons und des Wasserdampfes im sichtbaren Spektralbereich hierbei mit eine
* Rolle spielen. Eine befriedigende Theorie für den ganzen
* Erscheinungskomplex des grünen Strahls gibt es jedoch noch nicht."
* So this is one of the BEST and MOST TRUTHFUL accounts to be found!
* The "Luftspiegelung" article (pp.498-500) also cites P&E, and redraws
* several of Wegener's diagrams. Both articles are credited to Foitzik.
* Thanks to Siebren van der Werf for this reference!


R. W. Fairbridge
The Encyclopedia of Atmospheric Sciences and Astrogeology (Encyclopedia of Earth Sciences series, Vol. II)
(Reinhold, New York, 1967), p. 1048.

* Maybe this is the source of Fraser's and McIntosh's error:
* "It is related to the greater Rayleigh scattering and refraction in the
* short wavelengths (violet, blue, green) than in the long (red) waves of
* sunlight. Under hazy conditions it may appear blue or violet."
* (sure sounds as if one copied from the other.)
* (Fairbridge buries "Green Flash" under "Twilight")


G. Bradford
The Mariner's Dictionary
(Barre Publishers, Barre, Mass., 1972), p. 113.

* Standard textbook story, well presented


K. Heuer
Rainbows, Halos, and Other Wonders: Light and Color in the Atmosphere
(Dodd, Mead & Co., New York, 1978), pp. 23–26.

* a JUVENILE book
* Unaccountably quotes from Mostyn's 1891 Nature paper, but confuses
* him with Nijland's similar obsn. & says they were together!
* All the photos are in b/w, alas. Ch.2 is "Green and Blue Flashes".


R. Greenler
Rainbows, Halos, and Glories
(Cambridge Univ.Press, Cambridge, 1980).

* SUNSET PHOTOS and refraction in final chapter
* Ch.7 and Plates 7-10 and 7-11 show distorted sunsets
* p.177: "All are variations of the same effect and all, in my judgment,
* may appropriately be given the same name." (green flash)
* He even has a section called "The green flash legend" (pp.172-173), and
* quotes from Verne!
*      Note his good (though brief) treatment of the Fata Morgana on pp.
* 165-167 and Plates 7-4 to 7-7.


A. H. Batten
Rainbows, Halos and Glories by Robert Greenler,”
JRASC 76, 67–68 (1982).

* Alan H. Batten reviews Greenler's book, citing Hogg's JRASC mirage paper
* No mention of GF. Available from ADS.


A. Meinel and M. Meinel
Sunsets, Twilights, and Evening Skies
(Cambridge University Press, Cambridge, 1983).

* MEINELS' BOOK
* probably the best GF treatment available in hard covers, though the
* references are spotty
* Replete with errors from Botley, etc.;
* but they recognize that ADAPTATION plays a part.


K. Nassau
The Physics and Chemistry of Color: the Fifteen Causes of Color
(Wiley-Interscience, New York, 1983), p. 227.

* Kurt Nassau's "Fifteen Causes of Color" book
* A good explanation of the "textbook" flash, with "prism" analogy.
* Thanks to Dave Fenner for pointing this out!


E. S. Maloney
Dutton's Navigation and Piloting (14th edition)
(Naval Institute Press, Annapolis, 1985), p. 526.

* DUTTON
* The same passage appears on p.620 of the 12th edition, edited by
* G.D.Dunlap and H.H.Shufeldt (1969 - 1972), except that Maloney has
* changed "The" to "A" at the start of the final sentence.
* ". . . the longer waves of red being least refracted, the shorter blue
* and violet waves being more refracted. The red, orange and yellow light
* is cut off by the horizon when the blue and violet is still momentarily
* visible. These blue and violet rays cause the green flash." [SIC!]
* [This nonsense seems to have appeared in the 12th edition, in 1969.]
* [It is not in the 4th (1961) printing of the 1957/58 edition.]
* "It is estimated that at sea in the tropics, the green flash may be seen
* as often as 50 percent of the time; it is, of course, easier to observe at
* sunset. The green flash usually lasts for a period of between one-half
* and one second." Again -- cf. Bowditch! -- mysterious numbers.
* This can't be what Cotter (1968) was objecting to:
* "Using the time of the green flash to obtain a line of position is
* merely a variation of the horizon sight described in the previous article.
* It is somewhat easier to determine the time of the flash than to determine
* the instant the sun's upper limb disappears below the horizon, when there
* is no green flash." [because this appeared after Cotter's book]


D. H. McIntosh
Meteorological Glossary
(Chemical Publishing, New York, 1972), p. 133.

* 1972 edition of the glossary originally published in 1916 by the Met.Office
* Looks as if the GF entry was not updated since Mulder's book:
* ". . . greater degree of RAYLEIGH SCATTERING experienced by the violet and
* blue rays. In a hazy atmosphere such differential scattering may not be
* appreciable and the flash may then appear blue or violet."
* This is the same error made by Fraser (1972) and it is likely he got it
* from an earlier edition of this, or from Fairbridge (above).
* ". . . the analogous very rare phenomenon of the `red flash' . . . ."


V. J. Schaefer and J. A. Day
A Field Guide to the Atmosphere
(Houghton Mifflin, Boston, 1981), p. 167.

* Vincent J. Schaefer never saw a GF, I'll wager!
* "Plate 9. . . . The green flash is never seen under the conditions that
* produced the sun's image in this photograph." (Actually, it looks like a
* very good opportunity for a mock-mirage flash; the reddening is
* appreciable, but not excessive.)
* "Quite rarely . . . only occurs when the atmosphere is extremely clean . . . ."
* Caption to Fig. C.Pl.9 says "The atmosphere develops small density
* differences that create the spreading [sic] of the image."


?
Meyers kleines Lexikon Meteorologie
(Bibl. Inst. & F.A.Brockhaus AG, Mannheim, 1987).

* BLUE-SKY CONFUSION error: (quoted by Hechler, 1994)
* ". . . der noch etwas später verschwindende blaue Oberrand der Sonne
* wegen des mangelnden Farbkontrastes zur bläulichen Himmelsfarbe dem
* Auge nicht sichtbar wird."
* NOT YET IN HAND


C. F. Bohren
“The Green Flash,” in Ch.9 in "Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics"
(Wiley, New York, 1987), pp. 98–103.

* Craig Bohren wisely confines his attention to the Green Rim.
* But he brashly states that "there is a Scottish legend . . . ."
* (Thanks a lot, Jules Verne!)
* "It is indeed true that the green flash is rarely observed, but not
* because it is rarely observable. The sad truth is that most people are
* only dimly aware of their surroundings." You said it, Craig!


C. Raymo
Honey from Stone: A Naturalist's Search for God
(Dodd, Mead, New York, 1987), pp. 143–150.

* Chet Raymo describes his fruitless search for green flashes
* The reason is not hard to find: "I have sat on the high rocky spine of
* the Dingle Peninsula and watched the sun sag into the North Atlantic."
* Much of the peninsula is over 500 m above the sea; the highest point is
* some 950m high -- all much too high for a inferior-mirage flash to be
* seen without aid; and in a region not much subject to strong inversions.
* He depends mainly on O'Connell's 1960 Scientific American article,
* which he mistakenly thinks had the first color photographs. Much of the
* wording here is identical to his 1990s columns in the Boston Globe .
* [Placed here as it is a tutorial account.]


A. McBeath
“Rainbows, Halos, and Glories by Robert Greenler,”
JBAA 100, No. 4, 195 (1990).

* Review of the paperback edition of Greenler's book in JBAA
* GF is mentioned. Available from ADS.


T. Dickinson and A. Dyer
The Backyard Astronomer's Guide
(Camden House, Camden East, Ont., Canada, 1991), pp. 101–102.

* not exactly a textbook, but compiled by and for amateur astronomers
* This is one of the few places where one reads that ". . . it can be safely
* observed with binoculars or a telescope." The description applies to the
* inferior-mirage flash; the advice is sound.


C. D. Ahrens
Meteorology Today: An Introduction to Weather, Climate, and the Environment (Fourth Edition)
(West Publ.Co., St.Paul, 1991), p. 121.

* This popular textbook seems to be the source of the canard about the
* Byrd expedition: "Members of Admiral Byrd's expedition in the south
* polar region reported seeing the green flash for 35 minutes in September
* as the sun slowly rose above the horizon, marking the end of the long
* winter." The actual date was Oct. 16, and the observation was made at
* sunset, not sunrise -- see Owen (1929), Davies (1931) and Haines (1931).
* (Note that Little America was some 11 degrees from the Pole.)
* Also, there is a curious statement about "purple light".
* However, there is also the correct statement, "Usually, the green light
* is too faint to see with the human eye. However, under certain
* atmospheric conditions, such as when the surface air is very hot or when
* an upper-level inversion exists, the green light is magnified by the
* atmosphere."


Great Britain Meteorological Office
The Marine Observer's Handbook, 11th edition [Met. O. 1016]
(HMSO, London, 1995), pp. 166–167.

* MARINE OBSERVER'S HANDBOOK
* The 7th Edition (June, 1950) cited by Hilder (1951) bears the cover
* title: "Manual of Meteorological Observing. Part II. Marine Observer's
* Handbook". That edition gives GF on p.74, and very little on mirage.
* Final paragraph mentions 3 forms of GREEN RAY or fog


C. F. Bohren
“Atmospheric Optics,” in Encyclopedia of Applied Physics, Vol.12 , G. L. Trigg, ed.
(Wiley-VCH, New York, 1995), pp. 405–434.

* CRAIG BOHREN's encyclopedia article
* The GF treatment is on pp. 423-424.
* "Compared to the rainbow, the green flash is not a rare phenomenon."
* It is preceded by a section on the distortion of the setting Sun, which
* follows Fraser in forgetting about dip, so that the miraged multiple
* images are attributed to gravity waves.


H. S. Rice
“Atmosphere: Green Flash,”
Collier's Encyclopedia 3, 172 (1997).

* COLLIER'S ENCYCLOPEDIA
* The whole "Atmosphere" article is pp.161-172; the GF is only a
* two-sentence paragraph. The description is vague and incorrect.


P. Barnes-Svarney and T. E. Svarney
Skies of Fury: weather weirdness around the world
(Simon & Schuster, New York, 1999), pp. 46–48.

* A popular book on meteorology devotes 2 full pages to "the green flash"
* (including "the Scottish saying" and the textbook explanation.)
* Mirages get the same uneven treatment, and the Novaya Zemlya effect
* is made to appear a normal concomitant of green flashes, "after the Sun
* sets". The bogus term "fata bromosa" appears on p. 51. But the authors
* have tried hard to bring meteorology to the public, despite such lapses.
* A curious feature of this book is that all of the numerous photographs
* are in black-and-white -- no color work, even in the rainbow picture.
* [The authors tell me their publisher cheaped them out here.]
* Another odd thing is the confusion over the publisher. The title page
* says "A Touchstone Book . . . Published by Simon & Schuster"; the reverse
* says "A Fireside book" but also "Touchstone and colophon are registered
* trademarks of Simon & Schuster Inc." The authors retain the copyright.
* Amazon.com says "Fireside". The authors' Web page says "Simon &
* Schuster". The review in Kirkus Reviews says "Touchstone".
* [The Svarneys say the publisher should be given as S&S.]



*** GF PRECURSORS -- EARLY DISPERSION papers FILE ***

Delisle
“Observation de l'eclipse de Jupiter et de ses Satellites par la Lune,”
Mem. Acad. Roy. Sci. Paris , 210–212 (1715).

*
* [see also Hoppe (1941) in GF file, and Bessel (1823) in REFR. OBS. file.]
*
* DISCOVERY of RED and BLUE RIMS by Delisle
* Observing at Luxembourg, 25 Jul. 1715, Delisle says:
* "J'ai été fort attentif à examiner si Jupiter & ses Satellites ne
* prenderoient pas à l'approche de la Lune des couleurs semblables à
* celles que j'avois vû dans l'Eclipse de Venus le mois passé ; mais
* je n'en ai pu remarquer aucune qui se puisse attribuer à l'approche
* de la Lune." (He was accompanied by Chardeloup, from the Roy. Soc. in
* London; Delisle used a 20-foot telescope, and Chardeloup an 8-ft.)
* "Pour nous mieux préparer à observer ces couleurs, nous avions examiné
* avant l'Eclipse les couleurs que la Lunette causoit à Jupiter, & nous
* avons trouvé ces couleurs toûjours dirigées au centre de la Lunette,
* le rouge étant en dedans, comme cela devoit arriver. J'ai aussi aussi
* [sic] fait remarquer à M. Chardeloup que Jupiter prenoit vers l'horizon
* les mêmes couleurs, mais qu'elles provenoient d'une autre cause, car
* elles étoient dirigées autrement, le rouge paroissant toûjours le
* plus près de l'horizon, & le bleu le plus éloigné, & cela dans quelque
* situation de la Lunette que l'on place Jupiter. Ainsi les couleurs que
* nous avons remarqué dans cette Observation, provenoient ou des Lunettes
* ou de l'approche de l'horizon, & nullement de l'approche de la Lune,
* Jupiter nous ayant paru très-blanc pendant son Immersion & son Emersion."
*      Thus, he was not sure whether the effect near the horizon was real or
* a telescopic artifact. (Cited by Bouguer, 1748.)


[Bouguer]
“Sur la mesure du diamètre des plus grandes planètes,”
Hist. Acad. Roy. Sci. (Paris) , 87–94 (1748).

* RED and BLUE RIMS DISCOVERED on Sun by BOUGUER
* This is the ``meeting abstract'' -- evidently written by the Secretary,
* as Bouguer is referred to in the 3rd person.
*      The paper is mostly about Bouguer's invention of the heliometer;
* but, in the early observations, ". . . il a toûjours trouvé les bords
* supérieur & inférieur plus ondoyans que les bords latéraux, & de
* plus, toûjours affectés de couleurs qui y forment un iris incommode;
* cette apparence peu sensible, lorsqu'on se sert de lunettes de sept à
* huit pieds, telles qu'on les a jusqu'ici employées à la recherche du
* diamètre di Soleil, devient très-marquée dans l'heliomètre; & les
* couleurs même qu'on observe dans les deux bords, lui en ont indiqué
* la cause: on sait qu'un rayon qui nous vient du Soleil n'est pas un
* rayon simple, mais un composé de sept faisceaux de rayons de couleurs
* différentes, & tous différemment refrangibles. Le plus haut point du
* diamètre vertical sera donc vû par le faisceau de rayons bleus qui
* souffrira une plus grande réfraction, & qui par conséquent le fera
* paroître plus haut, & son extrémité la plus basse par le faisceau
* de rayons qui aura souffert la moindre réfraction, c'est-à-dire le
* faisceau de rayons rouges . . . ." (p. 93)
* So Bouguer understood that the effect is due to ATMOSPHERIC DISPERSION.
* No doubt SIMULTANEOUS CONTRAST helped him detect the color difference.
*      ". . .  on observera toûjours le bord supérieur terminé par un trait
* bleu, & l'inférieur par un trait rouge, au lieu qu'on n'observera rien
* de pareil dans les bords latéraux, parce que la réfraction de leurs
* rayons se fait dans un plan vertical, & sans les déranger en aucune
* façon dans le sens du diamètre horizontal, dont elle ne peut par
* conséquent altérer ni la couleur, ni la netté, ni la mesure." (p. 94)
* (mentioned, but not cited, by Arago in 1836.)
* Cf. St. Chevalier (1913)!
* Actually printed in 1752.


[P]. Bouguer
“De la mesure des diamètres des plus grandes planètes: Description d'un nouvel Instrument qu'on peut nommer Héliomètre, propre à les déterminer; & Observations sur le Soleil,”
Mem. Acad. Roy. Sci. (Paris) , 11–34 (1748).

* The details of Bouguer's HELIOMETER and COLORED RIMS on the Sun
* The first 2/3 or so of this paper are devoted to explaining why the
* horizontal diameter of the Sun could not be measured accurately:
* before equatorial telescopes with good clock drives were available,
* the image moved too fast to check the opposite limbs simultaneously
* with a filar micrometer, and the diurnal motion was too fast to allow
* accurate determinations of the east and west limbs by timings with a fixed
* telescope: "Tout la difficulté qu'on trouve dans cette observation,
* consiste à estimer les fractions de secondes . . . on se trompera
* aisément d'un tiers ou d'une moitié de seconde de temps, ce qui en
* produire jusqu'à cinq ou six, ou même sept de degré sur le diamètre."
* There is also the problem that the clock escapement is not exactly
* symmetrical, so that long and short intervals alternate (pp. 20-21).
* Furthermore, the Moon usually (because of its phase) shows only a full
* diameter in an oblique direction, and so cannot be well measured at all.
*      Bouguer seems to have been inspired by the binocular:  "On sait
* que le binocle avoit été imaginé pour procurer aux observateurs la
* prétendue commodité de regarder le même objet avec les deux yeux.
* Le nouvel instrument, l'héliomètre ou l'astromètre dont nous
* voulons introduire l'usage, fera voir au contraire avec un seul oeil deux
* objets à la fois, ou deux parties du même, quoique considérablement
* éloignées l'une de l'autre . . . ." [p. 23]
*      He diminishes both the brightness and the chromatic aberration by
* reducing the apertures to 6 or 8 mm: ". . . on peut diminuer extrêmement
* les ouvertures des objectifs; % ce sera toûjours le mieux, lorsqu'on ne
* se proposera de mesurer que les diamètres du Soleil. Il sera avantageux
* de réduire alors par des diaphragmes, les deux verres à une simple
* partie de pouce, ou à trois ou quatre lignes de largeur; car on évitera,
* par ce rétrécissement, presque tout le mauvais effet de la séparation
* des rayons colorés qui ternissent les bords de l'astre." [p. 25]
*      The state of technical optics in 1748 was dismal:  "Un Artiste adroit
* a taillé dans le même bassin huit objectifs de 18 pieds de foyer; &
* c'est entre ces huit verres que j'en ai choisi deux : la précaution
* d'en faire tailler plusieurs s'est trouvée utile; deux ou trois de ces
* objectifs, soit que cela vînt de leur figure ou de ls diverse densité
* de leur matière, avoient leurs foyers différens de 7 à 8 pouces,
* quoiqu'on eût tachéde les rendre parfaitement égaux." [p. 27]
*      Finally, he reports his preliminary attempts to verify the sphericity
* of the Sun: "On sait que c'est un des effets de notre atmosphère de
* diminuer un peu les diamètres verticaux apparens du Soleil & de la
* Lune; ce qui vient de ce que la réfraction élève un peu plus le bord
* inférieur de leur disque que le supérieur. Il n'y a personne qui n'ait
* vû ces deux astres sous une forme sensiblement elliptique, lorsqu'ils
* étoient très-voisins de l'horizon & sujets à des réfractions
* plus fortes. Il doit arriver encore quelque chose de semblable dans
* les grandes hauteurs, quoique la différence des deux axes soit alors
* moins considérable, & cesse d'être aperc,ûe à la vûe simple.
* Cette petite quantité devoit être de deux secondes sur le Soleil,
* aux environs de midi, pendant le mois d'Octobre dernier, qui est le
* temps où j'ai commencé à observer : cependant, bien loin de trouver
* cette différence, j'ai toûjours remarqué que le diamètre vertical
* étoit plus grand que l'horizontal ; c'est ce dont je me suis assuré
* en appliquant tantôt l'oeil immédiatement à l'héliomètre, & tantôt
* en recevant l'image des deux portions de disque sur une tablette que je
* plaçois en dehors perpendiculairement à l'axe de l'instrument. . . .
* Qu'on mette à une seconde, ou seulement une demi-seconde, le petit excès
* que j'ai aperc,û, ce sera une demi-seconde à joindre aux deux dont les
* réfractions raccourcissent le diamètre vertical. Il suivroit de là
* que ce diamètre seroit plus grand que l'autre de deux secondes & demie
* ou de trois secondes : le Soleil auroit la forme d'un sphéroïde oblong,
* & la différence des deux axes seroit au moins d'une 750e partie." [p.30]
*      He decided to suspend judgment until having made observations at
* different altitudes and with heliometers of different focal lengths.
* In examining the limbs more closely, he noticed that the upper and lower
* limbs were less well defined than the lateral ones, and more subject to
* "ondulations importunes". Then: "Lorsque cet inconvénient n'a pas
* lieu, le haut & le bas de l'image sone encore toûjours sujets à une
* gradation de couleurs qui nuit à sa distinction ; à peu près de la
* même manière que la pénombre empêche de distinguer les limites de
* l'ombre avec laquelle elle confine." [p. 31]
*      "Si le défaut continuel de netteté des bords supérieur & inférieur
* du Soleil, est très-capable d'embarraser les Observateurs scrupuleux, it
* offre aussi un sujet de problème pour les Physiciens, qui ne manqueront
* pas d'en demander la solution : elle n'est pas difficile à trouver, &
* je crois pouvoir l'indiquer d'une manière sûre. Cette apparence ne peut
* venir que de la décomposition que souffre la lumière en traversant notre
* atmosphère ; les rayons bleus ou violets qui partent en même temps que
* les rayons des autres couleurs, du haut du disque, sont sujets à un peu
* plus de réfraction que ces derniers, ils se courbent un peu davantage;
* ils nous paroissent donc venir d'un peu plus haut, en portant plus loin
* l'illusion ordinaire des réfractions. C'est tout le contraire si nous
* jetons la vûe sur le bord inférieur, nous devons le voir principalement
* par des rayons rouges qui souffrent un peu moins de courbure dans leur
* trajet ; ces rayons, en se courbant moins, doivent frapper nos yeux comme
* s'ils partoient d'un point plus bas, & par conséquent faire paroître
* un peu en dessous la partie inférieure du disque qu'ils étendent,
* pendant que les rayons bleus & violets contribuent à étendre ce même
* disque par sa partie supérieure.
*      "Tout ce que nous avançons ici deviendra incontestable, si l'on
* considère plus attentivement l'image du Soleil fournie par une longue
* lunette, & rec,ûe sur une tablette. On verra que la partie de l'image
* qui répond au bord supérieur, est terminée par un trait bleu, pendent
* que le rouge domine sur le bord opposé." [p. 32] -- and he cites
* Delisle's 1715 observation of Jupiter.
*      Then he introduces the analogy of the PRISM: "l'explication que nous
* en donnons, est outre cela tout à fait conforme à ce qu'on sait de
* la nature des couleurs, dont la lumière primitive ou celle du Soleil
* est formée. Lorsque les rayons de cet astre pénètrent obliquement
* les différentes couches de la masse d'air qui nous environne, & qui
* sont successivement plus denses, ils doivent être sujets aux mêmes
* accidens que s'ils traversoient obliquement les faces d'un prisme,
* puisqu'ils coupent les couches de l'atmosphère dans des endroits qui
* ne sont pas réciproquement parallèles les uns aux autres . . . ." [p. 33]
*      Dated 24 Avril 1748; actually printed in 1752.


S. Dunn
“An attempt to assign the cause, why the Sun and Moon appear to the naked eye larger when they are near the horizon. With an account of several natural phænomena, relative to this subject,”
Phil. Trans. Roy. Soc. 52, 462–473 (1762).

* RED RIM on Sun; EARLY MOCK MIRAGES
* "A little before sun-setting, I have often seen the edge of the Sun with
* such protuberances and indentures, as have rendered him, in appearance, a
* very odd figure; the protuberances shooting out far beyond, and the
* indentures pressing into, the disk of the Sun, and always through a
* telescope magnifying fifty-five times, the lower limb has appeared with a
* red glowing arch beneath it, and close to the edge of the Sun, whilst the
* other parts have been clear.
*      "At sun-setting, such protuberances and indentures have appeared to
* slide or move along the vertical limbs, from the lower limb to the higher,
* and there vanishing, so as often to form a segment of the Sun's upper limb
* apparently separated from the disk, for a small space of time.
*      "At sun-rising, I have often seen the like protuberances, indentures,
* and slices, above described; but with this difference of motion, that at
* sun-rising they first appear to rise in the Sun's upper limb, and slide or
* move downward to the lower limb; or, which is the same thing, they always
* appear at the rising and setting of the Sun, to keep in the same parallels
* of altitude, by the telescope. This property has been many times so
* easily discernable, even by the naked eye, that I have observed the Sun's
* upper limb to shoot out towards right and left, and move downward, forming
* the upper part of the disk an apparent portion of a lesser spheroid than
* the lower part at rising, and the contrary at setting."
* "These protuberances and indentures . . . enabled me to conclude, that
* certain strata of the atmosphere, having different refractive powers, and
* lying horizontally across the conical or cycloidal space traced out by the
* rays, between the eye and that part of the atmosphere first touched by the
* rays, must have been the cause of such apparent protuberances and
* indentures, in an horizontal direction, across the Sun's limbs . . . ."
*      Jim Mosher points out that Mr. Samuel Dunn was a prominent cartographer
* and mathematics teacher in this period. He died in 1794.


P. Dollond
“An Account of an Apparatus applied to the equatorial Instrument for correcting the Errors arising from the Refraction in Altitude,”
Phil. Trans. Roy. Soc. 69, 332–336 (1779).

* PETER DOLLOND's remark about dispersion
* This is mostly about the use of 2 glasses with a common spherical
* surface, placed before the objective (!) of a telescope to correct
* refraction by sliding the concave glass over the convex one.
*      But near the end, on p. 335 (mis-numbered 535), he says:
* "It must be observed, that when a star or planet is but a few degrees
* above the horizon, the refraction of the atmosphere occasions it to be
* considerably coloured. The refraction of the lens acting in a contrary
* direction would exactly correct that colour, if the dissipation of the
* rays of light were the same in glass as in air; but as it is greater in
* glass than in air, the colours occasioned by the refraction of the
* atmosphere will be rather more than corrected by those occasioned by the
* refraction of the lens."
* (mentioned, but not cited, by Arago, 1836.)


W. Herschel
“Catalogue of double stars,”
Phil. Trans. Roy. Soc. London 75, 40–126 (1785).

* WILLIAM HERSCHEL's remarks on atmospheric dispersion
* The remark appears as a footnote to the catalogue of double stars.
* On p.83, Herschel lists entry #107 as "Congerie Stellularum Sagittarii
* borealior" and gives his approximate measurement, with the remark:
*      "As accurate as the prismatic power of the atmosphere, which lengthens
* the stars, will permit." At the end of the entry he has the footnote:
*      "What I call the prismatic power of the atmosphere, of which little
* notice has been taken by astronomers, is that part of its refractive
* quality whereby it disperses the rays of light, and gives a lengthened
* and coloured image of a lucid point. It is very visible in low stars;
* FOMALHAND, for instance, affords a beautiful prismatic spectrum. That
* this power ought not to be overlooked in delicate and low observations,
* is evident from some measures I have taken to ascertain its quantity.
* Thus I found, May 4, 1783, that the perpendicular diameter of ε,
* FLAMSTEED's 20th Sagittarii, measured 16'' 9''', while the horizontal was
* 8'' 35'''; which gives 7'' 34''' for the prismatic effect: the measures
* were taken with 460, near the meridian, and the air remarkably clear.
* And though this power, which depends on the obliquity of the incident ray,
* diminishes very fast in greater altitudes, yet I have found its effects
* perceivable as high, not only as α or γ Corvi in the meridian,
* but up to Spica Virginis, and even to Regulus. Experiments on these two
* latter stars I made November 20, 1782; when Regulus, at the altitude of
* 49°, shewed the purple rather fuller at the bottom of the field of
* view than when it was at the upper edge; which shews that the prismatic
* powers of the edges of the eye lens were assisted in one situation
* by the power of the atmosphere, but counteracted by it in the other.
* I turned the lens in all situations, to convince myself that it was not
* in fault. This experiment explains also, why a star is not always best
* in the center of the field of view; a fact I have often noticed before
* I knew the cause."
* [Most of the footnote spills onto p. 84.]


S. Lee
“On the dispersive power of the atmosphere, and its effect on astronomical observations,”
Phil. Trans. Roy. Soc. Lond. 105, 375–383 (1815).

* RED and BLUE RIMS ON MARS
* "With a power of 170 and upwards, the disk of the planet appeared much
* elongated, especially when near the horizon; the upper limb was of a fine
* blue, the lower of a deep red." (p.378)
* [reprinted in German in Bode's Astron. Jahrbuch (1819) pp.113-120]
* [and in French, in vol. 5 of Bibliotheque Universelle (at BHL)]
* Stephen Lee, Clerk and Librarian to the Royal Society
* O'C #79


T. Forster
“Memoir on the variations of the reflective, refractive and dispersive powers of the atmosphere,”
Phil. Mag. 63, 192–210 (1824).

* Wide-ranging discussion of refraction, dispersion, scintillation,
* chromatic scintillation, spectroscopy, etc., with Greek and Latin quotes
* refers to Lee's 1815 paper.
* "Read before the Meteorological Society of London in February and March
* 1824, and published by permission."


[Arago]
“Correspondance,”
C. R. Acad. Sci. Paris 3, 233 (1836).

* ARAGO's fight with CAUCHY
*
* The trouble began when Cauchy donated to the Academie a copy of his
* work on the theory of light, which contained the claim that gases did
* not show dispersion. Arago noticed this lapse, and tried to correct it
* with a letter, printed under ``Correspondance'' at the end of the 29
* Aug. 1836 meeting:
*      "A l'occasion d'un nouveau mémoire de M. Cauchy  sur la théorie
* de la lumière, présenté aujourd'hui à l'Academie, M. Arago croit
* devoir signaler une erreur de fait dans laquelle l'auteur est tombé au
* sujet de la dispersion des substances gazeuses. M. Cauchy suppose cette
* dispersion nulle. M. Arago dit, au contraire, qu'elle est sensible et
* qu'il l'a mesurée pour un bon nombre de gaz simples et composés.
* Dans une prochaine séance, M. Arago fera connaître tous ses
* résultats."


Cauchy
“Théorie de la lumière,”
C. R. Acad. Sci. 3, 422–424 (1836).

* CAUCHY refuses to take his medicine:
* "Il serait assez singulier que l'erreur de fait se trouvât, non dans
* le mémoire lithographié, mais dans l'assertion qu'on vient de lire,
* appliquée, comme elle semble l'être, à ce nouveau mémoire; . . . .
*      Ce que M. Arago aura dit, c'est que jusqu'à ce jour les physiciens
* n'avaient point observé la dispersion dans les gaz. C'est là ce que
* j'ai dit moi-même dans la 9e livraison d'un mémoire plus ancien, où,
* après avoir établi et vérifié les lois de la dispersion dans les
* corps solides, après avoir expliqué comment on s'assure que ce
* phénomène disparaît dans le vide, j'ajoute que jusqu'à ce jour on
* n'a pu découvrir dans les gaz aucune trace de la dispersion des
* couleurs . . . . La note insérée dans le Compte rendu prouve
* elle-même l'exactitude de cette proposition à l'époque où
* j'écrivais ces lignes, et c'est parce que les physiciens n'avaient
* jusqu'ici rien découvert à cet égard, que les observations promises
* par M. Arago contribueront notablement au progrès de la science. Mais
* personne ne s'étonnera que je n'aie point parlé de ces observations
* plusiers mois avant qu'elles fussent publiées et peut-être même
* entreprises."
* [printed under ``Correspondance'' for the 3 Octobre 1836 séance.]


Arago
“Réclamation de M. Arago au sujet de la lettre de M. Cauchy à M. Libri, insérée dans le Compte Rendu de la séance du 3 octobre,”
C. R. Acad. Sci. 3, 459–462 (1836).

* ARAGO lambastes Cauchy for his obstinacy:
* He calls Cauchy's blunder "une erreur de fait capitale," and goes on:
* "En essayant ainsi de détourner M. Cauchy de persister dans la peine
* qu'il se donnait pour déduire de sa savante théorie une conséquence
* que l'observation démentait de tout point, M. Arago croyait avoir droit
* à des remercîments. Loin de là, M. Cauchy s'est montré offensé.
* Son confrère se voit donc obligé d'examiner ses griefs.
*      He then documents in detail Cauchy's wrong statements, and quotes
* Cauchy's claim that Arago should have said that the physicists had
* never observed dispersion in gases "to this day". Then: "M. Arago
* déclare ne pouvoir accepter cette rectification ; il montre en effet,
* que la dispersion de l'atmosphère terrestre avait été aperçue
*
*                        En 1748 par Bouguer
*                        En 1761 par Lemonnier
*                        En 1779 par Dollond
*            En 1783, en 1785 et en 1805, par Herschel"
*
* and tops this list with his own measurements from 1812, adding:
* "Enfin, en 1815, M. Stephen Lee lut à la Société royale de
* Londres, et publia dans les Transactions philosophiques , un mémoire
* intitulé : Sur la force DISPERSIVE de l'atmosphère et ses effets
* sur les observations astronomiques .
*      « Personne, dit M. Cauchy, ne s'étonnera, que je n'aie pas parlé
* des observations de M. Arago, plusiers mois avant qu'elles fussent
* publiées ET PEUT-ÊTRE MÊME ENTREPRISES. »
*      A l'insinuation peu bienveillante que ce passage renferme, M. Arago
* répond par deux faits : Ses mesures de la force dispersive de
* l'atmosphère datent de 1812; elles furent citées, quelque temps après
* cette époque, par M. de Lindenau dans le Journal astronomique de
* Gotha . Quant aux mesures de la DISPERSION des gaz et des vapeurs
* que M. Arago avait faites avec M. Petit, son beau-frère, elles
* remontent à 1815 ; on en trouve une analyse détaillée dans le
* premier article du premier cahier du premier volume des Annales
* de physique et de chimie PUBLIÉ en février 1816! M. Arago
* aurait donc, peut-être le droit de remplacer le dernier paragraphe
* guillemetté de M. Cauchy, par le suivant, où quelques expressions
* seulement sont changées :
*      « Tout le monde  s'étonnera que M. Cauchy n'ait pas connu les
* observations de M. Arago, vingt ans après qu'elles avaient été
* publiées! »


Arago
“Instructions concernant la Météorologie et la Physique du globe,”
C. R. Acad. Sci. 7, 206–224 (1838).

* ARAGO says the effect is well known
* "Les astronomes qui ont essayé, même une seule fois dans leur vie,
* de déterminer la valeur des réfractions horizontales, savent combien
* peu il est permis de compter sur les résultats. C'est ordinairement le
* bord du soleil qui sert de point de mire; mais près de l'horizon, ce
* bord paraît si fortement dentelé, si vivement irisé, si déchiqueté;
* ces diverses irrégularités sone d'ailleurs tellement changeantes que
* l'observateur ne sait où diriger le fil du réticule, à quel point, à
* quel hauteur arrêter sa lunette sur le limbe gradué de l'instrument
* qu'il emploie." (p. 211)


F. W. Bessel
“Sue la réfraction astronomique,”
C. R. 15, 181–185 (1842).

* BESSEL on DISPERSION
* ". . . la loi de la chaleur . . . est évidemment très-variable . . . ."
* "Jusqu'à ce qu'on ait réussi à exprimer cette loi en fonction du
* temps, il sera impossible de former une table qui représente parfaitement
* la réfraction pour chaque distance au zénith et pour chaque temps."
* ". . . quoique l'air parût être parfaitement clair, le rouge et le bleu
* du spectre étaient seuls visibles, de manière que l'étoile resemblait
* en quelque sorte à une étoile double, composée d'une étoile rouge et
* d'une bleu."
* "Il paraît donc que des observations faites dans des distances au zénith
* plus grandes que 85° ne seraient que d'un très-petit poids pour
* l'astronomie, même si l'on pouvait exactement calculer les réfractions
* nécessaires pour les réduire."
* ". . . l'influence des variations de la loi de la chaleur des couches de
* l'air ne commence à être sensible qu'au delà du 85e degré."
* "Au delà de cette limite, c'est-à-dire entre le 85e degré de distance
* au zénith et l'horizon, l'influence des variations de la loi de la
* chaleur des couches de l'air croît rapidement, ce que la théorie
* indique."
* Day-night variations in refraction residuals amount to 30" at 1/2 deg.
* altitude; "Il est évidemment impossible d'expliquer de telles
* différences sans connaître les variations de la loi de la chaleur des
* couches de l'air dépendantes du temps. . . . Mais cela serait un problème
* dont la solution, supposée possible, aurait plus de prix pour la
* météorologie que pour l'astronomie."
* (Many of these remarks are prefigured in his 1823 A.N. paper.)


F. Arago
“Sur la puissance dispersive de l'atmosphère,”
C. R. 15, 235–236 (1842).

* ARAGO indulges his penchant for priority disputes and reminds Bessel
* and others that he saw atmospheric dispersion first!
* "M. Arago a rédigé une Note historique où toutes ces recherches sont
* analysées et appréciées." [Was it ever published? Montigny (1855,
* p.55) thinks not; and in Arago's Œuvres Complètes, T. XI, p. 737, we
* read: "Le Mémoire annoncé par M. Arago n'a pas été rédigé. It then
* records his observations of atmospheric dispersion going back to 1811.]


S. Stampfer
“Ueber die Farbenzerstreuende Kraft der Atmosphäre,”
Denkschr. Kaiserl. Akad. Wiss. Math.-Naturwiss. Classe 2, 101–108 (1851).

* RED AND VIOLET RIMS PREDICTED (but thought unobservable)
* "Da nun die Strahlen bei ihren Durchgange durch die Atmosphäre
* gebrochen und somit ohne Zweifel auch zerstreut werden, so muss das Bild
* der Sonne ein in verticaler Richtung liegendes S p e c t r u m bilden.
* Unmittelbar ist freilich dieses Erscheinung nicht bemerkbar, dazu ist der
* Zerstreuungswinkel viel zu klein, dem ungeachtet können wir uns das
* Sonnenbild als eine Reihe farbiger Bilder denken, die einander zwar nahe
* aber nicht vollkommen decken, indem das rothe Bild die kleinste, das
* violette hingegen die grösste Höhe über dem Horizonte haben muss,
* woraus sogleich folgt, dass Blendgläser von verschiedener Farbe auch eine
* Verschiedenheit in der beobachteten Sonnenhöhe zur Folge haben werden."
* (He observed only through such colored glasses, so failed to discover
* the green rim.)
* REFRACTION DEPENDS ON STAR COLOR:
* "Wegen der Farbenzerstreuung der Atmosphäre muss bei den
* verschiedenfarbigen Sternen die Refraction etwas Verschieden sein, bei den
* rothen Sternen geringer, als bei den weissen oder grünen."
* ATMOSPHERIC REDDENING AFFECTS APPARENT REFRACTION:
* "Gewöhnlich ist das Sonnenlicht mehr oder weniger roth, wo dann die
* blauen Strahlen grossentheils absorbiert sind. Hieran knüpft sich von
* selbst die Bemerkung, dass die Refraction der weissen Sterne nahe am
* Horizont sich jener des rothen Strahles nähert, vorausgesetzt, dass die
* scheinbare Mitte des vorzugsweise roth erscheinenden Sternes pointiert
* wird." (p.107)
* (Here the double-s is spelled with two small s's.)


Ch. Montigny
“Essai sur des effets de réfraction et de dispersion produits par l'air atmosphérique,”
Mémoires couronnés et Mémoires des Savants Étrangers, publiés par l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique 26, 1–70 (1853).

* MONTIGNY:
* OBSERVATION OF --> SOLAR <-- COLORED RIMS (over a century after Bouguer!)
* "On sait sans doute, que, si l'on examine au télescope le soleil près
* de l'horizon, une partie des arcs inférieur et supérieur de son disque
* sont colorés, le premier en rouge et orangé, et le second en bleu.
*      "Les arcs rouge et orangé qui bordent la partie inférieure du disque
* solaire en s'amincissant à leurs extrémités, près du diametre
* horizontal, sont très-distinctes; le jaune l'est parfois aussi. Le 27
* septembre, le matin, alors que le bord infèrieure s'elevait sur
* l'horizon, l'épaisseur des trois teintes était de 19''.
*      "Quand le ciel est pur, on distingue aisément le teinte violette
* indigo au-dessus de l'arc bleu supérieure; elle est parfois
* très-prononcée. Le vert se voit aussi au-dessus du bleu, mais il se
* distingue moins fréquemment." (p.46)
* Also mentions colors in SUNSPOTS.
* NOTE: Read at the meeting of 5 Nov. 1853, but apparently published in 1855.
*      An extended German abstract of this paper appeared in
* "Fortschritte der Physik im Jahre 1855", 11, pp. 575-580 (1858).
* (A shorter version appeared the previous year, in FdP 1854, pp. 633-634.)
* O'C #92


W. B. Clarke
“Observations made at Sydney during the Eclipse of the Sun, March 26, 1857,”
M. N. R. A. S. 18, 39–44 (1857).

* Casual mention of blue and red rims seen at a low-altitude solar eclipse
* The passage is on p. 41; the observation was not understood.


F. Arago
Œuvres Complètes de François Arago, Tome Onzième
(Gide, Paris, 1859), pp. 733–748.

* ARAGO's collected works: unpublished material from his observing logs
* This volume has two title pages, one for the "collected works", and
* one for the "scientific memoirs". So this is Vol. 11 of the "Œuvres
* Complètes" but only Vol. 2 of the "Mémoires Scientifiques".
*      Arago's papers were edited by J. A. Barral, and amount to some 20
* volumes in all.
*      The discussion of atmospheric dispersion arose from a dispute with
* Cauchy, who incautiously said in 1836 that gases showed no dispersion.
* Arago, who knew better, had to protest; but never published his promised
* review of the subject, nor the details of his own early observations
* that are recorded here. The section on pp. 733-748 is entitled ``Sur
* les pouvoirs dispersifs'' and the section on air beginning on p. 737 is
* called ``Dispersion de l'atmosphère''.
*      Most curiously of all, nothing appears here about his observations
* with Biot. Perhaps those were recorded only in Biot's observing logs;
* perhaps Arago felt their publication on the meridian survey was enough;
* or perhaps the later disputes between Arago and Biot were the reason.
* Anyhow, this is useful supplemental material.
*      The discussion begins with the dispute with Cauchy (p. 736; see above)
* and he then mentions his own observations of 1812, which he says were
* cited by Lindenau in Journal Astronomique de Gotha.
*      The details of these observations appear on pp. 737 ff.:
* "9 mai 1811. -- A 12h 50m de temps sidéral la bordure rouge du
* bord inférieur réel de la Lune était encore bien visible avec le
* groissement de 200 fois (1ee lunette de Lerebours). Le bord supérieur
* réel (inférieur apparent) ne présentait alors que de très-légères
* traces de bleu verdâtre. Avec le groissement de 90 fois la bordure
* rouge était presque invisible; quant au bord inférieure on ne voyait
* pas la moindre nuance de couleurs." He also notices the colored rims on
* Mars, where (I suppose by contrast) the upper limb appeared blue-violet.
*      There is then reported an interesting series of experiments to null
* out the dispersion with a prism placed before the eyepiece, while
* looking at the colored rims of the Sun a little before sunset. The
* upper limb appeared "rouge jaunâtre" while the lower (apparent) limb
* was "bleu violacé" -- so I suppose the Sun was still several degrees
* high, though he says nothing about eye discomfort.
*      After describing in detail the prisms' deviations and dispersions in
* the laboratory, he concludes that the "dispersive power" of air was to
* that of crown-glass as 10 : 13.04.
*      The discussion of the dispersion of air is followed by those of
* various other gases and vapors.
*      A half-size scan of this is available at Gallica.


Ch. Montigny
“Note sur le pouvoir dispersif de l'air,”
Bull. Acad. Roy. Sci. Lett. Beaux-Arts Belg. 24, 523–536 (1867).

* MONTIGNY's first follow-up note, on dispersion of air
* He uses Cauchy's dispersion formula to calculate refractivity for 2
* additional wavelengths. He mentions the Sun's colored upper and lower
* rims. On p. 534, he gives the difference in refraction of red and blue
* at the horizon as 28''. He assumes the refraction is proportional to
* the refractivity, even near the horizon.


Ch. Montigny
“Note sur des phénomènes de coloration des bords du disque solaire près de l'horizon,”
Bull. Acad. Roy. Sci. Lett. Beaux-Arts Belg. 28, 425–434 (1869).

* MONTIGNY's second follow-up note, on solar colored rims
* Here he wants the occasional appearance of red in the blue rim to be due
* to the chromosphere!


A. A. Rambaut
“On the effect of atmospheric dispersion on the position of a star,”
M. N. R. A. S. 55, 123–145 (1895).

* RAMBAUT's DISPERSION paper
* Good historical coverage, going back to Bouguer (1729) and explicitly
* mentioning Stephen Lee (1815) and Montigny (1867).
* This is a lengthy discussion of observations, a few his, mostly others'.


St. Chevalier
“Effet de la dispersion atmosphérique sur le diamètre des astres photographiés,”
C. R. 157, 1377–1379 (1913).

* Not exactly an "early" paper; but it somehow seems to fit in here:
* He compares the Sun's vertical and horizontal diameters on photographs,
* finding the difference to be about 0.17 arcsec times tan Z.
* (The purpose of the original study was to look for polar flattening.)
* Note that this is a side-effect of the colored rims.
* Cf. Bouguer (1748)!



*** GREEN FLASH FILES -- see also the S&T and the Solar Afterimage files ***

R. Heber
Narrative of a Journey through the Upper Provinces of India
(Carey, Lea, and Carey, Philadelphia, 1828).

*                                                and the Popular Books file;
*                                                also Biot (1810) in Mirage file
*                                                Biot & Arago (1821) in Mirage file
*                                                Tait (1883) in Mirage file
*                                                Musgrave (1990) in Fake Mirage file
*
* Looks like a false alarm. When I first saw the German version in
* Kiessling's ``Dämmerungserscheinungen'' I thought it might be a
* genuine very early GF report; the phrase "green, such as I had never
* seen before, except in a prism, and surpassing every effect of paint, or
* glass, or gem" sounded promising. But the actual assertion that "there
* were in the immediate neighbourhood of the sinking sun, and for some
* time after his disc had disappeared, large tracts of a pale translucent
* green" makes it sound much more like the green of nacreous clouds.
* Reginald Heber was the Bishop of Calcutta.


"W. H."
“The blue colour of the sea,”
Magazine of Natural History 2, No. 8, 297 (1829).

* EARLIEST SUNSET GREEN FLASH (pre-1829)?
* The author is identified only as "W.H., R.N. Yeovil, April 22, 1829."
* "I remember once to have noticed the last ray of the setting sun,
* on a fine calm evening at sea, which was of a bright emerald green.
* I believe the fact is noticed by Lord Byron, in some of his works.
* Does not this prove the blue colour of the sea, in the same way that the
* green appearance sometimes observable on each side of the setting sun
* may be accounted for by knowing that his golden rays intervene between
* us and the colour of the blue sky beyond?"
*      (The reference may be to Commodore John Byron's 1764 Circumnavigation.)
* In the "Queries and Answers" section.
* Thanks to Google Books for making this discovery possible!


Sir G. Back
Narrative of an expedition in H. M. S. Terror, undertaken with a view to geographical discovery on the Arctic shores, in the years 1836-7
(J. Murray, London, 1838), p. 191.

* EARLIEST SUNRISE GREEN FLASH (Jan. 17, 1837)
* (Note that Meinels have both author & title wrong, in "Sunsets. . . " !)
*
* (after mentioning a daylight green meteor he had missed):
* "In the morning however, at a quarter before ten o'clock, while standing
* on a hummock about seventeen feet high, I had observed the upper limb of
* the sun, as it filled a triangular cleft on the ridge of the headland,
* of the most brilliant emerald colour, a phenomenon which I had not
* witnessed before in these regions." (p.191) -- Sir George Back


P. G. Maggi
“Sopra alcune apparenze del Sole presso all'orizzonte,”
Atti delle Adunanze dell'I. R. Istituto Veneto Sci. Lett. Arti , series 2, 3, 186–189 (1852).

* EARLIEST SCIENTIFIC ACCOUNT?
* PIETRO GIUSEPPE MAGGI
* This is a long meeting abstract. "The Author had often observed how,
* when the Sun sets behind distant mountains, the last disappearing edge
* is dyed a vivid blue. Because of its long duration, this coloration
* can not be caused by diffraction" but must be due to "the dispersive
* power of the middle air." "The telescope allowed him to know how the
* image of the Sun always appears (besides the well-known flattening)
* fringed with a blue rim in its upper half, and a red one below . . . ."
* "But neither of them has enough width for the naked eye to grasp,
* when, with the solar rays traversing a uniform atmosphere, the image
* suffers no greater alteration than the ordinary flattening mentioned.
* When the equality of temperature and humidity of the air are disturbed,
* new and very visible changes deform the solar disk, and the colored
* borders and then expand, so that the blue becomes clear and distinctly
* seen even by the naked eye . . . ." He mentions Biot's "treatise on
* physical Astronomy" in which "no mention is made of any colored light
* effect," though the distortions of the disk involved are similar.
* "The more notable conditions" involve "separated pieces . . . above and
* below the image of the Sun." So it seems he noticed mock mirages.
* He supposes there are "lenticular masses" of warmer air that are
* responsible, and thinks they are related to the formation of "the clouds
* called cumuli." So he thinks the "appearance of the blue light which
* dyes the last rays of the Sun" is a precursor of "the change of weather
* from clear to rainy."
* According to Pogg., Maggi was born April 30, 1809 and died March 17, 1854,
* not quite 45 years old. He became Professor of Mathematics at Padua in
* 1853.


J. P. Joule
“On an appearance of the setting sun,”
Proc. Manchester Lit. Phil. Soc. 9, 1 (1869).

* Former earliest scientific account. Nice OMEGA drawing
* DISCOVERY attributed to Joseph Baxendell (Pogson's brother-in-law!)
* who had been a sailor -- see obits in Nature 36, 585 (1887) and
* M.N. 48, 157-160 (1888), and (especially) James Bottomley in
* Mem. Proc. Manch. Lit. Phil. Soc. (4) 1, 28-58 (1888).
* N.B.: Title appears only in Index, not on article page.
* "Mr. Baxendell noticed the fact that at the moment of
* the departure of the sun below the horizon, the last glimpse is coloured
* bluish green. On two or three occasions I have noticed this, and also
* near sunset an appearance like what I have rudely depicted.
* Just at the upper edge, where bands of the sun's
* disk are separated one after the other by refraction, each band becomes
* coloured blue just before it vanishes."
* (The referent of "what I have rudely depicted" is an Omega-shaped sunset.)
*      A completely garbled abstract appears in Fortschritte der Physik
* im Jahre 1874, 30, 1377-1378 (1879): "Am unteren Rande der wenig vom
* Horizonte entfernten Sonne befand sich eine streifige Wolkenschicht,
* unter der nach dem Horizonte zu die oberen Theile eines Sonnenbildes
* erschienen." [signed Sch. (= Schwalbe), who noticed only the woodcut]
* Fisher #60; not read by him
* O'C #63


J. P. Joule
“On sunset seen at Southport,” in in The Scientific Papers of James Prescott Joule
(Dawson's of Pall Mall, London, 1887), (reprinted by the Physical Society of London, 1963) p. 607.

* reprint of Joule's letter


G. Giordano
“Singolari apparenze osservate nel tramonto del sole,”
Rend. Accad. Sci. Fis. Mat. 10, 230–231 (1871).

* GENUINE AFTERIMAGE REPORT
* Afterimage moves, is smaller than Sun, and "greenish" in color;
* timescale: 10 sec (4 such, gradually fading out)


D. Winstanley
“Atmospheric Refraction and the last rays of the Setting Sun,”
Proc. Manchester Lit. Phil. Soc. 13, 1–4 (1873).

* EARLY ACCOUNT by David Winstanley (RED and GREEN RIMS isolated)
* "During the past eighteen months the writer, from his residence
* in Blackpool, . . . has noticed the phenomenon of the final coloured ray
* certainly more than fifty times."
* FIRST MENTION of VARIABLE DURATION:
* "The period of its duration too is likewise variable. Sometimes it
* lasts but half a second, ordinarily perhaps a second and a quarter, and
* occasionally as much as two seconds and a half."
* TERMINOLOGY:
* ". . . the phenomenon of the final coloured ray . . . . To the naked eye its
* appearance has generally been that of a green spark of large size and
* great intensity . . . ."
* ". . . the green ray . . . ."
* FIRST USE of term SEGMENT (but not "green segment"):
* ". . . it begins at the points or cusps of the visible segment of the sun . . . "
* EVIDENCE for (but not recognition of) inferior mirage:
* "From the fact of the green cusps being rounded I apprehend that
* irradiation contributes to the apparent magnitude of what is seen."
* FIRST MENTION of (telescopic) CLOUD-TOP flash:
* "That the waters of the ocean have nothing to do with the production of
* the colour is made manifest by its visibility when the sun `sets' behind
* the edge of a well defined cloud. On the 14th and 15th of June, for
* instance, it was seen at upper contact of the solar limb with clouds.
* . . . And on several other occasions the writer has observed the effect
* when the disappearance of the sun has taken place at an elevation of
* six or eight degrees behind a heavy bank of clouds."
*
* "Of the objective nature of the phenomenon it is needless to offer
* evidence; for it needs to be but seldom seen to preclude the idea of an
* optical illusion."
* "The different colours seen, together with the order of their
* appearance, are suggestive of the prismatic action of the atmosphere as
* the cause of their production."
* (verified telescopically by using an artificial occulter)
* "I apprehend that the results here given sufficiently prove that
* atmospheric refraction is the cause of the coloured rays seen at the
* moment of the sun's departure below the horizon."
* O'C #160


Anonymous
“Societies and academies: Manchester,”
Nature 9, 20 (1873).

* Joule and Winstanley quoted in Nature -- but without Joule's figure!
* Fisher #161, O'C #161


Anonymous
“Sunset tints and arcs,”
Annual Record of Science and Industry for 1874, 68 (1875).

* Nature's reprint of Winstanley's paper, abstracted


J. Verne
Les Indes Noires
(Hetzel, Paris, 1877).

* JULES VERNE's FIRST mention of the "green ray" (1877)
* This novel is set mostly in a coal mine -- in Scotland! The heroine
* has spent her whole life underground, and is about to see her first
* sunrise, in Edinburgh:
* "Enfin, un premier rayon atteignit l'oeil de la jeune fille. C'était
* ce rayon vert, qui, soir ou matin, se dégage de la mer, lorsque
* l'horizon est pur." [This is in Chapter XVII, "Un Lever de Soleil".]
* I have seen only the 1967 Hachette edition, where this passage occurs
* on p. 186. Interestingly, the biographical note at the end (on
* unnumbered pages) claims that "Le physicien et astronom Jules Janssen,
* le mathématicien Joseph Bertrand refont les calculs de Jules Verne --
* et vérifient, dit-on (il serait sans doute imprudent de ne pas placer
* ici un point d'interrogation), l'exactitude des courbes, paraboles et
* hyperboles qui définissent le trajet du boulet-wagon de De la Terre
* à la Lune ."
*      As Verne went to Scotland in 1859, and was much taken with the place,
* it seems likely that he may have seen green flashes there: both his
* mentions of the flash are set in Scotland. Also, this book is full of
* talk about how superstitious and full of folklore the Scots are; so the
* invention of the ``legend'' later on seems more natural.
* Thanks to Hezi Yizhaq for pointing this out!


J. A. Froude
Short Studies on Great Subjects, Third Series
(Scribner,Armstrong & Co., New York, 1877), p. 345.

* James Anthony Froude's flash of Aug. 28, 1874
* FIRST USE of "FLASH" ??
* Froude was a controversial historian and excellent writer. This is
* from the section of his book called ``Leaves from a South African
* Journal.'' While sailing to South Africa, he says:
* "The sea calm as Torbay in stillest summer. . . .      Last night we had a
* remarkable sunset. The disk, as it touched the horizon, was deep
* crimson. As the last edge of the rim disappeared there came a flash,
* lasting for a second, of dazzling green -- the creation I suppose of my
* own eyes."
* He also tells many poignant stories of South Africa, and saw Kimberly
* in the early days, when the mine was only 120 feet deep.
*      An older brother, William Froude, was an engineer and naval architecht
* who devised the Froude Number of hydrodynamics. The family name rhymes
* with "food"; many supposedly authoritative websites get this wrong.
*      Many thanks to Agnes McLean for finding this!


C. R. Conder
Tent Work in Palestine. A Record of Discovery and Adventure. Vol. I
(Richard Bentley & Son, London, 1878), p. 264.

* The "BLUE SPARK" quote traced to its source!
* Lt. Claude Reignier Conder of the Royal Engineers was in charge of the
* survey of Palestine in 1872-1875, when he turned the work over to Lt.
* H. H. Kitchener (later to become an Earl, and controversial for his
* use of concentration camps in South Africa -- but this was the young
* Kitchener's first job in the Royal Engineers). On pp. 264-265, Conder
* describes a sunset and sunrise observed from the top of Mt. Hermon,
* including the TRIANGULAR MOUNTAIN SHADOWS. But our interest is in a
* single sentence, set off as a separate paragraph:
* "The sun underwent strange changes of shape in the thick vapours --- now
* almost square, now like a domed temple --- until at length it slid into
* the sea, and went out like a blue spark."
* MANY THANKS to Andrew Alden, of Oakland, CA, for finding this!
*      According to Wikipedia, Mount Hermon is 2,814 m above sea level, and
* the highest point in Syria. Conder says his observation was made from
* a height of 9150 feet. It appears to have been made on "Monday, the 8th
* of September" (1873).
*      Available at
*       https://archive.org/stream/tentworkinpalest01conduoft#page/264/mode/2up
* and
* https://books.google.com/books/about/Tent_Work_in_Palestine.html?id=ltiQteXzxNIC


H. Bedford
“A Long Day in Norway. Chapter III. To the north cape,”
The Month 35, 43–58 (1879).

* Henry Bedford's pre-Verne observation
* sunset and sunrise of July 14/15, 1878: ". . . the sun -- the green
* sun --- appears. A distant low range of rocks comes between us and its
* point of rising; and, as we glide on, an opening between them shows us
* the sun, a bright emerald, as pure and brilliant as ever gem that
* glistened; again we lose it, and again an opening shows it to us in
* its own golden light; and then once more it is the bright green; and
* now it rises higher, clears the ridge, and is once more the golden orb.
* This is what we saw, but another observer, our alter Ego , assures us
* that, when he first saw it, the colour was a fiery red, which soon turned
* to green. Evidently an optical effect of what is called polarization
* of light, as these complementary colours seem to show." (p.48)
* Bedford's long travelogue was serialized in Month 34, 290-304 (Ch. I),
* 395-411 (Ch. II) (1878); vol. 35, pp.43-58 (Ch. III), pp.167-184 (Ch.IV),
* 334-351 (Ch.V), 473-490 (Ch.VI) and vol. 36, 17-37 (Ch. VII) (all 1879).
* N.B.: these are volumes XV to XVII, New Series.
* Bedford was a convert to Catholicism; The Month appears to have been a
* magazine for British Catholics.


J. Verne
Le Rayon-Vert
(Hetzel, Paris, 1882).

* JULES VERNE's NOVEL
* I was surprised to discover, from the facsimile of the original edition
* that was published by Hachette in 1977, that the original title was
* hyphenated. The Hachette edition also has the original illustrations,
* including drawings depicting the "ray" like narrow crepuscular rays;
* see Mulder's complaint about this on p.3 of his book.
* Cf. Moncrieff's complaints (1905) about Scottish errors.
* Thanks to Stephen Williams for turning this up!
* Fisher #144, O'C #145
*      For the origin of the "legend", see the 2002 publication of Verne's
* correspondence with Hetzel, his editor -- and its actual inventor.


G. H. Hopkins
“The green sun,”
Nature 29, 7 (1883).

* (Quoted in its entirety in Rambaut's 1906 Met.Mag. paper)
* ". . . the parting ray is a brilliant emerald green."
* "The . . . effect is not produced by the sun setting behind a distant bank
* of clouds. Probably the first ray from the rising sun would be the same
* unexpected colour."
* Fisher #58


W. Swan
“Green sunlight,”
Nature 29, 76 (1883).

* former "EARLIEST" OBSERVATION (Sept. 13, 1865)
* William Swan observed from summit of the Rigi.
* misinterpreted as due to contrast with red sky:
* "I do not doubt the phenomenon was purely subjective, for before sunrise
* the sky was all lit up of a magnificent crimson hue."
* NOTE: This is the William Swan for whom the "Swan bands" of C2 are named.
* Fisher #141, O'C #135


W. H. Larrabee
“Green suns and red sunsets,”
Popular Science Monthly 24, 598–606 (1884).

* Mostly about the Krakatoa effects, but half a paragraph on GF
* (pp.601-602) says "Mr. Henry Bedford . . . in an English magazine" of
* 1878, as well as G.H.Hopkins (see above). The Bedford quote describes
* an Arctic Circle sunset and sunrise in July: ". . . the sun -- the GREEN
* sun --- appears. A distant low range of rocks comes between us and its
* point of rising, and, as we glide on, an opening between them shows us
* the sun, a bright emerald, as pure and brilliant as ever gem that
* glistened; . . . and now it rises higher, clears the ridge, and is once
* more the golden orb." (slightly mis-quoted; see Bedford, 1879)
* The Bedford quotation is pre-Verne, but no detailed citation is given.
* (in the March issue)


G. M. H.
“The Red Light round the Sun – The Sun Blue or Green at Setting,”
Nature 30, 633 (1884).

* Thinks it is a CONTRAST EFFECT
* "A sun seen as green or blue for hours together is a phenomenon
* witnessed only after the late Krakatoa eruptions . . . ; but a sun which
* turns green or blue just at setting is, I believe, an old and, we may say,
* ordinary one, little remarked till lately. I have a note of witnessing
* it . . . on June 23, 1877, the sunset being very clear and bright.
*      "The sunset was bright this evening, the sun of a ruddy gold, which
* colour it kept till nothing was left of it but a star-like spot; then this
* spot turned, for the twinkling of an eye, a leaden or watery blue, and
* vanished."


A. de Rochas
“Le rayon vert et l'équerre chromatique,”
La Nature 13:2, No. 634, 366 (25 Jul., 1885).

* a GEOMETRIC CRANK -- one of de Morgan's ``paradoxers''
* Starts off by mentioning Verne's novel, and quoting the florid paragraph.
* A wonderfully ingenious and completely CRANK THEORY OF COLOR is used to
* explain the green ray as the COMPLEMENT of the INVISIBLE INFRARED rays!
* It all is based on a confusion of additive and subtractive color mixing,
* together with the mistaken notion that the spectrum contains all possible
* colors. From these mistakes, he goes on to a marvelous GEOMETRIC
* CONSTRUCTION, and hence a mechanical device to illustrate the theory:
* "Ce petit instrument . . . donne, dans la practique des résultats
* beaucoup plus exacts que le cercle chromatique de Chevreul. . . ."
* ". . . il serait particulièrement curieux de blanchir une partie de
* l'espace v'v'' avec des rayons obscurs et, inversement, de rendre
* lumineux les rayons obscurs en les mélangement avec des rayons verts."
* [Indeed it would be!]
*
* NOTE: La Nature published 2 "Semestres" per year,
* BOTH with the SAME volume number, and both starting at p.1 !!
* Extreme care is required to determine the correct half of the year;
* either the date or the issue number must be given.


A. Trève
“Sur le rayon vert, observé dans l'océan Indien,”
C. R. 101, 845–846 (1885).

* AUGUSTE TREVE's observations and simultaneous-contrast theory
* (This was the great-uncle of the modern scientist Yvain Treve)
* "Sa durée est celle d'un éclair. C'est, pour le navigateur, comme un
* adieu chargé de promesses, toujours fidèlement tenues, d'un beau temps
* pour le lendemain; il est, en effet, bien peu d'exemples, s'il y en a,
* qu'un beau coucher de soleil ait été suivi d'un mauvais temps."
* Cf. the similar claims made by Wegener (1926), and the remark of
* "Another Engineer Officer" (1904) about this being standard French
* navigational instruction lore.
* Fisher #142


Trève
“Le rayon vert,”
La Nature 13:2, No. 649, 366 (7 Nov., 1885).

* Almost word for word the same letter published in C.R.
* cited by Polo in his 1904 letter


A. Trève
“Essai d'une explication physiologique des couleurs complémentaires,”
C. R. 102, 984–985 (1886).

* A short followup to the Trève paper of Oct. 1885
* He offers a mechanical theory for successive contrast!
* Thanks again to Yvain Treve for providing this reference!


Anon.
“Notes,”
Popular Science Monthly 28, 575 (Feb., 1886).

* One-paragraph abstract of the 1885 Trève paper in C.R.
* "M. Trève has described to the French Academy of Sciences a phenomenon
* of a beautiful green ray which he has observed . . . ."


M. Besson
“Le rayon vert,”
Revue Scientifique 37:1, No. 14, 444 (1886).

* Besson's sunrise observation, with a VENUS flash on setting as well
* A convert from the "contrast" idea, thanks to seeing a sunRISE flash
* in the Azores: "Voici une excellente occasion de vérifier la théorie
* du commandant Trève." He saw another (not as good) the next morning.
* "La théorie du contraste des couleurs me paraît donc fausse."
*      This is Vol. 22 of the 3rd Series, 1er Semestre, dated 3 Avril 1886
* in the section "Correspondance et Chronique".
* Available at Gallica.


H. de Maubeuge
“Sur le rayon vert,”
C. R. 103, 1147–1148 (1886).

* SUNRISE OBSERVATIONS OVER MOUNTAINS in letter to Mascart
* "Tous les touristes qui frequentent l'Égypte et la mer Rouge ont été
* témoins de ce phénomène . . . ."
* ". . . dans le mer Rouge, plusiers fois et notamment en octobre dernier,
* j'ai assisté, moi et mon second, au lever du Soleil à l'horizon de
* la mer, et que la première impression sur nos deux rétines a été
* d'un beau vert émeraude.
*       Le lendemain, assistant tous deux au lever du Soleil derrière des
* montagnes élévées de 1° à 2° au-dessus de l'horizon, la même
* impression lumineuse franchement verte a encore frappé nos yeux."
* [Note the correct altitude here, but not in his 1898 letter.]
* "Je ne puis citer le nombre de fois que j'ai observé et fait observer
* ce même phénomène au coucher du Soleil et encore derrière des
* montagnes."
* Fisher #87, O'C #237


de Maubeuge
“Le rayon vert,”
La Nature 15:1, 46 (1886).

* This is an extract from the C.R. letter
* No.707, 18 Dec. 1886
* O'C #238
* Fisher #88


de Maubeuge
“Le rayon vert,”
l'Astronomie 6, 232–233 (1887).

* de Maubeuge's letter quoted again, in l'Astronomie
* This was *before* it merged with B.S.A.F. The full title is:
*
*                                L' A S T R O N O M I E
*
*                                                  REVUE
*                                            D'ASTRONOMIE
*                                                POPULAIRE,
*                    de Meteorologie et de Physique du Globe,
*                                                 exposant
*                    les progrès de la science pendant l'année;
*                                            publiée par
*                                     CAMILLE FLAMMARION,
*      avec le concurs des principaux astronomes français et étrangers


R. T. Omond
“A Green Light at Sunset,”
Nature 35, 391 (1887).

* FIRST USE of term "GREEN FLASH"?
* "At sunset tonight I observed a phenomenon which has, I believe, been
* seen from on board ship, but never probably from a place with such a
* distant sea horizon as we have here -- some seventy miles. The sky for
* a short distance above the point where the sun set was perfectly clear
* of cloud or haze, and I watched carefully the last portion of its disk
* disappear into the sea. As soon as the last speck of the yellow
* vanished, a momentary bright green flash shone out. This was quite
* different from the complementary green seen after looking at the setting
* sun; brighter and bluer in tint. I have seen it stated that the cause
* of this green light is the sun shining through the water that hides
* it, and would be glad to know if such is the true explanation."
* Robert Trail Omond was a Scottish meteorologist, Superintendent of the
* Ben Nevis Observatory (1883-95) when this was written, and later (1903-?)
* Honorary Secretary of the Scottish Meteorological Society [see WW, 1909].
* Fisher #111, O'C #99


A. Riccò
“Green light at sunrise and sunset,”
Nature 35, 584 (1887).

* RICCO's reply to Omond
* Fisher #126, O'C #116


J. S. H. Pellat
“Del la couleur verte du dernier rayon solaire,”
Bull. Soc. Philomathique , series 7, 12, 22–23 (1887).

* Early description of GREEN RIM
* FIRST refutation of CONTRAST EFFECT by HUE ?
* ? Joseph Solange Henri Pellat (Pogg.)
* ". . . ni à un contraste des couleurs qui, du reste, vu la teinte jaune
* d'or du disque, donnerait une couleur bleue et non pas verte."


Pellat
“Von der grünen Farbe des letzten Sonnenstrahles,”
Naturwiss. Rundschau 3, 565 (1888).

* Pellat's report, in German


A. C. Ranyard
“Mountain Observatories,”
Knowledge 12, 125–126 (1889).

* Here is an explicit mention of THOLLON:
* "During the autumn of 1886 I visited M. Perrotin and M. Thollon, at the
* Nice Observatory, and watched the setting sun with M. Thollon on five
* clear evenings, to catch sight of the last blue ray . . . . The sun at that
* period of the year set over the bare edge of an opposite mountain, but on
* four out of the five nights I saw the blue ray, though I have only seen it
* on two other occasions from the sea-level."
* (article is mostly about Lick Obs.)
* N.B.: A. Cowper Ranyard was editor of "Knowledge" from 1904-1910;
* the editor when he published this article was R.A.Proctor.
* Ranyard was apparently impressed by John Evershed, who inherited
* Ranyard's instruments in 1894, after knowing him only a year.
* I see from the Nov. 13, 1863 issue of M.N. that Ranyard became a Fellow
* of the RAS at that time -- as Foucault and Bond became Associates.
* Fisher #124


H. B. F.
[30289]
English Mechanic and World of Science 50, 11 (1889).

* The ENGLISH MECHANIC series for 1889 follows.
* Note that Eng.Mech. published 2 volumes per year.
* The "Letters" section of E.M. occupied the ecological niche today held
* by Usenet: a heterogeneous mixture of professionals, amateurs, and cranks.
* Letter-writers often used only initials, or pseudonyms.
* Letters are numbered in squared brackets; I preserve those numbers here,
* as many letters in small print appear on each 9 x 12-inch page.
* One letter may touch on many topics besides the GF; rather than list the
* many irrelevancies, I simply give the number. Note that queries and
* letters have separate numbering systems!
*
* This thread was started by someone signing as "F.R.A.S." (i.e., "Fellow
* of the Royal Astronomical Society") in a previous issue. Here, "H.B.F."
* asks "F.R.A.S." for an explanation of the "Green Ray" at sunset, which
* he describes as "a drop of the most vivid emerald green". He continues:
* "My attention was first drawn to the alleged phenomenon by the perusal
* of M. Jules Verne's story, `The Green Ray,' and believing it to be
* fictitious, I set myself to observe. For about three months of the summer
* the place of my residence -- an island in the Levant -- allowed an ocean
* horizon for the setting sun. On the very first evening of observation I
* was rewarded with the sight of that wonderfully brilliant flash, and on
* successive evenings I continued the observations. About two out of every
* three observations were successful . . . . Believing that the phenomenon
* might still be a purely subjective one, I asked my wife to join in the
* observations, and, sceptical as she at first was, on each occasion,
* whether the green ray was visible or not, our observations exactly
* coincided. On the whole, out of some fifty successive observations, I
* should say we succeeded in obtaining a glimpse of the `ray' about thirty
* times."
*      Eric Hutton identifies "A Fellow of the Royal Astronomical Society" as
* Captain Noble, J.P. of Uckfield, Sussex. [EM ref. No. 3105 p326]
* No. 1275, Aug. 30, 1889
* Fisher #167


A Fellow of the Royal Astronomical Society
[30313]
English Mechanic and World of Science 50, 31–32 (1889).

* Alas, the otherwise reliable Fellow offers "H.B.F." the AFTERIMAGE theory!
* (Evidently, he had never seen a GF)
* "I fancy that the green ray of which my querist speaks must have a
* cognate origin to this, and that the eye, deadened to the sensation of red
* by the brilliant crimson of the sun's disappearing limb, must temporarily
* select the green from the more composite light illuminating the horizon."
*      Eric Hutton identifies "A Fellow of the Royal Astronomical Society" as
* Captain Noble, J.P. of Uckfield, Sussex. [EM ref. No. 3105 p326]
* No. 1276, Sept. 6, 1889
* Fisher #172


E. L. G.
“The `green ray' at sea [30324],”
English Mechanic and World of Science 50, 33 (1889).

* Another ignoramus offers the "WAVE" notion:
* "Surely the `emerald drop' so often seen by `H.B.F.' page 11, can be no
* other than solar light transmitted through the sea . . . ."
* No. 1276, Sept. 6, 1889
* Fisher #164


Autolycus
“The green ray [30345],”
English Mechanic and World of Science 50, 56 (1889).

* Another vote for afterimages:
* He cites the Pears' Soap ads as an example.
* No. 1277, Sept. 13, 1889


H. B. F.
[30351]
English Mechanic and World of Science 50, 58 (1889).

* "H.B.F." knows it isn't an afterimage:
* "I should have explained, however, that I failed to observe it on
* occasions when the sun presented a red appearance, and only when he set
* with a pale golden colour has it been visible. Moreover the ray has
* not that dull appearance noticeable in this and in other similar optical
* illusions, nor has it the like permanency."
* He also rejects the light-through-a-wave explanation of "E.L.G.", as
* ". . . only when the sea has been exceptionally calm, has it been visible."
* COMMENT: Note that the experienced observer here quite rightly dismisses
* the arm-waving of the would-be theorists who have *never* seen a flash.
* No. 1277, Sept. 13, 1889
* Fisher #168


Sm.
[30352]
English Mechanic and World of Science 50, 58 (1889).

* Another vote for afterimages:
* "I may, however, add that if this is the correct explanation, the
* phenomenon is more likely to be observed within the Tropics than at higher
* latitudes, since the more vertical the path of the setting sun, the
* greater the rapidity of its apparent motion, and the more sudden the
* change from light to darkness."
* No. 1277, Sept. 13, 1889


A Fellow of the Royal Astronomical Society
[30364]
English Mechanic and World of Science 50, 76–77 (1889).

* FRAS switches to the "wave" idea:
* cites HBF's 30351 letter
*      Eric Hutton identifies "A Fellow of the Royal Astronomical Society" as
* Captain Noble, J.P. of Uckfield, Sussex. [EM ref. No. 3105 p326]
* No. 1278, Sept. 20, 1889
* Fisher #173


F. R. C. S. Eng.
“The green ray [30368],”
English Mechanic and World of Science 50, 77 (1889).

* BLUE is commonest color at sea?
* Believes flash is due to Sun shining through water
* "I have had numberless opportunities of witnessing the same appearance
* in mid-ocean, where the water appears blue, and the flash is also of an
* exquisite blue."
* "I have repeatedly drawn the attention of others to this, especially
* between the Tropics, to all of whom the flash appeared blue."
* cites E.M.50,11
* No. 1278, Sept. 20, 1889
* Fisher #166


F. W. Reynolds
“The green ray [30369],”
English Mechanic and World of Science 50, 77 (1889).

* cites and quotes Ranyard's paper in Knowledge
* No. 1278, Sept. 20, 1889
* O'C #114


E. L. G.
“The green ray [30370],”
English Mechanic and World of Science 50, 77–78 (1889).

* "E.L.G." criticises "F.R.A.S." for afterimage theory
* ". . . no sunset, in any latitude, has a colour complemental to green."
* He now recognizes the problem with his model:
* "The emerald light must somehow have got a dip through sea-water; but
* how, is a great puzzle with so little refraction. It would seem, it
* must enter and leave very steep wave surfaces, though `H.B.F.' calls the
* sea `calm.' He does not give a hint of the height of his station, a most
* important element, if it is never, as he thinks, visible from a ship's
* deck."
* No. 1278, Sept. 20, 1889
* Fisher #165


H. B. F.
[30406]
English Mechanic and World of Science 50, 97 (1889).

* HBF's 3rd letter: he decides to accept the "wave" story, but modified:
* ". . . the last glimpse of the sun after he has passed beneath the visible
* horizon, seen through the depth of a clear and placid ocean , and not
* through a mere superficial wave or two." [N.B.: ignores refraction!]
* "The verandah from which most of my observations were made stands 664ft.
* above sea-level, at a distance of three miles from the shore."
* No. 1279, Sept. 27, 1889
* Fisher #169


E. L. G.
“The `green ray' (or blue?) [30407],”
English Mechanic and World of Science 50, 97 (1889).

* At last, "E.L.G." puts the pieces together!
* "If this is, after all, a blue ray, and can be seen, as the observer at
* Nice tells us, after sunset behind a mountain, of course the sea has
* nothing to do with it. The last explanation must be taken, and it gives us
* the first proof that air, like other refracting media, refracts the
* different colours with different indices. Now I believed, about thirty
* years ago, that I had a proof of this on watching, through a good
* achromatic glass, a very clear sunrise in the north suburbs of London.
* The sun rose . . . with so little colour that it could not be called even
* `pale golden.' It was merely creamy; but from the first emergence till
* the lower limb was up, the upper limb had a distinct edging of blue, and
* the lower one of red."
* (So we have here an independent, if uncertain, rediscovery of the colored
* limbs.)
* With this item, the *green* ray series ends. But see the next 2 items!
* No. 1279, Sept. 27, 1889


A. C. Ranyard
“The blue ray [30424],”
English Mechanic and World of Science 50, 116 (1889).

* A. COWPER RANYARD speaks up:
* "I need only remind `F.R.A.S.' of a paper by Sir G. B. Airy, published
* in the Monthly Notices for 1869, on an eyepiece for correcting the
* effects of atmospheric dispersion, to recall to his mind the phenomena
* which are always observed when a star or the sun is near to the horizon."
* "When the sun or a planet is near to the horizon the blue fringe along
* its upper limb and the red fringe along its lower limb is a very marked
* feature when it is observed with a power of two or three hundred."
* The Airy paper is probably O'C. #4
* FIRST CALCULATION SCALED TO HORIZONTAL REFRACTION ? (1/60)
* "To express it in numbers, the atmospheric dispersion from B to G of the
* spectrum is about one-sixtieth of the atmospheric refraction. On the
* horizon at the sea-level, the horizontal refraction is about 34 minutes,
* and the length of the spectrum from B to G is 34''."
* He favorably notes "E.L.G."'s observation.
* No. 1280, Oct. 4, 1889
* Fisher #125


A Fellow of the Royal Astronomical Society
[30464]
English Mechanic and World of Science 50, 156 (1889).

* "FRAS" recants, with an excuse, and a damning admission:
* "There can be no doubt that Mr. Ranyard does suggest a -- or the --
* vera causa for the phenomenon of the final blue flash incident on
* sunsets; but, as far as I am concerned, it is one which I have never
* witnessed . . . ."
* [NOTE: Both this and Ranyard's item were indexed under "blue" by the E.M.]
* This apparently ends the entire episode in E.M. for 1889.
* No. 1282, Oct. 18, 1889
* Fisher #174


L. Sohncke
“Zur meteorologischen Optik. Das blaugrüne Flämmchen,”
Meteorol. Zs. 6, 477 (1889).

* Possible GREEN RAY ?? or BLANK-STRIP flash?
* ". . . den Eindruck eines vertikalen blaugrünen Flämmchens . . . "
* "Ziemlich nahe vor Sonnenuntergang war hier die Sonne durch einen
* schmalen Wolkenstreifen in zwei Theile getheilt. . . ."
*
* Leonhard Sohncke (1842-1897) was a well-known crystallographer who
* became head of the meteorological stations in Baden when he was made
* professor of physics at the Technische Hochschule in Karlsruhe (1871-1883).
* His green-flash work is rather obliquely mentioned in the DSB.
* Fisher #138


Anonymous
“(note),”
Nature 41, 495 (1890).

* Sohncke's paper reported in Nature; cited by Michie Smith (see below)
* March 27 issue
* Fisher #139


Anonymous
“(note),”
Science 15, No. 395, 231 (1890).

* Nature's report of Sohncke's paper re-reported in Science
* in the "Notes and News" department, which began on the previous page.
* April 11 issue


C. Michie Smith
“The green flash at sunset,”
Nature 41, 538 (1890).

* SECOND MENTION OF VARIABLE DURATION
* "If the colour were due simply to refraction it would last for only a
* fraction of a second, and the colour would be much more blue than green.
* But, so far as my own observations go, the colour may last for several
* seconds, and is a bright pea-green . . . ."
* Charles Michie Smith's first appearance. He was Pogson's successor at
* Madras, and established the Kodaikánal Observatory in 1899.
* Note that Evershed, his successor, always refers to him as
* "Michie-Smith" (hyphenated) in his autobiographical note in Vistas,
* Vol. 1, p.33.
* Fisher #136, O'C #285
* April 10 issue


T. A. Dukes
“The green flash at sunset,”
Nature 42, 127 (1890).

* GREEN RAY
* ". . . the sun had sunk behind a hill, when, suddenly, my companion and I
* both saw a flash of green light against the thickest cloud; it lasted
* one or two seconds, just long enough for there to be no doubt about it.
* We compared it to the glare thrown by `green fire,' extending over an
* area whose diameter appeared about four times that of the moon."
* Fisher #39


P. Henry
“Sur une méthode de mesure de la dispersion atmosphérique,”
C. R. 112, 377–380 (1891).

* First calculation of duration of green at sunset ?
* 2nd CALCULATION SCALED TO HORIZONTAL REFRACTION ?
* "Cette dispersion atmosphérique démontre que, dans un coucher de
* Soleil, le rayon vert doit persister, sour notre latitude, une
* seconde environ après la disparition du rayon jaune."
* (Prosper Henry)
* The Henry brothers, Paul and Prosper, invented the 13-inch astrograph
* used to make the Carte du Ciel , the monster project that absorbed the
* efforts of a whole generation (or two!) of astronomers.
* Fisher #55, O'C #50


L. Biart
“Le rayon vert,”
l'Astronomie 10, 116–117 (1891).

* cited by F.K., who blames Fisher
* This is about crepuscular rays, NOT green flashes!
* Biart's letter is confined to p.116; but the editorial comment on the
* next page is included here.
* This was *before* l'Astronomie merged with B.S.A.F.
* Fisher #8


C. Mostyn
“in `Notes',”
Nature 44, 352 (1891).

* SUNRISE better than SUNSET (according to Charles Mostyn)
* NO GF under INVERSION conditions; TWO TYPES of sunsets distinguished
* "The best displays took place took place when the refraction near the
* horizon was of such a character that the sun assumed a balloon, or vase,
* shape as he came close to the sea-line. When, on the contrary, the sun
* appeared flattened out in its horizontal diameter, the `green ray' was
* either entirely absent, or was seen only in an indistinct and uncertain
* manner."
* Seen 3 times as the ship rose and fell on waves in "the Southern Ocean."
* Apparently, this refers to Mostyn's trip from London to Sydney at the end
* of 1890 and beginning of 1891 (thanks to Edward Gilbert for the info!)
* This is the Aug. 13 issue.
* Fisher #103, O'C #253


Anon.
“Notes and News,”
Science 18, No. 450, 159 (1891).

* Mostyn's note reprinted (with slight editing) in "Science"
* Sept. 18, 1891 issue; the column runs from pp. 157-159.


E. R. Blakeley
“A green ray [32643],”
English Mechanic and World of Science 54, 40 (1891).

* The 1891 E.M. series begins with E.Reginald Blakeley, who saw a
* crepuscular ray:
* "Surely it could not be the green ray Verne has written about?"
* No. 1379, Aug. 28, 1891


T. R. Clapham
“Green ray [32662],”
English Mechanic and World of Science 54, 40 (1891).

* A reply to E.Reginald Blakeley, pointing out that what he saw were
* crepuscular rays (though not so named).
* No. 1380, Sept. 4, 1891


H. B. F.
“Green ray [32663],”
English Mechanic and World of Science 54, 40 (1891).

* HBF's 4th letter: he continues to accept the "wave" story:
* "I have not the least doubt but that the explanation of the phenomenon
* given by `E.L.G.' (letter 30324) is the correct one . . . ."
* But there is a nice account here of a double flash at sunset made
* visible by "the sea . . . swelling in great easy rolls."
* No. 1380, Sept. 4, 1891
* Fisher #170


C. Mostyn
“The green ray,”
Scientific American 65, 168 (1891).

* Mostyn's Nature letter replayed by Scientific American
* Sept. 12 issue -- must have been a weekly then.


D. E. Packer
“Sunset phenomena — errata [32746],”
English Mechanic and World of Science 54, 113 (1891).

* Packer points out that crepuscular rays are often mistaken for green
* flashes and other things, citing Col. Markwick's letter in No.1281.
* No. 1383, Sept. 25, 1891


E. R. Blakeley
“A green ray [32747],”
English Mechanic and World of Science 54, 113 (1891).

* Blakeley thanks Clapham and "HBF", agreeing that he saw a crepuscular ray
* and not a GF.
* No. 1383, Sept. 25, 1891


H. Crew
“An unusual sunset,”
Nature 46, 391 (1892).

* A minor GF observation (blue, actually) from Mt. Hamilton
* This is probably an observation of a flash above a Wegener's
* "BLANK STRIP", from the description. The dark strip in the drawing is
* about 2 degrees above the apparent horizon, roughly right for the dip
* there.
* Fisher #33


W. Groff
“La plus ancienne observation d'un phénomène naturel ou astronomique,”
Bull. Inst. Égypt. , series 3, 4, 149–156 (1893).

* William N. GROFF's work on ANCIENT EGYPTIAN depictions
* contains some of his own observations
*
* Groff was an interesting character about whom little is known. He was
* born in 1857 in Cincinnati, Ohio, and died relatively young in 1901 in
* Athens, Greece. I'd guess he picked up his astronomical interest in
* Cincy, as the observatory there was important in the mid-19th Century.
*
* He was obviously an experienced GF observer; so we take his GF work
* seriously. He seems to have learned most of his astronomy from
* Flammarion's "Astronomie Populaire" and Burritt's "Geography of the
* Heavens". With such a weak scientific background, it is remarkable that
* he managed to figure out the correct cause of the GF on his own.
*
* Note that he describes the green flash at sea as ``le `soleil vert' des
* matelots,'' which confirms my opinion that these phenomena were long known
* to sailors.
*
* N.B.: Each volume, or "No." as it is called, was printed in the year
* after the date of the meeting in which the paper was given. Thus
* "1893" here really means "given in 1893, published in 1894".
* Fisher #50; O'C #40


Dr. Abbate pacha
“(discussion at a meeting),”
Bull. Inst. Égypt. , series 3, , No. 4, 326–327 (1894).

* comment on Groff's paper
* Dr. Abbate pacha thinks it is an afterimage.
* His comment that "Newton . . . a été le premier à parler de ce
* phénomène intraoptique, tout en le rapportant au changement qui
* survient du rouge intense à la couleur complémentaire, le vert"
* seems to have given rise to a mistaken impression that Newton commented
* on green flashes, not just on afterimages.
* Dr. Abbate seems really to be the FIRST to believe the Verne "LEGEND":
* ". . . le charmant petit livre a J. Verne, Le Rayon Vert . . . . Ceux qui
* le consulteront, sûrement avec plaisir, trouveront comme récompense,
* outre la délicate illusion qui est produite par la peine d'observer
* attentivement le phénomène du rayon vert , un bonheur ineffable,
* mystique, qui s'y rattache, selon la vielle légende, née au pays des
* Highlanders, en Ecosse."
* O'C #1


W. Groff
“Note sur la plus ancienne observation d'un phénomène naturel ou astronomique,”
Bull. Inst. Égypt. , series 3, 4, 360–364 (1893).

* Groff's 2nd paper
* This is the second of two notes published as a single item; the first is
* on the Nile. These notes were additions to earlier papers.
* Fisher #51; O'C #41


W. Groff
“Quelques notes. III. Sur l'emploi des couleurs verte et bleue chez les anciens Égyptiens,”
Bull. Inst. Égypt. , series 3, 5, 179–181 (1894).

* Groff's 3rd paper
* This is a short note mentioning the green flash, but associating green
* and blue with the "other world" and death (via the setting of the Sun).
* [Note that the "III" here means it is the third note in this group, not
* the third in the GF series (though it is that as well).]


W. Groff
“Note sur le role joué par les couleurs dans les représentations chez les anciens Égyptiens,”
Bull. Inst. Égypt. , series 3, 5, 221–223 (1894).

* Groff's 4th paper
* This is a short note giving further examples.


(unsigned news item)
“Météorologie: Le rayon vert du soleil,”
Cosmos 30, 543–544 (1895).

* Popular summary of Groff's work
* in No.531, 30 Mars 1895


G. Daressy
“Note sur un signe hiéroglyphique,”
Bull. Inst. Égypt. , series 3, 5, 253–256 (1894).

* Daressy objects to Groff's view that the Egyptians meant to depict the
* green flash: "Est-il probable qu'en peignant ainsi le caractère
* hiéroglyphique, les Egyptiens aient eu l'intention de représenter
* le phénomène du rayon vert? Plusiers arguments me semblent indiquer
* que telle n'a pas été leur pensée."
* Unfortunately, his second reason is that "On sait que le rayon vert est
* un phénomène dû à une illusion d'optique . . . d'une durée
* infiniment courte . . . ." -- and, as "mon honorable confrère parle d'un
* rayon vert au lever du soleil" when Daressy thinks "Les conditions
* requises ne se trouvent plus réunies: l'astre étant plus brillant que le
* ciel, son apparition ne peut donner lieu à une impression lumineuse de
* couleur inverse . . . ." Worse, he asserts that "Ce ne peut donc être que
* par une prédisposition spéciale aux illusions d'optique, une sorte de
* daltonisme, que certaines personnes croient voir le disque émettre une
* lumière verte à son lever." [Talk about adding insult to injury!]
* "Si donc les Egyptiens n'ont pas représenté le rayon vert avec le
* soleil couchant, il est fort improbable qu'ils l'aient reproduit avec le
* soleil levant."
* Fortunately, his later arguments are sounder; he argues that the colors
* are chosen for religious rather than observational reasons, and that
* the "sunrise" symbol is derived from the rounded shape of a box lid.


Mrs. F. A. Steel
Red Rowans
(Macmillan, London, 1895), pp. 125, 161–165.

* MRS.STEEL's NOVEL
* "And Marjory, cresting the knoll, thought instantly that here, indeed,
* was a chance of the Green Ray. For ever since she had read Jules
* Verne's book the idea of this, the last legacy of a dying day, had
* remained with her fancifully. . . . Even if the legend was no legend, and
* the phenomenon simply a natural one, due to refraction, there must be
* something exhilirating in seeing that which other people had not seen
* . . . ." (p.125)
* "`I have often heard you mention this Green Ray, Miss Marjory, but I am
* not quite sure to what you allude.'
* `To a fiction of Jules Verne's, that is all,' put in Paul quickly.
* `Nothing of the sort; people have seen it,' corrected the girl,
* eagerly." (p.161)
* " `. . . it is like the Green Ray, something to dream about.'" (p.162)
* Fisher #140 says "Flora Annie Steel" but not read


W. Groff
“Le soleil levant: les couleurs du soleil d'après les anciens Égyptiens,”
Bull. Inst. Égypt. , series 3, 6, 243–262 (1895).

* Groff's 5th paper
* This is his long paper that discusses the green flash in detail.
* GOOD QUOTE:
* "En traitant des questions scientifiques on rencontre deux difficultés:
* si l'on se borne à annoncer les résultats des recherches, on court le
* risque d'être obscur, ou même d'être incompris; si l'on donne, en
* détail, des preuves à l'appui de chaque assertion, on se perd dans des
* digressions et on court le risque d'être inintelligible."
* Well said! So, "Peut-être la meilleure méthode est-elle, tout en
* donnant les résultats des recherches, d'indiquer brièvement sur quoi
* elles sont fondées, puis, si l'occasion s'en présente, de discuter plus
* en détail le sujet et de développer à l'appui des conclusions ce qu'on
* n'avait fait qu'indiquer." So Daressy's note gives him this
* opportunity.
* TERMINOLOGY:
* "Nous disons rayon , mais il serait plus correct de dire
* zone lumineuse , zone lumineuse rouge, orange, jaune, verte, bleue
* (indigo ou violet), qui s'appliquerait à la lumière (en apparence)
* émise par le disque du soleil à l'horizon, et que differentes personnes,
* sur une même méridienne observeraient simultanément."
* Regarding AFTERIMAGES:
* "Si l'on regarde un objet rouge ou rougeâtre -- le disque du soleil,
* par exemple, puis qu'on ferme les yeux, on peut bien voir la couleur
* complémentaire verte ou verdâtre, mais on distingue bien entre le
* phénomène d'optique et la couleur verte du disque du soleil apparaissant
* ou disparaissant -- la sensation est tout autre."
* The TURNING-AROUND EXPERIMENT (this seems to be the FIRST mention of it):
* "Si plusiers personnes A, B et C par exemple, vont constater la couleur
* du dernier rayon du soleil couchant, A regarde le soleil, B et C ont le
* dos tourné vers l'occident; quand A voit la dernière partie du disque
* disparaissant prendre la couleur verte (ou bleue); il dit à B et C de
* regarder; B et C, qui n'avaient pas regardé le disque tournent et peuvent
* bien voir le disque disparaissant de couleur verte (ou bleue), mais est-ce
* à dire qu'on ne voit jamais la couleur complémentaire au moment du
* coucher du soleil? je crois l'avoir constatée, mais la sensation est tout
* autre que celle produite sur l'observateur par la couleur réelle, ou
* apparent du disque."
* HISTORY:
* ". . . j'avais espèré trouver le phénomène étudiée et expliqué dans
* des ouvrages et avoir, ou la confirmation de l'hypothèse à laquelle
* j'étais arrivé, ou la vraie explication. Mais, malgré toutes mes
* recherches, je n'ai rencontré nulle part l'étude du phénomène du
* premier et du dernier rayon (zône lumineuse) du soleil à l'horizon sur
* le désert. Mais assurément le phénomène des couleurs du soleil à son
* lever et à son coucher sur le désert a dû être étudié et expliqué
* et j'espère pouvoir compléter plus tard les indications données ici à
* ce sujet: la seule indication directe que j'aie rencontrée jusqu'ici est
* dans Jules Verne, Le Rayon vert, p. 181 s. . . . " [p.248]
* LATITUDE effect:
* He also predicted that the flash would be visible much longer in the
* polar regions: "Dans le pays du nord (et même près di pôle sud) où
* l'atmosphère est très lourde, le disque du soleil surgit et disparaît
* très lentement, le phénomène des couleurs du soleil à l'horizon (si
* l'atmosphère est assez pure), doit être plus long et plus marqué que
* dans les pays plus près de l'équateur." [Note, p. 250]


E. Franceschi
“Les couleurs du disque solaire à l'horizon, dans de désert et sur la mer,”
Bull. Inst. Égypt. , series 3, 7, 271–277 (1896).

* Mostly about scattering, which the author calls "diffraction".
* Having (correctly) attributed the red color of the normal sunset to
* this, he then gets into the green (or blue) flash. The whole paper is
* purely qualitative argument from analogy -- the worst kind of sloppy
* thinking. "Relativement au rayon bleu, je pense pouvoir dire aujourd'hui,
* presque avec certitude, qu'il n'est engendré ni par la réfraction ni par
* la diffraction." He tries to observe the spectrum of the setting Sun, but
* it fades out on him; so he argues it can't be due to refraction, which
* would cause one color to be left at the end.
* "Pour démontrer que le phénomène du rayon vert ou bleu, etc., n'est
* pas engendré par la réfraction, on pourrait citer beaucoup d'autres
* faits, mais j'ai hâte de finir." Yeah, sure.
* "On peut donc conclure que le phénomène du rayon vert ou bleu est un
* phénomène intraoptique, et je crois qu'il tire son origine du contraste
* entre la couleur orangée ou jaune du Soleil et la couleur bleu du Ciel;
* ou encore, entre la couleur blanch de l'auréole qui entoure le Soleil et
* la couleur noirâtre du désert et de la mer." (!!!) All garbage!


W. Groff
“Étude archéologique (Suite et fin),”
Bull. Inst. Égypt. , series 3, 7, 279–301 (1896).

* Groff's 6th paper
* This is the continuation of the long paper of the previous year.
* Mostly, it supplies examples of the uses of blue and green coloring in
* ancient art and writing to support his inferences about the sunrise
* and the green flash, so that ". . . par ces mentions, représentations et
* usages nous avons été induits à reconnaître que le phénomène naturel
* ou astronomique, le plus ancien dont on possède des attestations sur des
* monuments originaux, est le phénomène du rayon vert ou bleu."


H. Ekama
“Das blaugrüne Flämmchen,”
Meteorol. Zs. 13, 427 (1896).

* a novice's useless report
* Fisher #40


Anonymous
“The blue sun,”
J. B. A. A. 7, 23 (1896).

* DOUBLE BLUE FLASH due to MOTION OF SHIP
* (report of Captain Salveson of the Royal Norwegian Navy)
* Is this the first GF report in JBAA? (probably)


C. T. Whitmell
“The Green Ray,”
J. B. A. A. 7, 514 (1897).

* EARLY CALCULATION SCALED TO HORIZONTAL REFRACTION (1/40)
* note change of year but not volume number
* Goodacre (1905) thought this was the first in JBAA; it is not.
* But it is almost certainly Whitmell's first paper.
* (Note a paper by the infamous "Leo Brenner" (Gopchevic) above this!)
* Fisher #146


A. Cornu
“Soleil,”
BSAF 11, 427 (1897).

* Comment by "M. le President" on Schmoll's observations of a deformed Sun
* This seems to be the first GF mentioned in BSAF.
* Fisher #30, O'C #196


E. Wölffing
“Blaugrünes Flämmchen,”
Met. Z. 14, 199 (1897).

* Ernst Wölffing's adds to Ekama's observation his own (useless)
* Fisher #162


W. Noble
“The green ray,”
J. B. A. A. 8, 46 (1897).

* Mostly citations of earlier works, esp. in Eng.Mech., and Ranyard's
* "Knowledge" article (1889)
* Note change in volume number but not year: JBAA changed volumes
* between the Sept. and Oct. issues.


E. Brown
“The green ray,”
J. B. A. A. 8, 46 (1897).

* GF refs. in Nature
* Observations of green *Sun* and refs.


R. T. Mallet
“The green ray,”
J. B. A. A. 8, 94 (1897).

* unidentified PLANET flash
* Fisher #83


C. T. Whitmell
“The green ray and the green sun,”
J. B. A. A. 8, 95–96 (1897).

* Mostly citations of earlier works
* O'C #153


A. Mee
“Lettre de M. Arthur Mee,”
BSAF 12, 45–46 (1898).

* Arthur Mee indulges in purple prose
* Mostly references to JBAA reports; requests observations from SAF members.
* O'C #246


A. Mee
“The green ray — Meteors in India,”
J. B. A. A. 8, 136–137 (1898).

* relay of a GF report from J.F.Young; not useful, and confuses additive
* and subtractive color mixing (cf. his BSAF paper above)
* Note change of year but not volume number
* Fisher #163, O'C #245


H. MacEwen
“The green ray,”
J. B. A. A. 8, 190 (1898).

* Not about green flash or "green ray" at all, but green *Sun*
* (Note a paper by the infamous "Leo Brenner" (Gopchevic) immediately above!)


C. T. Whitmell
“The green ray, and the Astronomical Society of France,”
J. B. A. A. 8, 190–191 (1898).

* Whitmell corrects confusion between additive and subtractive color
* mixing, and provides some references
* Letter is dated 24 Jan. 1898.


C. T. Whitmell
“The green ray,”
Leeds Astronomical Soc. Journal & Transactions 5, 63–64 (1897).

* Whitmell summarizes his earlier papers
* The item is dated 5 March 1898, but the Journal is for 1897.
* Thanks to Ray Emery for supplying this!


E. Franceschi
“Les couleurs du disque solaire à l'horizon, dans de désert et sur la mer,”
Ciel et Terre 19, 125–132 (1898).

* Seems to be an exact reprint of his 1896 paper in Bull.Inst.Egypt.


C. T. Whitmell
“The green ray, 1898,”
Leeds Astronomical Soc. Journal & Transactions 6, 92 (1898).

* Whitmell reports seeing the colored rims
* One of a series of "Miscellaneous" items, signed by Whitmell, p.93.
* (This seems to have appeared about mid-year, 1898.)
* Thanks to Ray Emery for supplying this!


H. de Maubeuge
“Sur une observation du rayon vert, au moment du lever du Soleil,”
C. R. 127, 453 (1898).

* SUNRISE observation of GF over the Sinai (cf. Escher, 1930)
* ". . . ce fait, que le rayon vert ne se voit pas toujours , même dans
* les meilleures conditions de pureté d'atmosphère."
* Fisher #89, O'C #240


de Maubeuge
“Rayon solaire de couleur verte,”
La Nature 26:2, No. 1322, 287 (1 Oct., 1898).

* Abstract of de Maubeuge's report to the Académie des Sciences
* This version reports "un rayon de couleur vert émeraude, qui a couvert
* un arc de 10° au-dessus de l'horizon." But the C.R. version merely
* says "Le sommet des montagnes était à environ 10° au-dessus de
* l'horizon." Probably this was a typo, and 1 degree was intended; in any
* case, the C.R. report makes this appear to be a normal flash, not a green
* ray. Cf. his 1886 letter, in which the altitude is 1° or 2°.
* O'C #239; Fisher #90


H. de Maubeuge
“Une observation du rayon vert, au moment du lever du Soleil,”
Revue Scientifique , series 4, 10, 471 (1898).

* Report of de Maubeuge's letter, in the account of "Académie des
* Sciences de Paris, 26 Septembre --- 3 Octobre 1898"
* O'C #241; Fisher #91


L. Libert
“Sur le rayon vert, extrait d'une Lettre de M. L.Libert à M. A.Cornu,”
C. R. 127, 792 (1898).

* Another remark on the shape that predicts the inf.-mir. flash:
* ". . . le spectacle est souvent accompagné de déformations du disque
* solaire, déformations des plus curieuses, imitant depuis la forme d'un
* ballon jusqu'à celle d'une ligne brisée."
* Fisher #72


[J]. Piot-Bey
“A propos du rayon vert,”
C. R. 127, 893–894 (1898).

* PIOT-BEY invokes Groff and de Maubeuge
* "Peu de contrées paraissent se prêter autant que l'Égypte à la
* manifestation du rayon vert."
* Fisher #117, O'C #106


Piot Bey
“Physique du Globe. — A propos du rayon vert,”
Revue Scientifique , series 4, 10, 755 (1898).

* An account of Piot-Bey's C.R. paper
* MIS-cited by F.K., who gave the year as 1915!
* Fisher #118 has it right


W. Prinz
“Photographies du soleil couchant,” in XXV Anniversaire de la Fondation, 1874-1898: Album Jubilaire
(E.Bruylant, Bruxelles, 1898), pp. 111–119.

* RED and VIOLET rims observed; photographs of flattened sunsets
* Drawings of typical sunset distortions
* O'C #109 -- he has the wrong date


(anonymous)
“Der grüne Strahl bei Sonnenaufgang,”
Prometheus 10, 95–96 (1898).

* A report of de Maubeuge's CR paper, propagating the 10° error
* and giving his initial as K., not H.


Hix
“Le rayon vert [Question 536],”
l'Intermédiaire de l'AFAS (Bulletin Mensuel) 3, 237 (1898).

* Hix sets off a thread with Question 536
* Brocard (below) says Hix refers to de Maubeuge's CR paper.
* AFAS = Association Française pour l'Avancement des Sciences


H. de Maubeuge
Naturwiss. Rundschau 13, 636 (1898).

* Report on de Maubeuge's CR 127, 453 paper; cited by Plassmann
* This is issue Nr. 48


J. Plassmann
“Correspondenz,”
Naturwiss. Rundschau 13, 672 (1898).

* Plassmann objects to de Maubeuge's explanation in Nr.48
* He cites the obvious objections: that solar protuberances would be
* seen easily at eclipses, and that the green would be transmitted far
* better high in the sky. He then suggests it might be due to selective
* atmospheric absorption, giving a very vague and arm-waving concept,
* and suggests "Fortgesetzte Spectralbeobachtungen".
* This is Nr. 51, 17.Dez. 1898 of Naturwissenschaftliche Rundschau,
* Wöchentliche Berichte über die Fortschritte auf dem Gesammtgebiete der
* Naturwissenschaften.


A. Schülke
“Correspondenz,”
Naturwiss. Rundschau 14, 16 (1899).

* An experienced observer supports the refraction explanation
* Comments on the items in Nr. 48 (de Maubeuge) and Nr. 51 (Plassmann)
* Fisher #134, not read


(editorial summary)
Naturwiss. Rundschau 14, 39 (1899).

* Report on Libert's letter to Cornu in CR 127, 792 (1898)
* This is issue Nr. 3


(editorial summary)
“Astronomische Mittheilungen,”
Naturwiss. Rundschau 14, 80 (1899).

* Report on Piot-Bey, Groff, and de Maubeuge
* This is issue Nr. 6


A. Guébhard
“Le rayon vert,”
l'Intermédiaire de l'AFAS (Bulletin Mensuel) 4, 19–20 (1899).

* Reply to Hix (Question 536)
* "L'explication, toute physico-physiologique, et, par conséquent, je le
* répète, purement subjective, est des plus simples."
* AFAS = Association Française pour l'Avancement des Sciences


Argile
“Le rayon vert,”
l'Intermédiaire de l'AFAS (Bulletin Mensuel) 4, 20 (1899).

* Reply to Hix (Question 536), citing Piot-Bey and Groff
* "De ses observations M. Piot-Bey conclut que le rayon vert est un
* phénomène absolument objectif." [ A nice juxtaposition! ]
* AFAS = Association Française pour l'Avancement des Sciences


Schlum.
“Rayon vert,”
l'Intermédiaire de l'AFAS (Bulletin Mensuel) 4, 38 (1899).

* Reply to Hix (Question 536), naming (but not citing) Cornu.
* AFAS = Association Française pour l'Avancement des Sciences


J. Garnier
“Le rayon vert,”
l'Intermédiaire de l'AFAS (Bulletin Mensuel) 4, 38–39 (1899).

* Reply to Hix (Question 536)
* A curious explanation: at sea, he will have the waves be the prism; but
* on land. "l'effet de prisme y est formé par la couche atmosphérique
* ondulée, plus dense, qui avoisine le sol . . . ."
* Perhaps we could regard this as a precursor to Fraser's INVERSION-WAVE
* suggestion?
* AFAS = Association Française pour l'Avancement des Sciences


H. Brocard
“Le rayon vert,”
l'Intermédiaire de l'AFAS (Bulletin Mensuel) 4, 39–40 (1899).

* Final reply to Hix (Question 536)
* This remarkable letter terminated the discussion; and no wonder:
* it contains a remarkably complete bibliography.
* Brocard cites all of Groff's papers in Bull.Inst.Égypt,
* 14 references in all.
* AFAS = Association Française pour l'Avancement des Sciences


(anonymous)
“Der grüne Strahl,”
Prometheus 10, 415 (1899).

* Another reference to de Maubeuge giving his initial as K., not H.
* This is mainly about the reports of Plassmann and Schülke, however.
* Probably this is the note cited in Prometheus 14, 48 (1903), though
* the page number given there is 425.
* Note that volumes overlap years!
* 29 March, No.494


(editorial)
“Das ``grüne Flämmchen'',”
Met. Zs. 16, 281 (1899).

* reviews of the works of Piot-Bey, Groff and de Maubeuge


A. Guébhard
“Le `rayon vert'; sa pure subjectivité,”
Séances de la Société Française de Physique , pp.41*–43* (1899).

* Guébhard's talk at the 21 Avril 1899 Séance de la Soc.Fr.de Physique
* Guébhard mis-cites "Trèves" in C.R. 101, 845, as well as citing
* Dr. Abbate Pacha, Groff, and Daressy. He seems never to have seen
* a GF. His paper is contested by Pellat (see below), who cites his own
* observations in 1887. Then Guébhard cites Franceschi back at him.
* These discussions were reviewed in Ciel et Terre later in 1899
* (see below).
* Note that these are in the section "Résumés des Communications"
* where the page numbers bear a superscripted asterisk, not the
* full-length papers printed with simple page numbers.
* [This volume contains papers by the Curies and by Becquerel on radium;
* papers by Cornu on optics, by Amagat on the equation of state; by
* Poincaré and by Deslandres; by Pellin and Broca on their
* constant-deviation spectrometer; etc.! What a wonderful time this
* must have been to be a French physicist!]


H. Pellat
[comment on Guébhard's talk]
Séances de la Société Française de Physique , p.42* (1899).

* Pellat refutes Guébhard
* "M.Pellat, tout en reconnaissant que le phénomène des couleurs
* consécutives peut jouer un rôle dans la vision du rayon vert,
* considère le rayon vert comme ayant une existence réelle."
* He then cites his own 1887 paper and observations.


C. Raveau
[comment on Pellat's comment]
Séances de la Société Française de Physique , p.43* (1899).

* Raveau's GREEN RAY BELOW the horizon
* "M.Raveau a observé un phénomène très différent de celui que
* décrit M. Pellat. Au moment où le bord supérieur du soleil venait de
* disparaître, il a vu la mer s'éclairer, pendant un temps très court,
* d'une lueur verte; cette lueur a occupé d'abord un petit triangle, ayant
* sa base sur l'horizon, à l'endroit où s'était évanouie la petite ligne
* lumineuse qui constituait la dernière partie visible du disque du soleil.
* La région éclairée s'est graduellement resserrée vers l'horizon et a
* disparu, l'ensemble du phénomène ressemblant à l'écoulement rapide
* d'un liquide lumineux."


V. Turquan
“Rayon vert et rayon rouge,”
B. S. A. F. 13, 444–446 (1899).

* long, sensible account; RED FLASH DISCOVERED
* ". . . nombreuses observations que j'en ai faites."
* "J'avais . . . été frappé par ce phénomène réputé extrèmement rare
* (si l'on en croit la romanesque idylle de Jules Verne) . . . ."
* "Piqué au vif, par ces observations fréquentes et faciles . . . j'ai
* exploré avec un assez fort groissement, l'extrême bord apparent de
* l'astre radieux et j'ai eu la satisfaction de constater, au moment
* où le point opposé du limbe du Soleil quitte la Terre, un
* rayon rouge fort vif ."
* "Avec une lunette, il est facile de constater le rayon rouge et orange
* du dessous du limbe solaire, lorsque celui-ci prend contact, ou bien
* perd contact (au lever) avec l'horizon."
* "Le rayon vert est un simple phénomène de réfraction et il doit se
* produire aussi bien pour la Lune et pour les étoiles que pour le Soleil,
* aussi bien au lever qu'au coucher d'un astre suffisamment brillant, et
* le rayon rouge pourra être observé, avec certaines précautions; ces
* deux rayons complémentaires sont observables en montagne, aussi bien
* qu'en plaine et qu'en mer; . . . ."
* (Unfortunately, he then tries to connect the red ray with the color of
* lunar eclipses.)
*      This is almost identical to Turquan's note in Revue Scientifique (4),
* Vol. 11:1, No. 4, pp. 122-123 (28 Jan. 1899), which evidently appeared
* before the BSAF version.
* Fisher #143, O'C #143


F.-A. Mavrogordato
“Le rayon vert se réflète-t-il sur les nuages?,”
B. S. A. F. 13, 446–447 (1899).

* Useless nonsense; contrast colors
* O'C #85


J. J. T. Chabot
“Ueber die Grünstrahlung beim sogenannten Sonnenuntergang,”
Met. Zs. 16, 425–427 (1899).

* Wordy description of mock-mirage flashes. He seems to think some of
* this has to do with the Sun's atmosphere. Nice use of colored filters to
* bring out the red and green limbs.
* Early mention of WAVELENGTH DEPENDENCE of LIMB DARKENING: he knows the
* limb is redder than the center. He also invokes atmospheric dispersion,
* but apparently is flummoxed by the mock mirages.; vague references to
* the "black drop" at Venus transits, and atmospheric scattering.
* J.J.Taudin Chabot writes German as if it were French.
* See corrections of typos here in Met.Z.16,p.523. (Fisher #19)
* See corrections of typos here in his 1900 paper, Met.Z.17,p.335.
* Fisher #18


Kelvin
“Blue ray of sunrise over Mont Blanc,”
Nature 60, 411 (1899).

* LORD KELVIN's incredible estimate
* ". . . in an instant I saw a blue light . . . which, in less than the
* one-twentieth of a second became dazzlingly white . . . ."
* See further discussion in 1910 !!
*      This is in the 31 August issue.
* An Erratum appeared in the 1 Sept. issue, saying that 5 o'clock should be
* 4 o'clock, and that "of sunrise" should be added after "light" in line 7.
* Fisher #64, O'C #69


(editorial note)
“Blauen Lichtstrahl bei Sonnenaufgang,”
Naturwiss. Rundschau 14, 515–516 (1899).

* Report on Kelvin's letter to Nature
* This is issue Nr. 40


anonymous report
“Le rayon vert,”
Ciel et Terre 20, 425–426 (1899).

* (This is a report of the discussion at a meeting of the French
* physical society, involving Guébhard, H. Pellat, and Raveau.)
* "Guébhart" is Paul Émile Adrien Guébhard, who had recently
* published several papers on vision, and as a medical man was
* predisposed to a physiological theory of green flashes.
* Guébhart's "bibliographie complète dans un mémoire
* présenté à la Société française de physique" is probably no
* more than the references cited in the "Séances" (1899).
* Is Raveau's observation that "la mer s'éclairer, pendant un temps
* très court, d'une lueur verte" a green fog below eye level?


R. S.
“Ueber den grünen Sonnenstrahl,”
Die Natur 49, 274 (1900).

* Seems to be a summary of Groff's work; all derivative, anyway (no refs.)


Lebrison,Gérard,Le Blanc,A. O'Langer,Picard,G. Delcroix Legrand
“Le rayon vert,”
B. S. A. F. 14, 236 (1900).

* EARLIEST VENUS GREEN FLASH?
* passengers on board the "Saint-Laurent"
* part of O'C. #303


Lebrison,Gérard,Le Blanc,A. O'Lanyer,Picard,G. Delcroix Legrand
“Sur le rayon vert,”
Revue Scientifique , series 4, 13, 406 (1900).

* passengers on board the "Saint-Laurent"
* Note discrepancy in 5th passenger's name.
* 31 Mars issue
* Fisher #176
* part of O'C. #303


(editorial report)
“Vermischtes,”
Naturwissenschaftliche Rundschau 15, Nr. 20, 259 (1900).

* translated from the Revue Scientifique account
* part of O'C. #303


J. Garnier
“Sur le rayon vert,”
Revue Scientifique , series 4, 13, 505 (1900).

* Jules Garnier refers both to the St.Laurent report and his own in 1899
* This time he omits mentioning the waves; only atmospheric refraction
* forms "un spectre . . . devant l'oeil de l'observateur, lequel ne retient
* des sept couleurs de ce spectre que le vert, qui est la couleur la plus
* intense . . . ." [Seems to be the first to claim that green is seen
* because it is "brightest" to the eye!]
* 21 Avril issue


anon. [H. H. Turner]
“From an Oxford Note-Book,”
Obs. 23, 297–300 (1900).

* H.H.Turner sees a GF at the May 23 eclipse in Algiers -- see item on p.300


J. J. T. Chabot
“Die grüne Strahlung,”
Meteorologische Zeitschrift 17, 335–336 (1900).

* J.J.Taudin Chabot, thinking the "green radiation" has something to do
* with the Sun or Moon, observes a partial solar eclipse without result.
* Footnote corrects his earlier paper in Met.Z.(1899)
* Fisher #20


J. J. T. Chabot
“Grünstrahlung,”
Meteorologische Zeitschrift 17, 426 (1900).

* cites his earlier paper in Met.Z.(1899)
* As the Sun followed the slope of a mountain, "blieb dieses Mal eine
* grün leuchtende Stelle nahezu 30 Sekunden lang sichtbar"
* O'C #191; Fisher #21


(7 passengers on the Saint-Laurent)
“Grüner Strahl beim Venus-Untergang,”
Meteorologische Zeitschrift 17, 426 (1900).

* abstract of the 7 passengers' account in Revue Scientifique
* Fisher #177
* part of O'C. #303


E. E. Markwick
“Observation of the `Green Ray',”
JBAA 10, 364 (1900).

* not useful
* Col. E. E. Markwick, F.R.A.S.
* Fisher #84


F. S. Archenhold
“Die Beobachtung der totalen Sonnenfinsternis am 28. Mai 1900 in Bouzareah bei Algier,”
Das Weltall 1, 2–7 (1900).

* Not a very useful observation; only a couple of sentences on p.5
* This is the lead article in Vol. 1, No. 1 of "Das Weltall"


C. T. Whitmell
“The green flash,”
JBAA 11, 75 (1900).

* WHITMELL's first land-horizon flash (2nd GF)
* "Green Flash is a more suitable name than Green Ray."
* Fisher #147


C. T. Whitmell
“The green flash seen from Woodhouse Moor, Leeds,”
Leeds Astronomical Soc. Journal & Transactions 8, 107 (1900).

* The same item, cut down slightly, and citing his vol. 5 note.


Anonymous
“Sur le rayon vert,”
B. S. A. F. 14, 508–509 (1900).

* reference to previous year's Intermediaire de l'Assoc.fr. pour
* l'avancement des sciences


J. Janssen
“Note sur les travaux exécutés a l'observatoire du sommet du Mont Blanc en 1900,”
Annuaire du Bureau des Longitudes pour l'an 1901, F.1–F.10 (1901).

* JANSSEN reports Hansky's GF on Mont Blanc, and adds his own
*      Aleksey Pavlovitch Hansky was an assistant at Pulkovo who spent
* some time at the Meudon Observatory. He specialized in photographing
* the solar surface, and monitoring its activity. He seems to have been
* the first person to notice the relation between the shape of the corona
* and the sunspot cycle.
*      Hansky is quoted as describing a morning flash, with the textbook
* explanation; but modified: ". . . s'il existe beaucoup de vapeur d'eau,
* il ne reste du spectra que le partie rouge et une faible bande dans le
* vert ; mais, si l'air est très sec, la partie verte du spectre est
* intense et c'est elle que nous voyons au premier moment de l'apparition
* du Soleil, quand le spectre passe devant l'œil de l'observateur."
* To this, Janssen adds: "Cette explication est exacte, mais il faut
* remarquer que c'est encore plus l'absence de brumes que de vapeur qui
* importe à la production du phénomène, car j'ai vu très nettement le
* Rayon vert dans le Pacifique."
* (Presumably this was during his 1883 trip to the Carolines -- too late
* to have influenced Jules Verne.)
*      At the end of this volume are several scientific notes in sections
* denoted by capital letters; this is section F. The Hansky quotation
* is on pp. F.7 and F.8. The index is section I.
*      Reprinted in Janssen's works, Vol. 2, pp. 544-550 (see pp. 548-549)
* in 1930. A slightly edited extract from Hansky's account was also
* reprinted in 1907 by Radau (q.v.).
*      Available at Gallica.  The volume is a sort of combination of the
* Rubber Bible and the Nautical Almanac, with the World Almanac thrown
* in: there are the tables of weights and measures (and currencies) of
* various countries; conversions among the Julian, Gregorian, Moslem and
* French Revolutionary calendars, as well as a variety of physical and
* chemical tables.


H. Krone
“Der grüne Strahl kurz vor dem Untergang der Sonne,”
Eders Jahrbuch für Photographie und Reproduktionstechnik 15, 12–17 (1901).

* a badly confused account; thinks "actinic" rays change the response of
* the eye?
* O'C #74


J. J. T. Chabot
“Grünstrahlung,”
Met. Z. 18, 90 (1901).

* PRIORITY DISPUTE; no GF info
* J.J.Taudin Chabot has a priority fight with T.J.J.See over the use of
* colored glasses:
* ". . . erlaube ich mir die Anfrage, ob sie durch eine redaktionelle Notiz
* auf meine Priorität gegenüber Professor Thomas J. J. Se [sic], U.S.Naval
* Observatory, Washington, in Sache der Einschaltung selektiv absorbirender
* Medien zur Verdeutlichung der Beobachtung am Fernrohr hinweisen wollten."
* (and cites his paper in Met.Z.16,425(Sept.1899).)
* In fact, both were scooped by Stampfer (1851).


J. J. T. Chabot
“Grünstrahlung bei Sonnenaufgang,”
Met. Z. 18, 181 (1901).

* J.J.Taudin Chabot uses his filter method to examine colored rims, and
* finds that a smoke plume 450m away does *not* have colored edges.
* He seems not to be a "morning" person:
* "Der häufigen Beobachtung des `Sonnenaufgangs' . . . stellen sich
* Schwierigkeiten verschiedener Art in den Weg, deren nicht geringste,
* vielleicht indessen nur individuellen Charakters die ist, dass zu jener
* im Allgemeinen ziemlich frühen Tagesstunde die persönliche Schärfe
* des Wahrnehmungsvermögens sich nicht immer schon in vollem Umfange
* eingestellt hat . . . ."
* O'C #192; Fisher #22


W. H. Julius
“Le rayon vert,”
Arch. Néerlandaises des sciences exactes et naturelles 6, 385–389 (1901).

* EARLY CALCULATION SCALED TO HORIZONTAL REFRACTION (1/200 = 10" = 2/3 s)
* Anomalous dispersion proposed: cf. the Julius file (far below).
* ". . . the physicist of the Committee, Dr. W.H.Julius, of Utrecht. . . "
* (from Nijland's account of the Expedition to Sumatra, Amsterdam, 1903)
* (Nijland was the Sec.-Treas. of the Eclips-Commissie; part of his report
* is on the Web at http://www.exploratorium.edu/eclipse/1901.html .)
* Julius proposed anomalous dispersion as the explanation of everything
* in sight: the solar limb, prominences, sunspots, stellar spectra. . . .
* (see J. Hartmann, A.N.175, Nr.4197, 341-368 (1907) for refutations.)
* Fisher #61 indicates this volume is in series 2.
* O'C #64 agrees


S. Barker
“The green flash at sunset,”
JBAA 12, 32 (1901).

* not useful
* Fisher #6


A. Senouque
“Lumière zodiacale,”
BSAF 15, 256 (1901).

* not useful; only half a sentence is devoted to GF
* The page number is mis-printed without the "2", explaining the wrong
* reference to p.56 given by O'Connell, who also mis-copied the name.
* Why did he bother with such trivia and yet reject (as he says) 200
* references?
* O'C #282


J. Franklin-Adams
“The green flash at sunset,”
M. N. 61, 484–485 (1901).

* John Franklin-Adams sees a GF like Baily's beads [WAVES!]
* ". . . the phenomenon here described may have been caused by the waves of
* the sea taking the place of the mountains of the Moon. The evening was
* calm, and the waves not large enough to make this possible unless images
* of the waves were thrown up by a mirage state of the atmosphere. I have
* twice seen from a steamer's deck mirage images of the sea waves, about
* a mile distant, thrown up sufficiently to entirely hide the horizon."
* N.B.: We often see such an effect here; I have several pictures of it.
* cf. Evans, 1914.
* This is the May 1901 paper mentioned in Admiral Maclear's 1906 letters.
* Caution: M.N. volumes do not coincide with years here (Nov.1901).
* Fisher #1


J. Franklin Adams
“The green flash at sunset,”
JBAA 11, 367 (1901).

* JBAA abstracts the above


J. Franklin-Adams
“The green flash at sunset,”
English Mechanic 73, 422 (1901).

* This appears to be a reprint of J.F.-A.'s note in M.N.
* No.1892, June 28, 1901


F. R. A. S.
“The green flash at sunset [44881],”
English Mechanic 73, 425 (1901).

* "F.R.A.S." comments on Franklin-Adams's observation;
* he is troubled by the "Baily's beads" allusion, taking it literally.
* Note that the heading is a sub-head within a long letter of many parts
* that begins on p.424; the main title is "Greenwich Observations".
* No.1892, June 28, 1901


G. McKenzie Knight
[letter 44917]
English Mechanic 73, 449–450 (1901).

* The "BILIOUSNESS" tale:
* Only the last sixth of this letter deals with the notorious GF story:
* The full heading is:
* "Sunspots and terrestrial magnetism; To ``F.R.A.S.'' -- the green flash
* a sign of biliousness"
* "I was much interested in ``F.R.A.S.'s'' observations on the ``Green
* Flash.'' I have repeatedly seen this very curious phenomena [sic] ;
* but really, I have never taken any notice of it, and it is the first time
* I have observed it mentioned in print. I remember it struck me most
* vividly when I was staying at Torquay, and I communicated my ideas to a
* medical friend, who promptly said I was suffering from biliousness, and
* there and then prescribed. I remember I looked again for it the day after
* I had taken some medicine, and my friends saying that I should not see it
* again -- at all events for some time to come -- came true, and I had
* forgotten all about it until I saw the remarks of your valuable
* correspondent."
* No.1893, July 5, 1901
* O'C #71


"Treadle"
[letter 44918]
English Mechanic 73, 450 (1901).

* Langford [44949] identifies "Treadle" as C. Mostyn, from his letter in
* Nature 44,352(1891). Cf. similar remarks in his 1906 Knowledge paper.
* I regard this identification as secure.
* EXPERIENCED: "Having been much at sea in former years, I have had many
* opportunities of observing this very beautiful and interesting
* phenomenon. . . . many scores of observations . . . ."
* EARLY RECOGNITION of the Type A sunset and mirage effects:
* "I have noticed that a particular form of refraction was most favourable
* to its appearance. When the sun, on approaching the horizon, assumed
* curious shapes as of a goldfish-globe or a pear, then there would nearly
* always be a green or bluish flash at the moment of disappearance. On the
* other hand, when the sun assumed the shape of an oval with major axis
* horizontal, the flash did not appear."
* He correctly diagnoses Franklin-Adams's "beads": "I fancy they must be
* caused by ripples on the sea-surface at the horizon. . . ."
* His triple flash was seen from "the old Macquarie , now a training-ship
* for officers under Lord Brassey's scheme."
*       Edward Gilbert finds that this trip from London to Sydney was from
* October 28, 1890 to January 29, 1891, and that the ship was built in
* 1875 as the Melbourne ; renamed Macquarie in 1888, and renamed again
* to Fortuna in 1904, before being broken up in 1953. Gilbert also says
* that the pseudonym "Treadle" was taken from Mostyn's interest in treadle
* bicycles.
* No.1893, July 5, 1901
* Fisher #104


"F. R."
[letter 44919]
English Mechanic 73, 450 (1901).

* Completely irrelevant remarks that have nothing to do with green
* flashes, as Langford [44949] soon makes clear.
* No.1893, July 5, 1901


E. Smith
“The green (or red) flash at sunset [44947],”
English Mechanic 73, 474 (1901).

* The citation of letter 44819 of "T.R." actually means 44919 of "F.R."
* -- an example of the numerous typos in the E.M.'s letter columns.
* "But to some eyes it was red , not green."
* No.1894, July 12, 1901


Langford
[letter 44949]
English Mechanic 73, 474 (1901).

* Langford identifies "Treadle" as Mostyn, and implicitly chastises "F.R.".
* He succinctly summarizes the subject in 1 paragraph!
* No.1894, July 12, 1901


C. T. Whitmell
“The green flash [letter 45130],”
English Mechanic 74, 86 (1901).

* Whitmell's 1-sentence announcement of a cloud-top flash
* No.1902, Sept. 6, 1901
* Fisher #150


C. T. Whitmell
“The green flash,”
Leeds Astronomical Soc. Journal & Transactions 9, 100–101 (1901).

* Whitmell's full report of the above observation
* Evidence of VISUAL ADAPTATION:
* "I also noticed that, before sunset, the decreasing segment of the
* setting Solar disc, originally yellow, became gradually whiter in tint.
* Mr. Scriven Bolton, who was with me, also observed the flash. We both
* used opera-glasses."
* (This seems to be vol. 9, 1901).
* Thanks to Ray Emery for supplying this!


W. H. Pickering
“The green flash at sunset,”
M. N. 61, 629 (1901).

* PICKERING's original GF note, "confirming" Franklin-Adams's observation
* -- but without the beads!
* Cited as a "minor publication" in HCO's Annual Report for 1901/02, p.15
* Caution: M.N. volumes do not coincide with years here (Nov.1901).
* Fisher #113


W. H. Pickering
“The green flash at sunset,”
JBAA 12, 83 (1901).

* JBAA abstracts the above


W. H. Pickering
[Vermischtes]
Naturwissenschaftliche Rundschau 16, 648 (1901).

* Naturwiss.Rundschau abstracts Pickering's report
* Nr. 50
* Fisher #115


W. H. Pickering
“Additional note on the green flash,”
M. N. 62, 85 (1901).

* PICKERING's "optical illusion" paper
* Caution: M.N. volumes do not coincide with years here (Nov.1901).
* "The effect, I presume, is subjective, and merely a case of
* complementary colours . . . . The fact that my assistant could not see it at
* sunrise . . . confirms this view."
* Fisher #116, O'C #105


A. A. Nijland
“Over den ``groenen straal'' en eenige andere hemelsverschijnselen,”
De Zee 24, 60–68 (1902).

* This is the NIJLAND paper that prompted HAVINGA to observe!
* EXCELLENT ADVICE to amateur observers!
* ". . . Prof. W.H.Julius and J.H.Wilterdink, and me, members of the Dutch
* expedition to observe the total solar eclipse of 18 May near Padang . . . "
* Early use of the term "GREEN SEGMENT" (it was first used by Winstanley):
* "This green segment , that I have observed more, though not so
* brilliant, is badly conveyed by the name ``flamelet''."
* ALBERT ANTONIE NIJLAND


A. A. Nijland
“Ueber den grünen Strahl bei Auf- und Untergang der Sonne,”
A. N. 158, 93–96 (1902).

* 530 nm given twice
* double flash observed "Durch die Bewegung des Schiffes". (WAVES)
* (For the benefit of people unfamiliar with Astronomische Nachrichten ,
* I should point out that its columns are numbered, rather than pages.)
* Fisher #107


(Anonymous abstract)
“The green flash,”
JBAA 12, 143 (1902).

* JBAA abstracts the above


T. W. Backhouse
“The green flash,”
M. N. 62, 430–431 (1902).

* DISPERSION proposed (!) -- red and green rims seen
* Abstracted in JBAA 12, 299 (1902), which also mentions Hills (next).
* (I file the JBAA summary after Hills, some months too early.)
* See his obit. in M.N. 81, 245 (1921), which mentions his GF observations.
* He was VP of the RMS in 1918 and 1919.
* Fisher #4


E. H. Hills
“The green flash,”
M. N. 62, 431–432 (1902).

* BLUE and VIOLET seen after green with 12x binocular
* ". . . the narrowing segment . . . is first seen to turn green at its two
* extremities; the green colour then appears to run inwards until the whole
* area of the segment appears coloured. . . . after . . . about a second the
* green fades away and is momentarily replaced by a blue or blue-violet.
* The latter is immeasurably more feeble than the green . . . ."
* Major E.H.Hills, R.E.
* Fisher #57, O'C #51


A. Schmidt
“Der erste under der letzte Sonnenstrahl,”
Deutsche Revue 27, 108–110 (1902).

* Schmidt discusses Julius's chromospheric and GF theories, both based on
* anomalous dispersion. It seems the English word "FLASH" has led to this
* confusion (cf. "flash spectrum"). Schmidt compares Julius's theories to
* his own for the solar atmosphere, involving critical refraction --
* essentially, an early example of Hasse's ``Kimmfläche''. Schmidt doesn't
* accept Julius's chromospheric model, but seems favorably inclined toward
* his GF theory.
* cf. the shorter version in Met.Z. 19, 337 later in the year (below)
* Fisher #131


A. R[iccò]
“Photographies des déformations du soleil couchant – Nota del Prof. W. Prinz dell'Osservatorio Reale Belga a Uccle (Bruxelles),”
Mem. Soc. Spett. Ital. 31, 36–39 (1902).

* Ricco quotes from, and comments on, Prinz:
* He seems to draw no distinction between the green rim and "punto verde".
* the 2 photos reproduced show flattening, not distortion
* WARNING: the nutty librarians seem to catalog this journal as
* "Società Astronomica Italiana. Memorie" -- though nothing of
* the sort appears in the published volumes! (That's because the Italian
* Astronomical Society took it over later.)
* O'C #118


(W. H. Pickering)
“Zur meteorologischen Optik,”
Met. Z. 19, 282 (1902).

* Belated account of Pickering's *first* paper in M.N.
* Fisher #114


W.-H. Julius
“Le rayon vert,”
Ciel et Terre 23, 209–215 (1902).

* JULIUS republishes his SCALED REFRACTION calculation
* (This appears to be an exact reprint of the 1901 paper)
* NOTE: this appears to be Julius's last GF publication.
* O'C #65; Fisher #63


H. Keatley Moore
“Reply [to Query No. 69],”
J. B. A. A. 12, 218 (1902).

* Keatley Moore replies to Query No. 69
* and refers to Col. Markwick (see above, 1900)
* He believes it is an afterimage: "The ghosts persist with me about 2
* seconds, which is also the time the green flash lasted."
*      Incorrectly cited by Mulder (1922), whose error was copied by
* Feenstra Kuiper (1926). Fisher has it right.
* Fisher #102


H. Keatley Moore
“The green flash,”
J. B. A. A. 12, 248 (1902).

* Keatley Moore receives Whitmell's response (below)


C. T. Whitmell
“The green flash,”
J. B. A. A. 12, 248–249 (1902).

* Whitmell counters Moore with earlier references
* Fisher #148


H. R. Mill
“The voyage southward of the "Discovery". I. London to Madeira,”
Geographical J. 19, No. 4, 417–423 (April, 1902).

* HUGH ROBERT MILL's first GF report: green, blue, violet
* ". . . there was only one night on which the sunset was sufficiently clear
* to show the interesting phenomenon of the green ray. This was on Sunday,
* August 11, when, as the upper edge of the sun touched the sea-horizon, a
* beam of yellow light, almost instantaneously passing through green to blue
* and dying away in violet, was distinctly visible. It is remarkable that
* so few observers have noticed this striking appearance, which must [sic]
* be visible every time the unclouded sun dips beneath a sharp horizon."
* (pp. 418/419) -- so he evidently believed the "textbook" story.
*      This was the Antarctic expedition organized by the Royal Geographical
* Society in 1901 and led by Robert Falcon Scott. Mill notes on p. 422
* that "Lieut. E. H. Shackleton undertook the salinity determinations, and
* proved a very apt and enthusiastic pupil" -- a prophetic remark that
* reminds me of Picard's remark (1680) about Römer.
* A nice halftone photo of this sailing ship is on p. 421.


C. T. Whitmell
“The green flash and the red,”
Yorkshire Post , 9 (28 April, 1902).

* RED FLASH discovery? [No; it appears Turquan (1899) beat him to it.]
* "It occurred to me some time ago that, under suitable conditions, there
* might be seen at sunrise and at sunset not only a green flash but also a
* red flash. . . ."
*      "In the belfry of the Wesleyan Chapel, on the west side of Woodhouse
* Moor, there are narrow horizontal openings, through which, at certain
* times, the setting sun can send his rays to an observer at the large
* band stand, about 300 yards away.
*      "On Saturday, 26th April, between 7 1/4 and 7 1/2 p.m., I was so
* exceptionally fortunate as to observe through the openings no fewer
* than three green and three red flashes."
* (Monday, 28th April, 1902; col. 4.)


C. T. Whitmell
“The green flash and the red,”
J. B. A. A. 12, 289–290 (1902).

* Reprint of the above item, with minor differences in editing:
* "In the belfry of the Wesleyan Chapel, there are narrow horizontal
* openings, through which, at certain times, the setting sun can send
* his rays to an observer at the large Band stand, about 300 yards away."
*      An account of Whitmell's talk appears in Obs. 25, 226 (1902).
* Fisher #149, O'C #296


C. T. Whitmell
“The green flash and the red,”
Leeds Astron. Soc. Journal & Trans. 10, 77–79 (1902).

* The original manuscript of the above, printed in full, it appears. The
* JBAA version is improved by editing. But this version has appended the
* text of Prof. E. E. BARNARD's letter from Mt. Hamilton, in addition to
* an observation of a red flash due to cloud, as suggested by Whitmell.
* Barnard, in his letter, says "I have seen the phenomenon (at sunset),
* many, many times in the past fifteen years." (But, clearly, never at
* sunrise.)


C. T. Whitmell
“Reply [to Query No. 72],”
J. B. A. A. 12, 294 (1902).

* Whitmell answers Query No.72, adding further evidence


Mr. Backhouse
“The green flash,”
J. B. A. A. 12, 299 (1902).

* summary of Backhouse's M.N. paper in March


Anonymous
“(item under "General Notes"),”
Pub. A. S. P. 14, 118 (1902).

* A summary of W. H. Pickering's M.N. report
* This is the item mentioned by Katherine Bracher in 1992. It mentions
* Kelvin's observation "three years ago", and that "Professor Nijland, of
* Utrecht, Holland, has lately seen it several times at sea." As it says
* that ". . . Pickering calls attention . . . to what he names the `green flash'
* at sunset", one can see how the notion arose that WHP had named it.
* "Observations may be made with the naked eye, though a small telescope
* or opera-glasses will be found advantageous."


A. A. Nijland
“Ueber den grünen Strahl bei Auf- und Untergang der Sonne,”
Met. Zs. 19, 335–336 (1902).

* reprinted from A.N., with typos & other editorial changes added!
* Juli 1902 issue
* Fisher #108, O'C #255


M. Jautz
“Der ``grüne Strahl'' der untergehenden Sonne,”
Met. Z. 19, 336 (1902).

* a series of GF papers followed Nijland's:
* First, a simple visual observation of a few sec. duration.
* "Frau Marie Jautz aus Wien in St. Andra" bei Triest" sees a classic
* inf.-mir. flash:
* ". . . verwandelte sich der noch sichbare Rest derselben in ein flaches,
* grünes Scheibchen, welches auf der Meeresoberfläche zu schwimmen
* schien." [nice observation of the mirage!]
* Fisher #175 ?


J. J. T. Chabot
“Der ``grüne Strahl'',”
Met. Zs. 19, 337 (1902).

* J.J.Taudin Chabot's attempt to observe a GF at a partially-eclipsed
* sunrise was clouded out.
* Fisher #23


(Schmidt)
“Die Theorie des ``grünen Strahls'',”
Met. Zs. 19, 337–338 (1902).

* Condensed version of Schmidt's Deutsche Revue paper in April (above)
* Only the first half of Schmidt's D.R. paper is quoted here; the part
* comparing his solar theory with Julius's is omitted.
* Fisher #132


A. S. Herschel
“Heights of sunset after-glows in June, 1902,”
Nature 66, 294–296 (1902).

* Alexander Herschel's GF over cumuli (see footnote, p.294)
* Cites Hopkins (1883) and Swan.
* July 24 issue
* Fisher #56


G. Verhas
“Phénomènes d'optique atmosphérique,”
BSAF 16, 163 (1902).

* BOILING associated with an inferior-mirage flash
* O'C #293


J. Garcin
“Déformation du disque solaire,”
La Nature 30:2, 162–163 (1902).

* Brief review, citing Biot's text, Krifka/Sterneck, and Arctowski
* (Properly belongs in the "distorted sunsets" file; but kept here, as it
* elicited the following GF observations)
* (#1525, 16 Août 1902)


Em. Roger
“Un curieux phénomène d'optique,”
La Nature 30:2, 251 (1902).

* Seems to be a GREEN FOG observation
* ". . . tout à fait à l'horizon même, l'épais rideau de nuages noirs et
* pluvieux ainsi que le fond éloingé du paysage prirent une teinte
* verdâtre bien prononcée pendant quelques instants seulement,
* comme s'ils eussent été éclairés par la lumière électrique."
* (#1530, 20 Sept. 1902)


C. T. Whitmell
“Green ray or flash [reply to query 285],”
English Mechanic 76, 154–155 (1902).

* Whitmell corrects "H.P.", and argues TERMINOLOGY:
* "The term ``green ray'' is a bad one. ``Green flash'' is much better.
* . . . There is nothing like a ``ray.''"
* "On August 24 I witnessed three green flashes in succession, as the
* sun's tip sank behind two strips of clouds and the horizon."
* No.1957, Sept. 26, 1902


"Sigma"
“Green ray [reply to query 285],”
English Mechanic 76, 155 (1902).

* "Sigma" corrects "H.P." in a strange way
* "What ``H.P.'' describes is not the green ray, but only a dispersion
* effect among the clouds."
* Eric Hutton has identified "Sigma" (Mr Sprague) [ref. No. 3105 p326]
* No.1957, Sept. 26, 1902


"A Fellow of the Royal Astronomical Society"
[letter 200]
English Mechanic 76, 166 (1902).

* FRAS corrects "H.P"'s crepuscular-ray observation (query 285, p.135)
* One paragraph headed "The Green Ray" in a much longer letter
* No.1958, Oct. 3, 1902


C. T. Whitmell
“The green flash [letter 285],”
English Mechanic 76, 175 (1902).

* Whitmell takes "Sigma" to task:
* "The letter by ``Sigma'' (p.154) affords an excellent illustration of
* the danger of a writer dealing with a subject about which he is ignorant."
* No.1958, Oct. 3, 1902


(editorial report)
“Déformations du disque solaire,”
La Nature 30:2, 302 (1902).

* Refers to Prinz's paper (1898) and Riccò's work
* (#1533, 11 Oct. 1902)


L. Libert
“Déformations solaires et rayon vert,”
La Nature 30:2, 332 (1902).

* long observations of "green ray" [probably visual illusion; see below]
* "Le 13 mars 1899, il a duré 112 secondes 1/2, et le 14 mars 1899, 364
* secondes. A cette dernière date, beaucoup de personnes ont été
* frappées de la coloration verte si prolongée. Le 23 mars de cette
* année, j'ai encore revu le phénomène pendant 107 secondes.
* . . . Dans l'ordre de décomposition apparaìt d'abord le rouge, puis
* l'orangé et le jaune et enfin le vert."
* cf. Cornsweet et al. in VISION file for probable explanation (BLEACHING).
* (#1535, 25 Oct. 1902)
* Fisher #71, O'C #80


"Meteor"
“The weather in the British Isles in October, 1902 [439.] The `green flash',”
English Mechanic 76, 317 (1902).

* ADAPTATION?
* ". . . the flash was very distinct, but seemed to my vision to be such a pale
* green as to be almost white."
* No.1965, Nov. 21, 1902
* Fisher #96


(editorial)
“Deformationen der Sonnenscheibe und grüner Strahl beim Sonnenuntergang,”
Met. Zs. 19, 566 (1902).

* a 3-sentence abstract of Libert's La Nature 30:2, 332 (1902) paper,
* calling him "Lucian" (instead of Lucien) Libert;
* also mentions the original report in No.1525, (wrong) p. 161 (copied
* from Libert)
* also mentions Garcin's paper on p. 161 in Aug. 1902 (not naming Garcin).
* Dez. issue


F. Exner
“Der Grüne Strahl der untergehenden Sonne,”
Meteorol. Zs. 20, 42 (1903).

* WHITE, then GREEN FLASH -- evidence for ADAPTATION
* "Da ich den Sonnenuntergang mit Rücksicht auf das eventuell auftretende
* Phänomen erwartete . . . ."
* Clearly an inf.-mir. flash: ". . . den ganzen Tag über herrschte leichte
* Bora . . . ."
* Fisher #45


(editorial report)
“Der grüne Strahl,”
Prometheus 14, 48 (1903).

* a 3rd-hand account of the GF and Julius's theory, attributed to Met.Z.


P.-A. Conil
“Phénomènes d'optique atmosphérique,”
BSAF 17, 72 (1903).

* sounds like a useless novice report, but might be a real GREEN RAY?
* "Au moment précis où le disque solaire s'effeçait derrière la ligne
* des eaux, instantanément éclata à l'horizon un foyer d'un
* vert émeraude intense projetant dans tous les directions des rayons
* qui se détachaient sur une atmosphére émeraude très clair. Notre
* correspondant insiste sur la beauté féerique de ce phénomène
* absolument remarquable."


R.
“Der grüne Strahl,”
Himmel und Erde 15, 283 (1903).

* Nice summary of how the inf.-mir. "segment" becomes green from the ends
* and is followed by blue and violet (nameless observer using binoculars)


G. McKenzie Knight
[letter 250]
English Mechanic 78, 205 (1903).

* Knight again, observing in Italy
* "I am inclined to believe that a change in latitude affects its colour
* to a certain extent. Such is my opinion from thirty-three observations
* made in Italy since Aug. 17 to [Sept. 25]."
* GF mentioned only in short 2nd paragraph of longer letter.
* No. 2011, Oct. 9, 1903
* Fisher #66


T. R. Clapham
[letter 318]
English Mechanic 78, 248 (1903).

* Clapham is uninformative
* ". . . observed on several occasions, and always found it best to be seen
* on a clear sea horizon."
* No. 2013, Oct. 23, 1903


J. J. T. Chabot
“Sonnenaufgang und Sonnenuntergang,”
Das Weltall 3, 266–272 (1903).

* Chabot seems confused -- useless
* O'C #14 -- why did he bother with this? There are mentions of
* green and red rims, and the use of copper- and cobalt-glass filters.
* But Chabot's earlier papers are more interesting.


E. Dorn
“Eine Beobachtung des `Grünen Strahls',”
Met. Zs. 21, 197 (1904).

* MOUNTAIN sunset GF from 2565m
* Fisher #36


G. Jones
“Jules Verne at home,”
Temple Bar 129, 664–671 (1904).

* The interview with Jules Verne that was excerpted in "T.P.'s Weekly",
* in which Verne cannot recall the name of his novel, and has to be
* reminded of it by his wife: "'. . . a visit to Fingal's Cave . . . was the
* origin of my book, "The -- the --"' M. Verne paused. 'I really forget
* the name,' said he. 'Do you remember it?' he asked, turning to his wife.
*      '"The Green Ray," was it not,' suggested Madame Verne.
*      'Oh yes, that was it, of course -- "The Green Ray."  One must be
* excused,' added he, laughing, 'if, among so many titles the right one
* is not for the moment forthcoming.'"
* The interviewer was Gordon Jones.
* Available at HathiTrust:
* https://babel.hathitrust.org/cgi/pt?id=uc1.b3042632&view=1up&seq=676
* and at Google Books.
*      June, 1904 issue of this monthly.


(anonymous?)
“Jules Verne,”
T. P. 's Weekly 3, 752 (1904).

* BEGIN T.P.'s WEEKLY series
* As these items are mostly in the "T.P.'s Letter Box" section, and
* unsigned except for initials or pseudonyms, they are a bit difficult to
* give in standard bibliographical form. This magazine lacked the useful
* identifying numbers of English Mechanic, too.
*
* This is the item that started it off, merely by mentioning Verne's
* book:
* No GF, but an interview with Verne from "the current number of 'Temple Bar'"
* is quoted in which he mentions "Le Rayon Vert" -- as well as H.G.Wells.
*      Some of these early issues are now (2019) available at the HathiTrust
* website:
*                    https://catalog.hathitrust.org/Record/000503105
*
* as well as at Google Books. From the information in their catalog,
* one learns that "T.P." was Thomas Power O'Connor (1848-1929).
*
* Note: Part II of Joseph Conrad's "Nostromo" begins on the facing page!
* No. 83, June 10, 1904


"S. W."
“The green flash at sunset,”
T. P. 's Weekly 3, 841 (1904).

* A novice relates 2 sightings, with no useful details, and asks for an
* explanation: "I am curious to know whether it is only seen when the sun
* is setting over the sea."
* June 24, 1904


C. T. Whitmell
“The green flash [letter 543],”
English Mechanic 79, 556 (1904).

* Whitmell stirs up enthusiasm again, noticing the YELLOW stage:
* Another Southport flash!
* "The disc of the setting sun was decidedly orange. As it sunk below
* the horizon, the diminishing segment paled to yellow, the colour
* changing to a beautiful green when only the tip of the sun was left."
* No.2052, July 22, 1904
* Fisher #151


"Phusis"
“The green flash, &c. [letter 559],”
English Mechanic 79, 576 (1904).

* Responses to Whitmell begin here:
* "Phusis" fails because of his "low-lying hill horizon"
* "I have looked for this phenomenon rather vainly for a long time. Is it
* necessary that the horizon should be a sea level?"
* (The similarity to "S.W."'s question in TPW is remarkable.)
* No.2053, July 29, 1904


G. Whittle
“The green flash, &c. [letter 560],”
English Mechanic 79, 576 (1904).

* Whittle criticises "the crude idea that the sea water is the cause of
* the green ray, as if it were possible for light to pass through at such an
* angle."
* No.2053, July 29, 1904


T. R. Clapham
“The green flash, &c. [letter 561],”
English Mechanic 79, 576 (1904).

* "I examined it with a binocular, and distinctly saw the feather wisp as
* described by Mr. Whitmell at the final disappearance of the sun's limb."
* No.2053, July 29, 1904


"All my eye"
“The green flash at sunset,”
T. P. 's Weekly 4, 157 (1904).

* We now interleave the letters to E.M. and T.P. in chronological order:
* Responses to "S.W." begin here:
* Another novice responds with the "Pears' Soap ad" theory, with a good
* description of the ad itself.
* July 29, 1904


E. J. Cope
“The green flash [letter 19],”
English Mechanic 80, 14 (1904).

* Cope reports an INFERIOR-MIRAGE flash over LAND horizon
* "Through a field-glass the last visible part of the sun appeared to
* assume an oval shape, with its longest axis horizontal, and at the same
* time the two ends became of a beautiful green colour, which extended
* towards the centre . . . ."
* No.2055, Aug. 12, 1904
* Fisher #29


"M. D."
“The green flash at sunset,”
T. P. 's Weekly 4, 284 (1904).

* A more experienced observer refutes the "Pears' Soap ad" theory.
* ". . . several of us tested it, but with negative results. We looked
* fixedly at the red sun, and then looked quickly up at a white cloud, with
* the result that some saw a green image of the sun; but that is entirely
* different from the ``green flash,'' which is horizontal and very little
* more than momentary, whereas the visual impression of the sun on the cloud
* (and in Pears' experiment) lasts for some time."
* Aug. 26, 1904


"Another Engineer Officer"
“The green flash at sunset,”
T. P. 's Weekly 4, 348 (1904).

* FIRST CLASSIFICATION?
* This issue has 3 replies. The first is a SPLENDIDLY CLEAR account of the
* difference between green flashes and GREEN RAYs:
* "In the course of sixteen years sailing the seven seas I have very
* frequently seen the green flash and also the green ray. Fine weather and
* an absolutely clear horizon are, or course, essential, but this form of
* refracted light requires other atmospheric conditions, which have not yet
* been scientifically explained, and the flash may be often looked for in
* vain when the conditions seem to be most favourable. The flash appears
* like a magnificent emerald the moment the sun sinks -- sometimes vanishes
* instantly and sometimes fades in three or four seconds. Occasionally, in
* the latter case, a luminous green ray springs from the flash and shoots
* vertically upwards to a height of about five of the sun's apparent
* diameters. Strangely enough, this phenomenon is not commonly known among
* British seamen, although it has been described for many years in a
* standard French Naval Instruction Book as a sure sign of continued fine
* weather." [cf. Trève (1885) and Wegener (1926).]
* Sept. 9, 1904


"T. H. T."
“The green flash at sunset,”
T. P. 's Weekly 4, 348 (1904).

* Confusion between "green Sun" and green flash; ignore
* Sept. 9, 1904


"T. D."
“The green flash at sunset,”
T. P. 's Weekly 4, 348 (1904).

* A beginner notices the HEIGHT effect:
* "Although both of us gave our undivided attention, there was no green
* ray visible. At the same time, however, two other friends at a distance
* of several hundred yards from us, and on slightly lower ground, declare
* they witnessed the phenomenon."
* [This is evidently the paper "Phusis" (E.M., Oct.14) had in mind.]
* Sept. 9, 1904


"F. K."
“The green flash at sunset,”
T. P. 's Weekly 4, 380 (1904).

* a fuzzy-minded promoter of "color is entirely subjective" nonsense.
* Sept. 16, 1904


"J. G."
“The green flash at sunset,”
T. P. 's Weekly 4, 380 (1904).

* Another refutation of "Pears' Soap"
* "I know the ``Pears' Soap'' effect well, and have seen green suns often,
* but this flash could have nothing of the same character. . . ."
* Sept. 16, 1904


"Phusis"
[letter 165]
English Mechanic 80, 159 (1904).

* "Phusis" cites a troubling argument (evidence for ADAPTATION):
* ". . . the theory has been advanced that it is an optical illusion. How
* in else manner can any of our readers account for its visibility to some
* and its invisibility to other observers at the same time? In other words,
* is the colour flash produced by dispersion, or is it a complementary
* colour effect? If it is the former, then it should be visible to all."
* No.2061, Sept.23, 1904


"W. R."
“The green flash at sunset,”
T. P. 's Weekly 4, 412 (1904).

* Another after-imager.
* Sept. 23, 1904


"C. B. S."
“The green flash at sunset,”
T. P. 's Weekly 4, 412 (1904).

* "C.B.S." quotes an irrelevant passage from Longfellow; ignore.
* Sept. 23, 1904


"W. T. N."
“The green flash [188],”
English Mechanic 80, 182 (1904).

* Good explanation of the standard textbook story
* "`Phusis' . . . seems to doubt whether the phenomenon known as the `green
* flash' is anything more than an optical illusion due to a complementary
* colour effect (query, complementary to what?)"
* No.2062, Sept.30, 1904


C. T. Whitmell
“The green flash [189],”
English Mechanic 80, 182–183 (1904).

* Whitmell recommends a telescope, and mentions RED flash:
* "I have seen it once or twice, and believe I am the first to draw
* attention to it."
* No.2062, Sept.30, 1904


"Treadle"
[letter 190]
English Mechanic 80, 183 (1904).

* "Treadle" (Mostyn) relates a beautiful sunrise flash, and adds:
* "It is never seen unless a great deal of refraction is about, as is
* evidenced by the sun assuming curious shapes --- a goldfish globe, &c."
* A clue to his identity: of the "Bedford Level Experiment," he says
* "I was concerned in it."
* No.2062, Sept.30, 1904
* Fisher #105


"G. B. H."
“The green flash at sunset,”
T. P. 's Weekly 4, 444 (1904).

* Another ignoramus pushes after-images; ignore.
* "Though not having seen the green flash personally, . . . ."
* Sept. 30, 1904


L. Rudaux
“Observation du rayon vert,”
La Nature 32:2, No. 1637, 294 (8 Oct., 1904).

* SUPERIOR MIRAGES with SUNSET drawings
* "FOG" in blank strips; GF in "cap"
* Fisher #128, O'C #272


L. Libert
“Le Soleil vert,”
La Nature 32:2, No. 1637, 294 (8 Oct., 1904).

* GREEN SUN distinguished from green flash
* "J'ai à plusiers reprises observé le rayon vert, mais le soleil vert
* en différait par sa longue durée d'abord, par la situation du soleil
* au-dessus de l'horizon ensuite, et c'est à ce titre que j'ai voulu le
* signaler."


Dr. Polo
“Communications,”
La Nature Suppl. ``Nouvelles Scientifiques'' 32:2, No. 1637, 74 (8 Oct., 1904).

* letter to editor from a first-time observer who claims a green flash;
* but the description clearly shows that this was only a crepuscular ray.
* An example of CONFUSION due to inappropriate TERMINOLOGY.


"Phusis"
“The green flash [264],”
English Mechanic 80, 233–234 (1904).

* "Phusis" points out some visual effects (evidence of ADAPTATION)
* "Two persons watching the sun at the same time : one sees the flash and
* the other does not, although both are careful observers."
* (attributed to T.P.'s Weekly, Sept.30, p.444 and "previous issues for
* the past few weeks.") Cf. "T.D.", Sept.9, in TPW.
* No.2064, Oct.14, 1904


"Pathfoot"
“Explanation of green flash at sunset,”
T. P. 's Weekly 4, 508 (1904).

* More after-imagery; though "If fatigued by a red light and then exposed
* to a yellowish light, the yellow will appear green."
* Oct. 14, 1904


C. T. Whitmell
“The green flash [283],”
English Mechanic 80, 253 (1904).

* Whitmell cites some earlier works ("Phusis", Kelvin)
* No.2065, Oct.21, 1904


"Treadle"
“The green flash [284],”
English Mechanic 80, 253 (1904).

* Mostyn ("Treadle") counters "Phusis"
* "When I was at sea, the officers of the watch had orders to send and call
* me. . . " makes it sound as if he was the captain; but Edward Gilbert finds
* that Mostyn was only a passenger.
* No.2065, Oct.21, 1904


"D. Sc."
“The green ray,”
T. P. 's Weekly 4, 548 (1904).

* This might be Rambaut? There is a reference to Froude's "Leaves from a
* South African Journal" without details; see Froude (1877).
* ". . . take care not to fatigue the eyes by staring at the setting sun. A
* wise plan is to turn the back to the sun, turning round from time to time
* for a brief glimpse, to make sure that it has not disappeared, and only
* fixing the eyes upon it finally when nothing remains visible but the upper
* edge of the disc. Unless the horizon is distant and low, the watch may be
* in vain."
* Oct. 21, 1904


C. T. Whitmell
“The green flash [316],”
English Mechanic 80, 275 (1904).

* Whitmell gives several references, and confirms that "Treadle" is Mostyn
* No.2066, Oct.28, 1904


"C. M."
“Green flash at sunrise,”
T. P. 's Weekly 4, 588 (1904).

* Clearly this is Charles Mostyn, finishing the TPW series.
* "I have seen it dozens, nay, scores, of times at sunrise at sea. The
* horizon is much more frequently clear in morning than in evening."
* Oct. 28, 1904


E. A. Childe
“The green flash [348],”
English Mechanic 80, 299 (1904).

* VIOLET flash
* ". . . what we saw was a flash that was distinctly violet in colour."
* No.2067, Nov.4, 1904
* O'C #193; Fisher #25


C. T. Whitmell
“The green flash [373],”
English Mechanic 80, 321 (1904).

* Whitmell admits the simple explanation is not adequate:
* "Mr. Childe's question as to why the flash is often absent, though
* circumstances seem favourable to its production, is not easily answered."
* No.2068, Nov.11, 1904


"Treadle"
“The green flash [396],”
English Mechanic 80, 340–341 (1904).

* Mostyn ("Treadle") notices the symptoms of INFERIOR MIRAGE for shipboard
* flashes (again!)
* "I used to observe that the flash was most often seen when the sun, as
* it approached the horizon, was distorted horizontally and assumed the
* appearance of a gold-fish globe or an egg on its side . . . . On the other
* hand, when the refraction was vertical --- when the sun took on the shape
* of an egg on its end . . . --- the flash was seldom if ever to be seen."
* ("Treadle" was identified as C. Mostyn by Langford in 1901.)
* No.2067, Nov.4, 1904
* Fisher #106, O'C #291


J. W. Wilkins
“The green flash [397],”
English Mechanic 80, 341 (1904).

* Wilkins proposes sunlight shining through waves (!) despite Whittle's
* July letter
* No.2067, Nov.4, 1904


C. T. Whitmell
“The green flash [letter 430],”
English Mechanic 80, 366 (1904).

* Great line criticizing the "ocean waves" notion of Wilkin [sic]:
* "The horizon may be of sea, land, or cloud. Of course, this utterly
* demolishes Mr. Wilkin's explanation, which on other grounds also is quite
* untenable. Over land the flash might with equal probability be ascribed
* to waves of grass."
* No.2070, Nov.25, 1904


"W. T. N."
“The green flash [letter 431],”
English Mechanic 80, 366 (1904).

* Another put-down of Wilkins's "waves":
* "If Mr. Wilkins possessed the most elementary acquaintance with the laws
* governing the transmission of light through media of different densities,
* he would see at once that a horizontal ray of light entering a wave-shaped
* body of water would be deflected downward, and therefore could not
* possibly emerge from its opposite face to continue its original course in
* a straight line to the eye of a distant observer."
* No.2070, Nov.25, 1904


C. T. Whitmell
“The green flash,”
Leeds Astron. Soc. Journal & Trans. 12, 70–73 (1904).

* Most, but not all, of Whitmell's GF letters to E.M. during 1904;
* Contains several references to other people's letters, including Childe's.


H. Schering
“Referate. Astrophysik. W. H. Julius, Le Rayon Vert,”
Physik. Zs. 6, 24 (1905).

* SCHERING refutes Julius's anomalous-dispersion theory
* See Mon.Wea.Rev.33,408-409(1905) for a translation.
* Phys.Z. strangely indexes this under "Julius" and not "Schering", which
* explains Fisher's listing it under "Julius" as his #62.
* Hartmann's long refutation of Julius's other anomalous-dispersion
* theories in A.N.4197 mistakenly gives the year as 1904.
* 1 Jan. 1905 issue
* Fisher #62 ("Julius") *and* #129 ("Schering")!


J. Möller
“Beobachtungen von Dämmerungserscheinungen, angestellt auf See,”
Ann. Hydrog. 33, 55–58 (1905).

* Mentions GF only in 1 sentence: ". . . der übrigens sehr oft, aber nicht
* immer, im letzten Moment den viel erwähnten grünen Strahl zeigte . . . ."
* Feb. issue
* Fisher #100


Wm. F. A. Ellison
“The green flash [224],”
English Mechanic 81, 155 (1905).

* telescopic JUPITER FLASH
* No. 2087, March 24, 1905
* O'C #205; Fisher #41


C. T. Whitmell
“The green flash [letter 258],”
English Mechanic 81, 179 (1905).

* Whitmell's comment on Ellison's Jupiter flash
* No. 2088, March 31, 1905


C. T. Whitmell
“The green flash,”
Leeds Astron. Soc. Journal & Trans. 13, 96 (1905).

* An exact reprint of Whitmell's E.M. letter [258].
* Thanks to Ray Emery for supplying this!


Mr. Hardcastle
“(meeting report),”
JBAA 15, 265–267 (1905).

* Discussion of Whitmell's paper on the Sun's supposed reflection in the sea
* These two items really belong with the Ricco and Forel files, as they
* depend mainly on their work.
* "If one only occasionally watched the sun rise and set, one did not know
* what were unusual phenomena and what were not, and if one then saw an
* unusual phenomenon, one did not recognise it as such, because one did not
* know what the usual appearances were."
* ". . . it was noticeably green for a period of two seconds, not what might
* be called a flash, but lasting a sufficient time for it to be seen that it
* was green; . . . ."
* Fisher #53


C. T. Whitmell
“The Earth's rotundity proved by reflection,”
JBAA 15, 276–284 (1905).

* Whitmell's report on rotundity (cf. Forel and Ricco, whom he cites)
* ". . . I have left out of account the influence of refraction. Doubtless
* it would modify some of the results, but would not affect the general
* reasoning."
* "M. Ricco appears to have been the first to observe the contraction in
* the sun's image reflected from the sea." [but cf. Bravais, 1853!]
* Properly, this should be filed with either the Ricco or the
* Forel/Dufours file; but it is here as it logically follows Mr.
* Hardcastle's comments on green flashes (previous item).


Mr. Hardcastle (and others)
“(meeting report),”
JBAA 15, 366–367 (1905).

* Comment on oral presentation of Goodacre's paper (next item)
* and discussion by Goodacre:
* ". . . Mr. Goodacre said he always saw the flash with unaided vision,
* though he had read that it was much better seen with a binocular."
* "Mr. Hardcastle . . . would describe the duration of the flash as being
* two seconds, but, of course, a far greater amount of the sun was visible
* within two seconds of its rising than ought to be according to the
* movement of the sun. It occurred rapidly, as one saw it rising, evidently
* due to refraction, and not to the movement of the earth."
* Joseph Alfred Hardcastle was a grandson of Sir John Herschel, and worked
* as a professional astronomer (see his obits in JBAA 28, 28-29 (1917).
* and M.N. 78, 246-248 (1918).)
* Fisher #49 (listed under Goodacre); O'C #218


W. Goodacre
“The Green Flash,”
J. B. A. A. 15, 382–384 (1905).

* third mention of VARIATIONS IN DURATION and SIZE of flashes ?


[unsigned editorial]
“The green ray at sunset,”
Mon. Wea. Rev. 33, 408–409 (1905).

* This is mostly a translation of Schering's Phys.Z. paper, but
* the editor has an introductory paragraph that mentions Tyndall:
* ". . . the green ray seen just as the last glimpse of the sun disappears
* below the sea horizon was originally introduced into meteorology by
* Tyndall as an evidence of the special absorptive power of the aqueous
* vapor in the lowest layer of the atmosphere." He then mentions Julius's
* paper, and Schering's review of it.
* Fisher #130


C. T. Whitmell
“The Green Flash,”
J. B. A. A. 16, 23–25 (1905).

* REFRACTION SCALED:
* "If we take the horizontal refraction as 32', the factor 1/40 gives
* about 50" for the vertical length of the spectrum of a luminous point,
* such as a star or the tip of the sun when on the horizon."
* "With a telescope it is quite easy to observe, at low altitudes,
* a bluish-green fringe on the upper part of the sun's limb. The
* final development and sudden disappearance at sunset of this dispersion
* phenomenon constitute the green flash."
* Fisher #152


T. Molyneux
“The Green Flash,”
J. B. A. A. 16, 31 (1905).

* useless novice observation of sunrise GF
* Fisher #101, O'C #251


G. Napier Clark
“The green flash,”
English Mechanic and World of Science 82, 183 (1905).

* A dubious first-time observation; possible green RAY ??
* ". . . suddenly there shot out from the point where we had seen the last
* of the sun a brilliant flash like a beam of electric light.
* It appeared to flash white, blue, and green in succession . . . ."
* No. 2114, Sept.29, 1905
* Fisher #26; O'C #206? (garbled)


"A. R. H."
“The Astronomical Society of the Atlantic,”
Obs. 28, 414–418 (1905).

* Jocular account of an eclipse expedition, with passing mention of GF
* "The green flash has excited general interest, and some surprising
* observations have been made. A lady has seen a green flash extend almost
* to the zenith several minutes after the Sun went down, and it has been
* quite common to see the Sun reappear somewhat faintly, but distinctly
* green all over! It is, in fact, not quite easy to separate the real
* green flash from the effects of retinal fatigue, and the writer is not
* sure that he has ever succeeded. The last segment of the disappearing
* Sun certainly changes colour, but the result is not always a brilliant
* green. . . . it is to be wished that some observer returning from an
* eclipse could set up his instrument and get the `green flash' spectrum."
* [pp. 416-417] -- "A.R.H." may be A.R.Hinks.
* Thanks to the NASA ADS full-text search for turning this up!


J. P. Maclear
“Green flash at sunset,”
Knowledge (new series) 3, 353 (1906).

* Admiral Maclear: (has some earlier refs.)
* Apparently the Admiral sent nearly the same letter to Symons's (see below).
* Here, he says "stars"; there, "planet". There are other minor changes.
* Prof. W.M.Davis's "Elementary Meteorology" cited (p.50).
* The full title is "Knowledge & Illustrated Scientific News"
* conducted by Major B. Baden-Powell and E.S. Grew, M.A.
* (N.B.: this "volume" *begins* on p.315, though it spans a calendar year.)
* O'C #234


J. H. Worthington
“The green flash at sunset,”
Knowledge (new series) 3, 376 (1906).

* replies to Admiral Maclear (March issue)
* Many interesting observations described, including a sunset with
* multiple flashes. One observation notes the red lower limb.
* "I have seen the green, or rather many-coloured flash also behind the
* mountains at sunset in Egypt; but it is neither so clear nor of such long
* duration when seen over land as at sea."
* Evidence of ADAPTATION:
* "At first the whole of the visible portion of the disc of the sun
* turned intense fiery red. Then when a little more than half the disc
* had disappeared it changed to yellow."
* Good color description:
* "Then when the sun is almost down the whole visible part became greenish
* with violet flashes. Then the rest of the disc becomes a line with deep
* violet at each end, blue next to the violet, and green in the middle parts
* of the line."
* ". . . the altitude above sea level about 55 feet; weather calm, light
* S.W. wind . . . ."
* "I used no dark glass on the telescope."
* Full title: Knowledge and Scientific News (March, 1906)


C. Mostyn
“The green flash at sunset,”
Knowledge (new series) 3, 376–377 (1906).

* CHARLES MOSTYN again -- an experienced and careful observer.
* ". . . in a favorable display . . . the `flash' changes rapidly from green
* to blue and violet . . . ."
* SUNRISE better than sunset:
* ". . . far the finest view of the `green flash' is to be obtained,
* according to my experience, oft repeated, at sunrise . . . ."
* "And the horizon is more apt to be clear and sharp at sunrise than at
* sunset, while the brilliance of the flash to the un-tired eye is
* magnificent."
* "Also, the best shows were when the sun, on the horizon, was much
* distorted by refraction."
* [cf. his E.M. letter where this is made explicit.]


J. P. Maclear
“Green flash at sunset,”
Q. J. Roy. Met. Soc. 32, 67 (1906).

* Admiral Maclear: (has several earlier refs.)
* "The phenomenon is frequently observed, but very little has been
* published about it. . . ."
* [The Editor follows with a quote of the MWR Sept. 1905 paper, which
* mentions Tyndall. This quote continues on the next page.]
* Fisher #81


J. P. Maclear
“Green flash at sunset,”
Symons's Met. Mag. 40, 227 (1906).

* CAREFUL about Symons's dates: last issue of each volume (ca. p.210ff.)
* was always in Jan. of following year!
* Admiral Maclear: (has some earlier refs.)
* ". . . it is stated that after sunset every solar beam will be broken up
* into a short vertical spectrum; is this the explanation? if so why should
* the last flash be green? . . . I would like to see that matter worked out."
* Fisher #82


R. C. Cann Lippincott
“Green flash at sunset,”
Symons's Met. Mag. 41, 11 (1906).

* R.C.CANN LIPPINCOTT's crusade for afterimages begins!
* Fisher #75


G. H. Courtenay
“Green flash at sunset,”
Symons's Met. Mag. 41, 11 (1906).

* R.C.CANN LIPPINCOTT contradicted by Major George H.Courtenay
* N.B.: the 1854 date is VERY EARLY !
* "I saw it continually on my way from Tasmania, in 1854, in the South
* Pacific. But then it occurred at sunrise . I used to get up to
* observe it morning after morning."
* "[Major Courtenay's observation of the green ray at sunrise . . . seems to
* dispose of Mr. Lippincott's argument that the appearance is due to fatigue
* of the eye . . . , a suggestion often made before seeing the phenomenon but
* rarely upheld by one who has actually observed it. -- Ed. S.M.M.]
* NOTE that this is a VERY EARLY OBSERVATION, before Joule!
* Fisher #31


E. E. Markwick
[letter 40]
English Mechanic 83, 36 (1906).

* Col. Markwick reports a small naked-eye flash
* This is only the last paragraph of a long letter mainly on other topics
* No. 2134, Feb. 16, 1906
* Fisher #85


A. A. Rambaut
“The green flash on the horizon,”
Symons's Met. Mag. 41, 21–23, 41–45 (1906).

* FIRST REVIEW ARTICLE -- SCALED REFRACTION calculated again (1/72)
* N.B.: cites *nothing* but English journals!
* Dr. Arthur A. Rambaut, F.R.S.; earliest refs. are to Nature in 1883.
* Rambaut had been Radcliffe Observer since 1897.
* first mention of violet as complement to yellow?
* "It was then quite unmistakable, and those who are so fortunate as to
* see it, as I and several of my fellow-passengers on the Durham Castle
* did on that occasion, will not, I think, retain any lingering doubts
* as to the objective character of the phenomenon."
* Another independent inventor of the OCCULTING DIAPHRAGM!
* "This is an observation by which any possessor of a telescope can easily
* satisfy himself that the flashes are due to atmospheric dispersion of
* light, and is at least less expensive than building a Wesleyan Chapel
* with horizontal openings in the belfry." (cf. Whitmell's RF paper.)
* The curious figure purporting to show how the textbook flash is formed
* contains only red, yellow and blue -- suggesting that Rambaut made
* the common error of thinking that blue + yellow makes green.
* Fisher #122 and #123


R. C. Cann-Lippincott
“The green flash,”
Symons's Met. Mag. 41, 29 (1906).

* Cann-Lippincott again insists on afterimages, even at sunrise!


R. C. Cann Lippincott
“Green flash,”
Q. J. Roy. Met. Soc. 32, 159 (1906).

* Lippincott pursues the same line in QJRMS
* This letter is dated March 24, 1906.
* Fisher #73


I. F. H. Gregg
“The green ray [query 488],”
English Mechanic 83, 206 (1906).

* Gregg starts a round by inquiring about the green ray's visibility
* No. 2141, April 6, 1906


H. P. Hollis
“The green ray [247],”
English Mechanic 83, 221 (1906).

* H.P.Hollis replies to Gregg, citing Rambaut's first installment.
* Note: this heading is a sub-head of a long letter of many parts; the
* general heading is "Magnitude of the fixed stars".
* No. 2142, April 13, 1906


C. T. Whitmell
“The green flash [488],”
English Mechanic 83, 227 (1906).

* Whitmell replies to Gregg, and cites papers in Leeds Astr.Soc.
* No. 2142, April 13, 1906


D. Wilson-Barker
“The green flash,”
Symons's Met. Mag. 41, 67 (1906).

* Variability. . .
* "It should be noted that the green ray . . . is not always seen even when
* the sun sets at sea on a perfectly clear horizon."
* Fisher #7


(editorial)
“The green flash in fiction,”
Symons's Met. Mag. 41, 68–70 (1906).

* Unsigned editorial by H.R.Mill, with a synopsis of Verne's story
* "We have seen it only a dozen times in twenty years. . . ."
* Mill seems to believe the "old Highland legend".
* Cited with title in Kimball's "Recent Papers," MWR 34, 219 (May 1906)
* Fisher #97 and 98


C. Michie Smith
“The green flash,”
Symons's Met. Mag. 41, 91 (1906).

* GREEN RAY observation
* "The common `green,' or as I would rather call it `blue' flash which I
* have seen, perhaps a hundred times, is undoubtedly caused in the way
* described by Dr. Rambaut, but there is another phenomenon which I have
* seen on a few occasions, which is almost as certainly caused by
* atmospheric absorption. In it the upper part of the sun's disc when
* setting becomes a vivid green for several seconds before disappearing,
* and in the light then given objects of a green colour appear with
* extraordinary vividness. Probably closely allied with this phenomenon
* is one which I have seen here on two or three occasions, when the whole
* sky became filled at sunset with what seemed to be a green mist, which
* produced the most lurid effects." ("here" = Kodaikanal)
* Fisher #137


G. H. Courtenay
“The green flash,”
Symons's Met. Mag. 41, 91 (1906).

* (mostly useless)
* Fisher #32


C. T. Whitmell
“The green flash,”
Symons's Met. Mag. 41, 91 (1906).

* first ref. to Mrs. Steel
* "As another example of the mention of the Green Ray in fiction, I may
* instance Mrs. F. A. Steel's novel, `Red Rowans.'"


R. C. Cann Lippincott
“The green flash,”
Symons's Met. Mag. 41, 92 (1906).

* LIPPINCOTT refuses to give up!
* Fisher #76


A. Carpenter
“The green flash,”
Q. J. Roy. Met. Soc. 32, 232–233 (1906).

* Capt. Carpenter replies to Lippincott in QJ, who responds (next item)
* "The extraordinary explanation of the above . . . by Mr. R. C. Cann
* Lippincott, needs some correction. . . . a complementary coloured spot will
* only fade away slowly, whereas the green flash is momentary, seldom
* exceeding 1 1/2 seconds."
* This is in the July issue.


R. C. Cann Lippincott
“The green flash,”
Q. J. Roy. Met. Soc. 32, 233 (1906).

* Lippincott responds to Carpenter with nonsense


G. Napier Clark
“Atmospheric conditions and the green flash [628],”
English Mechanic 83, 529–530 (1906).

* Another report from Southport !
* This seems to be associated with looming; needs to be investigated.
* Cites his earlier report in E.M.No. 2114, p.183.
* No. 2155, July 13, 1906
* Fisher #27


R. C. C. Lippincott
“The green flash,”
Q. J. Roy. Met. Soc. 32, 287–288 (1906).

* Lippincott again
* This is a further reply to Capt. Carpenter's letter in the July issue.
* Fisher #74


A. Thurburn
“The green flash,”
Symons's Met. Mag. 41, 150–151 (1906).

* ramblings about particulate EXTINCTION and IRRADIATION
* "[. . . the question of the infrequency of the phenomenon is an
* interesting one, on which, perhaps, more can be said. -- Ed. S.M.M.]"


C. T. Whitmell
“The green flash,”
Symons's Met. Mag. 41, 189–190 (1906).

* "The duration may be largely affected by the observer's latitude and the
* extent by the refractive condition of the air."
* Fisher #153


R. C. Cann Lippincott
“The green flash,”
Symons's Met. Mag. 41, 190 (1906).

* "I cannot believe that the phenomenon has ever been seen, unless the red
* edge or red colour or red ray of the rising or setting sun has been first
* seen above the horizon."


J. G. McKendrick
“The green flash,”
Symons's Met. Mag. 41, 209 (1906).

* A "convert to the physical theory" testifies for Rambaut
* Fisher #80


C. T. Whitmell
“The green flash,”
Symons's Met. Mag. 41, 209–210 (1906).

* Whitmell sees a a red flash below cloud


A. Thurburn
“The green flash,”
Symons's Met. Mag. 41, 210 (1906).

* (Alex.Thurburn is still confused)


W. Lloyd Fox
“The green flash,”
Symons's Met. Mag. 41, 234 (1907).

* Varying width of green rim (N.B.: now Jan.1907)
* Fisher #46


R. Radau
“l'Astronomie au Mont-Blanc,”
Revue des Deux Mondes (5. Pér.), Vol. 37, No. 4, 876–892 (1907).

* Hansky's sunrise flash of Sept. 4, 1900, reprinted by Rodolphe Radau
*      The GF report is an extract of Hansky's report in Janssen's Note on
* his Mont Blanc observatory in the 1901 Annuaire.
*      An English translation of this item appeared in the Annual Report of
* the Board of Regents of the Smithsonian Institution, for the year ending
* June 30, 1906 [GPO, Washington, DC (1907]). Unfortunately, Radau's
* initial appears there as "H.", not "R." This error was then propagated
* by the Nov. 23, 1907, supplement to "Scientific American", which abstracted
* the English translations of this and earlier Radau articles on Janssen,
* omitting Hansky's GF observation.
*      Rodolphe Radau spent much of his life working at "Revue des Deux
* Mondes". He was part of the German community in Prussia, but moved to
* Paris after studying math and astronomy at Königsberg.


R. C. Cann Lippincott
“The green flash,”
Symons's Met. Mag. 41, 234–237 (1907).

* The Editor's patience is exhausted! LIPPINCOTT's last gasp
* Note the Editor's sermon at the end!
* Fisher #77


A. Guébhard
“Sur l'interprétation de certains faits de vision colorée,”
C. R. 144, 223–225 (1907).

* Adrien Guébhard won't admit defeat, and gets in another lick:
* "Quant au prétendu météore du rayon vert , il n'a pas davantage
* d'existence colorée objective : c'est la simple ombre portée,
* au milieu du crépuscule rouge, d'une pointe se détachant sur
* le disque solaire à sa disparition . . . ."
* This article is mostly about color perception; only 1 paragraph on GF.


J. Offord
“The green tints of sunset,”
Nature 75, 342 (1907).

* NOT a green flash -- completely PHONY description.
* "As the sun there [Egypt] descends nearer and nearer to the horizon,
* apparently hastening to disappear behind one of the Libyan hills, as if
* burying itself in the sand at their base, the immensely enlarged flaming
* disc suddenly becomes, for an instant, of a brilliant green colour, and
* immediately a series of green rays suffuses the sky in many directions,
* well-nigh to the zenith." (All a fantasy; certainly not seen.)
* Fisher #109, O'C #98


J. Offord
“The green tints of sunset,”
English Mechanic 85, 34 (1907).

* Joseph Offord's awful paper reprinted in E.M.
* No.2186, Feb.15, 1907
* Fisher #110


J. Kater
“De Groene Straal bij op- en ondergang der zon,”
Hemel en Dampkring 4, 170–171 (1907).

* an account of Nijland's A.N. paper; first mention of GF in H&D?
* exact citation is vol.4, no.2, Maart 1907
* Thanks to Ernst Raimond for a copy of this!


F. B. Allison
“Sundial and G.M.T. [letter 532],”
English Mechanic 85, 494 (1907).

* The second half of this letter concerns a TELESCOPIC green flash
* "In watching the sun set to-night beneath a land horizon, through a
* small telescope without eye-screen . . . it was evident that this green
* border was the more refrangible part of a spectrum ."
* [Looks like No. 2203 or 2205 -- can't read date on photocopy: June ?]


C. T. Whitmell
“The green flash [letter 576],”
English Mechanic 85, No. 2206, (1907).

* Whitmell's GF letter to E.M. published on 5 July 1907;
* refers to Allison's letter, p.494
* Whitmell discuses the prolongation of a flash at the Arctic Circle,
* calculating 12 minutes (6 each before and after midnight).
* "For such a duration the word `flash' seems scarcely suitable; but the
* disadvantage of the word `ray' lies in the fact that it conveys to many
* persons the impression that a long green streamer is seen shooting up
* towards the zenith. This is unfortunate, as observers are led to look
* for something which never occurs as part of the green flash, properly
* understood."


C. T. Whitmell
“The green flash [letter 576],”
Leeds Astron. Soc. Journal & Trans. 15, 67–68 (1907).

* Reprint of Whitmell's GF letter to E.M., 5 July 1907;
* refers to Allison's letter, p.494
* Fisher #154; not read (hence the error in journal name)


W. Krebs
“Strahlungen zur Zeit gesteigerter Sonnentätigkeit. I. Die grüne Strahlung der auf- oder untergehenden Sonne.,”
Das Weltall 7, 313–314 (1907).

* He thinks a GF is a SOLAR PROMINENCE
* He sees flashes with 10x telescope; but thinks the last previous
* observations were those of Exner in 1902 and Dorn in 1903.
* "Vermutlich ist er veranlaßt durch aufflammende Gasausbrüche am
* Sonnenrande, sogen. Protuberanzen besonderer Art." At sunrise,
* "Grüne Randerscheinungen konnte ich . . . mehrmals feststellen.
* . . . Es handelte sich dabei um eine ganze Korona grünlicher Flammen, die
* sich auf je etwa 30 Grad heliographischer Breite nördlich und südlich
* (im Sonnenbild links und rechts) vom Sonnenäquator aus erstreckten."
* (The continuation of the article on p. 329 is about ordinary solar
* activity.)
* Aug.1, 1907 issue


E. E. Markwick
“Signs of the sky – IV,”
English Mechanic 86, 27–28 (1907).

* Col. Markwick's review of atmospheric optics
* One long paragraph here devoted to the GF: ". . . the sight of it is
* decidedly rare, and should be treasured up in the memory afterwards."
* "It generally lasts about a couple of seconds, and the change of colour
* is most impressive. A binocular vastly assists the eye in the observation
* of the phenomenon, which is doubtless due to atmospheric dispersion . . . ."
* No.2212, Aug. 16, 1907


J. Hartmann
“Über die Erklärung astrophysikalischer Beobachtungen durch anomale Dispersion,”
A. N. 175, Nr. 4197, 341–368 (1907).

* HARTMANN's refutation of Julius's wild applications of anomalous
* dispersion to everything in sight. He cites Schering's 1904
* refutation of the GF model.
* This item is followed by a letter from the infamous H.H.Kritzinger!


F. B. Allison
[letter 284]
English Mechanic 86, 237 (1907).

* Allison's letter, describing the MOCK MIRAGE phenomena
* "It was curious to note how the refraction of the air caused both
* notches and projections to appear upon the limbs -- especially the upper
* one -- which notches and projections remained permanent for one or two
* minutes. Sometimes two notches would approach one another, and finally
* cut off, apparently, a piece of the luminous disc which floated above the
* rest of the sun. . . . the uppermost part of the projections on the upper
* limb continually shot out green flakes . . . ."
* No.2221, Oct.18, 1907


C. T. Whitmell
“The green flash and the red,”
English Mechanic 86, 264 (1907).

* Whitmell confirms what Allison's letter, p.237, reports
* Whitmell recommends using a telescope to see the green and red "flames".
* No.2222, Oct.25, 1907


W. N. Groff
Oeuvres Égyptologiques de William N. Groff, publiées par sa soeur avec l'aide de G. Maspero
(Ernst Leroux, Paris, 1908).

* GROFF's works reprinted
* The GF papers are on pp. 171-180, 190-196, 221-224, 225-227, 249-258 and
* 258-272. The biographical note is in pp. I-IV.


M. Hall
“The green flash,”
Symons's Met. Mag. 42, 235 (1908).

* use of PINHOLE to attenuate the Sun
* Maxwell Hall
* Fisher #52


R. C. Cann Lippincott
“The green flash,”
Symons's Met. Mag. 43, 154 (1908).

* our "last glimpse" of R.C.CANN LIPPINCOTT !
* "I am convinced that the so-called `green flash' is the after-image or
* visionary image of the impression produced on the retina by the last rays
* of the setting, or by the first rays of the rising sun, seen in the
* complementary blue-green colour."
* (Letter dated 10 Feb. 1908)


C. T. Whitmell
“The green flash,”
Yorkshire Post , 5 (26 March, 1908).

* Whitmell relays an observation by Ivo Gregg in Egypt
* ". . . where he has been staying with Professor Flinders Petrie."
* ". . . in the Libyan desert, near Wadi Halfa, he saw, with the naked
* eye, at sunset, the Green Flash, a phenomenon for which I had asked him
* to look out. Just as the solar disc disappeared, its tip assumed a fine
* green colour."
* As Whitmell asked Gregg to observe, this might be the cause of Petrie's
* 1914 report?


C. T. Whitmell
“The green flash,”
Leeds Astron. Soc. Journal & Trans. 16, 49 (1908).

* The same item, reprinted in the Leeds Trans.
* Thanks to Ray Emery for supplying this!


R. DeC. Ward
“Notes on weather and climate made during a summer trip to Brazil, 1908,”
Mon. Wea. Rev. 36, 333–339 (1908).

* 2 minor mentions of GF observations in a long article on other matters
* Prof. Ward calls it "the `green ray'" (in quotes) on pp. 335 & 339.
* Oct. issue.
* Fisher #145


D. Roguet
BSAF 23, 21 (1909).

* green rim + green flash
* O'C #271


R. C. Cann Lippincott
“The green flash,”
Q. J. Roy. Met. Soc. 35, 50 (1909).

* R.C.Cann Lippincott sees something at last: GF or Cornsweet effect?
* Fisher #78


F. C. Lees
“The green flash,”
JBAA 19, 354 (1909).

* ORANGE LINE becomes GREEN BAND at Southport !
* "The disc was much distorted as it sank; for the last 30 seconds or so
* it seemed an unvarying bright orange line; then the orange simply faded
* and all but disappeared. I was just about to register one more failure
* when a distinct and bright green band took the position and apparent size
* of the orange of about 20 seconds previously; it continued for perhaps
* seven seconds and then gradually faded away."
* Fisher #70


Prof. Flöckher
“Eine Beobachtung des grünen Sonnenstrahles,”
Mitt. Vereinigung von Freunden der Astronomie und Kosmischen Physik 19, 125 (1909).

* GF with inf.mirage, 10. August 1909 at Zandvoort
* ". . . ein Spiegelbild auf der Meeresfläche entstand. Nur ungefähr eine
* Sekunde vor dem völligen Verschwinden   w u r d e   d a s   l e t z t e
* s e g m e n t   d e r   S o n n e   g l e i c h z e i t i g   m i t   d e m
* S p i e g e l b i l d e   grün."
* Not certain about details, "da mir die Erscheinung neu war und mich zu
* sehr überraschte." (typical BEGINNER'S REACTION)
* Also a good story about the "junge Dame": "Im Augenblick, als die Sonne
* verschwunden war, wandelte sie sich mit dem Ausdruck höchsten
* Erstaunens zu mir und sprach nur das eine Wort: grün!"


E. Hawks
“The green flash [letter 70],”
English Mechanic 90, 67 (1909).

* Ellison Hawks reports a 6-second flash, "peacock blue" at end
* Fisher has "Hawkes" in error, and F.K. does too.
* No. 2317, Aug. 20, 1909
* Fisher #54


C. T. Whitmell
“The green flash [letter 98],”
English Mechanic 90, 95 (1909).

* Whitmell asks for an explanation of "the rarity of the flash although
* circumstances are apparently quite favourable for its appearance."
* "I have seen the green flash at least a score of times, but failures
* have outnumbered successes.
*      "The difficulty of the problem is enhanced by the fact that a
* telescope directed to a low sun in a clear sky invariably exhibits
* atmospheric dispersion, the upper limb being fringed with bluish-green,
* the lower with orange-red, and the green flash is simply the ultimate
* development of the former colour upon the tip of the setting sun."
* No. 2318, Aug. 27, 1909


E. Hawks
“The green flash,”
Leeds Astron. Soc. Journal & Trans. 17, 50 (1909).

* Reprints of the two E.M. letters by Hawks and Whitmell
* Hawks letter [70] dated Aug. 14, 1909
* Thanks to Ray Emery for supplying this!


C. T. Whitmell
“The green flash,”
Leeds Astron. Soc. Journal & Trans. 17, 50 (1909).

* Reprints of the two E.M. letters by Hawks and Whitmell
* Whitmell letter [98] dated Aug. 27, 1909
* Thanks to Ray Emery for supplying this!


A. Miethe
“Dämmerungsbeobachtungen,”
Prometheus (Berlin) 20, 737–740 (1909).

* pompous presentation of GF in a description of twilight phenomena
* must be # 1035, from F.K.'s citation
* O'C #90 -- there is a second installment on pp. 753-756, he says.


R. C. Lippincott
“The green flash [letter 204],”
English Mechanic 90, 188 (1909).

* LIPPINCOTT vs. WHITMELL in E.M. (1909)
* "R. Claude Lippincott" sees a green flash at last; but maintains it is
* due to "simultaneous physiological contrast".
* No. 2322, Sept. 24, 1909
* Fisher #79


C. T. Whitmell
“The green flash [letter 238],”
English Mechanic 90, 211 (1909).

* Whitmell replies to Lippincott:
* No. 2323, Oct. 1, 1909


R. C. C. Lippincott
“The green flash [letter 305],”
English Mechanic 90, 261 (1909).

* Lippincott augments his description, asserting "simultaneous contrast".
* No. 2325, Oct. 15, 1909


C. T. Whitmell
“The green flash [letter 324],”
English Mechanic 90, 283 (1909).

* Whitmell replies to Lippincott:
* No. 2326, Oct. 22, 1909


R. C. C. Lippincott
“The green flash [letter 385],”
English Mechanic 90, 332 (1909).

* Cann Lippincott has his final say in E.M., shooting himself in the foot
* as he does so:
* "With reference to Mr. Whitmell's suggestion that I should study the
* appearance of the sun through a telescope when it is low or setting, I may
* remark that the telescope would introduce a new condition, which would
* produce a modification of the natural phenomenon. My present residence
* is not well situated for observations of either sunrise or sunset, because
* it is surrounded by hills on which there are trees, which interfere with
* the view of the sun about the time of sunrise or sunset."
* No. 2328, Nov.5, 1909


[meeting report]
“Adunanza ordinaria del 14 Maggio [1907],”
Atti della Società dei Naturalisti e Matematici di Modena , series 4, 12, 75 (1910).

* CARLO BONACINI's early GF credential
* Short abstract of a paper presented in 1907: he saw the red and green
* rims, and realized that they should be attributed to atmospheric
* dispersion; and "that to this is connected, at least in part, the noted
* and discussed phenomenon of the `green ray'."


E. Andersson
[review of Groff's "Oeuvres égyptologiques"]
Sphinx 13, 25–31 (1910).

* Review of Groff's collected works
* Probably this belongs in the "biographies" file, but is included here
* for Ernst Andersson's comments on Groff's GF work: ". . . une série
* d'études très intéressantes." He seems to think it Groff's best work,
* and quotes at some length from Groff's conclusions.
*
* MANY THANKS to Orell Witthuber, Fachgebiet Aegyptologie der
* Philipps-Universität (Marburg, Germany) for providing this useful
* reference!


S. P. Thompson
“The Life of William Thomson, Baron Kelvin of Largs,” in Vol.II
(Macmillan, London, 1910), p. 1147.

* LORD KELVIN's first GF
* ". . . the first time I saw it, it passed quickly from white through green,
* to intense violet. The sun was very clear, with very little of the
* redness which we generally see at sunset." That was in 1896, before the
* sunrise flash of 1899.
* (See next 2 papers for discussion.)
* Fisher #65, O'C #70


E. A. Childe
“The green ray,”
JBAA 20, 321 (1910).

* little more info from Silvanus P. Thompson; comments on violet
* Fisher #24


C. T. Whitmell
“The green flash,”
JBAA 20, 383 (1910).

* Whitmell quotes most of Kelvin's Nature paper; further comments on violet


E. Carthaus
“Über seltsame optische Phänomene im Hochgebirge von Java,”
Weltall 10, 245–248 (1910).

* Described in part of one paragraph on p.246
* This is mostly about other weather phenomena, esp. anti-crepuscular rays.
* "Hochgebiete" turns out to be 1500-2000 m.
* Full title: Das Weltall, Illustrierte Zeitschrift für Astronomie und
* verwandte Gebiete, herausgegeben von Dr. F.S.Archenhold, Direktor der
* Treptow-Sternwarte


G. H. Baines
“The `green flash' at sunset,”
Symons's Met. Mag. 45, 53 (1910).

* ". . . about ten (or less) seconds after it had disappeared a bright green
* single flash, just like a railway signal lamp, but brighter far, met our
* view. . . "
* Fisher #5


H. R. Mill
“Three green rays in one sunset,”
Symons's Met. Mag. 45, 102–103 (1910).

* 3 GFs on an island horizon
* ". . . the reputed rareness . . . is a striking proof of the unobservant
* habits of most people."
* error: "Whitmill" for Whitmell
* Fisher #99


W. Krebs
“Seltene Erscheinungen auf der Sonne. Grüne Strahlung und chromosphärisches Netz,”
Phys. Z. 11, 645–648 (1910).

* KREBS's crank connection of green rims with solar activity
* ". . . eine grüne Umrandung besonders des Ostrandes der untergehenden
* Sonne . . .      der Westrand, solange es sichtbar war, gewöhnlich nicht die
* gleiche Erscheinung erkennen ließ." He seems to have used the low
* Sun simply to make use of the atmospheric extinction to render it
* observable in a 3-inch telescope. The reappearance of an active
* region "am Ostrande der Sonne war . . . begleitet von ausgeprägter
* grüner Strahlung. Besonders deutlich trat sie auf bei dem ersten
* Akte des Sonnenunterganges hinter einer 3° hohen bleigrauen Bank.
* Diese erwies sich in der Folge als der total reflektierende Teil einer
* Sprungfläche der Atmosphäre. Denn unterhalb des etwa gradbreiten
* dunklen Bandes, hinter dem die Sonne verschwunden war, trat sie wieder
* hervor. Doch war die Scheibe erheblich breiter und kirschrot statt, wie
* vorher, orangefarbig.  . . .      die grüne Berandung stellt sich vor und
* nach dem Passieren des dunklen Bandes, das sein Auftreten der
* Totalreflexion verdankte, am natürlichen Ostrande der Sonne ein, während
* sie an dem künstlich von diesem Bande geschnitteten Ostrande ausblieb."
* Nov. issue.


A. Kühl
“Optische Erscheinungen in der Atmosphäre. Der grüne Sonnenstrahl,”
Jahrb. Astron. Geophys. (1910) 21, 345–347 (1911).

* Kühl's "Nachbilderscheinung" with nice colored plate (Tafel V)
* He starts off by quoting Flöckher's account in full, and argues
* (correctly) that the green rim is too narrow and faint to be visible:
* ". . . durch die Absorption der Atmosphäre . . . muß schon der Farbrand
* wegen des Auseinanderziehens der Spektrum erheblich lichtschwächer
* als das Sonnenbild erscheinen und erleidet zudem eine vom Gelb zum Blau
* wachsende Absorption. Schon aus diesem Grunde scheint es zweifelhaft, ob
* die Dispersion die auffällige Erscheinung des grünen Strahles erklären
* kann." [A nice prefiguring of Dietze's quantitative demonstration!]
* But, strangely, ". . . der grüne Strahl, wenn er objektiv vorhanden
* wäre, doch leicht in einem Fernrohre bei niedrigem Sonnenstande . . . in
* Erscheinung treten müßte --- was nie beobachtet ist."
* So he knows nothing of Winstanley, Rambaut, Whitmell, etc.
* Finally, he admits that, in choosing between the two explanations, "Man
* könnte z. B. auch an eine Kombination beider denken, derart, daß die
* Nachbilderscheinung durch einen schwachen vorhandenen Farbring noch
* verstärkt erscheint." Which comes pretty close to the truth.
* His reference to p.56 of Arrhenius's "Kosm.Physik" makes no sense.
* Note that the date is 1910, but the actual publication date is 1911


T. B. Blathwayt
“Optical [reply to query 488],”
English Mechanic 93, 409 (1911).

* Blathwayt's DEMONSTRATION of GF
* About the middle third of this long paragraph deals with GF:
* "I find you can imitate it well by holding a little above your eye, and
* between it and a candle, an ordinary hand magnifying-glass, in such a way
* that the candle rays strike it at a very great angle on the upper surface
* of the glass. This produces two or three discs of light, and if you then
* turn the glass so that it lies nearly edge-on to the candle, the discs
* disappear, and at the instant of vanishing the last rays are all green."
* He also has the screwey notion that "in the usual condition of weather
* the various layers of air are of very different refractive powers, and
* thus act as a compound lens, and are free from colour." [!]
* But (maybe from dumb luck), he also says, "Perhaps it depends also on
* the height one is above the sea-level."
* Theodore B. Blathwayt was a noted discoverer and observer of comets;
* see his brief obituary in JBAA 45, 249 (1935)
* No. 2410, June 2, 1911


C. T. Whitmell
“The green flash [letter 481],”
English Mechanic 93, 432 (1911).

* Whitmell corrects Blathwayt's notion that the sea acts as a lens; adding,
* ". . . the sea horizon, being more definite, is apparently more favourable.
* It is possible also that the condition of the air over a water surface may
* be more favourable."
* No. 2411, June 9, 1911
* Fisher #155


C. T. Whitmell
“The green flash and the earth's shadow,”
Yorkshire Post , 9 (July 24, 1911).

* Whitmell reports a CLOUD-TOP flash
* "This is the celebrated Green Flash, so often looked for, but, for some
* mysterious reason, so seldom seen."
* (Letter dated 22 July 1911, published on Monday the 24th.)
* The previous page contains a note on "The Intense Heat", reporting that
* "Temperatures of over 90 degrees in the shade were recorded at several
* places in England on Saturday [i.e., the day of Whitmell's observation].
* Saturday was the tenth day during July on which the general level of
* shade temperature has been above 80 degrees, and the 23rd day in
* succession on which no rain fell on London."
* The letter following Whitmell's is amusing. . .


C. T. Whitmell
“The green flash and the earth's shadow,”
Leeds Astron. Soc. Journal & Trans. 19, 51 (1911).

* Whitmell reports a CLOUD-TOP flash
* "This is the celebrated Green Flash, so often looked for, but, for some
* mysterious reason, so seldom seen."
* (Letter dated 22 July 1911)
* Thanks to Ray Emery for supplying this!


C. T. Whitmell
“The green flash, 1911,”
Leeds Astron. Soc. Journal & Trans. 19, 51 (1911).

* Whitmell's scoreboard for 1911
* Useful for magnifications: "Binocular 9, Opera Glass 3".
* "Of 13 observations, only four . . . were satisfactory."
* The last observation was Sept. 6.
* Thanks to Ray Emery for supplying this!


E. E. Markwick
[letter 250]
English Mechanic 94, 186 (1911).

* "GREEN SPOT"
* Col. Markwick comments on his Mediterranean cruise:
* "This appears quite well known to many naval officers, one of whom
* called it the ``green spot.'' He had been acquainted with it for years."
* Only the 2nd paragraph of this long letter is headed "The Green Flash".
* No. 2426, Sept.22, 1911
* Fisher #86


T. B. Blathwayt
[letter 360]
English Mechanic 94, 278 (1911).

* Blathwayt thanks Whitmell, and adds, "I saw a brilliant Prussian-blue
* flash some time ago."
* Only the first short paragraph of this long letter deals with GF.
* No. 2430, Oct.20, 1911
* Fisher #9


E. E. Markwick
[letter 796]
English Mechanic 94, 582 (1912).

* Not a GF observation, but relevant comment on CONTRAST EFFECTS:
* "Gold, orange, and carmine were the prevailing hues . . . ."
* "The street lamps looked quite green by contrast with the sky."
* (properly, this belongs in the Vision File, but is here as an observation.)
* No. 2443, 19 Jan. 1912 (note change of year near end of even-numbered
* volumes!)


Monte
BSAF 26, 9 (1912).

* Brief account of paper presented at meeting of 6 Dec. 1911
* "M.Monte . . . présente une étude sur le rayon vert. Il en a recherché
* l'explication dans de nombreux ouvrages, où l'on avance, parfois, des
* hypothèses invraisemblables, et montre que l'explication par la
* dispersion atmosphérique seule rend un compte exact du phénomène."


Dr. B(raak)
[De groene straal]
De Natuur 32, 160 (1912).

* Braak replies to an earlier question from "G.L.T. te A."
* cites the article in H&D 4, Maart 1904.
* "I have read" the standard explanation, but can't judge its worth.


J. W. Scholes
Nature 89, 351 (1912).

* BEADS again
* "About one or two seconds after the sun had set, Mr. Scholes noticed
* some ``blue-beads'' above the point where the rim had been; these remained
* visible for two or three seconds, and the green flash was seen when they
* disappeared." Could that have been a GREEN RAY?
* (This item is next to Wilbur Wright's obituary in the previous column.)
* Fisher #133


A. Carpenter
[account of meeting of the B.A.A.]
Observatory 35, 264–265 (1912).

* Captain Carpenter's presentation at B.A.A. reported


A. Carpenter
“The green flash at sunrise or sunset,”
J. B. A. A. 22, 372–378 (1912).

* SYSTEMATIC SUNRISE OBSERVATIONS at Taormina, Sicily, 700 ft above sea
* Capt. Alfred Carpenter, R.N., D.S.O. (see Who's Who)
* "I observed every sunrise except four from the 10th December 1911 to
* the 14th March 1912. . . . Out of 91 mornings' observations the
* phenomenon of the Green Flash was observed on 21 occasions. Of the
* other 70 days about 45 sunrises were hidden by clouds low down on the
* horizon or by rain, and on the other 25 mornings, owing to mist or dust,
* the Sun rose out of the water a dull red, or gold, or white."
* ". . . I feel confident that, with a horizon clear of cloud or mist, the
* Sun will always show the Blue-green Flash on rising."
* "The prevailing wind was . . . blowing off shore."
* (These seem to be mostly inferior-mirage flashes, despite the altitude.)
* O'C #12
* Fisher #12


A. Carpenter
“The green flash at sunrise and sunset,”
Q. J. Roy. Met. Soc. 38, 236 (1912).

* summary of Carpenter's JBAA paper, citing Rambaut's 1906 review as motive;
* possibly this is what incited Lippincott's 1913 return in QJRMS?
* Fisher #13


C. T. Whitmell
“The green flash,”
JBAA 22, 433–434 (1912).

* useful lists of earlier refs. in JBAA
* O'C #297


(unsigned editorial)
“The ``Green Flash'',”
Scientific American Supplement 74, 139 (1912).

* Second-hand review of Kühl's paper and Rambaut's review
* Rambaut's article is the only reference cited; it is endorsed by the
* editor.
* Aug.31, 1912 issue (No.1913) of this folio-sized weekly


[meeting report]
JBAA 23, 17–18 (1912).

* E.W.Maunder's comments are most to the point
* This was the meeting at which Cann Lippincott's paper (next) was read.
* Fisher #178, O'C #243


R. C. Cann-Lippincott
“The green flash,”
JBAA 23, 37–39 (1912).

* R.C.Cann-Lippincott has a shot at the BAA
* N.B.: the volumes and years of JBAA do not coincide!


A. Carpenter
“The green flash and the green sun,”
JBAA 23, 97–98 (1912).

* An EXCELLENT and eloquent refutation of Cann Lippincott
* N.B.: the volumes and years of JBAA do not coincide!
* O'C #13


C. T. Whitmell
“The green flash and the green sun,”
JBAA 23, 98–100 (1912).

* not so sound a reply, from Whitmell
* (stapled with the previous copy)
* O'C #154


W. F. A. Ellison
[541]
English Mechanic 96, 439 (1912).

* Ellison recalls his 1905 telescopic JUPITER FLASH in last paragraph,
* giving circumstances: "Jupiter . . . set behind a clear-cut ridge of
* mountain. This ridge was elevated 1,450ft above my station, and was nine
* miles distant, so the elevation was 1° 44'."
* No. 2490, 13 Dec. 1912
* Fisher #42


C. T. Whitmell
[letter 574]
English Mechanic 96, 461 (1912).

* Whitmell comments on Booth;
* only the last paragraph of 7 in this letter deals with the GF.
* No. 2491, 20 Dec. 1912


A. Welznig
“Der "grüne Strahl",”
Kosmos 9, 145–146 (1912).

* WERFTINSPEKTOR WELZNIG
* later "G.Welzing" or "Melzing" -- see later Kosmos references
* One sunset and one sunrise obsn. in Indian Ocean (Sunda Straits).
* Thinks it is transmitted through the water.


R. C. C. Lippincott
“Green flash,”
Q. J. Roy. Met. Soc. 39, 63–65 (1913).

* Lippincott again, this time in QJRMS
* He now reconsiders his 1906 statements: ". . . I wrongly attributed to
* successive what was in reality an example of simultaneous contrast ."
* He also now admits there are flashes ". . . occasioned by the refraction
* of the atmosphere . . . " but he still insists ". . . that in the explanation
* of the ``Green Flash'' given by Dr. A. Rambaut, Mr. Whitmell, Capt. A.
* Carpenter, and others, the three quite distinct optical phenomena above
* described have been confused . . . ."


Seitz
“Wandern u. Reisen: Der grüne Strahl,”
Kosmos 10, XXXV (1913).

* Summary of readers' responses to the 1912 "Welznig" article
* ". . . bei ruhiger See . . . "
* "Manche Mitglieder verglichen sein Licht mit dem unter dem Horizont
* stehenden Leuchtturms, der seinen Scheinwerfer nach oben aufblitzen
* läßt; andern schien er mehr nach Art einer Rakete emporzufliegen"
* = GREEN RAY ?? (Miethe's "Prometheus" article is cited.)
* N.B.: This is on p.XXXV in the colored pages:
* Title page says at bottom in small print:
* "Notiz für den Buchbinder : Es sind nur die f o r t l a u f e n d
* (arabisch) p a g i n i e r t e n Seiten auf w e i ß e m Papier
* einzubinden"
* Fortunately, L.C.'s bindery can't read German!
* Here, it's "Werftinspektor Melzing" (probably the correct spelling)


A. Carpenter
“The green flash,”
Q. J. Roy. Met. Soc. 39, 153–154 (1913).

* Carpenter takes Lippincott's bait
* "Most of Mr. Lippincott's article appeared previously in last October's
* number of the Journal of the British Astronomical Association , and was
* fully answered by Mr. C. T. Whitmell and myself in the November number of
* the same journal. It seems a pity that Mr. Lippincott should repeat his
* erroneous descriptions of the Green Flash after his errors have been
* pointed out."


L. Libouban
“Observation du rayon vert,”
Ann. Soc. Met. de France 61, 323 (1913).

* A sea-captain sees a good display:
* Repeated green flashes due to heavy swell.


L. Rudaux
BSAF 27, 400–405 (1913).

* Nice drawings of green rim (Fig.180) in mountain sunset


Fouché
BSAF 27, 484 (1913).

* a useless comment
*O'C #214


A. Ignatoff
“Le rayon vert,”
BSAF 27, 500 (1913).

* a useless first observation between Sorrento and Capri
* O'C #221


R. C. C. Lippincott
“The green flash,”
Q. J. Roy. Met. Soc. 39, 327–328 (1913).

* Lippincott tries to have it both ways
* He grants refraction, but concludes that "the Green Flash most likely to
* attract the attention of the ordinary observer is the Green Flash due to
* Simultaneous Complemental Contrast." Ah, the power of ignorance!


Capt. A. Carpenter
“The green flash,”
JBAA 24, 187–189 (1914).

* Discussion of the following paper at BAA Meeting:
* There are several interesting comments, notably by M.A.Ainslie on
* variations of dip. What are the "American" observations he alludes to?
* He emphasizes the importance of height of the observer.
* Mrs. Brook's observation recalls Minnaert's later experience of running
* uphill.


Capt. A. Carpenter
“The green flash,”
JBAA 24, 216–217 (1914).

* EARLY FLASH IN INFERIOR MIRAGE (cf. Evershed)
* cited by Corliss as "unusual"!
* Fisher #14, O'C #187


L. Dumas
“Optique atmosphérique,”
BSAF 28, 13 (1914).

* utter nonsense about refraction through WATER


G. Isely
“Optique atmosphérique,”
BSAF 28, 165–166 (1914).

* a second BLUE SUNRISE flash over the ALPS


G. Isely
“Optique atmosphérique,”
BSAF 28, 271 (1914).

* BLUE SUNRISE flash over the ALPS


Ch. Salen
“Optique atmosphérique,”
BSAF 28, 271 (1914).

* BLUE flash of VENUS


R. C. T. Evans
“The `green ray' at sunset,”
Nature 93, 664 (1914).

* WAVE modulation (cf. Franklin-Adams's report)
* "I was using binoculars, and remarked that I had never seen the horizon
* so sharp. The waves could be seen on the edge of the sky."
* "The green line seemed to be broken into three, possibly by waves . . . ."
* Fisher #43


Kr(itzinger)
“Der grüne Strahl,”
Sirius 47, 209–210 (1914).

* Pogg. says Hans-Hermann Kritzinger was publisher of Sirius
* Kritzinger first cites and quotes much of Prof. Flöckher's 1909
* observation, reported in Mitt.VAP. Then he describes his own.
* Here he cites Kühl's article in "Der Sammler"; from the section quoted,
* it's plain that Kühl had never seen a GF (though Kritzinger describes one
* he had seen, along with a plain description of a SOLAR AFTERIMAGE, of
* which he says, "Daß diese . . . ein Agglommerat von Sonnennachbildern
* gewesen ist, scheint mir wohl kaum möglich . . . .")
* This is in the Sept. issue of Sirius
* Fisher #69


C. T. Whitmell
“The red flash,”
Nature 94, 61 (1914).

* WHITMELL on TERMINOLOGY
* "I venture to think that `flash' is a more suitable term than `ray,' for
* the latter may lead people to suppose that a long streamer of light is to
* be expected."
* Fisher #156, O'C #155


W. M. Flinders Petrie
“The green flash,”
Nature 94, 88 (1914).

* FLASH IS COMMON -- W. FLINDERS PETRIE (Piazzi-Smyth's Pyramid opponent)
* "At sea I have always seen it, if the horizon is clear and not too red."
* Petrie was a famous archaeologist who made several trips to Egypt.
* (cf. Whitmell, 1908)
* Fisher #112, O'C #104


Capt. A. Carpenter
“The green flash,”
JBAA 25, 47 (1914).

* Flash over "roof of the Russell Hill Schools, which are distant 1 1/4
* miles and only 50 feet higher than my house . . . ."
* Compared to the following observation by Edmund Clark.
* Fisher #15


J. E. Clark
“The green flash,”
JBAA 25, 47–48 (1914).

* Flash over "the roofs of Banstead Asylum, nearly 4 miles distant across
* the main Brighton Road valley and of just the same elevation."
* mentions 2 flashes he had "previously seen once from the Lion's Head
* Hill, Capetown, and once on the South Atlantic."
* NOTE that both this and Capt. Carpenter's flash were seen the same
* evening.
* J.Edmund Clark
* Fisher #28


P. C. Melzi D'Eril
“Le rayon vert,”
BSAF 28, 425 (1914).

* 10-second flash; otherwise similar to the Howard-Young note in S&T, 1957
* Signed "P.Camille Melzi D'Eril"; properly (in Italian), Padre Camillo
* Melzi d'Eril -- director of the geodynamic observatory in Florence.


C. Flammarion
“Le rayon vert,”
BSAF 28, 425–426 (1914).

* FLAMMARION's flash; useless
* O'C #212


J. K.
“De groene straal,”
Hemel en Dampkring 12, 86–88 (1914).

* cites the Sirius paper in Sept., partly translated into Dutch
* Also cites Kühl in "Sammler", 28 Juli 1914, and repeats his
* after-image explanation, which Kater seems to find persuasive.


[A. A. Nijland]
“Opmerking van A.A.N.,”
Hemel en Dampkring 12, 88 (1914).

* Nijland's comments on the above
* "It is really peculiar that people call the afterimage for help to explain
* the green flash again and again, without taking the trouble to find out,
* either in the literature or by their own observation, whether the
* phenomenon is to be seen at sunrise." After citing some examples of his
* own, he adds: "It is clear that the afterimage can hardly explain these
* morning observations."


W. G. Duffield
“The green flash at sunset and sunrise,”
Observatory 37, 452–453 (1914).

* Both ADAPTATION and PHYSICS are involved:
* "It is possible that the reason why doubt has been cast upon records of
* the green flash is that the colour may arise in the two different ways
* suggested above . . . ."
* 3 GFs observed; one probably affected by adaptation; one at sunrise.
* O'C #202; Fisher #37


[Prof. Dr. ] Riem
“Eine Beobachtung des grünen Strahles,”
Naturwissenschaftliche Wochenschrift 29, Nr. 40, 636 (1914).

* a report from moderately high latitude (57.6 deg.N)
* GF explicitly connected with MIRAGE and DISTORTION phenomena:
* "Es waren dabei über der See oft merkwürdige Verzerrungen und Fata
* Morgana- Erscheinungen wahrzunehmen . . . ."
* . . . and with cold air: ". . . verbunden mit starker Abkühlung der Luft."
* A classic mock-mirage flash, in which he mistakes a duct edge for
* the sea surface: ". . . an den beiden Stellen, wo Sonnenrand und
* Meeresfläche sich berühren, der Rand sich grün färbte, diese Färbung
* lief mit großer Geschwindigkeit nach oben bis zur Vereinigung, so daß
* der ganze noch ziemlich lange Sonnenrand in leuchtendem Smaragd oder
* Malachitgrün strahlte. . . . Dieser ganze Vorgang hat etwa 2 - 3 Sekunden
* gedauert. Es war also die Sonne durch anormale Refraktion noch über den
* Horizont gehoben gewesen."
* This is Band 13, N.F.; 4. Okt.


Dr. Kritzinger
“Anregungen und Antworten: Der Grüne Strahl,”
Naturwissenschaftliche Wochenschrift 29, Nr. 50, 799 (1914).

* the infamous KRITZINGER paper, so criticized by Mulder (deservedly)
* Contradicts Riem's earlier appeal for more observations in Nr.40, saying
* that "Zunächst ist das Phänomen inzwischen bereits vollständig erklärt
* und dann sind solche Versuche recht gefährlich . . .      Man weiß, daß
* Galilei durch unzweckmässige Sonnenbeobachtungen erblindete," and
* mentions cases of eclipse blindness. Then he asserts that "Vielleicht
* mißlingt aber dann gerade die Verfolgerung der an sich sehr interessanten
* Erscheinung, weil diese nämlich r e i n s u b j e k t i v ist."
* Here he cites Kühl's experiments in "Sirius", claiming that "eine
* gewisse Zitterbewegung" is required to intensify the afterimage, and that
* "Die unregelmäßige Verteilung verschieden erwärmter Luftschichten ist
* für die Hervorrufung der Zitterbewegung der Sonne wichtig, hat aber mit
* der `anormalen Refraktion' nichts zu tun."
* It's hard to find more misinformation, or bad advice, in so small a
* space anywhere else in the GF literature!
* This is Band 13, N.F.; 13. Dez.
* Fisher #67, but not read by him; he gives the N.F. vol., without "N.F."


J. Riem
“Beobachtung des grünen Strahls,”
Astron. Nachr. 200, 51–54 (1915).

* a detailed observation of the evolution of an inf.-mir. flash,
* observed through 6x30 binoculars
* This is a re-telling of the observation that Kritzinger objected to.
* O'C #269


"Carcinologist"
“Phenomena at sunset [Query 942],”
English Mechanic 100, 530 (1915).

* Attentive observations of GF and anti-crepuscular rays
* [of the GF]: "The topic is a good one for argument on board ship."
* No. 2598, Jan. 8, 1915


H. P. Hollis
[letter 718]
English Mechanic 100, 559 (1915).

* Merely summarizes Whitmell's views briefly.
* The GF part of this LONG letter is 1 para. 2/3 down
* No. 2600, Jan. 22, 1915


D. W. Walton
“Phenomena at sunset [letter 942],”
English Mechanic 101, 18 (1915).

* 1-sentence explanation of GF
* No. 2601, Jan. 29, 1915


C. T. Whitmell
“Phenomena at sunset [letter 943],”
English Mechanic 101, 18 (1915).

* Whitmell endorses Hollis's explanation.
* No. 2601, Jan. 29, 1915


"J. W. S."
“Sheaf of rays in east before sunset [reply to query 942],”
English Mechanic 101, 18 (1915).

* Crepuscular rays, not GF
* No. 2603, Feb. 12, 1915


A. W. Porter
“The Green Flash,”
Nature 94, 672 (1915).

* AFTERIMAGES demonstrated
* "It would not be fair for me to dogmatize and assert that this is
* the only phenomenon which comes under the head of the green-ray. But it
* is certainly the only one which I succeeded in seeing; and
* it must always be present even on the possible rarer occasions when
* colour changes arising from dispersion are also evident."

* (See also Nature 95,194(1915) for presentation to Phys.Soc.)
* Feb.18, 1915
* Fisher #119


A. Schuster
“The green flash,”
Nature 95, 8 (1915).

* refers to his 1875 observation, and others
* "Those who want to see the appearance at its best should keep one eye
* closed as long as possible, and when the sun is just about to disappear,
* shut the eye which has been watching the setting sun, and open the
* other, which is then unaffected by the troublesome after-images which
* are otherwise seen."
* Fisher #135, O'C #280


C. T. Whitmell
“The green flash,”
Nature 95, 35–36 (1915).

* Whitmell's comments on Porter, above; a good, concise summary of the matter.
* Refers to the 1906 debate in Symons's Met.Mag.
* ". . . I have observed the flash more than a hundred times. . . ."
* ". . . the nature of the horizon, provided it is clean-cut and low down,
* makes but little difference. It may be of cloud, land, or water, and, of
* course, the last is best."
* N.B.: recommendations in use of telescope (x100) and binoculars (x8).
* Fisher #157, O'C #156


W. G. Duffield
“The green flash,”
Nature 95, 66 (1915).

* cites his sunrise-flash paper in Obs., Dec.1914
* O'C #203; Fisher #38


T. B. Blathwayt
[letter 249]
English Mechanic 101, 205–206 (1915).

* Blathwayt slightly mis-quotes (and does not cite!) a literary reference:
* "The sun went down in the sea, and went out like a blue spark."
* (This turns out to be Conder, 1878 -- another pre-Verne observation!)
* The GF par. is in last col., p.205
* No. 2610, April 2, 1915


A. W. Porter and E. Talbot Paris
“A demonstration of the green flash at the setting of an artificial sun,”
Nature 95, 194 (1915).

* just a brief description of a talk to the Physical Society
* O'C #108; Fisher #121


[unsigned but obviously T. B. Blathwayt]
“The ``green ray'' at sunset,”
Nature 95, 204 (1915).

* This, though unsigned, is clearly T.B.Blathwayt (cf. his April 2 E.M.
* item, and his earlier one in E.M. June 2, 1911.)
* This is in the April 22, 1915 Nature.
* Fisher #10


J. Evershed
“The green flash,”
Nature 95, 286 (1915).

* EVERSHED and MIRAGES and VENUS
* "It seems to me very probable that the phenomenon is in some way
* connected with the abnormal conditions which at sea produce mirage
* effects."
* (cites his 1900 Venus obsn.)
* Evershed succeeded Michie Smith as Director at Kodaikanal in 1911.
* O'C #31; Fisher #44


W. G. Levander
“The green flash,”
JBAA 25, 349 (1915).

* useless query
* O'C #230


H. P. Hollis
[letter 435]
English Mechanic 101, 379–380 (1915).

* Hollis refers obliquely to the Nature discussion, and quotes Evershed
* The GF part is near the end, on p.380
* No. 2618, May 28, 1915


A. W. Porter
“The green flash at sunset,”
Mon. Wea. Rev. 43, 283 (1915).

* Porter's note from Nature 94,672 (Feb.18, 1915) reprinted in June MWR
* Fisher #120


C. A. and jr.
“Pernter and Exner on the green flash,”
Mon. Wea. Rev. 43, 283–284 (1915).

* The reprint of Porter's paper immediately followed by a summary of
* Pernter & Exner's older treatment, by Cleveland Abbe Jr.
* Discussion; Prosper Henry and Julius mentioned
* A "crank" theory is mentioned, based on the supposition that the green
* color is due to water vapor, and that this is much more abundant near
* the horizon over the sea. This ignores the many GFs seen over land
* horizons; but the editor is apparently quite unfamiliar with the GF
* literature. Of course there are no numbers attached!
* Actually, this idea was presented by Exner on the last page of the
* 1910 edition of P&E's Met.Optik.      But it was first mentioned in the
* editorial in MWR 33, 408 (1905) and there attributed to Tyndall.
* Could that be where Exner got the idea?


Dr. Kritzinger
“Der grüne Strahl,”
Met. Z. 32, 281 (1915).

* A reprint of Kritzinger's awful note from Naturwiss. Wochenschrift
* Again Kühl's work via Kritzinger in "Sirius" is cited.
* Fisher #68


G. Flaislén
“Le rayon vert,”
BSAF 29, 410 (1915).

* GREEN RAY over a field of corn at sunset
* ". . . une ligne vert, lumineuse, horizontale, de laquelle jaillissait un
* rayon vert vertical."
* O'C #211 -- name spelled wrong there.


Dr. C. Braak
“Een reeks waarnemingen van den Groenen Straal,”
Hemel en Dampkring 13, 52–56 (1915).

* Another classical SCALED DISPERSION CALC. (F to C = 1/80)
* (translated in Mulder's book)
* The entry in C. F. Talman's list of "Recent papers bearing on meteorology
* and seismology" on pp. 421-422 of the August issue of MWR confirms
* Mulder's attribution of this to the August issue, and gives Braak's
* given name as Cornelis.
* Mis-cited by Mulder (on p. 50) and Feenstra Kuiper


C. Jensen
“Meteorologische Optik,”
Fortschritte der Physik 71, 280–284 (1916).

* German abstracts of 1914-1915 papers on the GF
* Starting with Whitmell's "red flash" paper in Nature (1914); continuing
* with Petrie, Porter, Schuster, Duffield, [Blathwayt], Evershed, (Abbe),
*      Riem, Kühl, Kritzinger, "J.K.", and Nijland's remarks.
* The reviewer is "Prof. Dr. Chr. Jensen in Hamburg."
* In section 2.I, "Meteorologische Optik", Abt.3, pp. 257 ff.


A. W. Mansergh
“The green flash [letter 396],”
English Mechanic 102, 346 (1915).

* Drawings of crepuscular rays
* No. 2642, Nov. 12, 1915


C. T. Whitmell
“The green flash [letter 442],”
English Mechanic 102, 370 (1915).

* Whitmell points out that Col.Mansergh's observation is crep.rays, not GF
* "I have always strongly advocated the term flash rather than ray,
* because the latter term unfortunately led many persons to expect to see
* long green streamers shooting up into the sky."
* No. 2643, Nov. 19, 1915


A. Carpenter
“The green flash,”
JBAA 26, 168 (1916).

* Capt. Alfred Carpenter, R.N., once again:
* "distinct blue green flickers" as the upper limb sank behind cloud.
* 2 flashes above cloud layers; "I was using an opera glass, and I do not
* think the flashes would have been bright enough for the unaided eye."
* Fisher #16


P. Clem. Campariole
[letter 260]
English Mechanic and World of Science 103, 209–210 (1916).

* A TEXTBOOK-QUALITY GREEN RAY
* "Within about half a second of the disappearance of the Sun the pale
* green flash rose up, rather more deliberately than I expected, from where
* the Sun had gone down. It lasted about a quarter of a second and then
* disappeared. It did not have any sharp outline, but I got the impression
* that its height was greater than its width, that it occupied less space
* than the disc of the Sun, and that the borders were paler than the middle
* and lower part."
* If this is not a green crepuscular ray, I don't know what is!
* [The GF part is only the last paragraph, on p.210]
* No.2663, April 7, 1916
* Fisher #11


G. Guglielmo
“Intorno ad alcune particolarità del raggio verde,”
Atti R. Accad. Lincei Rendic. , series 5, 25:1, 296–302 (1916).

* GUGLIELMO's first paper
* He comes down strongly in favor of atmospheric dispersion as the main
* cause, though atmospheric absorption (this seems to refer to Exner's
* mechanism) and contrast effects "could accompany and modify the color and
* perhaps the duration of the ray."
* He considers but rejects Exner's water-vapor mechanism: "I don't believe
* that the absorption was produced by water vapor because the amount of it
* can be deduced pretty well from the temperature and the degree of humidity,
* and it bore no fixed relation to the color."
* "It's clear that various causes can influence the intensity of the
* green ray: the great brightness of the sun, fatiguing the eye, could
* make the green ray appear less intense; the brightness of the atmosphere
* where it is produced could dilute it and render it less evident; dust
* particles could have such dimensions as to absorb just those rays of which
* it is composed; finally, because of the movement of the green rim, it
* could happen that at the instant when the green ray is produced, it would
* have a minimum width or dilute coloration which would decrease the
* intensity."
* MODULATION BY WAVES suggested:
* "The wavy motion of the green rim continually varies its width, and could
* produce an increase or decrease of the green ray. Similarly, if the sun
* sets (or rises) at sea, the motion of its surface, raising and lowering by
* the effect of the waves which could be invisible to the naked eye and
* without a fixed point of reference, could cause an increase or a decrease
* of its duration."
* "Rendiconti, Reale Accademia dei Lincei. Classe di scienze fisiche,
* matematiche e naturalï
* O'C #44


G. Guglielmo
“Sulla durata teorica del raggio verde,”
Atti R. Accad. Lincei Rendic. , series 5, 25:1, 417–423 (1916).

* The other Guglielmo paper, calculating latitude and declination effects
* Includes the SPECIAL EFFECTS NEAR THE POLES:
* "Finally, at the poles the rising or setting is not caused by the
* rotation of the earth but by the increase or decrease of the declination,
* and the duration of the green ray will be the time needed for the
* declination of the point considered to vary by 15'', and will be about a
* quarter of an hour.
*      A still greater duration of the green ray can (theoretically) be
* reached about 11 km (6') from the pole, in the evening around the vernal
* equinox or the morning near the autumnal equinox, when the slight decline
* or ascent of the sun, due to the rotation of the earth, will be
* compensated respectively by the ascent or decline due to the increase or
* decrease of the solar declination." He finds a duration over an hour.
* O'C #45


(editorial report)
Nature 97, 228–229 (1916).

* 1-paragraph abstract of Guglielmo's paper earlier this year
* May 11, 1916 issue


H. Metcalfe
“``The Green Flash'',”
Manchester Guardian , p. 4 (1 July, 1916).

* Metcalfe triggers a brief exchange with his report (see also his E.M.letter)
* Notable for the following comment, rediscovering Evershed's idea:
* ". . . the sea plays no necessary part in the matter, for the flash can be
* seen when the horizon is a land instead of a water one, and the flash has
* also been seen as the sun has set behind a low bank of clouds, even in
* towns and cities far removed from the sea. At the same time, the sea
* horizon . . . is apparently more favourable. It is possible also that the
* condition of the air over a water surface may be more suitable."
*      He continued: "The flash was observed and its appearance recorded by
* the ancient Egyptian astronomers 3,000 B.C." (Evidently a reference to
* William Groff's works.)


A. N. Brayshaw
“``The Green Flash'',”
Manchester Guardian , p.10 (3 July, 1916).

* Brayshaw's observation is not useful. He refers to Metcalfe's, the
* previous Saturday; and Metcalfe quotes him in E.M.104,12. (July 28?)


A. A. Buss
“Special solar phenomena during the second quarter of 1916 – disc phenomena [537],”
English Mechanic and World of Science 103, 469–470 (1916).

* Albert Alfred Buss sees a GF in his penultimate paragraph:
* "The green flash was also observed well during a few bright days' stay
* at the seaside, but a competent friend expressed his belief that the green
* colour seen at the moment of the vanishing sun is the complementary effect
* of the reddish glare filling the eye just the moments before."
* No. 2676, July 7, 1916


H. Metcalfe
“The green flash [541],”
English Mechanic and World of Science 103, 470 (1916).

* Metcalfe's first letter of July 1 (bottom of col. 2)
* He reports an apparent inf.-mir. flash, lasting "two or three seconds."
* "The atmosphere was unusually clear at the time, a cold north-easterly
* wind blowing . . . ." on June 28.
* Quite a long list of previous reports in E.M. is given.
* No.2676, July 7, 1916
* Fisher #92


H. Metcalfe
“The green flash [542],”
English Mechanic and World of Science 103, 470 (1916).

* Metcalfe's second letter of July 1 (top of col. 3)
* Appeals to Whitmell for explanation of the latter's report in Leeds Trans.
* 15, 67 (1907)
* No.2676, July 7, 1916


C. T. Whitmell
“The green flash [559],”
English Mechanic and World of Science 103, 490–491 (1916).

* Whitmell's reply to Metcalfe
* No.2677, July 14, 1916
* Fisher #158


"Alpha Ceti"
“The green flash [560],”
English Mechanic and World of Science 103, 491 (1916).

* another reply to Metcalfe, from a novice
* ". . . this is the first time that I have seen it, and I must say that its
* brightness somewhat astonished me."
* No.2677, July 14, 1916
* Fisher #2


H. Metcalfe
“The green flash [6],”
English Mechanic 104, 12 (1916).

* Metcalfe thanks Whitmell [559, above] and "Alpha Ceti" [560], and
* quotes from Brayshaw's letter of 3 July in the Manchester Guardian.
* He also corrects an error in his earlier letter.
* [Date not available, but must be July 28, No. 2679.]
* Fisher #93


C. T. Whitmell
“The red flash and the green [28],”
English Mechanic 104, 30 (1916).

* Whitmell follows up Metcalfe's letter, and reports his July 22 observation
* which includes a GREEN RAY:
* "Over the point, at which the green flash was seen, there hovered for a
* moment a tiny wisp of light, too faint to have its colour determined. It
* was probably bluish."
* He adds his now-standard ADVICE: "For those who have not yet seen the
* flash I strongly advise the use of a binocular, as it is of great
* assistance."
* No.2680, Aug. 4, 1916
* Fisher #159, O'C #298


A. A. Buss
“The green flash [letter 51],”
English Mechanic and World of Science 104, 48 (1916).

* VISUAL SPECTROSCOPY proposed [cf. Dijkwel, 1936]
* "In any case it also would materially help forward in the settlement of
* the problem if some observer favorably situated for seeing sunrise or
* sunset across really open sea, watched with a direct-vision spectroscope."
* No.2681, Aug. 11, 1916


P. P. Gieve
“The green flash [letter 52],”
English Mechanic and World of Science 104, 48–49 (1916).

* awkward description of mock-mirage flash (cited by Corliss):
* ". . . distinct green flames . . . serrations, as a very rough saw, the
* edges of which from time to time came together and sort of floated up in
* parachute form, again and again. . . . I cannot describe what I saw in
* technical language, but the phenomena was [sic] so striking, and my
* impression so vivid that I could quite well describe in a roundabout way
* what I saw to anyone interested."
* No.2681, Aug. 11, 1916
* Fisher #48


H. Metcalfe
“The green flash [letter 53],”
English Mechanic and World of Science 104, 49 (1916).

* ordinary inferior-mirage flash
* No.2681, Aug. 11, 1916
* Fisher #94


C. T. Whitmell
“The green flash and the red [letter 78],”
English Mechanic and World of Science 104, 71 (1916).

* Whitmell replies to Buss
* "It would certainly be of interest to observe the setting sun with the
* spectroscope as he suggests. But there would not be the flashing out of a
* monochromatic line, but merely a spectrum, gradually shortening at the red
* end, the green, and under favourable circumstances, the blue, being the
* last to disappear."
* probably No.2682, Aug. 18, 1916


H. L. H.
“The green flash [letter 128],”
English Mechanic 104, 112 (1916).

* MANY interesting comments in reply to Buss's letter # 51
* ". . . I think that the further North one goes, the greener and paler does
* it become." (possible LATITUDE EFFECT ??)
* probably No.2684, Sep. 2, 1916
* O'C #217; Fisher #171


"Rigel"
[letter #336]
English Mechanic 104, 353 (1916).

* vague ruminations about green flashes, buried in a long paragraph
* "Has not the colour of the sea and the atmospheric conditions something
* to do with the phenomenon? . . .      Surely, then, when so many provisions have
* to be made in observing these flashes, such flashes are due to
* atmospherical effects."
* No. 2696, Nov. 24, 1916


G. Guglielmo
“Intorno ad alcune particolarità del raggio verde,”
Boll. bimens. Soc. meteor. ital. (Torino) 36, 17–18 (1917).

* Good introduction:
* "The so-called green ray . . . has been attributed to three diverse
* causes: atmospheric refraction and dispersion, atmospheric absorption,
* an optical illusion due to contrast.
* The first of these causes, whose action cannot be in doubt, is
* certainly the most important, the other two could be involved and modify
* the color and duration of the ray."
* An experienced observer: "For many years I have had frequent occasions
* to observe the green ray. . . ." from heights of 70 and 40 m; so he sees
* mock-mirage flashes as well (see the second part, p.50).
* [This seems to be the abstract of the paper printed the previous year.]
* First part of paper read on 5 March; continues on p.49


G. Guglielmo
“Sulla durata teorica del raggio verde,”
Boll. bimens. Soc. meteor. ital. (Torino) 36, 40 (1917).

* The main factor considered is the geometry, assuming normal refraction;
* so he mentions latitude and declination, giving numerical examples.
* Paper read on 19 March; see his 1916 publication in Atti Accad.Lincei


G. Guglielmo
“Intorno ad alcune particolarità del raggio verde,”
Boll. bimens. Soc. meteor. ital. (Torino) 36, 49–50 (1917).

* Evidence for BLEACHING of GREEN CONES?
* "If the Sun is still a little above the horizon (more than 5°) and
* quite bright, and if the image is projected on a screen, the upper limb
* appears green with a little blue on the outside; if, on the contrary, it
* is observed directly under the same conditions without reducing the
* brightness too much, the limb appears blue, and the green is invisible."
* Second part of paper read on 5 March; continued from p.18


J. G. Wood
“The green flash at sunset,”
Symons's Met. Mag. 52, 100 (1917).

* HORIZONTAL GREEN RAY of the most explicit sort!
* After a morning drizzle, "the distance continued hazy until well into
* the afternoon." Then at sunset, with clouds forming overhead:
* "The disc remained quite sharp and showed no appearance of flattening,
* or change of colour, as it touched and passed down behind the hill line.
* Then, at the instant of disappearance of the last fragment of the upper
* segment, a bright emerald green flash shot out horizontally right and left
* at what would have been a tangent to the disc had it remained visible."
* This seems an excellent example of a green crepuscular ray.


G. E. Danes
“The green flash at sunrise,”
Symons's Met. Mag. 52, 115 (1917).

* GREEN RAY at sunrise? (elicited by Wood's report, above)
* "Watched sunrise and noticed a peculiar blue light on top of sun,
* immediately before sun rose . . . ."
* "The clouds were only broken sufficiently for the sun to shine through
* for about ten minutes after sunrise, the sky being overcast."
* Fisher #34


S. Barker
“The green flash,”
JBAA 28, 71 (1917).

* Dec. 1917: GF seen in HAZE
* ". . . the Sun was setting into the western haze, and assuming the usual
* form of concentric inverted saucers. The colour was a bluish green, very
* brilliant as the upper `saucer' disappeared, less so at the sinking of the
* second, after which the light became too weak to observe further."
* O'C #169


J. W. Meares
“Green ray on land,”
JBAA 28, 71 (1917).

* GF seen from 10,000 ft. height "on the Hindustan-Tibet road".
* This may be the type associated with the Nachspiegelung?
* O'C #244


S. Fujiwhara
“Green flash at sunset,”
J. Met. Soc. Japan 37, 7–8 (1918).

* a first-time observer concludes Chabot is right: dispersion is the cause


P. A. Cobbold
“A green flash,”
Symons's Met. Mag. 53, 90 (1918).

* Probably a "green Sun" due to smoke


J. G. Wood
“The green flash,”
Symons's Met. Mag. 53, 99 (1918).

* GREEN RAY distinguished from the usual "flash"; TERMINOLOGY discussed
* ". . . what Mr. Cobbold . . . describes as a green `flash' is in fact a
* change in the apparent colour of a small sector of the sun during an
* appreciable, though short space of time, and is not really to be defined
* as a flash. What I, and I think a few other Observers, have described
* was a ray or rays of light darting out from the sun's limb at its
* disappearance, and quite momentary, and so a true flash.
* "If we are to arrive at a satisfactory explanation, we must carefully
* distinguish the two phenomena."


H. Metcalfe
“The green flash,”
JBAA 28, 157–159 (1918).

* A nice TABLE of 22 observations: 8 flashes and 14 "failures"
* 2 of these were reported in English Mechanic previously.
* Note the following comment by Whitmell, who communicated these:
* "It will be noticed that Mr. Metcalfe has included failures as well as
* successes; an important point, if we are ever to arrive at a satisfactory
* explanation of the reason why the atmospheric dispersion is of so erratic
* a character." [p.159]
* NOTE: the two best, reported in E.M., both are accompanied by cold winds,
* so these are surely inferior-mirage flashes.
* Fisher #95


A. Carpenter
“Green sunset bands,”
J. B. A. A. 28, 226 (1918).

* Carpenter's red and green flashes at clouds (?? or blank strips?)
* Drawing shows Sun perfectly circular.
* ". . . the 16th May . . . after a brilliant, clear hot day . . . ."
* "I have never seen the green bands so strong, and they remained so until
* the Sun left the two cloud bands.
* "When the lower limb of the Sun first appeared below the upper cloud
* it appeared a deep red, a not unusual phenomena [sic] allied to the
* green flash."
* Fisher #17


C. T. Whitmell
“A red flash and three green flashes,”
J. B. A. A. 28, 228 (1918).

* Whitmell reports a record:
* "This is the largest number of flashes seen by me in connection with a
* single sunset."
* Fisher #160, O'C #157


Chr. Jensen
“Die Fortschritte der meteorologischen Optik in den Jahren 1914, 1915 und 1916,”
Mitt. Vereinigung von Freunden d. Astronomie u. Kosmischen Physik 28, 43–67 (1918).

* listed here for reference only; not in the GF file, as only one
* paragraph on p.59 summarizes GF literature
* "Mitt.VAP" (as the AJB has it) apparently became "Die Himmelswelt"
* later, with the same volume numbers (=year+10)


G. J. Gibbs
“The Green Flash,”
J. B. A. A. 28, 255–258 (1918).

* NICE DRAWINGS and BLANK STRIP DEPICTED
* ". . . the telescopic view showed a series of sharply defined, horizontal,
* narrow, black bands, the Sun's limb in the neighborhood of the bands
* being much distorted."
* Fisher #47


C. T. Whitmell
“The green flash,”
JBAA 29, 25 (1918).

* Whitmell comments on the previous paper; urges use of TELESCOPE
* ". . . it is now twenty-one years since I first observed the Green Flash,
* and I have seen it dozens of times . . . ."
* "As Mr. Gibbs used a telescope, perhaps I may say that . . . I have again
* and again recommended this method to those who have hitherto not been
* fortunate enough to view this beautiful phenomenon with the naked eye."
* O'C #299


G. Coutinho
“The artificial green flash,”
Obs. 42, 80–82 (1919).

* COUTINHO's ARTIFICIAL GREEN FLASH (cf. Biot & Arago in Mirage file!)
* " . . . the Sun's movement . . . corresponds to 80 centimetres in a second
* for an observer 8 metres above water (average height of promenade-deck
* in a steamer of 6000 tons)."
* Mentions motion of the ship in this regard (cf. Nijland)
* O'C #21


C. T. Whitmell
“The green flash,”
Observatory 42, 123–124 (1919).

* Whitmell comments on Coutinho
* Charles Thomas Whitmell died 10 Dec. 1919.
* O'C #158


W. J. Humphreys
“Optics of the air: green flash,”
J. Franklin Inst. 188, 433–488 (1919).

* HUMPHREYS's precursor article -- the GF is treated only on pp.452-453.
* Fisher #59, O'C #53


Ch.-Ed. Guillaume
“Le rayon vert,”
B. S. A. F. 33, 515–516 (1919).

* yet ANOTHER SCALED REFRACTION calculation! (1/146 = 1 sec)
* Metrologist Charles-Edouard Guillaume was the inventor of Invar, and
* received the Nobel Prize in physics in 1920 for his work.
* Guillaume was the Director of the BIPM and discussed the matter with
* Henri Chrétien. He invokes successive contrast.
* Good balance of dispersion and ADAPTATION of eye:
* "Toutefois, le seul fait physique n'expliquerait pas l'éclat
* remarquable que l'on s'accorde à reconnaître au rayon vert.
* Celui-ci relève d'un fait physiologique: le contraste qu'il forme
* avec la teinte rouge du soleil, à laquelle il succède
* immédiatement dans son action sur l'oeil."
* Good comparison of sunset and sunrise observations:
* ". . . peu de gens voient se lever le soleil. . . d'autre part, cet oeil,
* qui n'a pas été fatigué par la lumière rouge, ne
* possède pas l'hypersensibilité relative au vert, que nous avons
* vu étre une condition de l'éclat subjectif du phénomène."
*
* "Maintenant, une question se pose: puisque la cause du rayon vert est si
* simple, pourquoi son apparition est-elle l'exception et non la règle?"
* GOOD QUESTION!
* (Variable extinction is invoked.)
* But he mistakenly supposes sunrise flashes are rare or nonexistent, and
* so gives adaptation more than its share of the credit. Still, this is a
* surprisingly realistic and balanced presentation.
*      This is the article quoted by Mulder on p. 130 of his book.  The
* discussion he quotes on p. 129 appears on BSAF p.514.
* O'C #46, allowing for errors


anonymous
“Notes of observations,”
Leeds Astron. Soc. Journal & Trans. 27, 17 (1919).

* Whitmell's final report, at the 27 Oct. 1919 meeting
* "Mr. Whitmell gave an account of the Green Fringe he had seen round the
* upper part of the limb of the setting Sun about 5:45 p.m. on 26th
* October. On 27th October, about 5:40 p.m., Mr. Burnet and Mr. Whitmell
* again observed the Green Fringe, using a 3 in. telescope with power 50.
* Mr. Tetley observing with a binocular from Woodhouse Moor failed to see
* the Flash." (Charles Thomas Whitmell died 10 Dec. 1919.)
* Thanks to Ray Emery for supplying this!


"A. Bc."
“Note et Actualités. Physique du Globe. Le rayon vert.,”
Revue Scientifique 58. , No. 8, 240 (24 Avril, 1920).

* A review of Guillaume's BSAF 1919 paper, with extensive excerpts


Ch.-Ed. Guillaume
“Les causes du rayon vert,”
La Nature 48:1, No. 2400-2401, 191–192 (24 Avril, 1920).

* Guillaume's 1920 paper in "La Nature"
* Here is his conversation with Henri Chrétien, "le sagace et érudit
* astronome de Nice," . . . .
*      "Le spectre du rayon vert ne semble pas avoir été observé;" but
* Danjon & Rougier were doing so just about then.
*      He rejects a role for MIRAGES: "Les réflexions totales, dues à
* une stratification déterminée des couches d'air, bien que possibles,
* exigeraient un tel ensemble de circonstances peu probables en
* elles-mêmes, que l'on pourrait à peine concevoir la fréquence du
* rayon vert dans des conditions dont la plus essentielle qui nous ait
* toujours été indiquée est un horizon absolument exempt de brume."


H. Piraux
“Optique atmosphérique,”
B. S. A. F. 34, 22 (1920).

* an adaptation experiment -- not relevant


Ch.-Ed. Guillaume
“Green Rays at Sunset,”
Scientific American Monthly 2, no. 2, 102–103 (1920).

* Translation of Guillaume's La Nature paper
* ". . . I may mention . . . that upon the discovery some twenty years ago
* of the presence of new gases in the atmosphere, it was suggested that
* the reason for this peculiar tint exhibited by the last ray of the sun
* might be found in the absorption caused by the passage through one of
* the said gases to be found in considerable quantities at the level of
* the sea."
* Here is his 1/146 factor again, from his 1919 BSAF paper.
* NOTE that Sci. Am. also had a WEEKLY mag. at this time!
* THANKS to Shaun Hardy for this reference!


H. Piéron
“Le rayon vert: facteurs physiques et facteurs physiologiques,”
La Nature 48:2, no. 2425, 206–208 (1920).

* Henri Piéron's physiology paper
* This seems to be the earliest suggestion that the maximum visibility of
* green plays a part; he cites the 1917 NBS work of Coblentz & Emerson.
* Also cites Guillaume's 1919 BSAF paper, and Fortin in C.R. (1907).
* Date: Sept. 25, 1920.
* THANKS to Shaun Hardy for this reference!


B. Brandt
“Zur Kenntnis des ``grünen Strahles'',”
Die Naturwissenschaften 8, 481 (1920).

* NATURWISSENSCHAFTEN SERIES
*
* a SELECTION EFFECT FAVORING OCEAN OBSERVATIONS nicely stated:
* "Da an Land die Sonnenuntergänge meist durch Verdeckung des Horizontes
* oder durch den Dunst der erdnahen Luftschichten getrübt werden, ist die
* See das geeignete Feld zur Beobachtung dieser Erscheinung."
* No. 24, 11 June 1920


A. Pütter
“Zur Kenntnis des grünen Strahls,”
Die Naturwissenschaften 8, 497 (1920).

* agrees with Brandt that BOTH PHYSICS & PHYSIOLOGY are involved:
* "Was die Erklärung anlangt, so scheint es mir, dass zwar besondere
* Bedingungen in der Atmosphäre vorhanden sein müssen, damit die
* Erscheinung beobachtet werden kann, dass aber die Färbung auf
* physiologischen Bedingungen beruht."
* No. 25, 18 June 1920


O. Meißner
“Zur Kenntnis des grünen Strahls,”
Die Naturwissenschaften 8, 582–583 (1920).

* GF ALWAYS visible
* "Ich bin überzeugt, dass bei klarem Horizont die Erscheinung -- die
* auch auf grossen Binnengewässern vorkommen soll -- stets sichtbar ist."
* Otto Meissner (cf. his 1940 note)


A. Danjon and G. Rougier
“Le spectre et la théorie du rayon vert,”
C. R. 171, 814–817 (1920).

* GREEN FLASH SPECTRA TAKEN
* O'C #23; Fisher #35


A. Danjon and G. Rougier
“The spectrum and the theory of the green flash,”
Mon. Wea. Rev. 48, 659 (1920).

* English abstract by Edgar William Woolard of the previous paper


A. Danjon and G. Rougier
“Le rayon vert,”
B. S. A. F. 34, 513–518 (1920).

* GREEN FLASH SPECTRA
* O'C #24


A. Danjon and G. Rougier
“Le rayon vert, étude spectroscopique et théorie,”
Ann. Obs. Strasbourg 1, 105–115 (1926).

* GREEN FLASH SPECTRA (details and spectra)
* FILED OUT OF ORDER to be with the previous papers
* O'C #25


Dr. B(raak)
“De groene straal,”
De Natuur 40, 330–331 (1920).

* Braak discusses visual effects
* "The phenomena, as we observe, always present themselves to us as the
* complex of two things, namely 1st of what really objectively happened, and
* 2nd of what we subjectively observe, in other words of what our senses do
* with what is objectively given."


M. Farman
“Le rayon vert,”
BSAF 34, 426 (1920).

* Maurice Farman discovers a green flash for himself.
* (The brothers Henri and Maurice Farman were aviation pioneers who
* invented ailerons. They built and flew pusher biplanes used in WWI.)
* Like most accounts by people noted in other areas, this is
* completely useless.
* O'C #209


A. B. Acin
Bulletin de la Société Astronomique de France (l'Astronomie) 34, 530 (1920).

* VENUS GF seen with naked eye (brief note)
* O'C#164


P.-L. Mercanton
“"Les Phénomènes d'optique atmosphérique", in "Ergebnisse der Schweizerischen Grönlandexpedition, 1912-1913", A. de Quervain & P.-L. Mercanton, eds.,”
Neue Denkschriften der Schweizerischen Naturforschenden Gesellschaft 53, 192–198 (1920).

* Mercanton's GF observation near Cape Skagen, Jutland, 20 Sept. 1912
*      The "rayon vert" section is on pp. 197-198.  His sunset GF in the
* DRAWING was seen through 8× Zeiss binoculars: "Le ciel était
* serein, la mer calme, l'atmosphère d'une rare limpidité . . . . Le
* soleil avait montré en se rapprochant de l'horizon une teinte orangée
* et des déformations changeantes, qui en dentelaient bizarrement le
* pourtour. Après que son centre fut descendu sous la ligne d'eau et
* au fur et à mesure que sa surface visible s'amoindrissait, ses bords
* furent envahis de plus en plus par une teinte vert émeraude refoulant
* vers le milieu l'orangé de plus en plus restreint. Au moment même
* où l'astre s'abîma dans les flots, le vert, resté seul maitre de
* la surface solaire, atteignit l'intensité d'un vif éclair, puis
* s'éteignit." (The drawing shows an inferior-mirage flash.)
*      He cites Evershed's 1915 Nature  paper.  "Mon observation corrobore
* singulièrement cette opinion plausible, également défendue tout
* récemment par C.-E. Guillaume." (citing the latter's 1919 paper in
* l'Astronomie.)
*      The title pages are given in both German and French; I give only the
* German here, as de Quervain (despite his name) writes only in German
* and was the expedition's leader; and this was published in Zürich.
* Dated 1. Dezember 1920; abstracted by Brooks in MWR, 1923.


C. Boulet
“Optique atmosphérique,”
BSAF 35, 17–18 (1921).

* standard inf.-mir.GF
* O'C #181


V.-E. Poiteux
“Optique atmosphérique,”
BSAF 35, 18 (1921).

* "une curieuse observation de Rayon Vert faite du sémaphore de Jobourg"


Camuset
“Le rayon vert,”
La Nature 49:2, No. 2467, 17 (16 Jul., 1921).

* Camuset's original report
* GF seen 3 times at reappearance from behind hills, from train.
* "J'ai donc assisté à 3 levers de soleil successifs accompagnés du
* rayon vert et ceci à l'heure du coucher du soleil."


R. Whitehead
“Le Rayon Vert,”
BSAF 35, 404 (1921).

* Isle of Man flash seen for "five or six minutes" via hill
* O'C #295


Camuset
“Le Rayon Vert,”
BSAF 35, 404 (1921).

* immediately follows Whitehead's note on same page.
* Reprinted in full from his earlier paper in La Nature.
* GF seen 3 times at reappearance from behind hills.
* O'C #186


V. Conrad
“A.Danjon und S. Rougier, Der grüne Strahl,”
Met. Z. 38, 349 (1921).

* somewhat garbled account of Danjon & Rougier's CR paper
* Besides getting Rougier's initial wrong, we have "Die Sonne erscheint
* von einem grünen Saum umgeben, der aber durch einen dunkelroten von ihr
* getrennt ist."
* Nov. issue


S. W. Visser
“Groene branding en de groene straal,”
Hemel en Dampkring 19, 83–87 (1921).

* first of a flurry of notes in H&D; supports Evershed's MIRAGE idea


J. F. d'Aumerie
“Waarneming van den groenen straal,”
Hemel en Dampkring 19, 100–101 (1921).

* another scientist suckered by Jules Verne's LEGEND:
* "There is also a legend about the green flash . . . "


G. F. Tydeman
“De groene straal, de groene branding en groene wolken,”
Hemel en Dampkring 19, 113–116 (1921).

* "The fairly numerous cases of ``green flash'' observed by me have left
* me the impression that the phenomenon never was observed by me with a
* completely flat or slightly rumpled water surface, and also not with
* waves of such a height that the horizon, observed from a height of 6 to 10
* m, still showed waves plainly, such as is the case with a strong wind, but
* always with a state of the sea such as occurs with a moderately strong
* wind with small wave heights, so that one placed some height above the
* water saw the horizon as a smooth, blue-black boundary."
*      This is vice-Admiral G.F.Tydeman, in the Dec. issue.


R. Lange
“Le Rayon vert,”
Revue des Questions Scientifiques , series 3, 30, 402–426 (1921).

* REVIEW ARTICLE, but few references
* Spends much effort in knocking down a series of straw men (improbable
* explanations).
* Green and red rims seen (pp.408-409), as well as colors on sunspots
* (pp. 415-416).
* Has "Dangeon" for "Danjon"; so I suppose he knew little astronomy, and
* had heard the name in a lecture somewhere (though he cites their paper
* in BSAF!).
* Invokes physiological effects to prolong sunset flashes, claiming that
* "Jamais en effet on ne trouve mention d'une durée plus longue du rayon
* matinal." (i.e., longer than 2 sec.) -- p.422
* But he recognises that the assumption that refraction is proportional to
* refractivity is not exact. [cf. Banakhevich (1915)]
* "Mais surtout, il est grand temps de le faire remarquer,
* l'homogénéité atmosphérique est un mythe, dont la seule utilité fut
* de simplifier nos calculs, en les faussant peut-être un peu." (p. 423)
* Because of the complications of calculating the actual refraction,
* "Expliquer le rayon vert, ce n'est pas étendre de beaucoup le royaume
* de la Science. Passe-temps de vacances, dira-t-on, ou distraction
* d'amateur." (p. 425)
* This is one of the few citations found by P.F.K. on his own; he gives
* the author's name as R.P.R.Lange; here he is "R. Lange, S. J.".
*      Published by Soc.Sci.Bruxelles
* O'C #78


A. E. Levin and S. Maxwell
“Meeting of the British Astronomical Association,”
Obs. 45, 69–72 (1922).

* passing mention of "the green ray" on p. 70
* This is a meeting of the BAA; the paper was by Lawrence Richardson,
* read by Dr. Crommelin. I have attributed this account to the
* secretaries. At the end (p. 72), "Mr. Walter Maunder read a paper on
* `The Prolonged Sun-spot Minimum of 1645 to 1715.' " (Mar.1922 issue)
* Notable for the accurate description of the Earth as seen from the
* totally eclipsed Moon (cf. Link's book). A tantalizing reference:
* "Proctor states that the bright ring into which the Sun is distorted
* will have, but for the effect of atmospheric absorption, the same
* surface-brilliancy as the Sun itself." (p.71; no citation)


"v. d. M."
“De groene straal,”
De Zee 44, No. 3, 203–206 (Maart, 1922).

* A renewed appeal for observations, with only a couple of references
*      Cites and quotes from Tydeman's 1921 paper in H&D, and Conrad's
* note on Danjon & Rougier in Met. Z.
* kindly supplied by C. de Jager!
*      The author was the editor of De Zee, Jonkheer J. P. F. van der Mieden.


M. E. Mulder
“De groene straal en de groene branding,”
Hemel en Dampkring 19, 129–130 (1922).

* MULDER explains his forthcoming BOOK:
* NOTE YEAR CHANGE IN MIDDLE OF VOLUME!!
* "As far as possible, I have collected everything written about the green
* ray and treated the articles historically and critically. The book is
* written in English, because the English, as a seafaring nation, have made
* many observations and still show much interest in the phenomenon."
*
* "That the green ray is observed so much more at sea than over land seems
* mainly, though not entirely, to lie in the fact that at sea the horizon
* is unobstructed."


M. E. Mulder
The ''Green Ray'' or ''Green Flash'' (Rayon Vert) at Rising and Setting of the Sun
(T.Fisher Unwin, Ltd., London, 1922).

* MULDER's book
* Prof. Dr. M.E.Mulder, Emeritus Professor of Ophthalmology
* useful for many earlier references, quoted in full.
*
* Marten Edsge Mulder -- thanks to Brenda Corbin of USNO library for
* his full name!
*
* quotes Verne's "legend" as if it were fact (p.1)
*
* his GREEN RAY observation:
* ". . . at the same moment, at which the last tip of the sun disappeared
* below the horizon, there suddenly shot, straight upwards, a clear
* narrow green ray, which vanished as suddenly as it appeared. . . . I
* estimated the length of the ray to be about 1/10 or 1/8 of the diameter
* of the sun. . . . . . . the phenomenon lasted but a fraction of a second,
* about as long as the visibility of a lightning flash. It almost made
* the impression, that the ray was ejected from the disappeared sun,
* but it also resembled somewhat a rocket or the light from a lighthouse
* below the horizon, throwing a ray of light upwards. . . ." (p.4) "But this
* [the dispersion] explanation I considered to be unacceptable in my case,
* for then one would expect that the last green part of the segment would
* disappear slowly below the horizon, as the sun itself sets slowly.
* Instead of shooting upwards, it would sink downwards." (p.6)
*
* mentions LIMB DARKENING & reddening for first time (p.7)
*
* "There has been far more written and far more observations are published
* about the green ray than I had expected. Moreover, those articles are
* published in all kinds of popular and scientific periodicals which are
* often difficult to obtain." (P.11)
* "But also those observers, who may be considered as more competent --
* for amongst them are many astronomers and physicists of repute -- have
* generally taken little notice . . . of what had been written concerning it
* by others." (p.12)
*
* "The observations at sunrise are naturally much less numerous than at
* sunset, because only few people see the sun rise. . . ." (p.15)
*
* ". . . it clearly appears that both had a different form of green ray in
* view, and consequently did not comprehend each other." (p.37)
*
* "Still I will dwell for a moment on the three forms, in which the green
* ray usually appears.
*      1°  the green or green-blue border, sometimes at the outer edge
* even violet, which can almost exclusively be observed with a telescope
* or a good fieldglass.
*      2°  the flash-like appearing or disappearing green or green-blue
* ray or flash, which can easily be observed by the naked eye and from which
* the phenomenon has undoubtedly taken its name.
*      3° the green or green-blue coloration of the last segment
* itself, which in the course of a few seconds disappears below the horizon,
* and which can also be seen with the naked eye." (p.134)
*
* "Finally we have the rare and abnormal forms . . . .
* As we see, the phenomenon called green ray is far more complicated than
* is generally supposed, and a long investigation will be necessary to
* explain all details." (p.139)
*
* "As the dispersion, increases and decreases in ratio to the refraction,
* the coloured border would, in such a case, be consequently much broader."
* (p.136)
*
* "The green ray is . . . too intensive, to be ascribed to simultaneous
* contrast." (p.141)
*
*
* Thanks to the efforts of Walter Nissen, this is now available at
* Google Books. The London edition is
*
* https://books.google.com/books?id=RSMyAQAAMAAJ&printsec=frontcover#v=onepage&q&f=false
*
* and the Dutch edition is
*
* https://books.google.com/books?id=sIkyAQAAMAAJ&printsec=frontcover#v=onepage&q&f=false
*
* The curious use of a double right quotation mark before the word
* Green on the title page appears in both editions.
*
* O'C #94


A. Schuster
“The Green Flash at Sunset,”
Nature 110, 370–371 (1922).

* Sir ARTHUR SCHUSTER's review of MULDER's book
* N.B.: Schuster was knighted in 1920.
* O'C #133


E. Havinga
“De groene straal,”
Hemel en Dampkring 19, 161–165 (1922).

* Claims "about 450 observations"! (estimate reduced to 300 by Nijland)
* Independent discovery of warm- & cold-water effects:
* "When the temperatures of air and water are similar, or the
* temperature of the air is higher than that of the water, there is no
* looming or distortion; but when the temp. of the air is more than
* 1° Celsius lower than that of the water, then looming and distortion
* occur. Then when one looks at the horizon through a telescope, the
* water seems to boil."
*
* "The observations and drawings are no longer in my possession, but I
* kept copies of the general remarks and collected this article from them."


A. A. Nijland
“Bijschrift,”
Hemel en Dampkring 19, 165 (1922).

* "The carefully described, excellent, and very numerous observations of
* Mr. Havinga (together about 300 pieces), are being worked up by Mr. van
* Genne, phil.-nat. cand. at Utrecht. I don't want to anticipate their
* outcome, but all agree that next to the material that Mr. Havinga has
* given us, any other material, as far as is provided by naked-eye
* observations, can hardly lay any weight in the scale."


E. Havinga
“De groene straal,”
De Zee 44, 449–455 (1922).

* This is exactly the text printed in H&D (see previous 2 items),
* including Nijland's "Bijschrift", and the figure!
* kindly supplied by C. de Jager!


A. A. Nijland
“Bijschrift,”
De Zee 44, 455–456 (1922).

* (see previous 3 items!)
* kindly supplied by C. de Jager!


(anonymous)
“Boekbesprekingen. The `Green Ray' or `Green Flash' . . . ,”
De Zee 44, 477–478 (1922).

* Another REVIEW of MULDER'S BOOK
* This is rather a sad piece of work. The reviewer enthusiastically takes
* up the "Scottish legend", and mis-reads "Coutinho" as "Corvalho".
* He also concludes with a paragraph warning against blindness from
* looking at the Sun, quite in opposition to the spirit of Mulder's
* discussion.
* kindly supplied by C. de Jager!


J. Voûte
“Beobachtungen des `Grünen Strahles',”
Met. Z. 39, 281–283 (1922).

* Some 20-odd flashes observed, mostly with binoculars from 12m on ship.
* Most common color reported is blue, or blue-green; some violet.
* 2 DRAWINGS of flashes behind clouds and island.
* (According to the masthead of H&D in 1929, Voûte was at Lembang.)


J. E. Clark
“A modification of the green flash,”
Met. Mag. 57, 184 (1922).

* J. Edmund Clark's flash "on hills nearly two miles distant, fringed with
* trees." ". . . it lingered for some seconds, probably three to five."
* (This is the flash cited in his 1926 paper.)


W. J. H(umphreys)
[review of "The Green Ray" by Dr. M.E.Mulder]
Mon. Wea. Rev. 50, 490 (1922).

* W.J.Humphreys's review of Mulder's book
* Takes a surprisingly naive view of the GF:
* ". . . an adequate description and complete explanation of the `green ray'
* can be given in a few lines . . . ."


E. W. Barlow
“The green flash — an unusual feature,”
Met. Mag. 57, 246 (1922).

* GREEN LIGHT THROUGH TREES?
* "Every tree projected on the disc became suddenly outlined with a narrow
* hazy border of green light, the rest of the sun retaining its normal
* colour; . . . ."
* Probably this effect is due to chromatic aberration in the 3-in. telescope.


A. W. Porter
“The green ray at sunset and sunrise,”
Nature 110, 513 (1922).

* ALFRED W. PORTER responds to SCHUSTER's review of MULDER's book
* "There are, in reality, two distinct phenomena which go under the name
* of the green flash. The first, probably the one most usually seen and the
* only one to which the epithet properly applies, is certainly an
* after-image in an eye fatigued by the red light of the sun." [SIC!]
* The second phenomenon, which I have never been successful in seeing and
* of which I can say little, is evidently due to atmospheric dispersion . . . ."
* Query: could Porter have been color-blind? Most people find the Sun's
* after-image dark and inconspicuous.
* Cited with title in Talman's "Recent Papers," MWR 50, 492 (Sep. 1922)


C. J. P. Cave
“The green ray at sunset and sunrise,”
Nature 110, 604 (1922).

* Cave and Petrie try to undo the damage Porter has done; first Cave:
* ". . . it is not due to eye fatigue, for the appearance at sunrise is
* precisely the same as that at sunset . . . ."
* Cited with title in Talman's "Recent Papers," MWR 50, 544 (Oct. 1922)
* Nov. 4 issue


W. M. F. Petrie
“The green ray at sunset and sunrise,”
Nature 110, 604–605 (1922).

* and now Petrie:
* "Moreover I have never seen the green light shift about, as an
* after-image does, by movement of the eye; it is always exactly on the
* segment."


A. Fry
“The green flash,”
Met. Mag. 57, 274 (1922).

* Agnes Fry's inf.-mir.flash, well described:
* ". . . with a pair of field-glasses (which it is quite safe to use when the
* sun is really low on the horizon) the green flash was clearly seen. . . ."
* ". . . the arc of the sun turned green, and then also the chord made by
* the sea horizon, and for a fraction of a minute these two lines enclosed
* an orange space. This rapidly disappeared and the last segment was wholly
* green. . . . if observers would use glasses the green flash would much more
* frequently be recorded."


W. Goodacre
“The green ray,”
JBAA 33, 57–58 (1922).

* Goodacre's second paper (Nov., 1922) [note overlap of years & volumes!]
* ". . . a high northern latitude . . . ."
* ". . . 1922 June 11, latitude about 65 N, made from the deck of the
* R.M.S.P. steamer Avon , time 10h 45m p.m."
* "As the Sun slowly sank whilst skirting the horizon, thin linear clouds
* passed rapidly across the disk and one of these separated a narrow segment
* of the N. limb from the rest of the disk. This segment immediately turned
* to a vivid green, and remained for several seconds till the Sun dropped
* out of sight behind the cloud."
* N.B.: The BAA meeting at which this paper was presented is reported
* in Obs. 46, p. 12 (1923).


Legras
“Optique atmosphérique,”
BSAF 36, 518 (1922).

* useless account of a 3-sec.GF
* O'C #229


J. Evershed
“The green flash at sunset,”
Nature 111, 13 (1923).

* EVERSHED and VENUS
* ". . . the ordinary mirage effect was conspicuous, that is, distant land
* appeared raised above the sea horizon by a small interval, due to the
* total reflection of sky and land at the surface of a thin layer of air
* of low density in contact with the sea. At sunset the last segment of
* the disappearing limb was similarly reflected and reversed, causing a
* lenticular shape. . . ."
*      "The striking thing about the setting of Venus was the sudden appearance
* of a reflected image moving upwards to meet the descending image, and
* the instantaneous and conspicuous change of colour from dull red to
* green at the moment of meeting of the two images."
*      "It seems to me evident from these observations that the mirage layer
* greatly intensifies the ordinary dispersion effect, by adding the light
* from the reflected image to the direct image at the moment of setting.
* The normal dispersion effect at sunset under conditions when there is no
* mirage is scarcely visible to unaided vision, although easily seen in
* a telescope of low power."
* This was the year Evershed retired to Surrey.
* O'C #32


A. E. Levin and S. Maxwell
“Meeting of the British Astronomical Association,”
Obs. 46, 10–13 (1923).

* BAA discussion of Goodacre's paper
* "In the discussion Capt. Carpenter, Capt. Ainslie, Major Hepburn,
* and Col. Maxwell took part, one point being raised as to whether the
* green ray could be kept in view by an aeroplane rising at a rate that
* would keep the setting Sun just touching the horizon." [p. 12, Jan.1923]
* I have attributed this account to the secretaries; the meeting date was
* Nov. 27, 1922.
* Thanks to the NASA ADS full-text search for turning this up!


M. Haret
“Le rayon vert,”
La Nature Suppl. 51:1, 113–114 (7 Avril, 1923).

* 3 mountain observations, and much useless speculation.
* One might be a "green fog", but I doubt it.
* ". . . la coloration vert n'est observable que par une atmosphère exempte
* d'humidité . . . ."
* (cf. Admiral Huguet (below); both contradict Feenstra Kuiper's
* HUMIDITY theory.)
* Issue No. 2557


G. O. E. Knight
“Atmospheric optical phenomenon,”
Geographical J. 61, 390 (1923).

* FINE account of GREEN RAYS in Tibet
* A second-hand report "quoting a description given by him last year in
* the Statesman of India . . . the appearance (seen for [sic] some two
* or three minutes after actual sunset) is described as
*      `very similar to a series of rapid, dark greenish shafts of light,
* cone-shaped, with their apex lying in the direction of the vanished
* sun, appearing to shoot across the horizon from right to left, and as
* rapidly disappearing. The apparition lasts from three to five seconds,
* and is not to be confused with the familiar green flash at sunset.'"
* (It would be nice to turn up that newspaper report!)
* [Note: the supposedly similar report referred to as on p. 66 of the
* same volume turns out to be a marine phosphorescent wheel.]
* May issue, in the "Monthly Record" department (pp. 385-392).


C. F. Brooks
“Winds and weather of central Greenland: Meteorological results of the Swiss Greenland expedition,”
Mon. Wea. Rev. 51, 256–260 (1923).

* An English summary of the Swiss Greenland expedition
* [Cf. Mercanton, 1920, in both the mirage and GF sections of this bibliog.]
* "Abnormal atmospheric refractions were observed. The setting sun was
* much distorted. Mirages were seen strongly developed over the water,
* where the surface layer of air was notably colder than that above.
* The green ray, occasionally observed at sunset, was evidently a phenomenon
* of mirage." (p. 259)
* May issue


W. B. Housman
“Multiple green rays,”
English Mechanic and World of Science 117, 192 (1923).

* nice drawing of MOCK MIRAGE flashes and SKY STRIATIONS:
* "Under telescopic scrutiny this zone was seen to be not clear sky, but a
* stratified form of cirrus in horizontal lines and bands, which increased
* in density rapidly near the horizon, so that the Sun's lower limb
* disappeared before reaching the land contour. These bands were so faint
* that they were scarcely to be seen on the Sun, but they produced
* remarkable results with the green ray effect. They formed faint chords
* across the disc, at the extremities of which, in the upper segment,
* shining prominences were projected from the Sun as elongations of the
* chords. These prominences rose upwards on the circumference as the disc
* sank. Approaching the top, they turned green, and meeting there they
* united and floated clear as a tiny cloudlet of brilliant green."
* May 11 issue.


Effère
“Le rayon vert,”
La Nature Suppl. 51:1, 199–200 (23 juin, 1923).

* Thinks it is all in the eye, and wanders off into the shape of the sky
* Totally USELESS
* Issue No. 2568


"le capitaine de frégate Chrétien"
“Le rayon vert,”
La Nature Suppl. 51:2, 73–74 (8 Sept., 1923).

* Contradicts the previous report, as he has seen a double flash due to
* waves, a sunrise flash, and a flash at mountain horizon.
* Issue No. 2579


"l'amiral Huguet"
“Le rayon vert — le bolide vert,”
La Nature Suppl. 51:2, 145 (10 Nov., 1923).

* Thinks it is due to light refracted through WAVES
* TRIPLE flash due to waves reported.
* Has never seen the flash in Pacific or Red Sea, so "J'attribue ce fait à
* l'humidité de l'atmosphère dans ces deux mers."
* (so much for Feenstra Kuiper's HUMIDITY link!)
* Issue No. 2588


F. Santschi
“A propos du rayon vert,”
La Nature Suppl. 51:2, 193 (22 Dec., 1923).

* Several observations (none in detail); one double flash via a railway ramp.
* Cites the Admiral's paper in No. 2588
* Issue No. 2594
* O'C #274


P. Crépy
“Optique atmosphérique,”
BSAF 38, 8 (1924).

* useless but typical inf.-mir.flash
* Pierre Crépy
* O'C #197


S. Barker
“The Green Ray,”
J. B. A. A. 34, 111 (1924).

* GREEN RAY ? Possible AFTERIMAGE?
* "The flash came at the usual time, but after the limb had entirely
* disappeared, a small ball of a brilliant blue remained for two or three
* seconds."


A. Carpenter
“The green ray,”
J. B. A. A. 34, 157 (1924).

* CARPENTER responds to Barker
* Captain Alfred Carpenter died the next year.
* O'C #188


F. J. W. Whipple
“An experiment illustrating the theory of the green flash,”
Brit. Ass. Adv. Sci. Report 94, 359 (1924).

* 5-line abstract; no useful details
* See slightly longer mention in JRASC 19, 4-9 (1925)
* O'C #152


C. D. Perrine
“On the cause of the green ray seen at sunset,”
P. A. S. P. 36, 319–322 (1924).

* C.D.PERRINE makes a dumb suggestion, but reports a YELLOW FLASH:
* "It is not seen at disappearances or reappearances of the Sun behind
* ordinary clouds.
* "It is not seen at disappearances behind land."
* "The green flash is a refraction phenomenon produced by the light from
* the thin disappearing limb of the Sun shining through the prism of water
* formed by the crest of a wave or waves which extends above the general
* level of the horizon."
* BUT:
* "The yellow portion of the flash is not ordinarily noticeable as it is
* usually lost in the general red of the sunset. If carefully watched for,
* it can be detected often as a lightening of the general color and where
* the air is exceptionally transparent the true yellow can be definitely
* detected."
* Cited with title in Talman's "Recent Papers," MWR 52, 592 (Dec. 1924)
* O'C #102


A. McAdie
“Abstract of letter from Alexander McAdie in comment on the preceding article,”
P. A. S. P. 36, 323–324 (1924).

* PERRINE shot down; STRATUS clouds favor the flash.
* ". . . no one at Blue Hill has ever seen the Green Flash, though many of
* us have looked, some for more than twenty years."
* ". . . if Professor Perrine means by ordinary clouds those of the cumulus
* type due to uplifting, we agree with him. But we are of the opinion that
* with clouds of the stratus type, the phenomenon may occur."
* "Finally, the significant feature in our opinion, is what we have called
* the capriciousness of the phenomenon. This indicates to our mind an
* atmospheric condition . . . . We think the phenomenon is essentially
* atmospheric, occurring possibly at times of an inversion of
* temperature. . . ."
* O'C #84


W. J. Fisher
“The green flash — note on its history and literature,”
P. A. S. P. 36, 325–326 (1924).

* Fisher's 1-page summary:
* Cited with title in Talman's "Recent Papers," MWR 52, 592 (Dec. 1924)
* O'C #35


J. Patterson
“Meteorology at the British Association for the Advancement of Science and the International Mathematical Congress,”
JRASC 19, 4–9 (1925).

* brief report of Whipple's Brit.Ass. report
* "Mr. F.J.W.Whipple of the London Meteorological Office gave a very
* beautiful experimental illustration of the green flash that appears
* under favourable conditions at sunset. It is believed to be due to the
* simultaneous action of dispersion and absorption and his experiment was
* in conformation of this view." [p. 7]
*      There is also mention of "Mr. L.F.Richardson, who has been making
* a special study of turbulence in the atmosphere and who has worked out
* from theory a criterion for the increase of turbulence . . . ." [p. 8]
* Thanks to the NASA ADS full-text search for turning this up!


R. Clements
A Gipsy of the Horn (2nd edition)
(Houghton Mifflin Co., Boston and New York, 1925), p. 125.

* Rex Clements's account -- the source of Botley's story
* "The old man used to say it was `the sun putting out his sidelights,'
* the emerald green representing a sailing-ship's starboard light."
* It appears to be one captain's idiosyncratic expression, not a term in
* general use. Clements tells this again in his "Times" letter, 1929.
* This also appears in the 1924 *first* edition by Heath Cranton Ltd.,London.
* As the subtitle is "The narrative of a voyage round the world twenty
* years ago," this is a turn-of-the-century observation, not an "old" one.
* cited by OED


W. J. Humphreys
“Note on the green ray,”
P. A. S. P. 37, 20 (1925).

* Humphreys's 1-page summary:
* Another scientist conned by Verne: ". . . whatever we may think of
* the legend that links it with love affairs . . . "
* O'C #55


M. Olmsted
“The green flash,”
Pub. A. S. P. 37, 105–106 (1925).

* MARGARET OLMSTED as a student at Vassar!
* "All of a sudden there popped out over the edge of the island a spark of
* brilliant violet-blue light, like a big blue star, which slowly took on a
* green-blue tinge, turning to a yellow-green just before the blinding Sun
* appeared some ten seconds after the first blue flash.
*      "As we were within the Arctic Circle, the Sun did not seem to rise
* straight up but swung toward the right and before the whole disk had been
* visible, disappeared with a greenish color behind a mountain, then
* reappeared in the same way as before. Passing behind another mountain
* before finally swinging clear of the land, it gave us three successive
* views of this beautiful phenomenon."
* O'C #260


R. T. A. Innes
“The green flash,”
Pub. A. S. P. 37, 106 (1925).

* R.T.A.INNES -- GREEN RAY? or ILLUSION of motion?
* "I only saw it when the horizon was perfectly clear at the point of
* sunset, and the flash seemed to rise from the horizon for the moment then
* disappear." (appended to the above)
* O'C #222


T. Köhl
“Note on the green ray,”
Pub. A. S. P. 37, 173 (1925).

* Second-hand accounts of other Scandinavians' observations; USELESS
* O'C #227


Sir David Wilson Barker
“Peculiar sunset effects,”
Marine Observer 2, 73 (1925).

* DRAWING 3 shows impossible structures
* ". . . the vapour took a beautiful emerald green colour and then
* vanished. This process was repeated several times before the sun quite
* disappeared, the green colouring lessening in effect and there was no
* `green ray.'"
* ". . . a rare and beautiful phenomenon is the appearance of very faint
* coloured rays springing up from the spot where the sun is just rising or
* setting, and before the sky is very light. Often they can only be seen by
* a `sideway' observation and only last a very short time."
* As he distinguishes these from crepuscular rays ("shadows cast by
* clouds") I assume this refers to GREEN RAY displays.


Em. Touchet
“Sur le `rayon vert',”
La Nature 53:1, 358–366 (6 juin, 1925).

* good REVIEW in French
* possible EARLIEST PHOTOGRAPH of Mock Mirage? (Fig.6, panel 6)
* Separate flashes on horns of partially-eclipsed Sun reported by
* Malburet (take that, Floor!)
* Profusely illustrated with Rudaux's dwgs. & photos
* Issue 2670
* O'C #141


S. Single
Met. Mag. 60, 136 (1925).

* "the only occurrence during a five weeks' voyage" -- useless
* July issue


Anon.
“(in notes of Oct. 20 meeting),”
JRASC 19, 260 (1925).

* 1-line mention; not useful
* Thanks to Stephen J. O'Meara for finding this.


L. Rudaux
“Photographie du rayon vert,”
La Nature 53:2, 303–304 (7 Nov., 1925).

* FIRST (b/w) PHOTOGRAPH OF GREEN FLASH by Lucien Rudaux
* "Le cliché montre, comme on le voit, une forte impression lumineuse
* correspondant à l'éclat vert magnifiquement intense pour les yeux
* des deux observateurs, et il fournit ainsi une pleine confirmation
* de la réalité du phénomène." (Nice inferior-mirage flash.)
* Issue 2692
* O'C #124


T. Kellen
“Der Grüne Strahl,”
Kosmos (Stuttgart) 23, 13–18 (1926).

* mostly a German version of Touchet's paper; the source of Schröder's
* concluding line:
* "Es hat also fast den Anschein, als ob die Astronomen recht hätten,
* die behaupten, dass der grüne Strahl nur deshalb eine selten
* beobachtete Erscheinung ist, weil man sich zu Unrecht einbildet,
* dass er selten zu sehen sei."
* Most of the same illustrations from Touchet's paper!
* O'C #225


P.-L. Mercanton
“Encore le `Rayon vert',”
La Nature Supplément (Paris) 54:1, No. 2706, 49 (13 Fév., 1926).

* EXCELLENT argument against the standard model !!
* "Cette observation corrobore d'une manière très nette, partant très
* précieuse, deux points sur lesquels nombre d'auteurs, et spécialement
* les deux derniers nommés [i.e., Touchet & Rudaux], insistent à juste
* raison, savoir : 1. l'apparition du rayon semble liée non à la
* réfraction atmosphérique dite `normalé, laquelle se borne à aplatir un
* peu le disque solaire à l'horizon, mais bien à des réfractions
* anormales qui déforment fortement, et irrégulièrement aussi,
* l'image de l'astre. . . . "
* O'C #87


L. Rudaux
“Couchers de Soleil et Rayon vert,”
BSAF 40, 16 (1926).

* ABSTRACT of a paper given by RUDAUX showing distorted sunsets
* reported by Em.Touchet as secretary:
* "Les réfractions inégales de l'atmosphère donnent à certaines images
* du Soleil des apparences invraisemblables."
* These are most likely the pictures reproduced in Touchet's paper (above),
* or in Rudaux's own article in L'Illustration (1927)
* O'C #125


K. I. Luchai
“Zelenii luch,”
Mirovedenie 15, 58–59 (1926).

* K.I.LUCHAI's table of 81 flashes seen at Petrovsk (Saratovskii gub.)
* Communicated by G.A.Tikhov
* "In the literature is often written that the green ray is a very rare
* phenomenon. I don't agree with this -- we see it in our area fairly
* often." Here again the appearance is described as like "Bengal fire."
* "Mostly the blue color predominates. The green ray is often seen when
* the Sun sets behind a thick layer of stratus on the horizon."
* "In most cases this phenomenon precedes a falling barometer and bad
* weather." But there are NO USEFUL DETAILS, only the dates when it was
* seen. The summer maximum runs from June through Sept., with very few in
* March and April.
* Note that O'Connell uses the AJB's spelling of "K.J.Lucaj", and their
* translated name of journal as "Weltkunde"! He also gives the year as
* 1927, probably because it appears in the 1927 volume of the Jahresbericht.
* In Russian, this is
* К. И. Лучай
* Зелёный луч
* Мироведение 15, 58-59 (1926)
* O'C #233


H. Bellet
“Optique atmosphérique,”
BSAF 40, 111 (1926).

* nearly useless


J. Druet
“Optique atmosphérique,”
BSAF 40, 111 (1926).

* SUNRISE flash "Par temps absolument calme et ciel d'une pureté parfaite."


C. D. Perrine
“On the cause of the ``Green Flash'' seen at sunset,”
PASP 38, 134–136 (1926).

* C.D.PERRINE again
* ". . . during my stay in Hermosa Beach, California. . . . Between March 11
* and August 27 definitely green flashes were seen on 34 occasions. Of
* these 20 were over land, 12 over water and 2 behind wet fog banks. It is
* significant that not only were flashes seen at Hermosa more frequently
* over the land but that the colors were on the average much more intense."
* O'C #103


C. Davidson and F. J. M. Stratton
“The `Green Flash',”
Observatory 49, 156–157 (1926).

* Davidson & Stratton report some observations from ship on return voyage
* from Sumatra solar eclipse. They notice that
* ". . . through glasses the tips of the setting segment of the Sun were seen
* as green distinctly before the final disappearance of the yellow rim."
* O'C #200


A. D. Verschuur
“Groene straal,”
De Zee 48, 446–448 (1926).

* WONDERFUL ACCOUNT of the effects of RETINAL BLEACHING! and a GREEN RAY!!
* This excellent account is accompanied by full circumstantial details:
* coordinates, barometer, air and sea temperatures, wind, sea state, etc.
* Translation given in full:
*
* On board the S.S. "Tosari", 12 September 1924, 6.15 p.m., steaming in
* the Indian Ocean, N. lat. 6° 32.'5, E. long. 78° 40.'5, corr.
* bar. 758.1, air temperature 28.5°, sea water 27.0° wind W by N 4,
* undulating sea, moderate SW swell. Very wet atmosphere, overcast sky
* with clear western apparent horizon.
*
* At sunset an especially beautiful green ray was observed. When half the
* solar disk had disappeared behind the horizon, the top part of the still
* visible Sun was light green, the lowest part harsh green in tint. This
* harsh green color moved slowly upward, displacing the light green color.
* When the last harsh green colored little segment had disappeared at the
* apparent horizon, plume-shaped green rays shot upward.
*
* The sky was almost completely clouded over, only the spot where the Sun
* had disappeared was bright. Almost all kinds of clouds were to be seen,
* nearly equally divided.
*
* After sunset it came to my attention that all sailors who had come on
* deck to see the natural phenomenon had such an intensely dark red skin
* color; arms, face, and hands had a color of dark mahogany. That was
* also true for myself. On the gilded buttons of my uniform lay a silver
* lustre, on the white uniform a pink glow. The Moon, which before sunset
* had been seen very well, was now pale and indistinct. The water was
* greyish in color, only the bow waves and the wake, which otherwise are
* white, were now harsh green. The sea phosphoresced light. Looking over
* the sea, I got the impression that a yellow haze (light topaz color)
* hung over everything.
*
* Around the West the color of the clouds was varying between chestnut and
* the light yellow-brown color of old gold, run through with strips of
* pink and pearl-gray and quite pale between the gaps through which the
* blue sky was seen.
*
* Around the East the color of the clouds was from pale to dark gray.
* After 10 minutes the whole sky was uniformly covered with stratus
* clouds. In the 10 minutes I had seen the entire cloud cover change and
* unite into one layer.
*
* The port (red light) gave its usual color; that on starboard (green
* light) however radiated a harsher green light. The aft top-light (white
* light) shone green blue; the color was approximately like that of a
* spark between two carbon points. Seen from the bridge, the lights on
* deck looked, as far as color and shape are concerned, like the blowtorch
* of an autogenous welding apparatus. Looking at the binnacle I noticed
* that the brass hood and the rose were tinted green (light emerald
* green); likewise the chart, which lay on the table in the chartroom.
* The light from the lamp above the chart had the color of absinthe.
*
* This peculiar green tint slowly faded away from all lights. At 6.34 all
* lights were again of the usual color, but much clearer. Also this
* greater brightness faded away after approximately 15 minutes.
*
* The sky cleared off and drifted to the west. At 6.45 the eastern sky
* was clear, with a few feathers which converged in the E by N. It began
* to lighten around the NE and at 7.30 p.m. a halo appeared around the
* Moon. The atmosphere was very moist. Before sunset the railing was all
* wet from the dew.
*
* At night at 12.20 H.W. Point de Galle was spotted, the air was thick
* and misty. The temperature of the sea water had fallen to 23.5 in these
* hours; there was a strong ?koraallucht? observed.
* [The observation was made just west of the southern part of Ceylon.]


J. E. Clark
“The green flash,”
Met. Mag. 61, 134–135 (1926).

* possible GREEN RAY *below* observer? CLOUD-TOP flash
* ". . . an almost dazzling emerald green, which seemed to emit rays
* downwards in a semi-circle from the last fraction of the sun's disc.
* Not only was its brilliance greater than it has been my fortune to see
* it before, even at sea in the tropics, but, instead of being an
* instantaneous phenomenon, it lasted at least two seconds or even longer. . . .
* Its duration was not quite so long as on the occasion reported to you a
* few years ago, when it was seen in a cleft between trees on the same
* ridge, but its brilliance was incomparably greater."
* [see his 1922 Met.Mag. report for the earlier one.]
* [Sounds like Bandfield's flash, but observed from slightly above the
* best height. An inversion at cloud top would be responsible.]


F. Santschi
“Nouvelles notes sur le rayon vert,”
La Nature Supplément (Paris) 54:2, 5 (1926).

* Telescopic observations of green or violet rims
* Blue/violet in winter, green in summer.
* Some of the phenomena may be contaminated by lateral color in the
* eyepiece, as "je n'en laisse passer que l'extrème bord dans le champ de
* la lunette." This might affect Part C, a claimed green color interior
* to the disk where masked off by clouds & mountains.
* O'C #126


Ch. Renard
“Observations du `Rayon Vert',”
BSAF 40, 221–222 (1926).

* 3 reports on contiguous pages stapled together
*
* Several GFs at successive sunsets, *except* that
* ". . . aucun rayon vert ne fut perceptible; le Soleil s'étala, du reste,
* en une longue bande plate sans être surmonté d'une calotte rouge."
* O'C #268


J. Malburet
“Observations du `Rayon Vert',”
BSAF 40, 222–223 (1926).

* MALBURET's observation of GF at PARTIAL ECLIPSE detailed
* Influence of height of observer stressed
* O'C #235


E. Bauer and A. Danjon
“Observations du `Rayon Vert',”
BSAF 40, 223–224 (1926).

* Standard double image of VENUS at setting
* O'C #173


J. L. A. Sillem
“The green flash,”
Observatory 49, 246–247 (1926).

* Sillem, responding to Davidson & Stratton (p.156), claims the flash is
* illusory because it is bluer when the sky is clear and the Sun yellow,
* and greener when the sky is hazy and the Sun red.
* Aug. 1926 issue
* O'C #283


A. Shalek
“The Land of Nitrate,”
The Living Age 330, No. 4287, 521–524 (4 Sept., 1926).

* Passing reference in Alice Shalek's travel fragment from Chile
* "The only compensation for living in this country is the magnificent
* sunsets." (p. 522) "Just after the blood-red ball of the sun drops
* below the horizon, the so-called `last green ray' quivers across the
* heavens. It is a phenomenon that even the oldest residents await as
* for a faithfully repeated miracle." (p. 523)
*      Reprinted from Deutsche Allgemeine Zeitung, June 2, p. 6.
* "Alice Shalek is an Austrian lady who has been living in South America
* and writing home about it from time to time." [inside front cover]


C. E. P. Brooks
“Green flash in London,”
Met. Mag. 61, 214 (1926).

* Sun set "over a long building some miles off and at a slightly lower level"
* "smoky white with a faint tinge of green" after "deep orange" sun.
* Oct. 1926


C. J. P. Cave
“The green ray,”
Observatory 49, 307–308 (1926).

* C.J.P.Cave responds to Sillem (p.246):
* "The appearance of the last segment of the Sun as seen through a
* telescope or field-glasses is utterly at variance with the theory that the
* green ray is subjective."
* O'C #189


C. R. Davidson and F. J. M. Stratton
“The green flash,”
Observatory 49, 308 (1926).

* refutation of Sillem's claim the flash is illusory
* O'C #26


J. Evershed
“The Green Flash,”
Obs. 49, 369–370 (1926).

* EVERSHED summarizes:
* "On a land horizon . . . the Flash, whether red or green, is generally
* less conspicuous than when seen on a sea horizon, partly because
* refraction and dispersion rapidly increase towards the lower sea horizon,
* and partly from another cause. At sea there is often a layer of air in
* contact with the water which causes mirage effects; distant objects on the
* horizon are reflected from it. These conditions cause an enhancement of
* the Flash, because the green segment of the Sun is reflected and reversed
* upon itself, producing a lenticular patch of green light of appreciable
* width." (O'C.#33)
* O'C #33


P. Feenstra Kuiper
De Groene Straal
(C.de Boer Jr., Helder, 1926).

* PIETER FEENSTRA KUIPER's thesis
* misunderstands Wegener's model; figures drawn wrong. But a good quote:
* "It is quite remarkable that case 1 (inferior mirage) is generally known
* and understood, while case 2 (Wegener's sunset model) has been seen
* again and again, but before Wegener has never been explained."
* (Actually, this refers to the Mock Mirage!)
*      Lagaaij's green-ray drawing is reproduced in color.
* N.B.: C.de Boer, Jr., in Helder, was the publisher of "De Zee".
*
*      Thanks to Thierry Lombry for pointing out that
* this thesis is available on the Web as a 134 mb (!) PDF, at
*
*      https://dspace.library.uu.nl/handle/1874/283890
*
* -- the full-text open-access link leads to the PDF file.
* [Unfortunately, as of Sept. 16, 2017, the pages are out of order.]
* O'C #75


P. Feenstra Kuiper
“The Green Ray,”
JBAA 37, 231–235 (1927).

* FEENSTRA KUIPER's SUMMARY
* here he again misunderstands Wegener: "In the case of upward reflection
* [i.e., superior mirage] an untransparent layer is found just above the
* horizon, behind which the Sun passes. If the lowest border of the Sun
* appears underneath this layer, it is reflected upward."
* O'C #76


G. Grandjean
“Optique atmosphérique,”
BSAF 41, 105 (1927).

* AFTERIMAGE reports


Rud. Meyer
“Die Lichterscheinungen der Atmosphäre und ihre Beobachtung,”
Korrespondenzblatt des Naturforschenden Vereins zu Riga 59, 145–164 (1927).

* MEYER's early atmos.-optics REVIEW -- filed separately (cf. Humphreys)
* A fine review article, or rather, popularization -- there are no
* references! This is an early example of Meyer's respect for the Dutch
* work: ". . . eine führende Stellung nimmt in dieser Beziehung Holland
* ein, . . . " (p.145)
* The GF gets only a paragraph on p.152. Everything imaginable is here:
* halos, rainbows, mirages, distortions, aurorae, meteors, zodiacal light,
* scattering, blue sky, flattened shape of sky, crepuscular rays, Moon
* illusion, Brockengespenst, coronae, heiligenschein, noctilucent clouds,
* scintillation, eclipse phenomena, glories, colored shadows, . . . !
* It seems patterned after Nijland's long article in De Zee (1902), and
* could equally well be the model for Minnaert's book.
* There are detailed instructions for observers, too.


T. Kellen
“Nochmals der Grüne Strahl,”
Kosmos (Stuttgart) 24, 282–285 (1927).

* kindly supplied by Brigitte Hofmann, Redaction "Kosmos"!
* Many new observations:
* Hansheinrich Mehnert: "double Sun" with upper image disappearing at a
* fixed almucantar at SUNRISE: "Die Scheinsonne zeigte während der ganzen
* Zeit [ungefähr drei Minuten] ihres Bestehens jenen grünen Strahl.
* Ihr oberes Viertel war von einem nicht stark glänzenden Smargdgrün,
* das nach det Mitte zu in Gelb überging. Jedoch war der ganze Farbton
* dieser Scheinsonne bedeutend dunkler als der der darunter befindlichen
* richtigen Sonne."
* Leopold Neumann: "Ich hatte in den beiden Sommern 1923 und 1924 an die
* hundert Male Gelegenheit, den angeblich seltenen grünen Strahl zu
* beobachten, ohne mir der Seltenheit dieser Erscheinung bewußt zu werden."
* (evidence for ADAPTATION:) ". . . einmal im entscheidenden Augenblick der
* Beobachtung meine Aufmerksamkeit abgelenkt wurde, während mein Begleiter
* den Horizont nicht aus dem Auge ließ. Plötzlich rief er: `Sieh hin!',
* und es zeigte sich, daß er noch verhältnismäßig lange den grünen
* Strahl sah, ohne daß ich ihn zu gleicher Zeit gewahren konnte."
* "Dieser oberste Rand erschien sekundenlang knapp vor dem Verschwinden
* als ein auf dem Wasser schwimmender, etwas vom Horizont abgerückter
* glühend roter Feuerball von der Größe einer Kirche, aus dem dann im
* Augenblick des völligen Untergangs ohne Farbenzwischenstufen ein intensiv
* leuchtendes, hellgrünes Flämmchen in der Form eines hohen spitzwinkeligen
* Dreieckes emporlohte, da durch die roten Reflexe im Wasser ein
* blitzartiges grünes Zucken jagte." (the figure closely resembles
* Lagaaij's drawing in F.K.'s thesis!) (GREEN RAY)


L. Rudaux
“Le coucher du soleil et le rayon vert,”
L'Illustration 85, 183–185 (1927).

* Lucien Rudaux's French article on the GF, illustrated by good B/W
* PHOTOGRAPHS of sunsets (including a nice MM) and 2 GFs, plus BEAUTIFUL
* COLORED DRAWINGS showing the visual appearance quite accurately, both for
* the naked eye and telescopically. p.183 has 2 nice photos of
* ASYMMETRICAL mirage development over an island. The center photo nicely
* shows the DARKENING of the SKY toward the horizon.
* [Rudaux was both an astronomer and an artist; he is regarded as the
* forerunner of Chesley Bonestell and other realistic space artists.]
* 27 August issue


F. Ruda
“Sulla spiegazione del raggio verde,”
Rend. della R. Accad. dei Lincei , series 6, 6, 152–156 (1927).

* attempt to test Julius's anomalous-refraction theory with ionized air in
* the lab
* O'C #122


F. Ruda
“Sulla spiegazione del raggio verde,”
Rend. della R. Accad. dei Lincei , series 6, 6, 228–230 (1927).

* rejects Julius's anomalous-refraction theory in favor of the usual
* scattering + dispersion


J. Stebbins
“The green flash at Mount Hamilton,”
PASP 39, 323 (1927).

* ONE FLASH SEEN BY TWO GROUPS at MT. HAMILTON
* "The place where the Sun was last seen was at a haze line. . . ."
* O'C #287


R. G. Aitken
“The green flash at Mount Hamilton,”
PASP 39, 323–324 (1927).

* SAME SUNSET as above
* ". . . a narrow horizontal band of vivid green projected against the sky
* at the point where the Sun was disappearing."
* This is the double-star Aitken
* O'C #165


Anonymous
“The green ray "mystery" explained: remarkable sunset phases,”
Illustrated London News 81, 712–713 (22 Oct., 1927).

* Lucien Rudaux's drawings and photographs; text not credited
* The page of drawings (presumably in color -- I have only a monochrome
* photocopy) is taken directly from Rudaux's "l'Illustration" article,
* less than 2 months earlier, and is headed:
*        The green ray at sunset: a meteorological "mystery"
* The explanatory drawings are also taken from "l'Illustration"; much
* of the text (p. 712) is a translation of his text there as well.
* The captions and explanations in the text are all right on the money.


C. Fitzhugh Talman
“Bibliography,”
Monthly Weather Review 55, 501 (1927).

* Rudaux/Ill. Lond. News item, cited with title only
* Nov. issue


W. L. Balls
“The `Green Flash' at Sunrise,”
Nature 120, 728–729 (1927).

* GREEN LINE OF DIFFRACTED LIGHT ?
* ". . . seemed to follow the minor prominences of the skyline, instead of
* first appearing between them."
* Nov. 19 issue


C. Bonacini
“Sul fenomeno del ``Raggio Verde'',”
Pubblicazioni dell'Osservatorio Geofisico dell'Università di Modena , No. 39, 115–130 (1927).

* A GOOD discussion based on numerous observations by a careful observer:
* Carlo Bonacini recognized the connection between thermal inversions and
* mock-mirage flashes. He also observed the spectrum of the green rim
* visually; realized that the phenomena are complex and depend on several
* factors, so that the textbook explanation is inadequate; realized the
* contribution of visual effects to what is seen; and connected sunset
* distortions, green flashes, and mirages. This is a thoughtful and
* insightful discussion, even though he believed that water vapor played an
* important part in producing the green color, and laid heavy emphasis on the
* variability of the rain bands in connection with his GF observations:
* ". . . our quite numerous observations [have] established a direct
* connection between the intensity of the rain-band and that of the GF:
* -- in the sense that when this is vivid, the humidity is always high.
* [Naturally, the reverse is not true, as other conditions are necessary
* for the formation of the GF.]
*      "This immediately clarifies how it is that the phenomenon is more
* showy and quite sharp at sea, where the atmosphere is extremely humid:
* while on land, or in the mountains, is almost always found the blue or
* blue-violet color.      . . .
*      "So while Guglielmo finds in the chromatic tail of the solar disk a
* prevalence of blue in the summer and green in the winter, I find in my
* statistics to have observed magnificent blue colors in the winter too,
* but in special conditions of low humidity (weak rain-band)." (p. 121).
*      He also recognized that physiological effects are not excluded by a
* physical cause: "And in fact, if it is true that the primary cause of
* the GF is real, this does not alter the fact that in particular
* circumstances of observation, that is when the observer has fixated for
* a long time, without being dazzled, the Sun can add to the sensation of
* objective green the negative image of the disk as well, of similar tint:
* since, as is known, a color appears of increased saturation when seen
* after fatigue by its complement . . . ." (pp. 122-123)
*      "And so could be explained still better that particular vividness of
* the green flash that has always amazed all the observers. . . ."
*      In discussing the width of the green rim and the duration of the
* flash, he seems to have confused seconds of time and seconds of arc, in
* reading the literature. (Indeed, he seems to mis-read many references
* that he cites.) Still, his general point that the observed duration
* exceeds the calculated one is correct. "This means that there is
* something else.      There must be some occasional circumstance that
* intervenes to modify the phenomenon and in an essential way." (p.124)
* This leads him (in section 7) to consider the irregularities of the
* solar limb.
*      That discussion focuses on the effects of "seeing", but leads to a
* discussion of static deformations of the limb (which, he says, are
* associated with the best GF displays) in section 8 (p. 126). He
* immediately attributes these structures to "stratification in calm".
* But he supposes that discontinuous images require discontinuities of
* density. "The literature, otherwise copious, is not generally
* accompanied by explanations." His own explanations largely involve
* arm-waving about "stratiform condensations" of water vapor in the upper
* atmosphere.
*      In section 9 (p. 127), he describes how pieces appear to be removed
* at the top of the setting disk by irregularities in refraction, and how
* this can be simulated with a white disk and a wavy glass, or "any glass
* whatever of very bad quality, which is not flat." So these pieces
* of "the extreme upper limb, separated like a cloud," cause good GF
* displays [i.e., mock-mirage flashes]. (Sect.10, p.128) He gives
* some examples from his observing records: Fig.2 shows "the separation
* of a red segment" at the lower limb -- i.e., a red flash. "And I
* predict therefore that when the upper limb will arrive at that zone,
* there will be a beautiful GF. Indeed, 2 or 3 times we have had the
* isolated green cloud (and a little blue at the end) with a duration
* greater than 2'' and of an unusual width."
*      In section 11 (p. 129) he discusses mirage effects:  "The bizarre
* forms of the Sun at the horizon can in fact become still more complicated
* by this cause: indeed the duplications, the more grandiose splittings
* etc., could not otherwise be explained . . . ", and naturally cites Wegener.
* Mirage should play a part in the GF because the reflected image
* of the green cloud is added to the direct image, thus enlarging the
* colored zone and (he thinks) its duration "if the disappearance of the
* two zones is not simultaneous."
*      Sect. 12 (pp.129-130) deals with high latitudes, where he thinks the GF
* is rarely seen. This fits in with his ideas about water vapor.
*      Note that he discovered that "spikes" on the upper limb occur at the
* same altitudes as indentations in the lower limb, and associated these with
* inversion layers, 30 years before O'Connell! (Compare Fig. 3 here with
* O'Connell's pp.135 and 137.)
* (No.39 of the Pubblicazioni is entitled:
* NEL PRIMO CENTENARIO DALLA FONDAZIONE DELL'OSSERVATORIO - 1827 - 1927
* Thanks to Luca Lombroso for providing this information!)


O. Lodge
“The `Green Flash',”
Nature 120, 807 (1927).

* OLIVER LODGE, obviously never having seen a GF, thinks "the sudden green
* flash, seen by some people . . . , is mainly physiological; for I see . . .
* a momentary greenness when I switch off a bright lamp, with metallic
* filament, suspended over my bed."
* Dec. 3 issue
* O'C #81


C. J. P. Cave
“The `Green Flash',”
Nature 120, 876 (1927).

* LODGE gets his comeuppance for speaking out of turn. . .
* "The literature of the green flash is very voluminous. . . ."
* "The explanation as a refraction phenomenon is so simple, and fits the
* facts so well, that it is curious that there should be such a reluctance
* to accept it."
* NOTE: Cave was President of the Royal Meteorological Society from
* 1913-1915 and 1924-1926. See QJRMS 77, 334-336 (1951)
* O'C #190
* Dec. 17 issue


H. R. Mill
“The `Green Flash',”
Nature 120, 876 (1927).

* ``Much confusion has beset this subject
* because two entirely different things are unfortunately covered by the
* phrase `green flash.' If separate names had from the first been given to
* the two things, each would have been treated apart from the other and a
* great amount of controversy avoided.''
* O'C #249


J. Evershed
“The `Green Flash',”
Nature 120, 876–877 (1927).

* EVERSHED replies to Lodge:
* "The physiological theory of the green flash, resuscitated by Sir Oliver
* Lodge, is not now held by any competent observer who has made a careful
* study of the phenomenon."
* "I have made very numerous observations of the green flash, at sea and
* on land, and have confirmed Mr. Whitmell's conclusions."
* Dec. 17 issue
* O'C #207


W. Semple
“The `Green Flash',”
Nature 120, 877 (1927).

* "I . . . suggested that five of us should turn our backs to the sun and
* close our eyes until the sixth should signal that the upper edge of the
* sun was disappearing. On his signal we turned, and each saw for an
* appreciable time a thread of bright green light lining the silhouette of
* the island at the point where the sun was last seen."
* O'C #281


O. Lodge
“The `Green Flash',”
Nature 121, 58 (1928).

* LODGE RECANTS
* "If in my letter . . . I am understood to have suggested that the green
* flash seen at sunset had no cause other than a physiological one, I
* withdraw any implied or hinted suggestion in that direction; for it is
* evident that a great weight of authority is in favour of a physical
* cause."
* "It was, I admit, rather hasty to send a letter on so small a point. . . ."
* O'C #82


Chr. Burdo
“Une observation particulière du rayon vert,”
La Nature 56:1, 44 (1928).

* DRAWINGS of MM-type flashes appear more schematic than detailed.
* Possible observation of SKY BANDING?
* "Temps clair, vent très faible; quelques légères bandes de brume
* parallèles à l'horizon donnent au disque l'aplatissement et les
* déformations bien connues."
* ". . . les lignes de brume accusent l'étranglement de la partie
* supérieure, et finissent par la séparer du disque, comme le montre la
* figure 2."


(anonymous)
“Royal National Academy of the Lincei – F.Ruda,”
Nature 121, 306 (1928).

* useless very brief report of Ruda's 1927 papers


R. W. Wood
“Factors which determine the occurrence of the green ray,”
Nature 121, 501 (1928).

* R.W.WOOD (Mar.31) -- see following papers
* "No person trained in the observation of optical effects, both real and
* subjective, who has seen the phenomenon at its best, will have any doubt
* about its reality."
* "It seems possible that the determining factor is the relative
* temperature of the air and the ocean."
* "With cold water and warm air, . . . the normal gradient of refractive
* index would be increased, the curvature of the rays augmented, and
* sunset would be delayed, giving a greater opportunity for atmospheric
* dispersion to come into play."
* (This error was propagated by Rayleigh two years later.)
* O'C #162


Anonymous
“Green Ray seen from ship,”
Science News Letter 13, 290 (1928).

* WOOD's unsuccessful appeal for observations (May 12)


Anonymous
“Green Ray seen from ship,”
Pop. Astr. 36, 382–383 (1928).

* Popular Astronomy reprints the Science News Letter item verbatim:
* O'C #163


E. A. Childe
“The green ray,”
JBAA 38, 183–184 (1928).

* double flash (first mountain, then sea horizon) from the St. Albans
* O'C #194 (he has wrong volume)


G. C. F(lammarion)
“Un rare spectacle dans le ciel et sur la terre,”
BSAF 42, 256–257 (1928).

* useless amateur report
* O'C #208


R. T. Harris
“Green flash at sunset. N.W. Pacific.,”
Marine Observer 5, 114 (1928).

* GREEN RAY of amazing size if no error; could it be a crepuscular ray?
* "Immediately after sunset a vivid emerald green flash was observed from
* the horizon point of sunset to an altitude of about 80° in a southerly
* direction. The sky immediately above the horizon was covered with A-St
* clouds to an altitude of about 5°. The remainder of the sky was
* covered with Cu-Nb/St. Cu. clouds."


S. J. Barnett
“The green flash,”
Nature 122, 171 (1928).

* GF COMMON in SOUTHERN CALIFORNIA
* "In some localities the green flash is by no means so rare a phenomenon
* as might be inferred from Prof.Wood's experience on the Atlantic Ocean and
* from the letters of some other correspondents of Nature. Here in Southern
* California I have seen the flash many times. . . ."
* O'C #170


G. Rougier
“A propos du `Rayon Vert',”
BSAF 42, 377–384 (1928).

* Observations at Pic du Midi
* Emphasizes the need for a high horizon to get BLUE or VIOLET.
* Admits that mirages can extend the duration, citing Evershed.
* "Si l'atmosphère était homogène, la durée theorique . . . ne saurait
* atteindre en aucun cas, sous nos latitudes, une durée de 2 secondes . . . .
* Mais it suffit d'avoir contemplé quelques couchers de Soleil pour être
* convaincu que l'atmosphère est bien souvent hétérogène , et cette
* circonstance suffit à expliquer les durées anormales fréquemment
* observées." BUT:
* ". . . la présence d'une couche d'indice minimum au point de disparition
* du Soleil est susceptible de donner lieu à une frange colorée
* exceptionnellement large. In convient toutefois de remarquer qu'elle
* ne saurait augmenter la durée de visibilité du Rayon Vert. . . ."
*
* Nice drawing of a marine mirage showing the bow-wake.
* Good advice to observers:
* "L'instrument idéal pour le bien observer est essentiellement portatif;
* je ne saurais en effet rien conseiller de mieux qu'une jumelle à prismes
* groissant huit fois."
* O'C #120


J. Devaux
“Sur le `Rayon Vert',”
BSAF 42, 384–389 (1928).

* Observations at Pic du Midi: COLOR REVERSAL
* Terminology critiqued; extreme variability of phenomena pointed out,
* including mock-mirage features.
* Discussion of "recrudescence" of green light.
* Much is made of Bellemin & Gallisot's "couche troublée";
* the interpretation is all garbage, but the observations are excellent.
* "Hypothèse du contraste ou des couleurs complémentaires . . . qui
* contient pourtant un fond de vérité."
* VENUS and JUPITER observed telescopically:
* "Parfois même il y a renversement complet des couleurs, renversement
* qui ne dure en général qu'un instant.
* "Mais le 8 février, il y eut renversement complet pendant plus d'une
* minute; le rouge occupait nettement la partie supérieure du disque de
* Vénus, avec cependant des oscillations marquées. . . . Le 11 février, le
* même phénomène s'est reproduit, mais moins nettement, et pendant moins
* longtemps." [cf. O'Connell, Plates XIII, XIV (pp.77 & 79)]
* Planetary analog of GREEN RAY?
* "De plus, il est essentiel de remarquer que la tache verte s'eloigne non
* seulement du disque, mais encore qu'elle s'élève réellement par rapport
* à l'horizon. La distance maxima entre le disque et l'aigrette au moment
* où elle va disparaître est de l'ordre de 1'."
* O'C #27


J. T. Bird
“The green flash,”
JBAA 38, 305 (1928).

* useless
* O'C #176


A. S. D. Maunder
“The green flash,”
JBAA 38, 305 (1928).

* useless -- another first-time observer
* O'C #242


W. B. Housman
“Green and blue flash,”
JBAA 39, 31–32 (1928).

* 5 reports from a moderately experienced observer; some blue
* Includes a nice RED FLASH:
* "Lower limb of Sun emerged from a cumulus bank 1/2° above distant
* horizon with a ruby light."
* Many mock-mirage flashes:
* "In certain states of the sky the green ray may be formed by successive
* strata of lofty clouds forming false horizons, and I once saw the upper
* limb sinking, at 1° altitude, through a close succession of these, and
* with × 18 glass counted about a dozen separate productions of the
* green ray, which formed on each side of the upper segment, and appeared to
* chase each other to the top, unite with the ray coming up the opposite
* side, and float clear."
* O'C #220


A. Fry
“The green flash,”
JBAA 39, 61 (1928).

* So brief I quote it in full here: USE of BINOCULARS
* "It is possible to see this with field-glasses when an observer could
* not see it with the naked eye. It is safe to use such glasses on the Sun
* when this is quite low on the horizon for the few moments necessary for
* this observation."


M. B. B. Heath
“The green flash,”
JBAA 39, 61 (1928).

* TELESCOPE recommended; BLUE-VIOLET reported
* "This has been seen many times. . . ."
* ". . . first was of a deep green hue, but the last tiny spark appeared of
* a most intense blue-violet colour."
* O'C #219


J. Boulinier
“A propos du Rayon Vert,”
BSAF 42, 529 (1928).

* BLUE flash over LAND
* O'C #182


H. Fleury
“Observation du Rayon Vert,”
BSAF 42, 582 (1928).

* Repeated or continuous GF for over a MINUTE of time
* "Il est très facile . . . de prolonger le temps pendant lequel le bord
* supérieur du Soleil est, pour l'observateur, tangent au parapet: il
* suffit de lever la tête progressivement au fur à mesure que le Soleil
* descend . . . .
* "Quand le Rayon Vert est visible, on peut l'observer pendant plus d'une
* minute d'une maniere continue ou, à plusiers reprises, en maintenant le
* tête au-dessous du plan parapet-bord superieur du Soleil . . . ."
*O'C #213


T. S. Dymond
“The green ray,”
Nature 123, 207 (1929).

* GREEN better seen over LAND than over SEA in polluted air
* O'C #204


L. Jacchia
“Optique atmosphérique. Le Rayon Vert.,”
BSAF 43, 252 (1929).

* Jacchia sees the green rim; Groubé sees a GF. Both useless.
*O'C #216


A. Fry
“The green flash,”
JBAA 39, 167 (1929).

* A curious proposal and experiment (see Agnes Fry's earlier report in JBAA)


C. J. P. Cave
“The green flash,”
Nature 123, 607 (1929).

* VENUS flash seen from 700 ft.: "peacock green"


J. A. Parker
“The green ray,”
JBAA 39, 222 (1929).

* Parker identifies Housman's RED FLASH (above)
* March issue
* O'C #262


Jno. A. Fleming
“Observations of green flash,”
Science 69, 298–299 (1929).

* Fleming reports an observation by Frank T. Davies (with Byrd exped.)
* "Frank T. Davies . . . reports . . . a green flash observed off Bermuda on
* the evening of August 28, 1928:
*      `Very smoky dull-red sunset . . . .'  -- so much for the rule that
* flashes can't be seen when the sun is red! ` It did not look to me
* like a flash but a definite change from yellow to green lasting about
* two to three seconds.'"
* No info about water temperature; but this is plainly an inf-mir. flash.
* March 15 issue


P. L. Shakespeare
“Green ray and crepuscular rays at sunset. North Atlantic Ocean.,”
Marine Observer 6, 243 (1929).

* Mostly about crepuscular rays, except for a useless passing mention that
* "Sun set . . . with a peculiar green tint as upper segment dipped . . . ."


[unsigned news item]
“Forschung Fortschritt: Der grüne Strahl,”
Kosmos (Stuttgart) 26, ?? (1929).

* VENUS GF
* refers to the Kosmoshandweiser 1926, S.13 and 1927, S.282
* kindly supplied by Brigitte Hofmann, Redaction "Kosmos"!


E. M. Dence
“Sunset and the ``Green Flash'',”
Times (Lond.) , p.8 (19 Aug., 1929).

* typical isolated report; useless except that
* ". . . as we had protected our eyes up to the last few seconds we were
* both able to agree that the transformation to green was unmistakable
* and was not accompanied by any change of colour in the region of sky
* near the sun." (inappropriately cited by Botley, 1930)


G. A. Cave Orme
“The ``Green Flash'',”
Times (Lond.) , p.8 (21 Aug., 1929).

* ". . . in most perfect conditions. The sun's disk was a brilliant deep red."
* Offers the afterimage explanation.


H. W. Ackland
“The Green Flash,”
Times (Lond.) , p.8 (22 Aug., 1929).

* "I see it fairly frequently at sunrise."
* CAUTION: horizontal refr. given as 36 deg., not minutes.
* "I have not infrequently seen grey or violet at sunrise."


W. C. Henderson
“``The Green Flash'',”
Times (Lond.) , p.8 (26 Aug., 1929).

* A muddled version of the standard story
* Thinks blue is seen only at sunrise
* Refers to earlier letters by Cave Orme [21 Aug.] and Druce.
* (Could "Druce" be Dence, above, on Aug.19?)


A. Fry
“The Green Flash,”
Times (Lond.) , p.6 (27 Aug., 1929).

* AGNES FRY offers her indoor afterimage example again (cf. her JBAA paper
* earlier this year)


R. Clements
“``The Green Flash'',”
Times (Lond.) , p.8 (28 Aug., 1929).

* This is the item Botley (1971) had in mind about
* "the sun putting out his sidelights"
* -- but see his book "A Gipsy of the Horn" (1925) for its first appearance!


E. D. Cooper
“The green flash,”
Met. Mag. 64, 207 (1929).

* YELLOW stage noted
* "The setting sun was of a deep yellow colour, and when partly set was
* still trying to the sight. As the last segment of the sun disappeared it
* turned a whitish yellow tinged with a deep orange colour, followed
* immediately by the green flash of a beautiful emerald shade."


P. Moureau
“Le rayon vert,”
La Nature 57:2, No. 2818, 294–299 (1929).

* A completely CRANK work. The author believes it is all contrast effects,
* and has a screwey theory about these, colored shadows, acoustics,
* hydraulics, electricity, etc. Basically, a well-meaning but ignorant
* amateur, who replicated Prof. Porter's experiments, but has even less
* understanding of their significance.
* Why did the editors see fit to publish this nonsense? [Oct. issue]


R. Owen
“Explorers see phenomenon in Pole area: Byrd party watches `Green Flash' blaze in sky at Little America,”
San Francisco Chronicle , p.5 (23 Oct., 1929).

* The ORIGINAL ADMIRAL BYRD story from an eyewitness (Russell Owen)
*      "Via New York Times radio station and Mussel Rock radio station.
* Robert Dollar Steamship Company, San Francisco. Copyright, 1929,
* by the New York Times Company, the San Francisco Chronicle and the
* St. Louis Post Dispatch. . . .
*                  "SPECIAL BY WIRELESS
*      "LITTLE AMERICA, Antarctica, Oct. 22 -- The ``green flash,'' that
* phenomenon seen at sea and which occasionally causes debate among
* scientific men, has been seen here recently so prolonged that instead
* of flash it resembled a green flare hung in the sky where the sun had
* just set. The green flash is usually seen at sea in the tropics where
* the sun drops suddenly below the horizon and vanishes so quickly that
* it is literally a flash.
*      "It comes from the last star like a point of light from the sun
* as it goes down, a point which changes rapidly in color of which
* the green is exceptionally vivid, giving the phenomenon its name.
* Atmospheric refraction causes the light to disappear in the order of
* its refractability or bending qualities. The red rays bend the least
* and so disappear first, then the green and finally the blue.
*                  "SUN SINKS SLOWLY
*      "Here the sun descends so slowly that it seems to roll along the
* horizon and as it will be only two days until it is above the horizon
* all the time for the rest of the summer it clings interminably before,
* with seeming reluctance, dropping from sight. As its downward movement
* is so prolonged the last rays shimmer above the barrier edge as it moves
* eastward, appearing and reappearing from behind the irregularities of
* the barrier surface. It trembles and pulsates, producing a vibration
* light of great beauty.
*      "The night the green flash was seen some one ran into the
* administration building and called, ``Come out and see the green sun.''
*                  "SEEN FOR HALF HOUR
*      "There was a rush for the surface and as eyes turned southward,
* they saw a tiny but brilliant green spot where the last ray of the upper
* limb of the sun hung on the skyline. It lasted an appreciable length
* of time, several seconds at least, and no sooner disappeared than it
* flashed forth again. Altogether it remained on the horizon with short
* interruptions for thirty-five minutes.
*      "When it disappeared momentarily it seemed to have been shut off by a
* tiny spurt, an inequality in the skyline caused by the barrier surface.
*      "Even by moving the head up a few inches it would disappear and
* reappear again and after it had finally disappeared from view it could
* be recaptured by climbing up the first few steps of the antanea post.
*      "Curiously enough at one time there seemed to be a brilliant red
* flash or spot of light a short distance from the green at just about the
* distance one would suppose the arc of the upper limb of the sun extends
* below the horizon."
*      The rest of the article continues Owen's running reports on the
* progress of the Byrd expedition. Note: all strictly [sic]. Most of
* the typos can be figured out: "last star like a" was meant to be just
* "last star-like" and "vibration" was obviously meant to be "vibrating".
* But how did "antanea" get past the proofreaders? "Eastward" is a typical
* mistake of a Northern Hemisphere resident new to the South.
*      Note that this was a sunset  flash seen at the end of the southern
* winter night, which explains the confusion in second-hand reports.
* According to Davies (1931) and Haines (1931), the flashes were seen on
* Oct. 16, several days before the dateline of this account.


R. G. Aitken
“The green flash,”
PASP 41, 317 (1929).

* Seen 20 times in 2 months at MT. HAMILTON
* This is the double-star Aitken
* O'C #166


A. P. Redington
“The green flash,”
PASP 41, 388 (1929).

* NORMALLY SEEN WITH 8X BINOCULARS in Santa Barbara
* "These observations . . . have been made through a pair of eight-power
* Hensoldt-Wetzlar binoculars, under which circumstances it is an
* exception when it cannot be seen, assuming that the horizon is clear. . . ."
* O'C #267


M. Pinkhof
“Waarnemingen van de groene straal,”
Hemel en Dampkring 27, 398–399 (1929).

* Pinkhof quotes from letters, mostly a wordy report from W. Meyers Cluwen:
* "Unusually clear weather, straight horizon, sharp as I have seldom
* seen it in our country.  North wind . . .  Quiet sea. . . .      The sun
* set without any deformation. . . . Just at the moment when the last bit of
* the sun disappeared, a green light appeared for a short moment, green
* with a touch of blue, shining to us and reflected in the water. . . . about
* 1/4 to 1/2 second, possibly 1 second. Short times are difficult to
* determine without special aids. One usually overestimates the duration of
* such observations, because the image `persists'."
* Pinkhof then reports a few of his own: ". . . the sun was quite well
* deformed: the outline looked angular and when it arrived at the horizon, a
* mirror image was formed in a layer of air, so that it was just as if the
* sun rested on a pedestal." He then adds a third-hand account of the
* Byrd expedition's observation, relayed via d'Aumérie. "Mr. d'Aumérie
* recalled a similar case that was brought about in a very different way
* (published some years ago in the Bulletin de la Société Astronomique de
* France): a hiker ran along a slope at the same pace as the speed of the
* sunset. The green flash then remained visible a long time." [NOTE: this
* must be Whitehead's report in BSAF 35,404(1921).]
* I have a botched copy of this; Berkeley's original was badly stained.


J. T. Bird
“The green flash,”
JBAA 40, 58 (1929).

* 2 useless "pale blue" flashes


C. Vaughan Starr
“The green flash,”
Met. Mag. 64, 290–291 (1930).

* GOOD EVIDENCE for ADAPTATION
* ". . . two of us watched the sun carefully until it had set, while the
* other two looked eastwards and on a signal from the sun watchers turned
* quickly just as the sun was disappearing. The two who had watched
* continuously saw the green flash, while to those who did not look till
* the very last moment, the sun went down orange-yellow, and no green was
* seen."


Anon.
“The `Green Flash' at sunset,”
Nature 125, 144 (1930).

* a blurb for Rayleigh's 1930 paper, in Nature
* "A satisfactory account of the origin of the `green flash' of the upper
* limb of the sun when it disappears at sunset is given by Lord Rayleigh
* in the January issue of the Proceedings of the Royal Society. "
*      Curiously, this cites the correct  reference for Wood's paper, though
* Rayleigh got it wrong in his paper! So I think the attribution of
* this item to Rayleigh by his biographer Egerton (1949) is in error.
*      Jan.25 issue, in the "Research Items" dept.


W. S. Thomas
“Green ray at setting of Venus. North Atlantic Ocean.,”
Marine Observer 7, 8 (1930).

* a useless and ordinary report, preceded by poor drawings of a solar Omega
* in the report by T.E.Earl, "Abnormal refraction, Mediterranean Sea".


G. A. Clarke
“Observation of the green ray at Aberdeen,”
Met. Mag. 65, 6–8 (1930).

* EXCELLENT INFERIOR-MIRAGE SUNRISE FLASH -- BEST DRAWINGS EVER
* VERY CAREFUL observation of Omega-type sunrise with 3-inch telescope.
* ". . . the first appearance of the sun was a small flattened button-shaped
* spot . . . of intense green light . . . ."
* ". . . in the first stages . . . the lower edge seemed to be separated very
* slightly from the sea-horizon . . . while in the succeeding stages the disc
* seemed to be joined to the horizon-line by a connecting strip . . . .
* This connecting strip appeared to be due to some `mirage' effect, for,
* at the instant of separation from the sun's disc . . . the last connection
* took the form of flickering orange-red flames in rapid vertical motion
* between disc and reflection. Separation was complete . . . when the sun's
* disc had an ovoid form, flattened at the top, but extended and much
* pointed below, the lower edge being orange-red while the upper edge was
* still narrowly green."
* Even the red flash at the stem was noticed!


C. M. Botley
“Observation of the Green Ray at Aberdeen,”
Met. Mag. 65, 8 (1930).

* Dumb comments by Botley on the above, comparing physiological effects at
* the SUNRISE flash with a SUNSET observation from the Times


Lord Rayleigh
“Normal atmospheric dispersion as the cause of the "Green Flash" at sunset, with illustrative experiments,”
Proc. Roy. Soc. A 126, 311–318 (1930).

* RAYLEIGH (younger)
* another SCALED DISPERSION calculation:
* "Thus the angular dispersion between the C and F lines, now more
* generally called @roman H sub alpha@ and @roman H sub beta@ is
* @1.04 times 10 sup -2@ of 35', or 22''."
* He also promotes Wood's (1928) erroneous suggestion that more refraction
* would make the green rim more visible.
*      Note that the reference to Wood on p. 317 is badly garbled: it says
* Nature "vol. 111, p.502 (1923)", but should be vol. 121, p.501 (1928).
* [Vol. 111, p. 13 (1923) is Evershed; Rayleigh got them confused.]
* O'C #112


T. Køhl
“Solens grønne Glimt,”
Nordisk Astronomisk Tidsskrift (Copenhagen) 11, 69–71 (1930).

* This is a collection of 10 other reports, accumulated at the Carina
* Observatory in Odder over a long period. Some are recognizable (Flöcker,
* Stebbins & Aitken at Mt. Hamilton, the Byrd expedition in Antarctica)
* but most are apparently either newspaper reports or individual reports
* sent in. #6 is interesting: ". . . he had looked long at the Sun, when it
* suddenly began, and made an impression nearly like that due to an
* irritation of the eye. . . " (cf. Mike Bandfield's reports)
* O'C #72


H. Lipp
“Beobachtungen des grünen Strahles auf der Zugspitze,”
Met. Z. 47, 113–115 (1930).

* A year of systematic observations at both sunset and sunrise. This is
* probably the best comparison of sunset with sunrise available. The
* duration was longer at sunset, the longest being 12 sec.
* EVIDENCE for ADAPTATION


F. Roßmann
“Beobachtungen des grünen Strahles auf dem Feldberg im Schwarzwald,”
Met. Z. 47, 368–371 (1930).

* Less interesting is Roßmann's paper on pp.368-371 of the same issue.
* He saw fewer GF's from the Feldberg, which is lower. Observations were
* timed with a stopwatch. The observations with refraction anomalies
* (superior mirages, distorted Sun, etc.) lasted longer, on the average,
* than those without.
* NOTE: Roßmann was the original owner of the copy of P&E on my desk.


C. W. A. G. Hamley
“Green flash. Ceylon,”
Marine Observer 7, 103 (1930).

* GREEN COLUMN (cf. Escher, below!)
* "In Ceylon at the end of April and beginning of May -- just before the
* break of the S.W. Monsoon -- at sunset, which is always very brilliant, as
* the sun finally disappears under the horizon, a great column of green
* light appears to shoot up into the heavens and then gradually disappear."


B. G. Escher
“De Groene Straal,”
Tijdschr. Kon. Ned. Aardr. Gen. , series 2, 47, 602–609 (1930).

* B.G.ESCHER comments on Feenstra Kuiper's thesis, with some useful ideas
* (as well as some gaffes). His main weakness is having seen only 4 GFs;
* and, as he says, "A complete classification could only be given by
* someone who has made very many observations himself and moreover is
* sufficiently educated in the natural sciences."
* [F.K. (below) unaccountably takes great offense at this sensible remark.]
* Nevertheless, Escher offers his classification.
*
* Escher allows a PERSONAL FACTOR: "The phenomenon sometimes lasts so
* briefly that a complete concentration of thought is required precisely at
* the moment of sunset or sunrise. If the concentration at that moment is
* not complete, it can happen that one has seen nothing, while his neighbor,
* who was completely concentrated, saw the green flash well." [If we
* replace "thought" with "vision", we see the presence of the bleaching
* effects; see C. Vaughan Starr below.]
*
* Escher makes a USEFUL DISTINCTION:
* "In the first place, a sharp separation must be made between the
* phenomena that are seen on the Sun itself, while it still (or already)
* stands above the horizon, and the phenomena that appear immediately after
* the Sun has set or just before it has risen." [The latter are the green
* crepuscular rays, though Escher seems to include the inferior mirage as
* well.]
*
* The chief value of this paper is his detailed description of a SUNRISE
* GREEN RAY, with essential circumstances:
* ". . . I have named a green column, which I have observed on 6 July 1929
* at sunrise in the Gulf of Suez. It was easy to predict where the Sun
* would rise on the pink illuminated parts of the mountains on the Sinai
* peninsula. Just above the profile line, where the Sun rose later on,
* appeared a bright light-yellow rim and simultaneously above that a
* light-blue segment. This segment rose and changed to green below.
* Suddenly the Sun itself appeared, absolutely not red or orange, as it was
* with the green flash at sunset, but intensely shining and white,
* surrounded by a light yellow shine. At the same time the mountain
* silhouette became light colored. The light between the mountain horizon
* and the sea was obviously laden with dust particles, which is hardly
* surprising in the Sinai desert. I estimate the duration of this
* long-lasting, broad and high green flash at 2 seconds. That abnormal
* refraction and dispersion occur here is certain; they were apparently
* caused by mineral particles in the air."
* "The diameter of the green column was estimated to be about half that
* of the Sun, while the height of the green column with blue cap was
* estimated by me at 2/3 of the diameter of the Sun."
* [He says earlier he used a 5 x 20 Spindler & Hoyer prism monocular; but
* does not say explicitly that it was used for this observation.]
*
* There is also an INTERESTING MAP showing the geographical distribution
* of the observations in F.K.'s thesis. From the concentration of GF
* observations in the Red Sea, the Gulf of Aden, and the south-eastern
* Mediterranean, he suggests that "the frequency of the green ray
* observations is greatest in the regions where the precipitation is the
* least, that is, where the shipping routes pass near or between deserts."
* So he concludes that "a dry climate is favorable for the appearance of
* this very remarkable phenomenon."
*
* Note: Escher was quite a famous geologist; thanks to G.P.Können for
* pointing this out. He was the sixth president of the International
* Association of Volcanology and Chemistry of the Earth's Interior, and
* the brother of the remarkable artist M.C.Escher.
*
* Tijdschrift, Koninklijk Nederlands Aardrijkskundig Genootschap =
* Journal of the Royal Dutch Geographical Society


P. Feenstra Kuiper
“De Groene Straal,”
Tijdschr. Kon. Ned. Aardr. Gen. , series 2, 47, 868–870 (1930).

* The thin-skinned Feenstra Kuiper angrily takes offense . . .


B. G. Escher
“Naschrift,”
Tijdschr. Kon. Ned. Aardr. Gen. , series 2, 47, 870 (1930).

* . . . and Escher then adds a few more off-base suggestions (that mineral
* crystals in the air could affect its index of refraction).


S. J. Barnett
“The green flash in Southern California,”
Nature 125, 446 (1930).

* COMMON in SOUTHERN CALIFORNIA
* "The observations of these beautiful but variable phenomena have been
* very numerous. . . . in the 32-day interval Aug. 20 - Sept. 20, 1928, I
* witnessed the flash at sunset 13 times."
* "Contrary to what appears to be the usual impression, the green flash is
* at least as easy to observe when the sun is considerably reddened as when
* it is bright."
* O'C #171


S. W. Visser
“Dutch observations of the green flash,”
PASP 42, 336–339 (1930).

* GOOD SUMMARY of Dutch work (cf. Meyer's 1939 paper!)
* This gives a better summary of Feenstra Kuiper's thesis than F.K. himself
* gave in JBAA. The history of Nijland's effort is also outlined.
* O'C #146


O. F. T. Roberts
“The Green Ray,”
Nature 126, 169 (1930).

* cites Wood's 1928 Nature paper
* "While descending in clear weather as a passenger in a motor-car into a
* valley in Kincardineshire I watched the artificial sunset due to the
* obscuring of the sun by a hill some three miles away, the country being
* several inches deep in snow; the sunset occupied about five seconds; the
* last-disappearing edge of the sun turned from orange through yellow to a
* grass green. . . . the sharp increase of temperature with height usual
* above a snow surface appears to have produced a sufficiently high
* dispersion."
* O'C #270


R. E. Byrd
“The conquest of Antarctica by air,”
National Geographic 58, 127–227 (1930).

* Admiral BYRD's account (cf. Haines, below)
* GF mentioned only on p.186, in section "The `green flash' flares at sunset"
* ". . . we had a series of sunsets."
* p.193 shows a picture of "William (Cyclone) Haines, meteorologist"


H. N. Russell
“The `Green Flash' and other odd phenomena,”
Scientific American 143, 114–116 (1930).

* HENRY NORRIS RUSSELL reports from Egypt on the GF and mirages
* (pretty standard textbook treatment)


T. W. Walford
“Green flash. South African waters.,”
Marine Observer 8, 7 (1931).

* std. 2-sec inf.-mir. flash


J. A. C. Teegan
“The green flash,”
Discovery 12, no. 2, 112 (1931).

* a trivial observation, but the Editor's comment (below) is noteworthy


Editor
Discovery 12, no. 2, 112 (1931).

* the Editor's comment:
* ". . . the mist may possibly have excluded the blue and violet images more
* completely than usual, which would give a purer green than is normally
* seen. This suggestion, however, is offered with diffidence."
*(cf. Dietze!)


F. T. Davies
“Notes on green flash observed August 29, 1928, and October 16, 1929,”
Terr. Mag. Atmos. Elect. 36, 61–62 (1931).

* This is the most detailed account of the Byrd expedition's GF display:
* "The green color lasted for about a second at a time. It could not be
* seen continuously with the head in a fixed position . . . ."
* "When the Sun sank too low to be seen from the ground, it was still
* visible from the radio towers, and the above effect was seen at intervals
* for as long as one-half hour after the first observation."


William C. Haines
“The green flash observed October 16, 1929, at Little America by members of the Byrd Antarctic expedition,”
Monthly Weather Review 59, 117–118 (1931).

* "The above effect was seen at intervals during a period lasting over
* half an hour."
* (translated by Roßmann, 1934)
* O'C #47


H. H. Dahlerup-Petersen
“Det grønne Glimt,”
Nordisk Astronomisk Tidsskrift (Copenhagen) 12, 63 (1931).

* prompted by Køhl's article in 1930
* An amateur discovers the green and red rims on the low Sun
* O'C #22


A. Marquet
“Optique atmosphérique,”
BSAF 45, 70–71 (1931).

* Green rim seen telescopically above cloud:
* "Au-dessus et surtout en dessous du nuage, les images ont été très
* agitées avec effilochements dans le sens horizontal."
* "Le temps était très nuageux, le vent très violent."
* O'C #236


M. B. Thomas
“Blue and green flash at sunset. Mediterranean Sea,”
Marine Observer 8, 101 (1931).

* 2 inf.-mir. flashes
* May issue


M. B. Thomas
“Green flash at sunset. Mediterranean Sea,”
Marine Observer 8, 126 (1931).

* useless inf.-mir. flash
* June issue


Em. Touchet
“La photographie en couleurs du `Rayon Vert',”
La Nature 59:2, No. 2862, 100–104 (1931).

* FIRST COLOR PHOTOGRAPH by Maurice de Kerolyr
* The AUTOCHROME PLATES! (These must be the ones mentioned by Minnaert)
* This is a longer account than that in BSAF the next year.
* Here, Touchet says de Kerolyr was "directeur de la Station
* astrophotographique de la Haute Provence, à Forcalquier (Basses-Alpes)."
* But it seems that OHP did not yet exist; he speaks of a later article
* "à l'occasion du projet de construction d'un grand observatoire
* français".
* This seems to have been a private observatory; the telescope was an f/10
* lens of 1.20 m focal length.
* There is a drawing made from the plate by Rudaux; but "le mode
* d'impression de ce journal ne le permit pas. . . ." so the pictures are all
* black-and-white.
* Issue of Aug. 1, 1931.
* THANKS to Shaun Hardy for this reference!


A. E. Stephenson
“Green flash at setting of Venus. South Indian Ocean,”
Marine Observer 8, 209 (1931).

* VENUS flash
* "As planet's altitude became . . . approximately equal to its diameter it
* appeared joined to the horizon by a ray of light." [DRAWINGS]
* cited in vol.13, p.8
* Oct. issue


G. Blum
“Observations du Rayon vert,”
BSAF 45, 452 (1931).

* Good inferior-mirage flash
* ". . . le vent, assez fort, avait tourné de l'Ouest au Nord."
* O'C #178


Mme. de la Rosa
“Optique atmosphérique,”
BSAF 45, 513 (1931).

* Ordinary inferior-mirage flash


J. Plassmann
“Über die Färbung der tiefstehenden Sonne und einige Nebenerscheinungen,”
Met. Zs. 48, 421–425 (1931).

* NO GF stuff; why did O'Connell include this?
* Could be useful for study of visual effects
* O'C #107


G. P. Kuiper
“Een opmerking over de zichtbaarheid van de groene straal,”
Hemel en Dampkring 30, 81–83 (1932).

* GPK has a look at the green rim
* This is a curious piece of work, done while Kuiper was a student at
* Leiden. He states that he's never seen a naked-eye green flash, but
* once saw a good telescopic one. He then relates his observations on
* one [!] evening at the 26.5-cm refractor of Leiden Observatory.
* The "cloud" sounds as if it might have been a Wegener blank strip.
* The whole argument is full of inconsistencies: if there really was a
* cloud, then his observation says nothing about clear-weather observability
* of the flash, as he claims; you can't have both less refraction and more
* absorption simultaneously; etc. The paper is notable for the suggestion
* that unspecified "waves" in the air are responsible for the pieces that
* break off the upper limb and turn green, but I doubt that he really
* understood Kelvin-Helmholtz waves at this point (and no meteorological
* data are given.) The best that can be said for it is that he recognized
* that something besides extinction is affecting the visibility of the
* flash.
* (NOTE: volume number not certain.)


P. Blanc
“Le rayon vert,”
BSAF 46, 87–88 (1932).

* A GENUINE LEGEND at last !!
* ". . . plusiers légendes, surtout celle du voeu à formuler pendant sa
* fugace apparition et qui doit se réaliser dans le cours de l'année."
* Ignorant of earlier work: "On peur se souvenir de l'explication physique
* qui en a été donnée ici-même par notre illustre collègue M. Ch.-Ed.
* Guillaume, en 1919. . . ." [cf. his BSAF paper.]
* "L'idée préconçue, fausse et très répandue, que le rayon vert est
* un phénomène rarissime et mystérieux en a éloigné les observateurs
* sérieux, et il en est des plus éminents qui doutent même de sa
* réalité, parce qu'ils ne l'ont jamais vu."
* O'C #177


A. Baronnet
“Le rayon vert,”
BSAF 46, 88–89 (1932).

* Green rim seen with 16x telescope
* O'C #185


Em. Touchet
“La photographie, en couleurs, du Rayon vert,”
BSAF 46, 89–92 (1932).

* FIRST COLOR PHOTOGRAPH of a green flash
* The AUTOCHROME PLATES! (These must be the ones mentioned by Minnaert)
* Touchet's shorter account of Maurice de Kerolyr's color photography
* on "Plaques ``Autochromes'' de Lumière."
* "Nous ne pouvons reproduire ici le cliché obtenu par M.de Kerolyr.
* Il faudrait pour cela une planche en couleurs -- dont le prix est fort
* élevé -- et puis . . . l'image très petite de l'aigrette verte viendrait
* certainement fort mal au tirage trichrome."
* "Après les expériences de MM. Danjon et Rougier à Strasbourg, les
* photographies de M. Lucien Rudaux à Donville, les clichés en couleurs de
* M. de Kerolyr, on peut dire que la question du Rayon vert est liquidée.
* "C'est peut-être un peu de mystère qui s'en va; mais, ajoute M. de
* Kerolyr, ``c'est si beau à voir''! Aussi continuerons-nous, toujours,
* à regarder le Rayon vert chaque fois que l'occasion sera favorable."
* O'C #142


G. Dam
“Det grønne Glimt,”
Nordisk Astronomisk Tidsskrift 13, 15 (1932).

* Gunnar Dam -- a first-timer. Nothing useful.
* O'C #199


P. Bergsœ
“Det grønne Glimt,”
Nordisk Astronomisk Tidsskrift 13, 51 (1932).

* Comment on the above Gunnar Dam:
* "The undersigned does not agree with Hr. Gunnar Dam that the phenomenon
* `the green flash' can be a rarity. The two times I observed it, I simply
* stood and waited for it."
* (Account of 8 GFs at alternate disappearances and reappearances behind
* Lofotens mountains as Sun grazed the horizon.)
* "My opinion is that the phenomenon is far more everyday than is believed
* up to now; it requires completely clear and calm weather and an observer
* who is prepared beforehand."
* Paul Bergso/e
* O'C #175


H. Moncharmont
“Optique atmosphérique,”
BSAF 46, 115 (1932).

* Double flash due to sunset behind ISLAND
* O'C #252


R. Gindre
“Optique atmosphérique,”
BSAF 46, 177–178 (1932).

* GOOD detailed account of mountain sunrise with green illuminations
* RED/GREEN rims on CLOUDS as well
* Effective wavelengths estimated at 0.47 micron at start, 0.53 after 2
* sec, 0.57 after 6 sec.
* O'C #215


G. Menier
“Le rayon vert,”
BSAF 46, 250 (1932).

* GF behind mountains
* O'C #247


R. Croste
“Le rayon vert,”
BSAF 46, 250 (1932).

* Repeated GF by climbing rapidly up mountain
* O'C #198


J. P. F. van der Mieden van Opmeer
“Groene straal,”
Hemel en Dampkring 30, 234 (1932).

* an impressionistic description; not useful


P.-L. Mercanton
“Beobachtung des "blauen und violetten" Strahles,”
Met. Z. 49, 271 (1932).

* (violet) GREEN RAY
* He saw the GF from the deck of a ship, but two observers on the bridge
* (2 m higher) failed to see it.


P.-L. Mercanton
“Observation de rayon ``bleu et violet'',”
BSAF 47, 73–74 (1933).

* BLUE and VIOLET flashes behind CUMULUS clouds
* with VIOLET RAY shooting up (slightly longer account of the observation
* above; so filed here out of order).
* O'C #248


H. F. Tiarks
“The Green Flash,”
JBAA 42, 226 (1932).

* Observed from the Mauretania!
* "Immediately after the Sun set, a brilliant blue-green blaze of light
* shot up and hovered for a full three seconds at the spot where the Sun had
* been, then wavered and disappeared."
* O'C #290


E. B. Vignoles
“The green flash,”
JBAA 42, 302–303 (1932).

* Comments on the above
* ". . . I have seen it not infrequently when conditions were favourable."
* O'C #294


R. Fingado
“El rayo verde,”
Rev. Soc. Astr. Esp. y Amer. 22, 103–104 (1932).

* 2 GREEN RAY reports from small boats; one HORIZONTAL RAY
* "At the very moment when the Sun's disk disappeared, a beam of green
* vertical rays clearly rose up, fan-shaped, with a central angle which I
* estimate as some 20 degrees and of height approximately equal to a solar
* diameter. The color of the ray was a green which can be called
* ``metallic'' and the duration did not reach half a second."
* "Another time . . . without deformation of the Sun's disk near the horizon,
* as the Sun set into the sea, I observed a double green flash effect. For
* an instant two green beams went out to the left and right, horizontally,
* and immediately afterward another vertically, similar to the one observed
* [before]. The horizontal beams were less wide than the vertical ray."
* And a useful observation:
* "During 15 days' stay on Ibiza I saw the green ray every time when the
* Sun set behind bare mountains; but when (because of my location) the Sun
* disappeared behind wooded mountains, there was never a green flash."
* (cf. Justice, 1930)
* O'C #210


J. S. Haldane
“The physiological significance of Weber's law and colour contrast in vision,”
J. Physiol. 79, 121–138 (1933).

* HALDANE's paper (belongs in VISION file, but filed here for continuity)
* (cited in Rayleigh's 1934 paper)
* "Lord Rayleigh . . . devised an experimental arrangement which enabled
* this effect [i.e., dispersion] to be studied at leisure. The colour seen
* was, however, blue, not green. It now seems evident, in view of the
* experiments described above, that the cause of the actual sunset or
* sunrise coloured ray being vividly green, is the simultaneous contrast
* effect due to the light coming from round the sun being red."


T. Browne
“A strange light at Tintagel,”
Times (Lond.) , p.10 (31 May, 1933).

* A first-time observer asks for an explanation


F. Addey
“The Green Flash,”
Times (Lond.) , p.10 (31 May, 1933).

* A clear "textbook" explanation in reply to Tidwell Browne.
* "It is not actually essential for the production of the green flash
* at sunset that the sun be seen setting directly over the sea. What is
* necessary is a sharply defined object, low down, behind which the sun
* disappears."


R. M. Chambers
“The Green Ray,”
Times (Lond.) , p.10 (2 June, 1933).

* A 35-year-old observation recalled, with exaggeration:
* Possible PHYSIOLOGICAL EFFECT? (Could be BLEACHING.)
* ". . . though the ball was bright red it was not too bright to allow of
* direct vision. The ray, which tinged the whole seascape, lasted for
* about two or three minutes, and was intensely green. I had been
* looking directly at the sun before it set."


Rayleigh
“The Green Ray,”
Times (Lond.) , p.11 (6 June, 1933).

* LORD RAYLEIGH's letter to The Times:
* "I have before me a Dutch monograph `Der [sic!] Groene Straal' . . . ."
* "I was interested in this subject after a voyage home from South Africa
* in 1929 . . . ."
* "This investigation is published in the Royal Society's Proceedings ,
* Vol. 126 (1929)." [N.B.: Actual date is 1930, though received in
* Nov.1929.]


J. S. Haldane
“The Green Ray,”
Times (Lond.) , p.13 (10 June, 1933).

* "As a physiologist I should like to point out that Lord Rayleigh's
* inference . . . that the green colour of the `ray' seen in very clear
* weather at sunset and sunrise does not depend on physiological contrast
* is inconclusive. . . . I think there can be no doubt that the greenness
* depends on `simultaneous' contrast."
* On firmer ground:
* "I think that not only physicists, but also many physiologists, have a
* very imperfect conception of the extent to which physiological contrast
* enters into what we actually see. According to Newton's teaching the
* sensation of colour produced by light depends simply on the refrangibility
* (in more modern language, the wavelength) of the light. This is only true
* under certain physiological conditions. Under other and quite usual
* conditions it is not true at all, as can easily be shown experimentally."


F. Petrie
“The Green Ray,”
Times (Lond.) , p.15 (13 June, 1933).

* Sir FLINDERS PETRIE gets a word in . . .
* Argues (implicitly) from SCALED REFRACTION again.
* "By standing on a slope facing the sunrise the blue can be kept in view
* for some minutes by walking downhill."


J. Evershed
“The Green Ray,”
Times (Lond.) , p.17 (20 June, 1933).

* EVERSHED debunks HALDANE (temporarily)


J. G. Kerr
“The Green Ray,”
Times (Lond.) , p.10 (27 June, 1933).

* "subjective" phenomena:
* "It moved as I moved my eye!"
* "We may then cease to feel surprised at the constantly recurring
* discussions as to the cause of the Green Ray -- all resting on the
* assumption that this expression connotes a homogeneous phenomenon."


J. S. Haldane
“The Green Ray,”
Times (Lond.) , p.10 (27 June, 1933).

* HALDANE again; points out that colors seen telescopically differ from
* those seen in context (i.e., "related" colors)


A. H. Borgesius
“De groene straal,”
Hemel en Dampkring 31, 281 (1933).

* Sounds at first like a GREEN RAY, but seems to be inf.-mir.flash
* ". . . after [sic] an unusually beautiful sunset, [I] saw it blaze up.
* The brightness of the Sun's disk had been very great . . . ; the green
* flamelet, which shot up immediately after its disappearance, was also
* very bright, it had the form of a small lying-down rectangle."
* [So maybe this "shooting up" stuff is just a belated realization that
* the mirage is above the visible horizon?]


M. P(inkhof)
“Korte Berichten: De groene straal,”
Hemel en Dampkring 31, 448 (1933).

* A couple of green flashes, including at JUPITER setting
* (cites Borgesius's paper on p.281)
* O'C #261


M. Bedford
“The Green Ray from the air,”
Times (Lond.) , p.15 (27 Nov., 1933).

* Possibly the EARLIEST AIRPLANE FLASH?
* ". . . lasted quite two or three seconds. . . ." [sic]
* Mary du Cauroy, Duchess of Bedford, was an early airplane owner who
* first flew in 1926 at the age of 61. In 1937, she took off on a solo
* flight, and was never seen again -- a sort of elderly Amelia Earhart.


M. Bedford
“The Green Ray from the air,”
Q. J. Roy. Met. Soc. 60, 88–89 (1934).

* Possibly the EARLIEST AIRPLANE FLASH?
* ". . . lasted quite one to two seconds. . . ." [sic]
* (a "reprinted" letter from The Times of Nov.27, 1933, p.15,col.5)
* (with a remarkable alteration! WHOSE?? The Editor's, or the Duchess of
* Bedford's?)


J. Hoppe
“Das Geheimnis des grünen Sonnenstrahls,”
Das Weltall 34, 43–44 (1934).

* a textbook account; Hoppe seems only to have observed the green & red rims,
* and attributes variations to changes in opacity
* O'C #53


S. W. Visser and J. Th. Verstelle
“Groene straal en kimduiking,”
Hemel en Dampkring 32, 81–87 (1934).

* HEIGHT effects:
* "The visibility of the green flash depends on the height of the eye."
* Maart 1934
* O'C #148


E. Havinga
“Groene straal en kimduiking,”
Hemel en Dampkring 32, 114–118 (1934).

* NICE SUMMARY of 303 observations!
* (quotes from his 1922 H&D paper)
* HEIGHT effect:
* "Usually I observed from the lower bridge, the 2nd Officer on watch
* from the upper: when the sun set directly forward, I went and stood
* next to him. In the first case I saw the green flash a few seconds
* earlier, but it was never obvious to me that the green flash depends
* on the height of the eye. . . ."
* Comments on letters to the newspaper:
* "All the writers have heard
* of the `green flash' at least once, don't know what and how much has
* already been written about this subject, have seen the phenomenon a
* single time and suppose that they have made an important discovery worth
* reporting."
* "Now that Dr. S.W.Visser and Mr. J.Th.Verstelle have published observations,
* made on the Marnix van St. Aldegonde, in the March issue, I beg
* to be allowed to add some further details to mine (i.e. my observations)."
* [THANKS to MART DE GROOT for this last sentence!!!]
* "I made my first observation on 25 July 1902, the last on 20 Oct. 1905.
* This series, 303 observations, formed the basis of the dissertation
* of Dr. P. Feenstra Kuiper for the doctoral degree in physical and
* natural science. From that time I traveled another sixteen years, only
* interrupted by an interval of one year . . . . How many observations
* have I made in all these years? I do not know, as I kept no notes . . . .
* A ``green ray'' such as was observed by D. P. Lagaay on 22 July 1911, and
* afterward reproduced in the thesis of Dr. F. K., I have never seen, a
* proof that it occurs extremely seldom; one sees such a thing by chance ."
*
* probably April issue?
* O'C #49


G. Schröder
“Kleinere Mitteilungen. 1. Klimatographische Witterungsschilderung. Nr. 19: Seeverkehrsweg: Golf von Aden,”
Ann. Hydrog. Maritim. Met. 62, 215 (1934).

* Gustav Schröder's first GF?
* A GF in the last 3 seconds before disappearing. ". . . außerordentlich
* klare Luft. . . . ein prächtiges Grün (mit bläulichem Schimmer) . . . ."
* Thanks to Gerhard Czeplak of DWD Hamburg for this item!
* probably May issue


S. J. Barnett
“Some remarkable multiple sunset flashes in Southern California,”
Phys. Rev. 46, 75–76 (1934).

* Good account of typical phenomena, including SQUARE SUN and a display
* like Rudaux's 1904 drawing:
* "Much more remarkable flashes appear when atmospheric stratification
* causes, as it often does, the sun's image to be distorted in such a way
* that the sides are more or less serrated like those of a Japanese lantern
* or an accordion bellows. When the serrations are sufficiently marked, one
* layer after another in succession, beginning with the uppermost, separates
* itself from the lower part of the image, becomes narrower horizontally and
* much thinner vertically, turns green or blue, often at least at the
* pointed ends first, and disappears. In the last two or three years I have
* repeatedly witnessed this phenomenon, obtaining all the way from two to
* six green and blue flashes."
* ". . . the image took on the form of a rectangle capped by an isosceles
* triangle with somewhat rounded top. The top of the triangle now came off,
* turned blue, and disappeared. Then in between the point at which this
* disappearance occurred and the flattening disk another blue flash
* appeared, where nothing had been visible before. The image then became
* more and more flattened, and thinner vertically, without changing
* appreciably in horizontal width, and disappeared red (as the image often
* does).
* "Most of these observations were made with one inch achromatic
* binoculars magnifying about six diameters."
* O'C #172


M. Cl.
“De groene straal,”
De Zee 56, 592 (1934).

* a report from the N.R.Crt., 21 July, 1934:
* ". . . color nearly of the copper Bunsen-flame."


anonymous
“Haben Sie den grünen Strahl gesehen?,”
Zweiten Beilage zur Rigaschen Rundschau , Nr. 170, 9 (31 Juli, 1934).

* cited by Kupffer
* A fairly good popular account, though marred by attributing the color
* photography to Lord Rayleigh (!)
* Some rather overdone writing: "Zur Zeit, als der Roman von Jules Verne
* erschien, nahm die wissenschaftliche Welt die geistreiche Geschichte mit
* einiger Geringschätzung auf und verbannte den grünen Strahl in die
* Rumpelkammer pseudowissenschaftlichen Aberglaubens oder erklärte ihn als
* optische Täuschung."
* And, after the textbook story, then says: "Die Wissenschaft hat wieder
* ein Stück Poesie getötet. Bleibt der grüne Strahl darum nicht doch ein
* Wunder?"


G. Schindler
“Zwei Beobachtungen des ``grünen Strahls'',”
Die Sterne 14, 136–137 (1934).

* Schindler sees 2 GFs at sea, but none at home, where "geht die Sonne
* hinter nur 20 km entfernten Gebirgen unter, und der Aufgang erfolgt unter
* noch ungünsterigen Verhältnissen."
* Heft 6 is probably Juni
* O'C #278


C. Kellner
“Der grüne Strahl,”
Die Sterne 14, 211 (1934).

* Comments on Schindler's paper in Sterne 1934 Heft 6
* "An der See scheint mir dieser Strahl durchaus nicht so selten, wie es
* in dem genannten Artikel stand . . . ."
* no useful details; Heft 9, so probably Sept.
* O'C #226


"Lord Rayleigh"
“Further experiments in illustration of the green flash at sunset,”
Proc. Phys. Soc. Lond. 46, 487–498 (1934).

* the younger RAYLEIGH's second paper. Some of the "DISCUSSION" is
* more valuable than his work:
*
* Instructor-Capt. T. Y. Baker (pp. 493-495 of the "Discussion"):
*      "My objection to this explanation is that refraction through the
* atmosphere is different in its nature from refraction through a prism,
* and an explanation based upon measurements of refractive index and
* dispersion at sea-level densities alone is not adequate.  . . .      if the
* author's explanation is adequate the green flash should always be seen
* when the sun sets cleanly behind the horizon.  . . .      And it must be
* remembered that the green flash is not a common phenomenon. It is the
* exception rather than the rule.
*      "The true explanation of the green flash is, in my opinion, much
* more complicated than the author suggests." . . .
*      "One has only to look at the form of the integral to see that a
* change of only a few units in the ninth decimal place for the bottom
* layers of the atmosphere (say up to 200 feet) is sufficient to alter
* the value of the integral by 20" . . . The rarer occasions when the green
* flash is seen are departures from the normal. I am almost tempted to go
* further and suggest that the abnormalities conducive to the green flash
* are most probably found in the lower levels of the atmosphere. . . . But in
* support, though not in proof, of my contention I would like to refer to
* measurements of the dip of the sea horizon made by ships of the Navy a
* few years ago. In this case abnormalities of the dip were entirely due
* to an abnormal condition of an extremely small part of the atmosphere,
* some seven or eight miles horizontally and 50 or 60 feet vertically. The
* normal condition of the atmosphere shows that a ray, nearly horizontal,
* has a curvature of about 8" per mile. Our measurements of the dip, some
* three thousand in all, showed variations between 32" and -17" per mile.
* If there are these wide variations in dn/dh , which is proportional to
* the curvature, is it not extremely likely that there may be differences
* . . . in these lower levels sufficient to account for a green flash?"
* [Note observation of possible CONCAVE surface.]
*
* Mr. W. H. White: "Green flash, turning blue, seen from foredeck (20 ft.)
* and exactly reproduced from forecastle deck, 9 ft. higher, 10 sec. later;
* a longer interval than simple theory suggests." (pp. 495-496)
*
* Dr. W. D. Wright: "Moreover the effects of successive contrast are very
* much stronger than the similar effects of simultaneous contrast. . . ."
*
* Mr. W. F. Floyd: "I am willing to accept a purely physical explanation of
* the green flash, but I would suggest that the present paper establishes
* only one possible explanation. That a physiological effect may
* contribute to the phenomenon, or may even provide the sole explanation of
* it, has not been disproved, nor can it be disproved by purely physical
* arguments." [cf. Rayleigh's footnote on p.491: "I do not enter upon these
* more or less physiological questions without misgiving, bred partly of
* lack of familiarity with this field, and partly from dislike of the
* vagueness inherent in the use of words for describing subjective colour
* impression."]      [See also Worley (1935) for further comment.]
*
* LABORATORY DEMONSTRATION that scattering can remove the blue and leave a
* green last ray:
* No.255, July 1, 1934
* O'C #113


W. Norlind
“Beobachtungen über den Grünen Strahl,”
A. N. 253, No. 6056, 171–172 (1934).

* A slavish imitation of Nijland's A.N. paper (cited), including several
* repetitions of the magic 530 nm wavelength; no useful data
* "Geschlossen 1934 Sept. 4"
* O'C #257


R. de Terwagne
“Observations du rayon vert,”
Gazette Astronomique 21, 162 (1934).

* classical inf.-mir. flash at sea horizon
* ". . . couleur vert tendre (comme de l'herbe fraîche)."
* "Les trois fois que j'ai pu faire une observation positive du rayon
* verte à la jumelle, il s'est formé à une petite distance au-dessus
* de l'horizon, sans contact avec la mer."
* followed by a letter dated Octobre 1934
* O'C #288


F. Roßmann
“W.C.Haines, Grüne Strahl-Beobachtung,”
Met. Z. 51, 392–393 (1934).

* Fritz Roßmann translated Haines's report:
* and added a noteworthy comment:
* "Nach Meinung des Referenten ist in polaren Gegenden der grüne Strahl
* . . . recht selten. . . . Zweitens wird die Beobachtungsmöglichkeit aber
* weiter eingeschränkt durch das Wetter. Selbst bei Hochdrucklagen, in
* denen häufig auch günstige anomale Refraktionsverhältnisse vorhanden
* sind, ist die Lufttrübung meist gross, wenigstens an Orten geringer
* Seehöhe. Die günstigen Brechungsverhältnisse bleiben dann wegen der
* gleichzeitig fast stets ungünstigen Extinktionsverhältnisse meist
* unwirksam."
* Okt. 1934


G. Blum
“Rayon Vert,”
BSAF 48, 563 (1934).

* Blue sunrise flashes over the Alps
* "Séance du 7 Novembre 1934"
* O'C #179


(Professor Yamamoto)
“A typical green flash observed,”
Kwasan Observatory Bulletin (Kyoto) 3, 1 (1934).

* an uninformative report
* This is a bilingual publication; every item is in both English and
* Japanese. The pages seem not to be numbered; this is No. 294.
* Dec. 18, 1934
* O'C #301


Ed. Thibault
“Rayon vert,”
BSAF 49, 15 (1935).

* Blue and green flashes with "trainée lumineuse"
* ? May be our BRIGHT LINE in SKY at HORIZON ??
* 3 days of observations; the middle one with probable Fata Brumosa
* MYSTERIOUS "traces":
* ". . . j'ai vu une traînée lumineuse très rapide glissant de gauche à
* droite et présentant une teinte bleue très faiblement verdâtre.
* (next day): "Comme la veille en suivant à l'oeil nu le coucher du
* Soleil, j'ai vu une traînée lumineuse d'un ton vert très intense."
* 2nd & 3rd days were accompanied by "FOG": "près de l'horizon des
* bandes brumeuses avec des stries horizontales."
* O'C #289


C. M. Botley
“Green ray at sea,”
Met. Mag. 70, 12–13 (1935).

* Botley reports a letter from the Radio Times , Nov.2 (1934).
* Report of "TWO SUNS" and each giving a flash.
* original report from Mr. Stewart:
* ". . . I saw it (the green ray) scores of times, probably because after
* seeing it once it became a temporary superstition to look for it on
* every possible occasion . . . ."
* "We saw the green ray from the first and then several minutes again from
* the second when that set in its turn, both equally vivid."
* Botley likens the observation to Applegate, Met.Mag.64,67(1929)


M. Rawnsley
“The green flash seen from Anacapri,”
Met. Mag. 70, 115 (1935).

* Nice DRAWINGS of sunset distortions induced by inversions, with a "cap"
* flash like Rudaux's (1904)
* "The stages numbered 5, 6, 7, seemed to take a long time."
* (No doubt they did! This is an extreme Type B sunset.)


J. S. Dines
“The green flash seen from Crinan,”
Met. Mag. 70, 115 (1935).

* flash seen over land horizon despite light smog


F. T. Davies
“The green flash,”
Terr. Magnetism Atmos. Electricity 40, 117 (1935).

* A SUNRISE inf.-mir. flash, prolonged by HIGH LATITUDE
* "A vivid green point changing quickly to a fairly sizable ball of green
* fire. . . . lasted from two to three seconds." (in Hudson's Bay)
* "There was hardly any wind and the sea was calm."
* N.B.: Davies's 1931 note in TMAE detailed the Byrd expedition's GFs.
* THANKS to Shaun Hardy at the DTM library for pointing this out!


W. Norlind
“Weitere Beobachtungen über den Grünen Strahl,”
Astron. Nachr. 254, 215–216 (1935).

* 7 GFs seen in 15 attempts, with several long ones: 6, 10, 11 sec!
* (continued from AN 6056)
* ". . . die Erscheinung in unseren Breiten keineswegs so selten ist, wie
* oft behauptet wird."
* Many references to Pickering's seeing scale.
* A.N. Nr.6084
* O'C #258


Chr. Jensen
“Neues über den `grünen Strahl',”
Die Himmelswelt 45, 209–210 (1935).

* Review of recent literature, especially Rayleigh's papers
* O'C #62


E. Rahir
“Observation sur le rayon vert au coucher du soleil,”
Ciel et Terre 51, 158–160 (1935).

* two color changes reported: first WHITE, then green.
* (observed from 8 m height "à l'aide d'une bonne jumelle . . . d'un
* grossissement de 7 diamètres . . . .")
* The "white" stage is probably the yellow flash, although bleaching
* should be important here:
* "Depuis le moment où le soleil rouge et aux rayons si puissants
* touchait l'horizon, jusqu'à sa disparition complète, nous avons observé
* le phénomène sans la moindre interruption, malgré la fatigue que cela
* occasionnait aux yeux."
* Two other observers in the same general area saw GFs when Rahir did not:
* "Le rayon vert peut donc être visible d'un point du littoral et ne pas
* se manifester à quelques kilomètres de distance. Cette diférence peut
* être due au fait que notre point d'observation est plus haut de quelques
* mètres que ceux des deux autres observateurs."
* O'C #111


E. L[agrange]
“Le rayon Vert,”
Ciel et Terre 51, 173–174 (1935).

* A half-hearted literature review in one paragraph
* This is a followup to Rahir's note. It mentions Guillaume, Coutinho,
* Danjois [sic!] & Rougier, Julius, and Rayleigh; no citations.
* [The item just above this is signed by Lagrange; this bears only his
* initials.]


F. P. Worley
“The green flash at sunset,”
Nature 135, 760 (1935).

* Another novice reports both common flashes:
* HEIGHT EFFECTS:
* ". . . from a hill about 180 feet high. On one occasion Mr. H. B. Lusk
* . . . was on the beach at sunset and reported that no green flash was
* visible, though it was clearly seen by me and by other observers from the
* hill."
* ADAPTATION:
* "Although the primary cause of the coloured flash may be atmospheric
* dispersion, simultaneous colour contrast may very considerably modify the
* subjective colour effect."
* COMMENT on RAYLEIGH:
* "The discussion following Lord Rayleigh's paper read before the Physical
* Society indicated, however, that before a satisfactory explanation of all
* the observed phenomena could be given, further observations were
* required."
* O'C #300


(Lord) Rayleigh
“The green flash at sunset,”
Nature 135, 760 (1935).

* EVIDENCE that RAYLEIGH never saw flashes before his 1930 and 1934 papers:
* "On a recent trip to the West Indes, I saw it three times out of a total
* of five sunsets observed, using a field glass x7. It was just about as
* conspicuous as the experimental work would lead one to anticipate.
* Circumstances unfortunately prevented my observing further sunsets . . . ."
* O'C #266


Anon.
“The green flash,”
Nature 135, 866 (1935).

* editorial summary of GF correspondence:
* H.Carey Gibson "states that he has observed the flash several times . . .
* from . . . 150 ft. above sea level. In October 1933, while in the Gulf of
* Aden . . . , `the flash could be clearly seen, with or without glasses,
* almost any evening', and was even observed from a port-hole about 18 in.
* above the water." ** RECORD LOW EYE LEVEL?
* Northcote Thomas reports from 800 ft. that "On occasions the colour
* persisted for half a minute." ** HALF A MINUTE??
* O'C #307


Anonymous
“The green flash,”
Nature 135, 992 (1935).

* R.M.Bell of Penn.State cites Byrd's account (1930)
* O'C #174


S. T. A. Mirrlees
“The green flash,”
Met. Mag. 70, 159 (1935).

* An ORKNEY blue flash
* "The actual colour of the `flash' under comparable conditions of
* temperature lapse probably depend on the amount of atmospheric pollution,
* in this case practically nil."


A. A. Nijland
“Een merkwaardige waarneming van den groenen straal,”
Hemel en Dampkring 33, 219 (1935).

* GF over ROOF of building seen from Utrecht Obs.
* "From the time of the observation, the zenith distance of the upper limb
* of the Sun was 89° 16', taking 36' for the refraction."
* O'C #256


Anon.
“Varia: De groene straal,”
De Zee 57, 446–447 (1935).

* This is a report of the meeting Schröder refers to:
* (abstract of Minnaert's report on the GF in Utrecht, from N.R.C.)


G. Schröder
“Beobachtungen des 'Grünen Strahls',”
Ann. d. Hydr. u. Maritim. Met. 63, 336–340 (1935).

* Annalen der Hydrographie und Maritimem Meteorologie
* (Tafel 46) Nice colored plates of typical sunsets + GF
* Bildreihe 6 shows classical evidence of ADAPTATION
* more interesting solar distortions than in 1937 paper
* Kapitän Gustav Schröder, Hamburg-Amerika Linie
* See note at 1937 refs.
* O'C #279


A. A. Nijland
“Sterrekundige waarnemingen door amateurs. IV.,”
Hemel en Dampkring 33, 435–440 (1935).

* NIJLAND's revised criteria for observers
* only the 2nd part of this paper (section 4, p.438) deals with the GF
* Here we are 9 years after Feenstra Kuiper's thesis, of which he says:
* "The conclusion of the discussion is that the green flash can in general
* be explained by the following three atmospheric effects:
* 1. the normal dispersion, which forms a spectrum from the low-standing
* sun, with red below, blue or violet above;
* 2. the normal scattering, which removes the blue and violet from the
* light that reaches us from the direction of the sun;
* 3. the important absorption of yellow and orange, especially by moist
* air.
* There remains then practically only red and green; a solar image with
* red lower limb and green upper rim. Thereby a first step in explaining
* the phenomenon is made, but all sorts of details remain enigmatic at
* present and make regular observation necessary, whereby in particular
* those who live by the sea can take part productively."
* O'C #97


I. Yamamoto
“On Green-flash,”
Kwasan Observatory Bulletin (Kyoto) 4, No. 308, (1935).

* A moderately experienced observer's views: "I myself have many
* experiences of witnessing the phenomena, mostly when I was on board the
* ship, in past years.  . . .      At present I am convinced that such
* observations on land are not quite difficult as formerly thought. . . .
* Meanwhile I have several occasions when I failed to see the green flash
* on the apparently clear sea-horizon. It is doubtless that some
* critical circumstances of floating clouds near the setting sun will
* interfere the phenomena."
* ISSEI YAMAMOTO was Director of the Kwasan Observatory.
* Pages are not numbered, but this is on 3rd page.
* O'C #302


G. A. Tikhov
“Anomal'naya dispersiya sveta v zemnoi atmosfere,”
Mirovedenie 24, 361–372 (1935).

* TIKHOV's anomalous-refraction paper in MIROVEDENIE
* Mostly about anomalous refraction, but several important parts about the
* `green ray', and some interesting observations:
* He notes that the color depends on atmospheric clarity, but subscribes
* to the "segment" model. As he calculates only a 12" width for the green
* rim, he clearly needs to make it wider. He proposes to do this by
* invoking abnormally large refraction, like many earlier workers; but
* he then models the atmosphere as a prism, using the minimum-deviation
* formula! This allows him to handle refraction up to 2° 42' (= 2 x
* 1° 21'). Larger refraction requires greater obliquity of the
* incident rays, hence nonlinearly more dispersion.
* The alternating red and green lines observed at sunrise on 11 Jan. 1926
* are interesting, and might be due to ducting. He notes that mirage was
* observed quite often, but doesn't say which kind of mirage.
* In section 9, he reports 8 GFs at sunrise and 2 at sunset in a month.
* The longest reached 9 sec.; one was blue. The horizontal refraction for
* these summer observations was from 30' to 37' (mean, 33'), though his
* winter observations reach 2 degrees.
* This is the last issue of the year (No.6) of this bimonthly.


G. C. Copeland
“Green ray at setting of Venus. North Indian Ocean.,”
Marine Observer 13, 8–9 (1936).

* useless observation made with prism binocs.


G. A. Tikhov
“Sur la dispersion anomale de la lumière dans l'atmosphère terrestre,”
Poulkovo Observatory Circular , No. 17, 3–12 (1936).

* TIKHOV thought he had detected anomalous dispersion in the B band:
* N.B.: Fig.2 is an actual photographic print, now turning brown!
* Dated Feb., 1936.
* O'C #140


K. R. Kupffer
“(in Sitzungsberichte),”
Korrespondenzblatt des Naturforschenden Vereins zu Riga 61, 67–69 (1936).

* A remarkably LONG GF (10 sec) associated with SUPERIOR MIRAGE
* After a detailed description of afternoon superior mirage around the
* horizon, he reports (p.69):
* "Die Sonne erschien beim Untergang ganz besonders stark abgeplattet, ihr
* vertikaler Durchmesser erreichte kaum 2/3 des horizontalen. Am
* schwindenden Sonnenrande spielten etwa 10 Sekunden lang blaugrüne
* Lichter, was sonst --- wenn überhaupt --- nur von viel kürzerer Dauer zu
* sein pflegt. Alle diese Umstände beweisen eine besonders starke
* Krümmung der Lichtstrahlen in den unteren Lichtschichten, die wohl ---
* der Jahreszeit und dem Wetter entsprechend --- unmittelbar über der
* Meeresoberfläche kühl und darum dicht, höher hinauf beträchtlich
* wärmer und darum undichter gewesen sein müssen."


E. B. Macfarren
“Green flash at sunset. South Pacific Ocean.,”
Marine Observer 13, 48–49 (1936).

* This is the S.S.Mataroa observation mentioned by Barlow (below)
* Appears to be an inf.-mir. flash, though same temp. is given for water
* and air. Color changes of Venus also reported at 2 1/2 deg. altitude.
* Dated April 1936.


E. W. Barlow
“The green flash at sunrise and sunset,”
Marine Observer 13, 55–57 (1936).

* Summary of earlier reports in Marine Obs., plus mentions of Rambaut,
* Whitmell, Capt. Carpenter, J.E.Clark (1926), and Admiral Maclear.
* Only the M.O. references are actually cited. Michie Smith is called
* "Mickie" Smith. "As far as is known the first account of it was
* published in Nature in 1882." [probably meaning 1883]
* O'C #7


N. Dijkwel
“Enige waarnemingen van de Groene Straal, verricht op een heen- en terugreis naar Ned. Indië,”
Hemel en Dampkring 34, 235–239, 258–262 (1936).

* VISUAL SPECTROSCOPY OF SETTING SUN AND GF -- orig. proposed by Buss, 1916
* "- The phenomenon is caused by absorption on the one side of the green
* and scattering on the other, while the red set earlier because of
* dispersion. -" [cf. Dufay]
* O'C #28


C. Hailstone
“Notes and Queries: The Green Flash,”
JRASC 30, 299 (1936).

* GF with RAY
* ". . . just as the last particle of the sun's disc was visible, it turned
* a bright light green, with short and broadening rays of the same green
* shooting up from it . . . ."


W. G. Kendrew
“The green flash and flashes of other colours,”
Q. J. Roy. Met. Soc. 62, 127–128 (1936).

* The letters from Kendrew and Evershed are excerpted and printed together
* with the remarks of the editor, Gilbert T. Walker; I list Kendrew's and
* Evershed's contributions separately, but include the same covering title
* with all:
* KENDREW reports a GREEN GLOW after the GF:
* "As the upper limb of the sun finally disappeared it assumed the same
* green colour, and a distinct green glow continued for a second or two
* after the sun itself had gone." ?? GREEN RAY ??


J. Evershed
“(comment on: The green flash and flashes of other colours),”
Q. J. Roy. Met. Soc. 62, 128–129 (1936).

* John Evershed's clearest and most explicit explanation of the
* inferior-mirage flash:
* ". . . it may also be enhanced by a mirage effect, due to refraction by a
* layer of warm air in contact with the sea: this has the effect of adding
* to the green segment an inverted image of it, producing in effect a
* lens-shaped green patch."


G. T. W(alker)
“(comment on: The green flash and flashes of other colours),”
Q. J. Roy. Met. Soc. 62, 129 (1936).

* Gilbert T.Walker, editor of QJRMS, muddles the terminology:
* "My experience is that at sea sometimes the sun's light fades out
* steadily, being green for about two seconds, while at other times there is
* finally a sudden increase and decrease in brightness. The latter effect,
* presumably due to abnormal refraction, on a still night, constitutes the
* `green flash' while to the former the title of `green ray' is more
* appropriate."


C. M. Botley
“The green flash, folklore and weather,”
Q. J. Roy. Met. Soc. 62, 246 (1936).

* Cicely M. Botley provides an indirect reference to the Manx folklore
* reported in letters to the Times in the summer of 1929:


"W. H. McC."
“Meeting of the British Association, 1936,”
Obs. 59, 297–301 (1936).

* brief mention only
* ". . . several members . . . witnessed an excellent occurrence of the
* `green flash'. At Blackpool the Sun sets behind a horizon of open sea,
* and on that date the western sky became exceptionally clear . . . ." [p.301]
* "W.H.McC." must be W. H. McCrea.
* Thanks to ADS full-text search!


E. M. Antoniadi
“La Planète Venus,”
BSAF 50, 181–189 (1936).

* Rehash of a few older VENUS flashes on p.182


Prof. G. A. Tikhov
“Zelenii luch [Green ray],”
Nauka i Zhizn , No. 9, 29–33 (1936).

* TIKHOV's big article starts with TERMINOLOGY complaint:
* "This phenomenon bears the not very fortunate name `green ray'."
* "That which is observed corresponds poorly with the usual conception of
* a ray as something long, drawn out along a straight line."
* He believes the Rambaut/Rayleigh model, but also describes
* mock-mirage flashes.
* Table 2 shows the non-linear growth of dispersion with refraction, based
* on his 1935 paper in Mirovedeniye. So he thinks excessive normal
* refraction is responsible. There is the interesting result that the
* longest theoretical duration is almost 6 hours, at latitude 89° 56'
* (just 7 km from the Pole), where the diurnal and seasonal motions cancel
* to first order. "All these calculations are purely theoretical. In
* reality, faster and irregular changes of refraction near the horizon can
* completely violate the calculated duration of the phenomenon." He then
* cites Byrd's observation, and one from Julius Peyer (?). The last section
* shows his Pulkovo spectra of the red and green rims, which he equates to
* red and green flashes.
* This is a cut above the usual popular article on the subject, which he
* has clearly approached with much care and thought.
* The Russian reference is:
* Проф. Г. А. Тихов
* Зелёный луч
* Наука и Жизнь No.9,
* 29-33 (1936)


G. H. van den Bergh
“Waarneming van den groenen straal in het hooge Noorden,”
Hemel en Dampkring 34, 407 (1936).

* Brief report of sunrise GF behind MOUNTAINS at 67° lat., on Norse coast
* Between 1 and 2 am, MET. There is a sketch of only the mountain horizon.
* Two flashes seen in low corners. "According to the captain, it had
* been an uncommonly clear observation of the green flash." Thanks a lot!


N. Boneff
“Le rayon vert,”
BSAF 50, 588–589 (1936).

* Curious appearance; related to MOON ILLUSION?
* Or a HORIZONTAL GREEN RAY display?
* Sun set behind MOUNTAINS:
* "Immédiatement après la disparition du bord supérieur du Soleil,
* un tache verte clair, allongée dans le sens horizontal et
* dépassant dans ce sens un peu le diamètre du Soleil, est apparue
* à l'endroit où était le bord du Soleil et a duré, peut-être,
* une seconde."
* O'C #180


G. Schröder
“Weiteres vom «Grünen Strahl»,”
Ann. d. Hydr. u. Maritim. Met., Zweites Köppen-Heft , 91–93 (1936).

* 15 SECONDS COUNTED
* Kapitän Gustav Schröder, Hamburg-Amerika Linie
* "Von dem Augenblick an, als das feuriggelbe in ein grünes Oval
* übergegangen war, bis zum Verschwinden konnte ich 15 Sekunden zählen,
* und es war beinahe der schönste Grüne Strahl, den ich jemals sah."
* See note at 1937 refs.
* O'C #129


H. E. Ruddy
“Optique atmosphérique,”
BSAF 51, 128 (1937).

* routine inf.-mir.flash: "un globule, vert éclatant."
* O'C #273


R. F. Murray
“Green flash. North Atlantic Ocean.,”
Marine Obs. 14, 53 (1937).

* useless inf.-mir. flash report
* There are 2 interesting mirage reports earlier on this page.
* in April issue


W. M. Lindley
“Sunset Phenomena,”
JBAA 47, 297–298 (1937).

* PINK SUNSPOTS at inferior mirage
* June issue


H. Edeler
“Klimatographische Witterungsschilderung. Nr. 99: Seeverkehrsweg: Golfstrom-Region.,”
Ann. Hydrog. Maritim. Met. 65, 340 (1937).

* a rather breathless account of a SUNRISE GF, 3 to 4 sec. long
* A nice inf.-mir. flash; water over a degree warmer than air; calm.
* Followed by a sunset flash the same day!
* Thanks to Gerhard Czeplak, DWD Hamburg, for this item!
* Juli 1937


L. G. Taylor
“Colours of Venus at setting. South African waters.,”
Marine Obs. 14, 98 (1937).

* VENUS GF at setting
* in July issue


R. Toussaint
“Query no. 71. — Green flash in Greek and Latin literature,”
Isis 27, 322 (1937).

* This query incorporates observations
* "It s'agit d'une lueur verte intense qui se produit exactement au moment
* où le soleil entre dans les flots à l'horizon. Si le ciel est un peu
* opaque au-dessus de cet horizon, mais qu'il y ait cependant une ligne
* assez large de ciel bleu et clair entre l'horizon de la mer et ce début
* de nuage plus élevé, le phénomène est encore plus intense, comme
* j'ai pu le voir tout ce mois à Hendaye où je me trouvais en vacances!
*      Ce rayon vert est de la couleur du cuivre en fusion lorsque le métal
* brûle par suite d'un excès de chaleur dans le creuset. C'est donc un
* vert très vif."
*      He can't believe the ancients could have missed it.  "Bois-Colombes"
* is the only address given.
* August issue (No. 2)


J. B. Smith
“Green flash. South Atlantic Ocean.,”
Marine Obs. 14, 143 (1937).

* Both common types of flash reported; seen with telescope
* ". . . the change was gradual from green to green-blue and then dark blue."
* "When about one-third of the sun was below the horizon, the upper limb
* became curiously affected: tiny strips seemed to peel off and melt away;
* some were coloured green and some violet. They bore a slight resemblance
* to flames."
* in Oct. issue


K. Wegener
“Der grüne Strahl,”
Meteorol. Zs. 54, 427–428 (1937).

* typical account of first-time observer (Kurt Wegener):
* "war aber so wenig von der Erscheinung befriedigt, dass ich die
* bisherigen Beobachtungen für Sinnestäuschungen und die ganze Frage für
* einen Irrtum hielt, bis es mir im vergangenen Sommer auf der Insel Lopud
* bei Ragusa gelang, die Erscheinung in voller Deutlichkeit zu sehen."
* ADAPTATION: "Ein grünes Licht, das im Augenblick des Verschwindens der
* Sonne aufleuchtet, aber aus Blendungsvorgängen des Auges erklärt werden
* konnte, hatte ich öfters beobachtet."
* POSSIBLE GREEN RAY? "Ebenso habe ich öfters in der Arktis bei
* Sonnenuntergang einen breiten grünlichen Streifen beobachtet, der von der
* Sonne senkrecht nach oben wies, aber nach meiner Ansicht Teil eines Halo
* war." [Nov.1937]
* O'C #151


G. Schröder
“Vom 'Grünen Strahl'. . . . I. Beobachtungen zur Ermittlung der atmosphärischen Vorbedingungen für das Auftreten des Grünen Strahles und der Farbenschwankungen,”
Ann. d. Hydr. u. Maritim. Met. 65, 489–492 (1937).

* Annalen der Hydrographie und Maritimem Meteorologie
* these have the "beautiful colored plates" mentioned by Minnaert on p.58
*
* "Wenn man bedenkt, dass ich den Strahl im Verlauf von zwei Monaten
* mindestens 35mal gesehen habe -- davon mehr als zehnmal bei
* Sonnenaufgängen --, muss man den Astronomen recht geben, die behaupten,
* das der 'Grüne Strahl' nur deswegen als seltene Erscheinung gilt, weil
* man sich zu Unrecht einbildet (wie die 'Morning Post' und Jules Verne),
* dass er selten zu sehen sei." (cf. Kellen!)
*
* (Tafel 61)
* Kapitän Gustav Schröder, Hamburg-Amerika Linie
*
* According to letter from H. Stüve (Public Relations, Hapag-Lloyd)
* the height of the observer's eye was about 14 m above the water line
* for both the "Reliance" and the "St. Louis".
* Issue is dated 15. Nov.
* O'C # 131a


G. Schröder
“Vom 'Grünen Strahl'. . . . II. Der Grüne Strahl an einem 140 Seemeilen entfernten Bergabhang,”
Ann. d. Hydr. u. Maritim. Met. 65, 492–493 (1937).

* (Tafel 62, links)
* Kapitän Gustav Schröder, H.-A. L.
* O'C # 131b


W. Hartmann
“Vom 'Grünen Strahl'. . . . III. Beobachtungen des Grünen Strahles an der Nordseeküste,”
Ann. d. Hydr. u. Maritim. Met. 65, 493–495 (1937).

* Dr. Wilhelm Hartmann, Hannover
* O'C # 131c


O. Klaehn
“Vom 'Grünen Strahl'. . . . IV. Beobachtungen des Grünen Strahles im Golf von Siam,”
Ann. d. Hydr. u. Maritim. Met. 65, 495–496 (1937).

* (Tafel 62, rechts) much poorer drawings than Schröder's
* Evidence for adaptation: blue -> green at sunset
* Note that Schröder (1941) attributes the suggestion in footnote 2 to
* G. Castens; it is signed merely "Die Schriftwaltung".
* O'C # 131d
* Otto Klaehn, II.Offizier, D. "Reliance", H.-A.L.


K. R. Kupffer
“Der grüne Strahl,”
Korrespondenzblatt des Naturforschenden Vereins zu Riga 62, 145–148 (1937).

* Kupffer was the president of the Naturforschenden Verein in Riga; Meyer
* was its VP. Kupffer says his article is based on references supplied by
* Rudolf Meyer. So this posthumous paper might be regarded as a dry run for
* Meyer's review paper in 1939. He says he has seen the GF many times,
* and his account shows it; his own flashes have run from a fraction of a
* second to 5 sec. At the end he describes in some detail 2 of his
* inferior-mirage flashes in 1934.
* O'C #228


C. S. Beals
“An astronomical pilgrimage,”
JRASC 31, 353–361 (1937).

* GF observed from south rim of the Grand Canyon
* "As it approached the point of disappearance the reddish colour
* changed to yellow and then to brilliant green. The theory ordinarily
* advanced . . .      is that of atmospheric dispersion.  If this is correct, then
* the green should change to blue at the last moment before disappearance.
* The fact that the blue was not observed is perhaps due to the steepness
* of the visibility curve of the eye combined with the brightness of the
* sky background." [pp. 358-359]
* Thanks to the NASA ADS full-text search for turning this up!


W. Beebe
Zaca Venture
(Harcourt, Brace and Company, New York, 1938), pp. 197–198.

* William Beebe's RAY-type flash off Baja California
* "We steamed out of the quiet of San Lucas Bay into a tempestuous sea,
* a sea with so rough a skyline that we had two sunsets and a green ray.
* On deck we finished dinner at the very moment of sunset or, more
* accurately, earthrise. From almost a full half-sun it diaphragmed
* suddenly to a speck of gold, almost instantly to return to half a
* sphere again. For a second it seemed to hold steady, then vanished,
* and was replaced by a sheet of clear, pale green. Only two of us saw it,
* so it must have occurred between winks."


J. Jousset
“Optique atmosphérique,”
BSAF 52, 19 (1938).

* TOTALLY USELESS !! Why print this stuff?
* the next page has an equally useless report by Treilhat


F. C. S. Schiller
Our Human Truths
(Columbia Univ. Press, Morningside Heights, 1939), pp. 68–69.

* GF mentioned in a textbook on philosophy
* The author thinks that philosophy can settle disputes among conflicting
* scientific disciplines, and offers examples:
* ". . . crude phenomena are often so ambiguous in status and character
* that they are bandied about among the sciences and no science wants to
* recognize them. . . . For example, when an astronomer looks at the disc
* of Mars through a good telescope under specially good conditions of
* visibility, he may see a network of straight lines, the famous `canals
* of Mars.' Is the physical reality attested by this observation?
* By no means. They may be optical illusions, because the eye at the
* limits of visibility has a trick of importing regularity into what it
* sees and so will interpret a number of irregular markings as a pattern
* of straight lines. Does the phenomenon then belong to astronomy or to
* psychology? The matter is still in dispute." [This was a reasonable
* statement in 1939.] "A still simpler case is the seeing of what is
* called the `green flash' of the setting sun at sea. If the sky is
* quite clear and cloudless, the last bit of the sun's disc, as it dips
* below the horizon, turns a vivid green. This is a fact, though I have
* always found some people who could not see it. But the explanation of
* this fact is in dispute. Is this green objective or subjective? [Not
* a reasonable question in 1939, in view of the photographs made by
* Rudaux in 1925 and de Kerolyr's Autochrome plates -- not to mention
* old laboratory measurements of the dispersion of air, and the even
* older observations of red and blue rims on the low Sun.] . . . Either
* there is a selective absorption [sic] of rays in the atmosphere such
* that those which reach the eye turn the sun green; or else the green is
* merely a contrasting colour due to the redness of the surrounding sky.
* Both interpretations seem possible, and the actual effect may be due
* to both, for they may reinforce each other. Hence there is plenty of
* occasion for philosophy to offer its mediation in connexion with ambiguous
* phenomena and the disputed territory on the border of several sciences."
*      Schiller (1864 - 1937) was once a well-known pragmatist, but is now
* (for obvious reasons) largely forgotten.


W. W. Spangenberg
“Grüner Strahl,”
Meteorol. Z. 56, 201 (1939).

* 450 nm BLUE wavelength estimated in Warnemünde, 1.Sept.1938
* "Als die gelbrote Sonnenscheibe etwa 3/4 untergetaucht war, erschien der
* Rest ganz plötzlich über der Kimm in ausgesprochen blauer Farbe, der man
* im Spektrum eine Wellenlänge von rund 450 mμ zuordnen müsste."
* "Um bei der Beobachtung etwaigen optisch-physiologischen Täuschungen so
* weit wie möglich aus dem Wege zu gehen, beobachtete der Verfasser die
* Sonne beim Untergehen stets nur mit einem Auge, während das andere erst
* dann geöffnet wurde, wenn der grüne Strahl auftrat, so dass dieser mit
* einem ungeblendeten, nicht ermüdeten Auge wesentlich leichter beobachtet
* werden konnte."
* O'C #286


R. Meyer
“Der ``Grüne Strahl'' nach niederländischen Arbeiten,”
Meteorol. Z. 56, 342–346 (1939).

* EXCELLENT REVIEW and synopsis of Feenstra Kuiper's thesis;
* first suggestion of WAVES on inversions as a cause;
* too many good quotes to give here!
* O'C #89


R. G. Aitken
“The green flash,”
ASP Leaflets 3, 177–182 (1939).

* ASP LEAFLET 123
* has a few interesting refs.
* This is the double-star Aitken
* O'C #5


O. Sitwell
Escape with Me! An Oriental Sketch-Book
(Harrison-Hilton Books, New York, 1940), pp. 20–21.

* Osbert Sitwell thinks GFs are afterimages, but does not use that word
* ". . . just before sunset each evening, trouble would begin about
* Le Rayon Vert, the Green Ray. Recently there had been correspondence
* in the columns of The Times, and also, presumably, of certain French
* journals, concerning this mysterious and, indeed, mythical ray . . . ." All
* treated with great sarcasm. Pity this supercilious twit is misinformed.
* The original edition was published by Macmillan, London; (1939) there,
* this appears on p. 42, according to Google Books.


H. Vogel
“Das Problem des `Grünen Scheines' und seine Lösung,”
Kosmos (Stuttgart), ??, 132 (May, 1940).

* Deliberate observations of SOLAR AFTERIMAGES
* (offered as explanation of GF by Ing. Hans Vogel)
* "In den Heften des `Kosmos-Handweisers' liest man immer wieder Berichte
* von Augenzeugen über eine seltsame Himmelserscheinung, die unmittelbar
* nach Sonnenuntergang auftritt und sich so darstellt, daß von der eben
* untergegangenen Sonne aus ein zuckender grüner Schein über den Himmel
* huscht, oft bis zum Zenith reichend, aber immer nur wenige Sekunden
* andauernd. Die Erscheinung wurde von vielen angezweifelt, weil sie nicht
* von allen Menschen gesehen wird."
* Maybe this is where the rare reports of green stuff up to the zenith
* come from?
* He apparently has a method of smearing the afterimage into a "ray":
* "Nicht jedes Auge scheint das Phänomen richtig bemerken zu können."
* No volume number available; this is in the section "Kosmos-Handweiser".


O. Meißner
“Kleine Bemerkungen zur atmosphärischen Optik,”
Zs. f. angew. Met. ``Das Wetter'' 57, 263–265 (1940).

* O'C #86
* GF is section 2, p.264: mentions his repeated observations in 1909,
* but does not cite publication. (cf. Naturwiss.1920)


L. Tavernier
“Rayon vert,”
BSAF 55, 156 (1941).

* Useless.


G. Schröder
“Der grüne Strahl,”
Der Seewart 10, 182–184 (1941).

* Schröder reveals he is no scientist
* This is Gustav Schröder's final publication on green flashes.
* It contains comments people have sent him about his earlier
* observations. He thinks Meyer's 1939 paper can "den Leser mit fast der
* gesamten Literatur über den `Grünen Strahl' bekannt machen"! -- and
* then picks on Meyer for mentioning the Green Segment before the Green rim,
* because "Ich habe bei meinen vielen Beobachtungen nie ein grünes Segment
* vor dem grünen Saum gesehen." Then he adds some interesting further
* observations of his own:
* He and a fellow-officer saw (with binoculars) a flash over a roof only 1
* km away.
* Then, after giving credulity to Dr. Reinhold Quasig's notion that the
* green and blue colors come from emission lines of copper and nickel in the
* Sun, he cites the EARLIEST PROPOSAL to prolong a flash via AIRPLANE:
* G. Castens, Ann.Hydr.(1937) p.496, footnote 2 (see Klaehn), in connection
* with his suggestion for the use of high latitudes. Then relates his own
* observation at Murmansk "minutenlang" as the Sun skimmed a tree-covered
* ridge. "Augeshöhe 18 m" agrees reasonably well with the 14 m estimated
* in my letter from Hapag-Lloyd.
* O'C #130


J. Hoppe
“Die Farbe des oberen Sonnenrandes,”
Zs. angew. Met. 58, 360–363 (1941).

* EXCELLENT EXPLANATION OF THE *WRONG* (classical) model!
* Perhaps the EARLIEST ATTEMPT to allow for EXTINCTION
* Nice drawing of Mock Mirage at upper limb;
* says SCALED REFRACTION ". . . gilt . . . mit hinreichender Genauigkeit"!
* Observed RED and GREEN RIMS at 50 deg. zenith distance (x220)
* "Dort, wo die Luft meist frei von Dunstschwaden ist, im Gebirge
* oberhalb des ersten Inversion und am Meere ist das Auftreten des grünen
* Strahles daher keine Seltenheit."


Dr. H. Ahlenstiel
“Der grüne Strahl,”
Kosmos (Stuttgart) 39, 63 (1942).

* A good popular account
* Cites Kosmos-Handweiser Maiheft 1940, S.132 as well as Kellen's 1926
* article.
* kindly supplied by Brigitte Hofmann, Redaction "Kosmos"!


W. Collmann
“Beobachtung des ``Grünen Strahls'',”
Ann. Hydrog. Maritim. Met. 70, 326–327 (1942).

* Very observant account of details, including RED FLASHES
* cites Evershed, and notes importance of mirages at inversions
* O'C #195


Sir N. Shaw and E. Austin
Manual of Meteorology, vol.3
(Cambridge Univ.Press, Cambridge, 1942).

* Napier Shaw's Meteorology text, with long Ch.III on Atmospheric Optics
* Useful references on mirages, including naming Flammarion as the source
* of the Diodorus Siculus reference. "Since the introduction of the
* practice of making roads with a very smooth surface the inferior mirage is
* a very common experience on a sunny day.  . . .      The details of lapse-rate
* require investigation." (p. 65)
*      The Fata Morgana is discussed on pp. 66 and 67, citing Minasi,
* Pernter, and Forel (via QJRMS 38, 219 (1912).)
*      About 1 page on GF, mostly a quote of Wood's 1928 Nature  paper.
* Unfortunately, they endorse Wood's wrong-way mirage theory, thus buying
* into the mistaken idea of super-refraction. (p. 68)
*      This is the 1942 reprint of the 1930 first edition.
* Paper copy filed in "Textbook accounts of GF" file.
* Google Books mis-labels this as Vol. II, due to faulty OCR.


M. Badel
“Divers,”
BSAF 57, 6 (1943).

* Green rim? seen telescopically over mountains
* probably useless; fewer than 4 lines.


G. M. Wrigley
“`Green Flash',”
The American Neptune 3, 86–87 (1943).

* Extensive quotations from "sources in the American Geographical
* Society's library": Humphreys's book, Minnaert, Wood's "Physical Optics"
* and Evershed in QJRMS (1936). No original information.


E. L. Hawke
“Optical phenomena of the atmosphere [summary],”
JBAA 54, 89–97 (1944).

* Interesting Report of the Ordinary General Meeting of the BAA, 31 May 1944
* with a good talk on meteorological optics by E.L.Hawke
* The GF stuff starts in the last line of p.95, but there is an
* interesting explanation of Newton's numerology leading to the 7 named
* colors in the spectrum on p.89.
* He says the GF "used to occupy a great deal of space in our
* Association's Journal ." This is consistent with my observation of a
* great diminution of GF reports after the middle '30s. both here and in
* BSAF.
* GREEN RAY observations:
* "At the actual moment of apparent sunset this last segment of the disk
* sometimes seems to shoot upwards like a little tongue of flame; sometimes,
* too, it is said to give the impression of a flash from a rapidly rotated
* searchlight fitted with a green screen. I have myself seen the former
* effect over an Atlantic horizon on at least a dozen occasions, but never
* the latter."
* In the note added later, he again says: ". . . on a number of occasions I
* have seen a small ray or beam, resembling a tongue of green flame, shoot
* upwards from the Sun as it disappeared below a sea horizon . . . ."
* The subsequent discussion is of some interest.


F. C. Molesworth
“The green flash,”
JBAA 54, 180 (1944).

* ignorant novice fitting Havinga's characterization
* O'C #250


D. R. Barber
“The `Green Flash' at sunset with a near `horizon',”
Nature 156, 146 (1945).

* NAKED-EYE FLASH on ROOF at 440 yards
* O'C #168


C. E. P. Brooks
“The `Green Flash' at sunset with a near horizon,”
Nature 156, 368 (1945).

* Brooks comments on Barber and recalls his 1926 observation


S. E. Ashmore
“A note on the green ray,”
Q. J. Roy. Met. Soc. 71, 383–384 (1945).

* DRAWINGS of GREEN TIPS and LOWER EDGE of INFERIOR MIRAGE FLASH
* Nice Omega drawings and a sketch of a stratus CLOUD-top flash.
* "details of how the colour progresses across the last remaining visible
* part of the sun at sunset."


G. A. Tikhov
“Atmosfernaya Optika. Zelenii Luch,” in Sto Let Pulkovskoi Observatorii
(Izd.Akad.Nauk, Moskva, 1945), pp. 233–235.

* Tikhov reviews his work historically
* The main interest here is a short account of a GF seen by Tikhov's
* predecessor A.P.Ganskii at Mont Blanc, 4 Sept. 1900.
* Tikhov makes much of his search for anomalous dispersion and claims
* to have found it around the B band.
* The whole article on atmospheric optics runs from p.233 to 246; but the
* GF section cited here is only 3 pages.


N. K. Johnson
“The Green Flash observed over the Atlantic,”
Met. Mag. 76, 21 (1947).

* Professor Sir Geoffrey Taylor's CLOUD TOP FLASH problem
* This is the N.K.Johnson who wrote on optical retrieval of lapse rate
* with Roberts in 1925.
* "I had hardly expected a cloud sheet to have a sufficiently definite top
* to show the green flash, but it was a really fine display."
* The observation was in June, 1944; these are leftover letters from WW II.


S. E. Ashmore
“The Blue (?) Flash,”
Met. Mag. 76, 21 (1947).

* Ashmore thinks the blue color is odd.
* ". . . a beautiful blue, a trifle bluer than the deepest sky-blue seen
* with maritime polar air in spring."
* "I was viewing it through powerful binoculars. . . . Perhaps it [the
* unusual colour] was due to the use of the binoculars themselves."
* Another leftover from the War; observed Aug. 20, 1943.


A. H. Joy
“Refraction in astronomy,”
ASP Leaflets 5, no. 220, 162–169 (1947).

* Spectroscopist ALFRED H. JOY covers the GF and other refraction effects
* 2 paragraphs on pp. 163-164 describe green flashes; a third describes
* simple dispersion at large Z.D. A little of the history of astronomical
* refraction follows: Tycho, Kepler, Newton. Modern "tables are
* reasonably accurate except at points near the horizon."


D. S. Hancock
“A green flash,”
Weather 3, 148 (1948).

* GREEN RAY ? or afterimage?
* "There was plenty of stratocumulus about, though the sun set in a clear
* patch. Just as its lower rim touched the horizon there was a `flash' of
* pale green at `10 o'clock' from the sun's centre and about two diameters
* distant. This did not last more than a second at the most and appeared
* almost circular, with a radius slightly larger than the sun's.
* Immediately after, I noticed that the small clouds just above the sun were
* tinged with the same shade of green."


R. Walgate
“Green flash, Gulf of St. Lawrence,”
Marine Obs. 18, 144 (1948).

* SUNRISE FLASH "lasting about 1.5 seconds and approximating to the flash
* of a green-shaded Aldis lamp at one mile range."


G. S. Willis and Jnr.
“Mirages and green flash, Australian waters,”
Marine Obs. 18, 145 (1948).

* A complex display; difficult to interpret. The sunset mirages seem to
* be superior; but the sunrise phenomena appear to be inferior mirages.


L. J. Comrie
“The Green (?) Flash (?),”
Journal of the British Astronomical Association 58, 280 (1948).

* The famous compiler of 6-place math tables sees his first flash:
* "All my life I have looked . . . for the so-called green flash; I had
* conspicuously failed to catch it. To-night, over the smooth water of the
* Red Sea, I have seen it.
* "I now know the main reason for my previous failures; my conception of
* what I was looking for was at fault. I had expected something green --
* and pictured emerald green; I had expected a flash , i.e., something
* momentary like lightning, . . . and I had expected something extending
* perhaps 20' or 30' above and around the sunset point. It was none of
* these things."
* ". . . the smallness of the whole effect was contrary to my expectation."
* (reprinted in Met. Mag. the next year; see below)
* Note: this appeared only 2 years before Comrie died.
* O'C #20a


J. E. Bowman
“The green flash,”
JBAA 59, 40 (1948).

* 5 MINUTES from SLOPE OF HILL
* "The slope of this hillside was such that by walking uphill I could
* keep the upper limb of the Sun just at the point of setting, and by
* varying my pace could make it `rise' or `set' at will ... for over five
* minutes."
* (Note that years and volumes of JBAA still do not coincide.)
* O'C #183


W. H. Steavenson
“The green fringe,”
JBAA 59, 41 (1948).

* ". . . the fringe has been clearly photographed in natural colors."
* "The phenomenon has been very thoroughly studied in the past and there
* is quite an extensive literature on the subject, which is not really
* astronomical but belongs rather to what the French call
* optique atmosphérique ."
* O'C #134


J. Houtgast
“Het observatorium van Haute Provence,”
Hemel en Dampkring 47, 4–11 (1949).

* Houtgast sees two SUNRISE flashes over the Alps (see pp.10,11)
* He estimates the durations as 0.5 and 0.1-0.2 seconds.
* The footnote on p.11 also reports a brief WHITE FLASH at sunrise.
* described as a "witte flits". So perhaps this gave the editor the
* inspiration for "groene flits" a few pages later? (See next item.)


L. J. Comrie
“De groene flits?,”
Hemel en Dampkring 47, 17 (1949).

* The editor presents a Dutch translation of Comrie's JBAA note
* Can the introductory remarks be the first use of "groene flits" instead
* of "groene straal" in Dutch? The editor explains that it is the literal
* translation of "green flash". (The editor's note is on p. 16, under the
* heading "De groene straal"; Comrie's note begins p. 17. The editor
* refers to Houtgast's piece on Haute Provence in the same issue.)
* (I assume the script-R signature stands for "Redacteur".)


R.
“Nogmaals: De groene straal,”
Hemel en Dampkring 47, 32 (1949).

* Comrie's remarks attacked
* "Dr. J. Comrie writes me: `I seem to have stuck my head in a hornets'
* nest. Everyone is attacking me, everyone is indignant about the
* physiological explanation I gave of this phenomenon.'" The editor
* replies that Comrie's remarks were, in fact wrong; but "the readers
* should have understood this, for the piece by Comrie was put on purpose
* into the number wherein also Dr. Houtgast gave his description of the
* green flash." [Note that Houtgast's flashes were at sunrise.]
* He cites Minnaert's book.
* (I assume the script-R signature stands for "Redacteur".)


L. J. Comrie
“The Green (?) Flash (?),”
Met. Mag. 78, 27 (1949).

* Comrie's JBAA article reprinted


L. J. Comrie
“The Green (?) Flash (?),”
Pop. Astr. 57, 42–43 (1949).

* his JBAA article reprinted again (N.B.: NOT COPIED; not in paper files)
* O'C #20b


P. R. Lewis
“Green flash, North Atlantic Ocean,”
Marine Obs. 19, 80–81 (1949).

* uninformative but temps suggest inf.-mir. flash
* May be just an enhanced green rim


W. Ley
“The Green Flash,”
Pop. Astr. 57, 147 (1949).

* Willy Ley's GF, with a gap between disappearance and GF
* Possibly a GREEN RAY?
* "Later I experienced .. being passed over by the slowly turning
* searchlight of a distant warship. Except for the difference in color the
* two sensations were exactly alike."
* O'C #231


H. O. Grönstrand
“Den gröna strålen,”
Populär Astronomisk Tidskrift 30, 26–36 (1949).

* Good review in Swedish, but few references
* N.B.: The GF spectrum reproduced from Danjon & Rougier shows nothing
* (all black) on the page in our library.
* O'C #42


(P. Doig)
“The green flash,”
JBAA 59, 105–106 (1949).

* SUNRISE IS BETTER?
* (short reports from all over)
* "M.Gentili of the Pic-du-Midi Observatory writes that the phenomenon
* `occurs every time the Sun sets or rises behind a distant object,
* mountain, or cloud, when the low atmosphere is not much absorbing (in
* winter or spring) -- I can say, perhaps two hundred times in seven years.
* The fact that it can be seen much more frequently at sunrise proves that
* there cannot be question of a physiological ``after image'' phenomenon.'"
* (Peter Doig was editor of JBAA from 1930-1937.)
* O'C #201


D. Hay
“Green flash, North Atlantic Ocean,”
Marine Obs. 19, 150 (1949).

* GREEN RAY for sure; probably produced by a SUB-DUCT FLASH
* "The sun . . . had been below the horizon for an appreciable time before a
* vivid green ray was seen. The ray extended 1 - 2 degrees above the
* horizon and was emerald green in colour. It lasted about 8 - 10 seconds
* and most nearly can be described as resembling a green aircraft flare
* hanging in the sky."
* "Note. . . . The radio-sonde ascent at 2000 showed a shallow layer of
* cold air from the surface to 935 mb. where a rise in temperature began.
* The temperature drop in the cold surface layer was 14°."


P. R. Lewis
“Green flash, North Atlantic Ocean,”
Marine Obs. 19, 190 (1949).

* CUMULUS
* ". . . seen above distant Cu . . . ."


P. R. Lewis
“Green flash, South African Waters,”
Marine Obs. 19, 190 (1949).

* 3 flash sequences:
* a) flash above cloud and again at horizon (18 Dec.);
* b) "final colour violet" (8 Dec.);
* c) "blue-green to apple-green (very bright), the blue-green again."
* (30 Dec.) [probably due to effect of waves on ship]


J. Ranneft
“De groene straal,”
Hemel en Dampkring 47, 159 (1949).

* A first-timer sees an inf.-mir. flash
* Followed by 2 brief reports, from J.Blom and C.J.P.va Duin.
* Blom reports light blue *before* emerald green at sunset.
* O'C #265


Commandant Cornu
“Optique atmosphérique,”
BSAF 63, 341–342 (1949).

* Classical OMEGA display described, including the introductory LINE
* explicit evidence for ADAPTATION:
* "Auparavant, je constate que lorsque je regarde à l'oeil nu le ciel
* rouge à      côté  du Soleil, je vois le Soleil rouge; puis, quand je fixe
* le Soleil, il me paraît par moments vert-jaune . Dans la jumelle, le
* Soleil paraît toujours jaune-orangé avant le verdissement final."


E. O. Hulburt
“The green segment seen from an airplane,”
J. Opt. Soc. Amer. 39, 409 (1949).

* Early AIRPLANE FLASH at 8000 ft.
* "If what I saw was a fair example of the green segment I was left with
* the impression that the phenomenon was rather fleeting and not very
* impressive, and that it would usually escape casual observation."


D. M. Barringer
“Note on the ``Green Flash'',”
Pop. Astr. 57, 252–253 (1949).

* PHOTOGRAPHIC DIFFICULTIES -- evidence for visual adaptation?
* EARLY MOVIE ATTEMPT
* "It was perhaps the finest example I have seen . . . . The film, when
* developed, was very sharp and clear and gave a beautiful picture of the
* sunset, but the flash did not appear."
* D. Moreau Barringer
* O'C #8


W. Norlind
“Additional note on the ``Green Flash'',”
Pop. Astr. 57, 301 (1949).

* STATISTICS: 26 yes, 13 not seen
* O'C #259


F. A. Perret
Volcanological Observations
(Carnegie Institution of Washington, Washington, DC, 1950), p. 112.

* Posthumous monograph of Frank Alvord Perret (1867 - 1943)
* Perret devotes nearly a column to "The `Green Ray'", ". . . a momentary
* flash of brightest green whose evanescent beauty invariably excites
* admiration, especially when a binocular or telescope is used.
*      "Hesitant though I may be to say it, I believe the appearance to
* be purely subjective. The last-seen tiny segment of the sun's disk is
* still intensely brilliant, and its sudden disappearance leaves the retina
* abnormally irritated at this spot, yielding by reaction the complementary
* wave length, which gives us green. Yet I have seen the `green ray'
* described as wholly objective and capable of being photographed on a color
* plate. It would be interesting to know what process was employed . . . ."
* [Evidently this is an oblique reference to Kerolyr's Autochrome plates,
* as this must have been written before 1943.]
*      "It will be evident that, by our hypothesis, the setting sun must
* be very red -- which indeed is normally the case -- in order to give
* the green flash. It was with interest, therefore, that I awaited
* a strongly yellow sunset, not uncommon in autumn. This, in fact,
* showed an intense violet flash without the least suggestion of green,
* and I subsequently observed a pure blue ray from a yellow-orange sun.
* There is, then, no green or other flash at the horizon or upon the sun."
*      A fine example of the fact that false theories can produce true
* predictions; only contradictions can reveal and eliminate error.
* [As the low sun cannot appear yellow without retinal bleaching, which
* is stronger when the extinction is less, the observations are equally
* consistent with variations in atmospheric extinction.]
*      This is Carnegie Institution Publication 549.


R. E. G. Simmons
“Green flash off San Diego, California,”
Marine Observer 20, 10–11 (1950).

* Drawings showing a mock mirage off San Diego
* Nice term "crown" used to describe the piece that breaks away.
* The observer says the "edges" of the crown were initially red; I think he
* meant the upper and lower edges, not the *ends* as the Editor assumes.


J. B. Harbord
“Visibility, mirage, and green flash, approaching Montreal,”
Marine Observer 20, 66–67 (1950).

* Drawings of mirages and distortions of setting sun; GREEN RAY ??
* "Finally the green flash was observed with green rays quite distinct."
* But, alas, no drawing of the "green rays"!
* "Air temperature 36° F., sea 37°."
* Some of the sunset drawings show impossible structures.


Contre-amiral Bongrain
“Optique atmosphérique,”
BSAF 64, 148 (1950).

* Rear-Admiral Bongrain offers a curious phrase
* ". . . compare à un effet de capillarité optique entre les bords de
* l'arc du Soleil et l'horizon."
* So I suppose this is an Omega forming (inf.-mir. display)


Houdard
“Optique atmosphérique,”
BSAF 64, 465 (1950).

* useless


L. R.
“The green ray,”
Pop. Astr. 58, 419–420 (1950).

* Translation of article from Bull.Mens.Soc.Astron.Pop.Toulouse
* standard account of the usual (wrong) theory.
* gross error: blue, etc. supposedly absorbed by water vapor.
* O'C #110


V. V. Sharonov
“Nablyudeniya zelenogo lucha,”
Astron. Tsirk. , No. 108, 9–10 (Dec. 29, 1950).

* SHARONOV's actual observations
* "1. A green flash can be observed repeatedly on a given evening (in
* our case, up to 6 times), accompanying the passage of the upper limb of
* the Sun not only through the line of the visible sea horizon, but also
* through the edges of cloud strips, strips of mist and boundaries of
* atmospheric layers that are invisible, but are revealed by causing
* deformations of the solar disk.
* 2. A green flash often accompanies the formation of `plumes', being
* separated from the upper edge of the disk on passage of the latter through
* the indicated boundaries. Sometimes it has the appearance of a green
* distortion at the side limbs of the solar disk.
* 3. A `plume' has the appearance of an elliptical or lens-shaped patch
* being separated from the solar disk, at first having the brightness and
* color of the Sun. A green tinge appears at the right and left edges of
* such a patch and quickly spreads along the edge, enveloping it from both
* above and below, and enclosing the red center in a bright green ring.
* Spreading to the center, the green color fills up the whole area of the
* plume, giving a bright green flash at the moment of final disappearance.
* 4. A green flash is often seen when the solar disk is weakly colored
* and very bright (dazzling), but is not seen if the solar disk is dim and
* red (evidently, owing to strong attenuation of the green rays). It is
* also not observed at `linear' sunsets, when before disappearing the solar
* disk is stretched along the horizon in a bright narrow strip, whose width
* gradually decreases.
* 5. For a moderate degree of weakening of the solar light the green
* flash is reduced in intensity, but does not change its saturated
* blue-green color, which points to the idea of a monochromatic character of
* the phenomenon.
* 6. The hypothesis, usually cited in textbooks, just explaining the
* phenomenon of the green flash by spectral dispersion in the terrestrial
* atmosphere, agrees poorly with the particulars of observed pictures at
* the edge of the sea if its usual form is borne in mind."
* В. В. Шаронов
* Наблюдения . . .
* Астр. Цирк. No. 108, 9-10 (1950)
* O'C #276


N. R. Srinivasan
“Pan Indian Ocean science congress,”
Science 113, 164 (1951).

* A.D.Ross -- mentioned by title only
* This is just a meeting report: "The delegates presented in all 19 papers
* . . . [including] `The Green Flash at Sunset' by A.D.Ross (leader of the
* Australian delegation . . . )". But Rosanne Walker, the former librarian
* at the Adolph Basser Library of the Australian Academy of Science, has
* checked the conference Proceedings, and found that they do not contain
* the scientific papers.
*      Ross was a solar astronomer at the U. of Western Australia; he had
* several papers in MNRAS in the early 1920s. Maybe his GF paper was
* published in Aust.J.Phys. in the early 1950s???
* This report is the lead item in the "News and Notes" department.
* Feb. 9 issue


S. B. Wade
“Green flash, Red Sea,”
Marine Observer 21, 84 (1951).

* GF with drawings of DISTORTED SUN


V. V. Sharonov
“Noviye danniye o `zelyonom luché,”
Priroda 40, no. 7, 50–53 (July, 1951).

* SHARONOV's excellent article
* There are some useful observations here; in particular, Sharonov has
* recognized typical sunset sequences (see Fig. 1, where a "standard" sunset
* is followed by Fisher's type B and type A sunsets, with a mock-mirage type
* B at the last. The last 2 show inf.-mir. GF and MM GF, respectively.)
* He did not understand what he was seeing, but his observations are
* careful, and the descriptions of the various types are now more detailed
* than in his Astron. Circ. note.
* Unfortunately, he chose to portray "typical" examples here rather than
* actual individual cases; in particular his Fig. 3 has all sorts of sunset
* forms run into one another indiscriminately. His observations, like mine,
* were made from 100 m above the sea, so he got to see the major types.
* "Various hypotheses have been proposed to explain the green flash, but
* not one of them can explain all the details of this phenomenon. In
* meteorology textbooks and handbooks of atmospheric optics the phenomenon
* of the green flash is usually explained as the narrow segment of the
* setting Sun, drawn out by atmospheric dispersion into a vertical spectrum,
* so that the violet color appears above and the red below. Therefore the
* red end of the spectrum sets before the green, and as the blue and violet
* rays are completely scattered in the depth of the atmosphere, then at some
* moment one green ray reaches the observer and produces the impression of a
* green flash.
* "It is necessary to recognize that such an explanation is insufficient
* to account for the actual picture of the green flash. First of all, it
* is repeatedly recorded that if the cause lay in the phenomenon of normal
* spectral dispersion, then the green flash should be observed very often,
* but in reality it seems to be a fairly rare phenomenon and it usually does
* not appear even with good atmospheric transparency at the horizon.
* Further, the order of appearance and distribution of the green color along
* the edges of ``plumes'', described above, does not correspond to the fact
* that if it were due to a single dispersion, the green rim would appear
* only on the upper edge of the ``plume'', while the lower edge should be
* red, but in reality the green border envelops the ``plume'' both from
* below and above. To fit this observed picture with the dispersion theory,
* it is necessary to assume that a ``plume'' consists of two images of a
* segment of the disk, joined at their bases. In this case, the upper of
* these would be the true segment, and the lower its inverted reflection in
* an atmospheric layer, formed like an inferior mirage".
* But unfortunately he thinks the color is independent of the extinction,
* and hence inclines toward the anomalous-dispersion theory, though he
* recognizes that there are no strong telluric lines in this part of the
* spectrum, and that Tikhov's work shows that even near the strong ones in
* the red, the anomalous dispersion is very small. The physiological
* contrast theory is even worse, so "at the present time we have no
* satisfactory theory of the green flash and therefore the question
* requires further investigations."
* The article has a fair bibliography of earlier Russian works.
* В. В. Шаронов
* о «Зелёном луче»
* Природа No.7, 53-55 (1951)
* NOTE: issues of "Priroda" are separately paginated, so the issue
* month and/or number MUST be given.
* O'C #277


I. I. Putilin
“Zelenii luch,”
Astron. Tsirk. , No. 118, 9–11 (Sept. 12, 1951).

* PUTILIN observes from 10, 50 and 200m and sees GF abundantly from lower
* two, using 8x binocs.
* "The observations show that the green flash does not seem to be such a
* rare phenomenon as is generally thought."
* "Both the color and form of the green flash were different on different
* days."
* CLASSIFICATION into FOUR TYPES:
* "I. Vague formless `green flash' with the aspect of a horizontal strip,
* separated by a dark strip from the horizon. . . . The strip gradually
* shrinks and disappears, not reaching the horizon. Duration not long,
* 2 - 3 seconds.
* II. The green flash has the form of an unsymmetrical oval, separated
* from the horizon. The major axis is parallel to the horizon. The upper
* part of the oval is usually more convex than the lower. The coloring in
* green light proceeds simultaneously in the whole area of the oval. . . .
* The oval disappears at some height above the horizon (does not set behind
* the horizon). Duration 7 - 10 seconds.
* III. The green flash appears to be a segment, not separated from the
* horizon. The green color in most cases begins at the corners of the
* segment, and then, as the sea reduces the size of the segment, spreads to
* its whole area. Duration on the order of 10 seconds.
* IV. The green flash appears to be a segment, not separated from the
* horizon. After becoming green, the segment gradually acquires a blue, and
* sometimes even a violet color. This type is characterized by exceptional
* brightness, distinctness, and purity of the observed colors."
* "A green flash of the 1st type is observed when conditions are not
* optimal. At this time usually there is light haze at the horizon and the
* atmosphere at the horizon is not quite calm. The setting disk of the Sun
* has an orange-red color and undergoes moderate distortions (except, of
* course, the usual flattening due to refraction).
* On the other hand, a flash of type IV (`blue flash') is observed under
* unusually good atmospheric conditions, when the atmosphere has unusually
* high transparency and tranquillity. At this time the setting disk of
* the Sun appears very bright, has a yellow color and hardly shows any
* distortions."
* "It's interesting that in the case of cloudy weather the visibility of
* the green flash often happens better than with a clear sky. Sometimes
* the flash was not observed with a completely clear sky . . . , or was
* observed very weakly.
* It's possible to think that the presence of clouds can create better
* conditions for the appearance of the green flash than with a clear sky
* because of the calmer condition of the atmosphere in its lower layers."
* Note: for details and drawings, see his 1953 paper.
* И. И. Путилин
* Зелёный луч
* Астр. Цирк. No. 18, 9-11 (1951)
* O'C #263


M. D. Ward
“Green flash, South Pacific Ocean,”
Marine Observer 21, 217 (1951).

* std. inf.-mir. GF; water measured 2 deg. warmer than air


H. Swift and D. A. Davies
“Green flash, Indian Ocean,”
Marine Observer 21, 218 (1951).

* Possible GREEN RAY (according to Editor's comment)
* "One and a half seconds after the sun's upper limb had disappeared below
* the horizon, a green flash was observed which lasted for 4 seconds. To
* the observers it looked like a green occulting light flaring up on the
* horizon."
* O'C #306?


B. Hilder
“Longitude by the green flash,”
J. Inst. Navigation (London) 4, 211 (1951).

* Captain Brett Hilder's letter on use of GF to determine LONGITUDE
* (see also Rawlins, 1979, in DIP file)
* This is evidently what Cotter gets exercised about in 1968 !
* The Editors reply mentions Weston's method for using sunrise and
* sunset: "Tables . . . were published by the Admiralty in 1851."
* [These must be the tables mentioned in Nautical Mag. 17, 620 (1848).]
* "It was certainly to my knowledge used in about 1925, and for the most
* part it seems to have been handed down by word of mouth."
* Hilder's letter is followed by a somewhat longer editorial comment.
* See Hilder's followup in vol. 6 (1953) in "Variable Refraction" file!
*
* N.B.: There are two things called "Journal of the Institute of
* Navigation." This one (called "Journal of Navigation" since vol.25, 1972)
* is published in London by the Royal Institute of Navigation. The other
* (now called simply "Navigation") was published in Los Angeles at UCLA and
* was produced in Washington, DC, from 1960 to 1992.


A. Savrukhin
“Zelyonii luch Venery,”
Astron. Tsirk. , No. 120, 8 (Nov. 12, 1951).

* VENUS flash in Ashkhabad
* Cites Sharonov's 2 papers (above) and Putilin in No.118.
* Remarkably, the place where Venus set (at a 50-km distant mountain) was
* 4 deg. above the horizontal! Repeated observations gave a short flash
* in every case.
* O'C #275


V. M. Chernov
“Redkii sluchai poyavleniya zelenogo lucha,”
Astron. Tsirk. , No. 120, 8–9 (Nov. 12, 1951).

* GF at Sea of Azov
* Only 1 successful observation from "several meters above the sea."
* Looming allowed western shore to be seen a few minutes above the sea
* horizon. No deformations aside from flattening. The image of the far
* shore divided the Sun into 2 parts (probably this means an inferior
* mirage). The lower part disappeared first [because of perspective
* effects -- aty]; each part gave a GF on disappearing.
* Most attempts were frustrated by clouds or haze at the horizon, so
* conditions in the southern Ukraine were judged to be unfavorable for GF.
* O'C #292


M. Hanzawa
“Green flash observed in the Antarctic Ocean,”
Oceanographical Mag. 3, 139–140 (1951).

* FIRST COLOR PHOTO ? (But cf. Touchet, 1932, and Dauvillier, 1962)
* METEOROLOGICAL DATA show sea 1.4C warmer than air.
* Drawing suggests Omega before GF
* O'C #48


R. E. G. Simmons
“Observations of the Green Flash,”
J. Inst. Navigation (London) 4, 415–417 (1951).

* GOOD OBSERVATIONS, but badly confused in trying to explain them:
* (garbled explanation involving "diffraction".)
* "From numerous personal observations . . . the green flash can be observed
* under conditions of extreme cloudiness, haze and humidity so long as the
* horizon is visible . . . ."
* ". . . the flash is of very weak intensity when compared to the normal
* brilliance of the body observed."
* nice drawings of Joule's 2 types of GF
* REVERSED ORDER:
* "On one occasion, under conditions of abnormal refraction, when the Sun
* had assumed grossly distorted forms, the detached segment showed a
* bright red light at its outer edges prior to turning green. This is
* most unusual . . . ."
* "Observations of the green flash are best carried out through
* binoculars; it is quite comfortable to look at the setting Sun when
* three-quarters of its area is behind the horizon, except, possibly, when
* there is a total absence of haze; then, however, the last stages of the
* green flash phenomenon are never too bright."
*
* N.B.: There are two things called "Journal of the Institute of
* Navigation." This one (called "Journal of Navigation" since vol.25, 1972)
* is published in London by the Royal Institute of Navigation. The other
* (now called simply "Navigation") was published in Los Angeles at UCLA and
* was produced in Washington, DC, from 1960 to 1992.
* O'C #284


Mme. de la Rosa
“Optique atmosphérique,”
BSAF 65, 474–475 (1951).

* DOUBLE FLASH -- sounds like a MM, then an inf.-mir.
* "Le temps était brumeux, soudain la partie supérieure du Soleil
* (en forme de petite calotte) disparuit et fut remplacée par une plage
* vert intense; puis la forme normale reparut et le Soleil se coucha
* définitivement sous la mer, en produisant au moment de sa disparition, un
* second rayon vert, mais bien mois intense que le premier."


Fr. Raymund Devas
“The green flash,”
Caribbean Quarterly 2, No. 2, 40–43 (1951).

* a popular account full of errors; at least he has SEEN some flashes
* "Editor's Notes" on p.3 says Father Raymond Devas "is at present a
* parish priest in Grenada." They spell him "Raymond" on Contents page
* but he is "Raymund" in the by-line.
* Much nonsense about refraction; but he reports seeing a 3-second flash.
* NOTE: each issue separately paginated, so issue number is vital.
* The title page of the volume says "1951-52" so we will guess 1951.
* The OED's date of 1950 is wrong. Separate issues are not dated.


J. W. Ross and D. A. Watt
“Green flash at setting of planet Venus, off Montevideo,”
Marine Obs. 22, 12 (1952).

* VENUS flash; no useful details


M. Hanzawa
“Green Flash,”
Met. Mag. 81, 28–29 (1952).

* Details of Masao Hanzawa's GF photograph described:
* "The copy sent, a half-tone reproduction, clearly shows the green
* segment of the sun on the sharp sea horizon. There is no apparent
* distortion."


W. Weigel
“Die Sonne springt,”
Zeitschr. f. Meteorologie 6, 30 (1952).

* GREEN RAY? observation with DARK STREAK at sunrise
* "Jedesmal beim `Durchstoßen' einer Sprungschicht, die sich bisweilen
* durch einer zarten Dunststreifen verriet, erschien über der
* Sonnenscheibe ein kleiner grüner Fleck, der bei Vereinigung mit der
* höhersteigenden Sonne deren Farbe annahm, während das Grün nach
* links und rechts außen rückte und schwächer wurde. Plötzlich,
* offenbar bei erreichen einer besonders ausgeprägten Sprungschicht,
* plattete sich die Sonnenscheibe stark ab, hierbei erschien etwa eine
* Sekunde lang ungefähr ein Drittel Sonnendurchmesser über derselben
* ein fast ebenso ausgedehntes büscheliges zartgrünes Licht, der
* Grüne Strahl. Im nächsten Augenblick buchtete sich die Sonnenscheibe
* mit einem Ruck auf das gesamte Gebiet des Grünen Strahles aus, also
* um etwa ein Drittel ihres Durchmessers, sie war damit tatsächlich
* `gesprungen'."


editorial report
“Colour photograph of the green flash,”
Marine Obs. 22, 66 (1952).

* HANZAWA reports his photograph to M.O.
* "Air temperature was 30.9 F, the sea being warmer, 33.8 F."
* "As Mr. Hanzawa remarks, this is probably the first colour photograph
* taken of the green flash." Sorry, guys. Maybe third?


T. S. Jacobsen
“On the spectrum of the green flash at sunset,”
J. Roy. Astr. Soc. Canada 46, 93–102 (1952).

* Jacobsen's SPECTRUM
* As the flash is in fact dimmer than the red or yellow Sun that precedes
* it, Jacobsen's results are spurious, and probably due to inter-layer
* adjacency effects in the color film used.
* This paper was reprinted as Contrib. DAO no.26 -- thanks to
* Brenda Corbin of USNO library for the reference!
* Theodor Siegumfeldt Jacobsen -- thanks again, Brenda Corbin!
* NOTE: The L.A.Times carried Jacobsen's obituary on p. B11 of the
* Orange County edition, July 24, 2003. He was for many years the only
* astronomer at University of Washington. No mention is made of his
* connection with DAO.
* O'C #56


Ch. Biemans
“Le Rayon vert,”
Ciel et Terre 68, 220 (1952).

* evidence for FATIGUE?
* "L'observation a été suive par moi aux jumelles prismatiques 6x30.
* Madame Biemans, qui a observé à l'oeil nu, n'a pas vu le rayon vert."


H. M(ichel)
“Réponse,”
Ciel et Terre 68, 220–222 (1952).

* Editor's reply to the Biemans letter
* numerous references in l'Astronomie, La Nature, etc.
* Believes Jacobsen's paper.
* O'C #83


S. E. Ashmore
“The green ray,”
Weather 7, 157 (1952).

* BLUE-GREEN flash over MOUNTAINS
* ". . . there was a stream of maritime polar air; visibility was excellent
* . . . with a NW wind never exceeding force 2. The sun went down without a
* tinge of ruddiness, and at the last glimpse was bluish-green, a colour not
* often seen even in coastal observations."


Anonymous
“Setting of a bright star or planet,”
JBAA 62, 90 (1952).

* Comments on the Marine Obs.21,216(1951) report
* "It would be interesting to look for this spectrum from a position where
* Jupiter or Venus or other bright planet or star rises or sets in a sea or
* flat plain horizon." (Unaware of numerous such observations already!)
* O'C #305


A. D. Thackeray
“Setting of bright planet or star,”
JBAA 62, 206–207 (1952).

* Further comments inspired by the Marine Obs. report
* "The dark spaces in such an atmospheric spectrum can be simply explained
* in terms of atmospheric layers of different densities which produce rapid
* changes in the refractive index. Such variations in refractive index are
* also responsible for the `notched' appearance of the setting sun which can
* often be seen. On these occasions it is sometimes possible the see the
* green flash several times as each `notch' reaches the upper limb of the
* sun."
* Thackeray's comments about the "dark spaces" in the spectrum must refer
* to the chromatic scintillations that run through the spectrum, as it
* is swept across the atmospheric turbulence by the Earth's rotation.
* O'C #138
* May issue


Rear Admiral N. M. Kindell
“The blue flash,”
Proc. U. S. Naval Institute 78, 557–559 (1952).

* An astute Rear Admiral's REVIEW of flashes, with a wartime OBSERVATION
*       Altogether a splendid account!
* Begins with Humphreys's "proverb", and an account of a blue flash seen
* off Okinawa from the carrier U.S.S. Independence in April, 1945, that
* "after thirty years at sea, was the first I had heard of THE FLASH."
*      "Now, what is this thing that no one you happen to be with has
* seen or heard of, but which is as old as the Ocean and probably has
* been obscurely mentioned in thousands of old papers and argued over in
* forecastles and cabins for centuries?"
*      ". . .  A recent news dispatch reports that two ladies connected with the
* University of Washington have good color pictures, taken in Hawaii of the
* green." [These would be the ones referred to by Jacobsen (1952, 1953).]
* "Without looking it up I can tell you what you need if you want to take
* pictures. A long focus camera, a telescope lens, fine grained film of 35
* mm. or larger should do the trick. A normal exposure, say one-fiftieth
* at f.8 would be enough." And this, 5 years before O'Connell's book!
* ". . . in a week or less I was able to get the last of the sun right
* in my 7× binoculars for a fine clear sight of the blue button
* that sat on the line like a bright bead and snapped out like a spark.
* From then on for the rest of the summer of 1945, it appeared many times,
* and it became commonplace to those of us who frequented the bridge.
* And I began to observe something else. `Good' conditions started of
* course with an unobstructed sky horizon clear and sharp. If the sun
* got down to within one diameter of the line and was still quite yellow,
* that meant that the air behind the horizon was clear too and conditions
* were very good. This was especially true if the sun's surface was viewed
* through glasses had a `boiling' appearance. When things were like that,
* a little blue fillet showed at each end of the line which the water cut
* across the sun. As the sun sank, the blue spots followed the sun's rim,
* receding to the maximum diameter and then approaching each other as the
* last half of the sun disappeared. Just as the thin red rim of the sun
* sank, the two sparks joined and it was this instantaneous doubling of
* the blue light that makes the appearance of a flash.
*      "After the Tokyo surrender I began trying to catch this thing on
* film and immediately found out why it isn't more widely known. In the
* first place, only on very, very, good days does the joining of the
* sparks bring the intensity up to a point visible to the naked eye. . . .
* I got a good many feet of pretty sunsets and, between Midway and Iwo,
* a few fair frames of the spark.
*      "Is there a scientific explanation?  For me it lies in the interaction
* of two effects. Refraction. . . is least at the red end of the spectrum
* and increases through yellow and green to the blue end. And, dust and
* moisture interfere more with blue light and less with green, yellow
* and red. . . . The red strikes through better than all the rest and its
* brightness blots out the other colors. But, just for an instant, when
* the red is cut off, the blue's still showing above the waves and we get
* the BLUE FLASH.
*      "The next time you are near Agrihan or north of there to Japan,
* or even up on the eastern shore of Lake Michigan and a cold front has
* swept off the dust and left a sparkle in the air -- take a look.
*      "The foregoing was written three years or more before I was able,
* through the kindness of Dr. T. S. Jacobsen of the Department of Astronomy,
* University of Washington, to obtain a couple of references and to find
* those references and others at the library of the Naval Observatory. . . .
* A famous French author described, in 1882, its most usual appearance. . . "
* [here he quotes Verne's description of the color].
*      "It has been widely observed and extensively written about, the
* [sic] reference alone listing no less than 178 other references."
* [That would be Willard Fisher's 1921 review.]
*      "The phenomenon of the BLUE (or GREEN) FLASH is spectacular, famous,
* mysterious, controversial and, therefore, altogether the most interesting
* of the minor solar spectacles that Naval personnel have opportunities
* to see."
*      NOTE: Nolan M. Kindell was Naval Aviator Number 370 in WWI, according to
*
* http://www.navalaviationmuseum.org/ExhibitsAndCollections/Exhibits/Exhibits-Frontiers/WorldWarI/Views-of-World-War-I-Exhibit-(1).aspx
*
* He was Captain Kindell when in command of the Independence , retiring
* as a Rear Admiral in 1948.
* May issue


Read Admiral H. H. Jalbert
“The blue flash,”
Proc. U. S. Naval Institute 78, 795 (1952).

* Followup to the previous item: another Rear Admiral mentions CALM AIR
*      "The meteorological phenomenon of the blue flash  is a fairly
* commonplace occurrence in the Mediterranean particularly in the summer
* months. It was observed quite frequently by this writer during the
* three years he served in Algeria and Tunisia. There, it is known as
* le rayon vert -- the green ray or beam -- and has engendered the
* superstition that it brings good luck to anyone who sights it. . . .."
*      ". . .  It is presumed that that clear, transparent hue is produced
* by the blending of the pure-yellow rays from the setting sun with
* the refracted or reflected blue coloration of the surface of the
* Mediterranean. [!]
*      "The factors which seem to govern the possibility of observing
* the flash are (1), extremely dry atmospheric conditions which are
* usually prevalent from May through September in that locality; (2), a
* cloudless horizon which is generally a corollary of and is present under
* factor (1) at that season of the year; and (3) a practically dead calm.
* Given those three conditions, le rayon vert can almost invariably be
* observed provided the observer maintains a superlatively alert watch
* focused on the sun's upper rim as it dips below the horizon. A flat
* calm is the one factor that is most likely to be unavailable. . . ."
* (He then gives a clumsy description of the sea breeze.)
* July issue


M. Forster and H. Dormer
“Green flash, North Atlantic Ocean,”
Marine Obs. 22, 127–128 (1952).

* peculiar sunrise flash report; probably just the inf.-mir.flash
* "A brilliant green flash, lasting for some two seconds, was observed at
* sunrise. In contrast to the green tinting of the sun's upper limb which
* is frequently observed, on this occasion it was completely obscured by a
* vivid green light, distinctly round in shape, as if from a green-shaded
* searchlight. The wind was SE force 3 and the sea was slight. . . . Air
* temperature 52 F, sea 53."


N. D. Selwood
“Green flash, Pacific equatorial waters,”
Marine Obs. 22, 198 (1952).

* Possible Wegener's bar? Double flash at sunset
* CUMULUS CLOUD-TOP GF and another cloud-top BLUE flash (with binoculars)
* Useful editorial comment: ". . . there is a somewhat better chance of
* seeing the flash as blue or even violet, because at a little distance
* above the horizon some light of these very short wavelengths may be
* transmitted . . . .      The writer of this note has similarly seen the blue
* flash at a cloud edge."


J. K. Wyles
“Green flash, off Freemantle,”
Marine Observer 23, 12 (1953).

* BLUE CORNERS and sunset distortions
* DRAWINGS show MM layers above a square Sun, and a very flattened disk
* "1 minute before sunset".


P. Harrison
“Green flash, South Pacific Ocean,”
Marine Observer 23, 80 (1953).

* 2 GFs reported with no useful data
* "a brilliant green flash . . . duration 1 1/2 sec" 2 days in a row.


B. J. Pratt
“Green and red flashes, North Atlantic Ocean,”
Marine Observer 23, 144–145 (1953).

* GREEN and RED FLASHES


W. L. Montgomery
“The (Blue or Green) Flashes,”
Proc. U. S. Naval Institute 79, 902–903 (1953).

* A Chief Gunner proves no match for a couple of Rear Admirals (above)
* ". . . this writer has had many opportunities to observe the setting
* sun off the coast of California and on numerous occasions has seen the
* `Blue Flash.' Some flashes were very dim; others relatively bright.
*      ". . .  I would like to set forth a simple and obvious theory of my own.
* This theory might have been raised in one or more of the various articles
* and references on this subject, but has not to my knowledge. The flash
* is an optical illusion." [Has R. Cann Lippincott been resurrected???]
* ". . . the brightness of the sun compared to its surroundings and the fact
* that observers are staring at it as it disappears causes a complementary
* image to appear briefly at the point the sun has vacated."
*      What can one say in response this ignorance, refuted many years before
* by Rudaux's photography? Why did the Proceedings publish something so
* obviously uninformed?
*      "Naturally, my theory would be invalid for a flash someone has
* captured on film but I believe it will account for the vast majority of
* `Blue (or Green) Flashes.'"
* August issue


I. I. Putilin
“Nablyudeniya zelenogo lucha v 1950-1951 gg.,”
Byull. Vsesoyuz. Astron.-geod. Obshchestva , No. 12, 26–32 (1953).

* PUTILIN's detailed observations (see his note in Astr.Tsirk.#118,1951)
* complete with numerous DRAWINGS indicating progress and coloring.
* This is written in the wordy and repetitive Soviet style, so it's
* tedious reading. However, the details of the observations are worth the
* effort. The 4 classes are described a little more than in the A.C.
* version. There was also an attempt on 13 Aug. to keep the left eye closed
* until the Sun was half set, so as to look for physiological effects;
* however, this failed, and the appearance was identical to the two eyes.
* Putilin draws a careful distinction between sunsets in which the "segment"
* touches the horizon, and those in which it is raised (a real inferior
* mirage). The former examples plainly show that a GF can be produced when
* the gradient at the horizon surface is insufficient to produce image
* inversion (either because of small temperature difference or because the
* waves truncate the lower part of the surface layer). In every case the
* green grows in from the ends, so the gradient at the surface is plainly
* visible, even if an inferior mirage is not produced.
* One can certainly agree that "From everything described above we may draw
* the conclusion that the green flash is a more complex and interesting
* phenomenon than is usually thought."
* O'C #264


Ye. Ya. Bugoslavskaya
“Tri nablyudeniya zelenogo lucha [Three observations of the green flash],”
Byull. Vsesoyuz. Astron.-geod. Obshchestva , No. 12, 32–34 (1953).

* A novice asks the "Interesting question: from what height above sea
* level is the Green Ray best seen?"
* 2 well-described inferior-mirage flashes from 8 m height, and a
* mock-mirage sunset with flash.
* O'C #184


N. A. Møller Nicolaisen
“Solens grønne Glimt,”
Nordisk Astronomisk Tidsskrift 35, 117–118 (1953).

* useless; first-time observer. Volume number not certain.
* O'C #254


J. W. Ross and W. W. Ross
“Green flash, Mouth of English Channel,”
Marine Obs. 24, 80 (1954).

* "A prolonged green flash of about 2 seconds"


L. V. Antonov
“Zelenii luch,”
Izv. Vsesoyuz. Geograf. Obshchestva 86, 102–104 (1954).

* Probably THE BEST article on GREEN RAY displays
* Here's an author who seems to take the term "green ray" literally!
* He appears to be a sailor who made a hobby of collecting green flashes
* -- or rather, green rays. The whole article deserves to be translated;
* but here are a few samples:
* "From 1895 to 1948 I sometimes succeeded in observing the green ray just
* after sunset. . . . sometimes from shore, sometimes from ship, and always
* with the naked eye.
*      "Not once did I succeed in seeing the green ray before sunrise.
*      "In the tropics the green ray after sunset sometimes was seen as a
* bundle of rays, sometimes only 3 -- 5 rays; it appeared instantly after
* sunset, lasted 0.3 -- 0.4 sec. in a vertical position, then instantly the
* top turned over to the right (in the Northern Hemisphere), so that the base
* of the bundle remained stationary, and the phenomenon vanished; the general
* duration is not more than 0.5 sec. In the Southern Hemisphere the green
* ray turned over to the left. . . . The height of the green ray or rays was
* generally not greater than the diameter of the setting Sun; the color of
* the ray is pale whitish green. The green ray, falling from its vertical
* position to the right or to the left, went out, not reaching 20 -- 30
* degrees of the horizon.
*      "The green ray at temperate latitudes is almost the same at in the
* tropics, but somewhat deeper --- without whiteness; it rose in the form of
* a single ray, as if instantly blazing forth from the point of sunset,
* remained vertical 0.5 -- 0.7 sec., then fell over to the right or left
* (according to the hemisphere) and disappeared, also without reaching
* 20 -- 30 degrees of the horizontal; the width of the ray is almost
* identical from bottom to top, but the top always was more pointed; the
* height of the ray was typically the diameter of the Sun; the whole
* phenomenon lasted 1.0 -- 1.5 sec."
* (Details are given of a few of the observations.)
* "According to the color and shape of the Sun itself shortly before it
* sets, it is possible to foresee in advance whether there will or will not
* be a green ray."
* "The green ray appeared only when clear calm weather set in . . . .
* Usually 1 -- 2 days passed before the appearance of the green ray and
* as many again after it was gone, calm, clear weather. The very
* appearance of the green ray also was a forecast of good weather."
* [This is the 3rd such statement: cf. Trève (1885), "Another Engineer
* Officer" (1904), and also Wegener (1926).]
* He also claims the best time of year to see this thing is around the
* autumnal equinox, and the best month is September (in the Northern
* Hemisphere).
* There is also a claim that almost all observations were in years of
* sunspot maximum, except for 1943.
* (Based on records kept for 54 green rays, with at least another 50 not
* recorded.)
* [in the Jan/Feb. issue (no.1), 1954]
* O'C #167


UNESCO
[unknown Antwerp newspaper] , (11 March, 1954).

* A 1954 newspaper clipping in Dutch found by R. H. van Gent in a copy of
* Flammarion's "l'Atmosphère":
* This appears to have been an Antwerp paper, to judge by the frequent
* references to Antwerp on the back side. It's a generally accurate
* account, and seems to be from a question-and-answer column. The main
* objection to this version would be the attempt to explain the loss of
* blue and violet by water-vapor absorption, which supposedly would
* explain why the GF is seen best at sea. But "It was photographed -- for
* the first time, we think -- by the French astronomer L. Rudaux. Seen
* with a strongly magnifying telescope -- e.g., 100 times -- one sees the
* ray spread out as if in a spectrum." (Evidently this refers to the
* green rim.) There is also the usual erroneous statement about "the
* American explorer Byrd, and the people of his expedition," who "could
* see the phenomenon in the Antarctic lasting 35 minutes."
* Curiously, it's signed: UNESCO.


W. Weigel
“Luftspiegelung der untergehenden Sonne und Grüner Strahl, beobachtet auf dem Brocken am 2. Januar 1954,”
Zeitschr. f. Meteorologie 8, 126–127 (1954).

* CLASSICAL WEGENERIAN BLANK STRIP + GF
* Gets a flash at the "lid" of the soup terrine, then a second one after
* the hourglass stage.
* "Offensichtlich hatten die parallelen oberen und unteren
* Begrenzungslinien der Erscheinung immer gleichen Abstand."
* Good description of Mock Mirage flashes.
* Thinks the intensity increases when it turns green (cf. Jacobsen):
* "Bemerkenswert ist die sprunghaft zunehmende Leuchtkraft."
* Terminology: "An sich ist die Bezeichnung Grüner `Strahl' sprachlich
* inkorrekt, ja geradezu irreführend. .. Ich konnte aber bisher stets nur
* ein Aufblinken feststellen, so daß ich die Bezeichnung `Grüner Blink'
* für richtiger halte. Leider ist diese Bezeichnung `Blink' gerade in der
* Meteorologie durch den sprachlich ebenso irreführenden Begriff `Eisblink'
* korrumpiert, so daß derjenige, der den Eisblink kennt, unter einem
* Grünen Blink wieder etwas anderes erwarten könnte."


W. Groubé
“Optique atmosphérique: Le rayon bleu,”
BSAF 68, 140 (1954).

* BLUE FLASH at SUNRISE over Atlas Mountains


P. P. O. Harrison
“Abnormal refraction, New Zealand waters,”
Marine Obs. 24, 141 (1954).

* "At sunrise an instantaneous bluey-white flash occurred, followed by a
* deep red." The really interesting part is that the Sun became RED ABOVE
* and YELLOW BELOW -- see the DRAWINGS of interesting distortions.
* Note that the change in the lower part from red to yellow as the Sun
* rose is evidence for ADAPTATION.
* [This probably should be filed with the "distorted Sun" file.]


J. W. S. Dunn
“Green flash, North Atlantic Ocean,”
Marine Obs. 24, 144 (1954).

* Several brief observations from Marine Obs. follow (all on same sheet):
*
* "A cobalt-blue flash . . . about 4 sec."


E. R. Jenkins
“Green flash, Indian Ocean,”
Marine Obs. 24, 144 (1954).

* "A brilliant blue and green flash . . . lasting 2 to 2 1/2 sec."


P. P. O. Harrison, T. Bennett, and B. Smith
“Green flash, Pacific Ocean,”
Marine Obs. 24, 144 (1954).

* ". . . a brilliant green flash which turned to cobalt blue at the last
* instant. The whole phenomenon lasted for 3 1/2 sec (timed)."


P. P. O. Harrison
“Green flash, New Zealand Waters,”
Marine Obs. 24, 144 (1954).

* SUNRISE FLASH


B. N. Kasmer
“Green flash, Sea of Japan,”
Marine Obs. 24, 144–145 (1954).

* "At sunset, as the upper limb of the sun dipped behind a band of Sc, it
* turned from orange to whitish-yellow . . . , then flashed a bluish-purple or
* violet colour. Air temp. 72.3 F, . . . , sea 73.4."


L. Hamer
“Green flash, Gulf of St. Lawrence,”
Marine Obs. 24, 211 (1954).

* GREENISH-PURPLE ???
* "At sunset a greenish-purple flash was observed" (!)
* Probably the observer means green and changing to violet, perhaps with
* both colors visible together?


F. B. Stewart
“Green flash, South Atlantic Ocean,”
Marine Obs. 24, 211–212 (1954).

* ASYMMETRICAL FLASH (cf. ATY photo of 30 March 1998)
* "The flash started at the left-hand side and moved rapidly along the
* segment which, at the beginning was about 2 1/2' deep."


R. B. Oliver and E. F. Boyd
“Green flash, Gulf of Aden,”
Marine Obs. 24, 212 (1954).

* Crepuscular rays after GF


P. Moore
“Green flash, Gulf of Aden,”
Marine Obs. 24, 212 (1954).

* COBALT BLUE flash
* "no abnormal distortion was apparent", and air = water temp.


H. V. Todd and R. L. Collins
“Green flash, Gulf of Aden,”
Marine Obs. 24, 212 (1954).

* SUNRISE flash, PURPLE --> GREEN


W. Groubé
“Deux observations d'un rayon bleu,”
Comptes Rend. Séances Mensuelles Soc. Sci. Nat. Phys. Maroc 20, 205 (1954).

* 2 BLUE FLASHES over MOUNTAINS at SUNRISE


A. Boudoint
“Optique atmosphérique,”
BSAF 69, 12 (1955).

* useless


W. E. Richardson
“Optical effect at Alston,”
Weather 10, 29 (1955).

* NO GF, but useful sunset CONTRAST EFFECTS
* ". . . this same continuous cloud sheet glowed a coppery-red . . . .
* . . . the fading greens of the trees and meadows had been transformed to a
* brilliance which might be described as `fluorescent'. So brilliant were
* these greens that I developed a headache from the strain of observing."


J. Franz
“Beobachtung des Grünen Strahls,”
Nachrichtenblatt der Astronomischen Zentralstelle 9, 32 (1955).

* GF in TREES on distant hill
* "Die Sonne ging hinter einem 15 km entfernten bewaldeten Berge . . . unter
* und war dabei hell orange gefärbt."


J. W. Spiers
“Green flash and rays, Indian Ocean,”
Marine Obs. 25, 37–38 (1955).

* NOT "Green Ray" display; the "rays" here seem to be crepuscular, seen
* green only by contrast. The Editor correctly notes this, citing
* M.O.24,213.
* Note: the "Green Sun and Moon" reports immediately before this are NOT GFs
* This is a trivial and non-useful observation.


W. H. Forthman
“The green flash,”
Navigation 4, 212–214 (1955).

* Navigation = Journal of the Institute of Navigation (at UCLA, apparently)
* Entirely derived from Aitken's ASP Leaflet, Fisher in PA, and Groff,
* with some errors introduced (e.g., calls Danjon "Donjon".)
* N.B.: There are two things called "Journal of the Institute of
* Navigation." One (called "Journal of Navigation" since vol.25, 1972) is
* published in London by the Royal Institute of Navigation. The other
* (now called simply "Navigation") was published in Los Angeles at UCLA and
* was produced in Washington, DC from 1960 to 1992. Yet another "Navigation"
* is published in Paris!
* This is the LOS ANGELES version.


A. W. Finch and B. Anstey
“Green flash, South Pacific Ocean,”
Marine Obs. 25, 104 (1955).

* NAKED-EYE VENUS GF that "lasted for several seconds"
* Editor notes a similar observation: M.O.23,202(1953)
* also Jupiter GF


K. W. Mayhew
“Green flash, North Atlantic Ocean,”
Marine Obs. 25, 153 (1955).

* Possible GREEN RAY?
* "Viewed through glasses (7x) the flash could be seen for 7 to 8 sec,
* rising to several minutes of altitude, where there was a thin line of fair
* weather Cu."


J. D. Sandry
“Green flash, North Atlantic Ocean,”
Marine Obs. 25, 153 (1955).

* VENUS BLUE FLASH


A. Maclean
“Green flash, Eastern Pacific Ocean,”
Marine Obs. 25, 153–154 (1955).

* VENUS green flash
* What the Editor calls "twilight due to the planet" is its aureole.


P. P. O. Harrison
“Green flash, Red Sea,”
Marine Obs. 25, 216 (1955).

* TIMED GF: "a jade green flash of 2 1/2 sec (timed)."
* The "ball of pale green, perhaps half the diameter of the sun," that
* "pulsated for at least 5 sec" after sunset was probably an afterimage?
* UNSATISFACTORY, for lack of details.


R. Cox
“Lunar green flash, Japanese waters,”
Marine Obs. 25, 216–217 (1955).

* LUNAR GF with binoculars
* Ed. notes that Moon's age was only 6.3 days.


P. P. O. Harrison and S. Lambrick
“Red flash before sunset, Indian Ocean,”
Marine Obs. 25, 217 (1955).

* Classical RED FLASH below cloud
* Ed. notes the only similar report in M.O. 23, 144. July 1953


D. J. Lovell
“Photograph of the green segment,”
JOSA 45, 490 (1955).

* useless: "a photograph has been made" is the only substantive content.
* Of minor historical interest in that it precedes O'Connell's book.


G. C. Varley
“Seeing is believing,”
Weather 10, 355–356 (1955).

* "The evidence was clear that it was a morning of unusual refractive
* properties, as radar signal-echoes were being received from far beyond
* horizon-range. Downward refraction of centimetric waves is known to be
* due to low-level temperature inversion. . . ."


W. Weigel
“Luftspiegelungen und grüner Strahl, auf dem Brocken beobachtet,”
Zs. f. Met. 9, 158 (1955).

* MOCK MIRAGES with SUNRISE green flash (described; no figures)
* "Am 19. März 1955 ging die Sonne in einer Dunstschicht auf, die oben
* scharf begrenzt war. Beim Durchgang durch diese Schicht zeigte die Sonne
* die typischen scharfen Einschnürungen und abgerundeten Ausbuchtungen. . . .
* "Als die Sonne noch etwa zwei Sonnendurchmesser unterhalb der
* Dunstobergrenze stand, erschien auf dieser Obergrenze ein grünes
* `punktförmiges' Licht, das sich seitlich rasch ausbreitete."
* Remarkable for the large separation!
* Werner Weigel, Brocken


G. Dietze
“Die Sichtbarkeit des ``grünen Strahls'',”
Zeitschr. f. Meteorologie 9, 169–178 (1955).

* superb calculation of CHROMATICITY for 3 different AEROSOL amounts
* considers BACKGROUND CONTRAST and LIMB DARKENING
* but ignores molecular absorptions, and scales aerosol to Rayleigh
* airmass


A. J. Lawrie
“Green flash, East Pacific Ocean,”
Marine Obs. 26, 15 (1956).

* GF + crepuscular ray (unrelated)
* Editor says that "some form of green sky coloration" of this sort has
* been "classed as varieties of the green flash at sunset"; which is
* improper (even though they have actually done this; so beware!)


P. P. O. Harrison, S. Lambrick, and R. Pook
“Red flash at sunset,”
Marine Obs. 26, 15–16 (1956).

* CLASSICAL Inf.-mir. RED FLASH below cloud
* ". . . a piercing brilliant red flash . . . ."


P. W. G. Everett
“Red flash at moonrise,”
Marine Obs. 26, 16 (1956).

* CLASSICAL Inf.-mir. RED FLASH of Moon
* ". . . a bright crimson flash, conical . . . as the lower limb parted from
* the small image left at the horizon."


F. F. Cheshko and N. Sh. Tavadze
“Zelenii luch nad Sushei,”
Priroda 45, no. 4, 113 (April, 1956).

* Indexed as GF but just a green CREPUSCULAR ray
* Seen in hilly country; lasted 6 minutes
* Note that the first author is given as "Chishko" in the responses (below)


A. M. A. Majendie
“Green flash (letter to the editor),”
Weather 11, 372 (1956).

* Majendie's AIRPLANE FLASH at 22,000 ft. -- White Ray?


H. O. L'Estrange, R. M. Frederick, and I. R. Norrington
“Green flash, Eastern North Atlantic Ocean,”
Marine Obs. 26, 206 (1956).

* Inf.-mir. mirages of Sun and Venus; not useful


J. S. Fitzwalter
“Green flash, Arabian Sea,”
Marine Obs. 26, 206 (1956).

* Inf.-mir. mirage of Venus
* Some possibly interesting remarks about brightness changes


G. Ramage and R. B. Douglas
“Green flash, Red Sea,”
Marine Obs. 26, 206 (1956).

* double flashes on mountain peaks, and in valley between


A. C. Myhill
“Green flash, Gulf of Aden,”
Marine Obs. 26, 207 (1956).

* Crepuscular ray, not GF -- ignore.


J. F. Newton
“Green flash, North Pacific Ocean,”
Marine Obs. 26, 207 (1956).

* An odd description leading up to a GF. No useful data.
* ". . . an intermittent light green mist of varying intensity appeared to
* drift fairly rapidly across the sun's surface . . . ." [retinal bleaching?]


J. Marks
“Green flash, North Pacific Ocean,”
Marine Obs. 26, 207 (1956).

* GREEN RAY? Useful details are lacking: ". . . lasted for about 1 1/2 sec.
* It extended over an arc of some 5° and had an altitude of about 7°."


P. Kirkpatrick
“The green flash,”
Am. J. Phys. 24, 532–533 (1956).

* "Rayleigh to the contrary notwithstanding, light cloudiness and
* stratified inhomogeneity of the western atmosphere do not invariably spoil
* the effect. I have repeatedly seen it when the sun's disk was grotesquely
* distorted and even striated."
* "I think it is likely that observable green flashes over land horizons are
* more frequent at sunrise than at sunset, since the morning terrain is the
* nearer to thermal equilibrium with its adjacent atmosphere."


(letters from A. A. Mikhailov, I. Gal'perin, A. V. Klupnikov, and A. Kh. Khrgian)
“O zelenom luche,”
Priroda 46, no. 1, 127–128 (Jan., 1957).

* Responses to the crepuscular-ray observation of Chishko [sic] & Tabadze


P. P. O. Harrison and D. Moran
“Red and green flashes at sunset, North Atlantic Ocean,”
Marine Observer 27, 14–15 (1957).

* RED and GREEN FLASHES
* Ed.: "We now have four observations of the red flash. . . ."
* Again the editor cites M.O.23,144(1953).


W. M. Wheatley
“Green flash, South Atlantic Ocean,”
Marine Observer 27, 15 (1957).

* BLUE FLASH


R. E. Baker
“Green flash, Red Sea,”
Marine Observer 27, 15 (1957).

* GREEN Inferior FLASH with elongated SUNSPOTS
* "The green flash was seen all the time the upper half of the sun was
* disappearing, approximately 30 sec; not only the detached pieces appeared
* green but the edges of the main body as well."


W. P. Crone
“Green flash, North Pacific Ocean,”
Marine Observer 27, 15 (1957).

* VENUS FLASH


D. J. Lovell
“Green flash at sunset,”
Am. J. Phys. 25, 206 (1957).

* Lovell refers to his movie of a GF (JOSA, 1955)


J. W. Ellis
“Green flash from a looming setting sun,”
Am. J. Phys. 25, 387 (1957).

* Clearly a SUB-DUCT green flash!
* Sounds very like the flash of Wegener's Nachspiegelung .
* ". . . I arrived at the palisades overlooking the Pacific Ocean at Santa
* Monica, California, during sunset and was amazed to see two images of the
* sun, one directly above the other. The sun had already half set, so the
* images appeared as half disks. The upper image appeared appreciably
* larger than the lower one and seemed to rest upon a clear-cut stratum of
* cloud which was separated from the well-defined ocean horizon by a narrow
* band of clear sky. . . . The upper image diminished and soon disappeared,
* leaving only the lower partial disk. . . . As this remaining image decreased
* in area it gradually ascended and seemed to disappear into the lower
* surface of the cloud stratum above. As the final strip of this image was
* disappearing upward into the cloud, it turned brilliantly green and
* remained so for a few seconds."


H. C. Gorton
“Method to facilitate observation of the green flash,”
Am. J. Phys. 25, 586 (1957).

* PROJECTION recommended
* (Nov. issue, but filed here to keep AJP items together)


P. P. O. Harrison
“Red and green flashes, North Atlantic Ocean,”
Marine Observer 27, 85 (1957).

* RED and GREEN FLASHES with "considerable mirage effect" at horizon
* P.P.O.Harrison again!


A. N. Howie
“Green flash, Tasman Sea,”
Marine Observer 27, 85–86 (1957).

* SUNRISE BLUE --> GREEN flash
* ". . . a very brilliant deep blue flash followed by a brilliant green one.
* The combined flash lasted for 1 1/2 - 2 sec."


G. Snow
“Green flash (letter to the editor),”
Weather 12, 199 (1957).

* TYPICAL NOVICE REMARK
* "As one who has twice seen the Green Flash, at sunset in the open sea,
* I was surprised to read that Mr. Majendie saw the flash while a
* considerable portion of the sun's disc was visible."


E. W. Barlow
“Green flash (letter to the editor),”
Weather 12, 199 (1957).

* "MOST DIVERSIFIED"
* ". . . it exhibits many different forms and is probably one of the most
* diversified of optical phenomena."


P. S. Cousins
“Green flash (letter to the editor),”
Weather 12, 199–200 (1957).

* GREEN RAY
* "When about three-quarters submerged, the red quite suddenly changed to
* bright green and a beautiful green aura spread outwards like a fan.
* Almost before I realized what I was seeing, the fan collapsed, the green
* arc of the sun disappeared and only a red glow remained. Total time,
* possibly 7 or 8 seconds."


G. A. Bull
“Green flash (letter to the editor),”
Weather 12, 266 (1957).

* METEOROLOGICAL DATA showing INVERSION for Majendie's observation


A. L. Franklin
“Green flash (letter to the editor),”
Weather 12, 265–266 (1957).

* ADAPTATION!
* ". . . the large cream building to the east was so brilliantly illuminated
* with green, that my son whom I called to see it remarked that he hadn't
* noticed the workmen were using green paint!"


W. F. Dan and A. E. Robinson
“Green flash, South Pacific Ocean,”
Marine Observer 28, 15 (1958).

* Good DRAWINGS of typical "segment" growing green from ends inward


P. P. O. Harrison
“Red flash, South Pacific Ocean,”
Marine Observer 28, 15 (1958).

* Another classical cloud-base RED FLASH, at sunrise, by P.P.O.Harrison


F. Pearson
“Lunar green flash, Eastern Pacific Ocean,”
Marine Observer 28, 16 (1958).

* Naked-eye Moonset GF, "bright enough to be seen without binoculars."


G. A. Bull
“Green flash at sunset,”
New Scientist 3, No. 72, 37 (3 April, 1958).

* G. A. Bull cites Dietze, Rayleigh, and Minnaert
* in response to 20 March letter from A. R. C. Engels


R. L. Reid and A. Temperly
“Abnormal refraction, South Pacific Ocean,”
Marine Observer 28, 76 (1958).

* GREEN in setting JUPITER


E. Norman
“Green flash, South Pacific Ocean,”
Marine Observer 28, 76–77 (1958).

* GREEN -> BLUE -> VIOLET FLASH


D. Moran and J. Rice
“Green flash, North Atlantic Ocean,”
Marine Observer 28, 77 (1958).

* Sunrise GF


J. A. Cotton
“Green flash, North Atlantic Ocean,”
Marine Observer 28, 77 (1958).

* GREEN RAY?
* ". . . a slight green arc of about 4° span and 3° altitude was seen."


P. P. O. Harrison, P. Bower, and L. Money
“Green and red flashes, South Pacific Ocean,”
Marine Observer 28, 77 (1958).

* Sunrise GF and classical RF "lasting fully 3 sec" below cloud


M. G. Highley
“Green flash at setting of Venus, Bay of Biscay,”
Marine Observer 28, 77 (1958).

* VENUS GF and counter-image


P. G. Morris
“Green flash, North Atlantic Ocean,”
Marine Observer 28, 135 (1958).

* Sunrise GF, "observed through the ship's telescope"
* ". . . a small mushroom-shaped patch, emerald green in colour, appeared on
* the highest point of the green rim. The patch then became detached from
* the limb, rising a little, but remained visible for about 10 sec."
* Ed. says there were "coloured sketches sent."


C. M. Botley
“The Green Flash,”
Weather 13, 175 (1958).

* Botley refers to Simons


J. C. Vint
“Setting of the planet Venus, Indian Ocean,”
Marine Observer 28, 194 (1958).

* VENUS GF, observed with binoculars


H. Michel
“Le rayon vert,”
Ciel et Terre 74, 370 (1958).

* compared to Biemans (1952) in C&T, but over mountains instead of sea.


R. W. Ditchburn
“The "Green Flash" at sunrise or sunset,”
New Scientist 5, No. 113, 118–120 (15 January, 1959).

* DITCHBURN's GF article in New Scientist
* The green rim "may be seen conveniently through a telescope with a
* magnification of about 20. . . . If a dark filter is used while following
* the Sun before sunset, it should be of good optical glass. Many plastic
* filters or dark glasses do not absorb sufficiently in the infra-red and
* continuous observation of the Sun through them is dangerous.
*      "On some days the colour is more vivid and the last segment  of the
* Sun above the horizon looks green at the extremities. The colour may
* move in towards the centre as the Sun disappears. This green segment may
* be seen by the naked eye or with hand-held glasses and may last five
* seconds. It is almost certainly due to `mirage effects' . . . .
*      "But under certain conditions, which are fairly rare in Western
* Europe, the green segment becomes detached from the rim of the setting
* Sun . . . and remains as a vivid green `flash' after the Sun's disc has
* disappeared beneath the horizon." [Here he reproduces O'Connell's
* incorrect diagram of the mock-mirage flash.]
*      He also garbles Minnaert's account of prolonging the flash to many
* seconds "by running along [sic] a dyke." Misunderstanding the effect of
* height, he then supposes that "He must have been assisted by special
* conditions at the horizon because the necessary speed . . . with a flat
* road and horizon is about 600 m.p.h."
*      "The true green flash is somewhat capricious in its appearance both
* over sea and over land, as would be expected if it is essentially a
* mirage effect." He mentions (but does not cite) R. W. Wood's
* observation in this connection. But, seemingly unaware of the
* importance of extinction, he is surprised that it was not seen by the
* Novaya Zemlya observer. So, a mixed bag.
*      Thanks to Ken Stone (of the Times of San Diego) for finding this!
* Their "free news website" cites this at
* http://timesofsandiego.com/life/2017/01/16/rare-green-flash-at-sunset-dazzles-san-diegans/
*


T. J. Cain
H.M.S. Electra
(Frederick Muller, London, 1959), p. 156.

* This is the book mis-cited by Mrs. Bond in 1975
* ". . . legend has it that at sunset a great flash of green light spreads
* across the horizon. . . . as the sun went down, the triumphant shout of the
* believers, all of who swore they'd seen the flash . . . was followed by a
* derisive jeer from the infidels who said they hadn't."
* Note: "Eastwards to Singapore" is the chapter title


E. Bradford
The Mighty Hood
(World Publishing, Cleveland and New York, 1959), p. 140.

* Another book about a ship, with a casual GF mention
* This is about the British warship Hood , sunk by the Bismark.
* Ernle Bradford seems confused about color, as well as about the GF:
*      "If the horizon was quite clear and the sea unruffled the old hands
* would say:
*      `Now you'll see it!  Watch for the green flash.'
*      Just as the sun's rim dipped, if you watched carefully enough, there
* was a brilliant green flash -- or so they said. Was there really a
* flash, at that moment when the yellow disk fused with the blue sea?
* Or was it merely an optical illusion, caused by straining one's eyes
* into the flaming path of the sun?"
* (also: Hodder and Stoughton, London,1959)


L. Poncelet
“A propos du rayon vert,”
Ciel et Terre 75, 25–27 (1959).

* Lucien Poncelet first quotes from 2 letters from Ch.Biemans; then
* briefly mentions O'Connell's recent book.
* "La structure thermique verticale de l'atmosphère joue, semble-t-il,
* un rôle important dans l'intensité du phénomène, par l'action
* réfléchissante de couches d'air de propriétés optiques différentes,
* et dont la surface de séparation est quasi horizontale (inversions).
* Il y a souvent des réflexions apparentées aux phénomènes de mirage.
* Parfois un petit déplacement vertical de l'observateur lui fait perdre
* la vision du rayon vert."
* After noting that blue flashes are most common in highs with northerly
* winds, he says:
* "C'est d'ailleurs assez logique so l'on tient compte de ce que
* l'anticyclone est, en principe, un lieu où l'air subsident en altitude
* est relativement sec et pur, ce qui diminue la diffraction de longueurs
* d'ondes bleus, due en partie à la vapeur d'eau et aux aérosols."
* If we leave out "diffraction by water vapor", this seems to be the
* FIRST decent EXPLANATION of BLUE FLASHES.


S. W. Visser
“Belangrijke waarnemingen van de groene straal,”
Hemel en Dampkring 57, 57–59 (1959).

* VISSER's review of O'Connell's book, ILLUSTRATED with spare copies of
* O'Connell's frontispiece (facing p.57).
* Technically, this should go in the "reviews of O'Connell's book" file;
* but as Visser is one of the few reviewers to know something about green
* flashes himself, I put it here.
* "It is an extraordinarily difficult task to photograph the green flash
* in a scientifically accountable way in all its capriciousness, its
* variations in shape, color, and brightness. What Treusch, of the
* Vatican Observatory, has achieved, with experience and patience, is certain
* not to be surpassed." [But Treusch's photographs fail to show all the
* GF phenomena, because he worked at 450 m above the sea!]
*
* "My impressions, summing up: The green light phenomenon is certainly not
* limited to the moment when the upper limb of the Sun and the Earth's edge
* come into conjunction. It includes more than just the light ``ray'' that
* the naked eye supposes it sees. Long before this supreme moment, the
* green itself develops at the extremely small edges on the upper side of
* the Sun, and then can extend more and more, up to the fantastic forms of
* which the photos give many impressive examples. But there never develops
* an actual green ray of light." [A footnote says: "Father O'Connell
* would certainly never agree with the communication in the international
* cloud-atlas (World Meteorological Organization, 1956, Vol. I, p. 75):
* ``Flashes up to an altitude of several degrees have sometimes been
* observed.'' Well, this is O'Connell's loss for having not seen what is
* visible near sea-level.]
*
* And: ". . . deformations of the Sun (notchings of the limb, the obscured
* strip), which must be ascribed to diverse discontinuous temperature layers
* of small vertical extent. The radiosonde measurements, which return the
* details of the atmosphere only in a very coarse way, probably cannot
* contribute to the explanation of these."


G. S. Schwarz
“The green ray,”
Science 130, 276 (1959).

* Gerhart S. Schwarz's response to Smiley's review of O'Connell
* (placed here slightly out of order to be next to Visser's review, above)
* "Scottish belief has it . . . " once again.
* "The green ray can be seen only when one views the horizon from an
* elevation, and this -- plus factors of latitude, season, and weather --
* probably explains why few sea captains are familiar with it."
* (see the replies to this by Palmer and Smiley, in the Oct. 23 issue.)
* (31 July 1959)


A. L. R. McNeil
“Green flash at moonset, South Pacific Ocean,”
Marine Observer 29, 15 (1959).

* Editor notes that a lunar GF near 1st quarter is unusual.


I. K. Grindrod
“Double green flash, North Atlantic Ocean,”
Marine Observer 29, 57 (1959).

* Double sunset due to "Very heavy SW'ly swell."


S. Foulkes and J. B. Kirkham
“Double green flash, North Atlantic Ocean,”
Marine Observer 29, 58 (1959).

* Cloud flash, then horizon. No useful info.


R. E. Ekman
“Recommended navigational aid,”
Proc. U. S. Naval Institute 85, 101–102 (May, 1959).

* GF in NAVIGATION:
* Lieutenant Roger E. Ekman's dangerous suggestion; cf. Cotter (1968).
* "One additional line of position . . . that has often assisted me with
* very good accuracy, is an observation of the exact time of sunset and
* solution of a time sight."
*      "If the navigator uses a good pair of 7× 50 binoculars and
* observes the last segment of the upper limb of the setting sun, a bright
* bluish-green flash may be seen. This phenomenon lasts about two seconds.
* By marking the time and solving the navigational problem for an altitude
* of 00° 00.'0, he may obtain the intercept. By coupling this intercept
* with the azimuth (amplitude) previously determined, he has a reliable
* line of position. This method may also be used at sunrise; however,
* the bluish-green flash from the upper limb is not as pronounced at this
* time. In using this means of gaining an additional line of position,
* the navigator does not have to consider such correction factors as height
* of eye, refraction, or parallax." The last sentence is simply incredible!
*      Note that each issue is now paged separately; the month is vital!


R. C. Riseley and D. M. Wright
“Abnormal refraction, Straits of Gibraltar,”
Marine Observer 29, 113–114 (1959).

* DRAWINGS of DISTORTED SUN before GF:


J. Land
“Green flash, Mozambique Channel,”
Marine Observer 29, 118 (1959).

* DRAWINGS of SUN with green moving in from ends, as in Minnaert:
* Drawn as segment; but temps. fit Inf.-mir. better. (air: 70; sea: 74)


J. Ponsen
“Een waarneming van de groene `straal',”
Hemel en Dampkring 57, 245 (1959).

* curious verbal description of an "Omega" (inf.mirage) from a first-timer
* Certainly a classical example of the inf.-mir. flash;
* "It was quite cold" (though 14 June)


H. S. Palmer
“The green ray,”
Science 130, 1044 (1959).

* Replies to Schwarz's letter (31 July issue) by Harold S. Palmer . . .
* ". . . Schwarz says that the green ray can be seen only from an elevation
* but does not say how great an elevation . . . .
* . . . I have seen the green ray several dozens of times when my eyes were
* about 16 feet above sea level.
* "I have also seen the green ray from shipboard . . . .
* "Most remarkable, however, was seeing the green ray once from the
* observation platform at the rear of an eastbound train somewhere on the
* Great Plains."


C. H. Smiley
“The green ray,”
Science 130, 1044 (1959).

* . . . and Charles H. Smiley, whose review started all this.
* Schwarz's comment "is misleading". And Smiley has noticed the
* mock-mirage flash: "From an elevation, the green flash may at times
* be seen before the sun sets. On such occasion, two notches may be
* seen on the sides of the sun, and these notches coming together at the
* top of the sun result in a green flash."


D. J. K. O'Connell
“The green flash,”
Scientific American 202, 112–122, 189 (Jan., 1960).

* O'Connell's summary article in SCIENTIFIC AMERICAN
* cites Rayleigh's 1934 paper as 1 of 5 references
* This is reprinted on pp.91-97 of Lynch's book (1980).


S. Ayles
“Green flash at setting of Venus, Indian Ocean,”
Marine Observer 30, 20 (1960).

* VENUS flash
* "Air temp. 77.6 F, wet bulb 70.6, sea 80; wind SÉly, force 3;
* visibility excellent; sea slight." So, a std. Inf.-mir. flash.


B. Baggott and R. Bayliss
“Green flash at setting of Venus, South Pacific Ocean,”
Marine Observer 30, 20 (1960).

* VENUS flash


A. Mak
“De groene straal waargenomen op Fuertaventura,”
Hemel en Dampkring 58, 98 (1960).

* a useless first-time observation


J. Bain
“Blue flash, South Pacific Ocean,”
Marine Observer 30, 70 (1960).

* Description fits Inf.-mir. flash.
* "Air temp. 79 F, sea 80; wind calm."


H. H. McGibney
“Green flash, Irish Sea,”
Marine Observer 30, 130 (1960).

* NAKED-EYE SUNRISE FLASH -- ATY TYPE? (no drawing)
* Peculiar phenomena -- wish there were more details


A. Batt
“Green flash, South Pacific Ocean,”
Marine Observer 30, 130 (1960).

* Flash seen in binoculars -- ATY TYPE? (no drawing)
* seen at 52 ft. but not 40 ft.


M. Jenkins
“Blue and green flash, South Pacific Ocean,”
Marine Observer 30, 130–131 (1960).

* Flash seen in binoculars -- Drawing suggests inf.mirage type truncated
* by waves


C. Myles-Hook and R. J. Evans
“Green flash at setting of Venus,”
Marine Observer 30, 131 (1960).

* VENUS GF (belongs in Venus file but on same page as previous 3 reports)
* Nice drawing


T. Rackham
“Observations of the green flash at the Pic-du-Midi,”
J. Brit. Astr. Assoc. 70, 361–362 (1960).

* useless


B. Smith
“Green flash, North Pacific Ocean,”
Marine Observer 31, 21 (1961).

* Adaptation phenomena?
* ". . . the margin of the cloud sheet assumed a bright green tint which
* lasted from about 30 sec before the flash to approximately 90 sec.
* after it."


D. Hawkins
“Purple flash, South Pacific Ocean,”
Marine Observer 31, 21 (1961).

* VIOLET FLASH


F. A(ddey)
“The green flash,”
JBAA 71, 35 (1961).

* Addey, the director of the BAA's Sun section, comments on Rackham's note.
* [Livesey (1968) explicitly identifies him as Addey.]
* "It could be repeated as often as one wished by performing the necessary
* gymnastics."


C. L. Stong
“The Amateur Scientist,”
Scientific American 204, 177–188 (Jan., 1961).

* B/W PHOTOS by Walter A. Feibelman


H. Townsend and B. M. Norwell
“Abnormal refraction, Red Sea,”
Marine Observer 31, 67–68 (1961).

* GREEN RAY display with drawings
* ". . . the cone dissolved for about 2 sec. into a sheet of green flame
* extending 2° to 3° above the horizon."


I. Lister
“Scintillation and green flash, South Pacific Ocean,”
Marine Observer 31, 68 (1961).

* SATURN GF


J. McCaughrean
“Red flash at moonrise,”
Marine Observer 31, 68 (1961).

* RF -- maybe a MM flash


R. E. Seebold
“Green Flash,”
J. Opt. Soc. Amer. 51, 237 (1961).

* GREEN RAY observations
* Observations by Robert E. Seebold: CONTRAIL ILLUMINATION


D. J. K. O'Connell
“The green flash and kindred phenomena,”
Endeavour 20, 131–137 (1961).

* some GOOD COLOR PHOTOS
* misattributes first account to Winstanley;
* confuses inferior and superior mirages


C. de Jager
“Een avontuurlijke zons-opkomst in het hooggebergte,”
Hemel en Dampkring 59, 98–100 (1961).

* DE JAGER -- nice MOUNTAIN SHADOWS
* GF followed the mountain slope like Ricco


M. Jenkins
“Blue flashes at sunset,”
Marine Observer 31, 123 (1961).

* Double BLUE FLASH behind cumuli
* "kingfisher blue"


W. Frith, M. Brisley, J. Harrison, C. Harrison, and J. Elliot
“Green rays at sunset,”
Marine Observer 31, 123 (1961).

* Green crepuscular rays?
* "visible for just over half an hour" -- contrast effect?
* see sketch facing p.128


L. W. Fulcher
“Red flash at moonrise, South Pacific Ocean,”
Marine Observer 31, 124 (1961).

* "Moonrise was observed through the bridge telescope and a brilliant red
* flash was seen for 2 sec. as the lower limb cleared the horizon . . . ."
* "Air temp. 65 F, wet bulb 62.5, sea 66.9." [so, Inf.-mir.]


M. Jenkins and J. S. Allen
“Green flash, North Atlantic Ocean,”
Marine Observer 31, 187–188 (1961).

* 10 flashes at clouds observed through binoculars
* "In all, ten separate green flashes were thus seen, and at one stage
* with the sun half set, the whole of the visible surface, with the
* exception of the parts crossed by the narrow bands of cloud, turned a
* bright green for about 2 secs."
* ?? possibly Cornsweet's phenomenon?
* "Air temp. 82 F, wet bulb 77, sea 81.5. Wind E, force 4."


M. R.
“Raggio verde,”
Coelum 29, 189 (1961).

* NOT a GF at all, but a greenish crepuscular ray. Ignore!


M. W. Burke-Gaffney
“A green flash,”
J. R. A. S. C. 56, 148 (1962).

* ADAPTATION EFFECTS? CLOUD-TOP FLASH? Seen at an elevated (hilltop) horizon
* "The afternoon . . . had been sunny, cold, and clear" so inversions are
* involved. The "dash" is a compressed mock mirage, probably of Fraser's
* hilltop type. "All this happened in the space of about a minute."


L. Rudaux and G. de Vaucouleurs
Larousse Encyclopedia of Astronomy, 2nd Ed
(Hamblyn, London, 1962), pp. 98–103.

* Nice HOURGLASS PHOTO (b/w), p.102


A. Dauvillier
Physique Solaire et Géophysique
(Masson, Paris, 1962), pp. 227–228.

* indirect report of early GF photos c.1949
* "Nous en avons projeté des photographies en couleurs, obtenues au Pic,
* devant la Société Astronomique de France, en 1949."
* NOT confirmed by searching in BSAF.


R. MacEwan
“Green flash, Eastern North Pacific Ocean,”
Marine Observer 32, 183–184 (1962).

* interesting drawings


R. M. McNair
“Turquoise-green flash, Gulf of Aden,”
Marine Observer 32, 185 (1962).

* textbook flash


W. A. Feibelman
“Low Sun Phenomena,”
Appl. Opt. 2, 199–200 (1963).

* B/W PHOTOS by Walter A. Feibelman
* a few green flashes and many airplane wakes crossing the Sun


D. A. Browne
“Lunar green flash, off Somaliland,”
Marine Observer 33, 20–21 (1963).

* LUNAR GREEN FLASH at one cusp, not at the other
* (First flash probably drowned out by remaining part of disk)
* cf. partial-eclipse flash reported by Touchet, 1925


N. Sloan and W. Burnett
“Abnormal refraction, Persian Gulf,”
Marine Observer 33, 69 (1963).

* NICE DISTORTED SUNSET drawings; GF at end


M. Jenkins and Mr. Lennon
“Venus – green flash, Western Pacific Ocean,”
Marine Observer 33, 70 (1963).

* VENUS GF


H. Dishman
“Venus – green flash, South Atlantic Ocean,”
Marine Observer 33, 71 (1963).

* VENUS GF


M. H. Weston and D. F. Craddock
“Green flash, South Pacific Ocean,”
Marine Observer 33, 71 (1963).

* GREEN RAY?
* "The flash extended over an arc of 15-20 degrees and was of an intense
* green colour."


N. S. Milne
“Green flashes, South Pacific Ocean,”
Marine Observer 33, 188 (1963).

* 3 flashes at successive cloud layers; NICE SKETCHES


S. V. Sharp
“Red flashes at moonrise, Gulf of Aden,”
Marine Observer 34, 74 (1964).

* typical INFERIOR-MIRAGE RED FLASH


G. E. D. Alcock
“Green flash and telescopic meteors,”
The Astronomer 1, No. 3, 10–11 (July, 1964).

* GEORGE ALCOCK's GREEN RAYS and CLOUD-TOP flashes
* Notable for explicitly suggesting a GREEN CREPUSCULAR RAY:
* "On 1964 June 13 at 20.13 UT the Sun went down behind a sharply-defined
* belt of distant strato-cumulus some 1½° above the horizon.
* The last upper fringe of the disappearing limb turned a brilliant copper
* green. The visibility was about 30 miles, the air stream unstable,
* behind a cold front - these seem to be the normal conditions for a
* display of the Green Flash.
* "Such displays are the usual feature reported, but I do not consider
* this to be the true Green Flash, which I have seen only twice -
* on both occasions at sunrise. The first was off Cape Trafalgar,
* Spain, on 1942 November 17; the second at Farcet on 1950 December 25.
* On these occasions the Sun remained completely hidden behind large
* distant cumulus, until appearing suddenly behind the sharply-defined
* indented mountain-like summit. At the moment of the Sun's appearance
* a brilliant copper-green crepuscular ray shot up from the cloud top
* to near the zenith - a magnificent, unforgettable phenomenon. As the
* vivid green limb emerged the ray vanished just as suddenly. The whole
* phenomenon lasted about 1¼ seconds. I have never read any reports of
* any other observer witnessing this spectacle, which I consider to be
* the true Green Flash."
* Thanks to Guy Hurst, the current editor, for supplying a copy!


R. N. Cumbers and A. B. Joubert
“Green flash, vicinity of Adelaide Island,”
Marine Observer 35, 17–18 (1965).

* typical MOCK-MIRAGE FLASHes with drawings
* "The whole process took about 10 min and as the last vestige of the sun
* finally passed from sight we looked for, but saw no flash." !!!
* "The elongated button-shape became separated from the main body of the sun
* by a thin translucent line and became a brilliant ultramarine colour.
* The button-shaped part reformed and separated a second time."
* "Just before passing from sight the sun lost all semblance of its original
* shape and became a pyramid of flaming ultramarine coloured vapour which
* gradually sank below the horizon. . . ."


P. V. Haswell and J. Nott
“Green flash, North Atlantic Ocean,”
Marine Observer 35, 64 (1965).

* typical MOCK-MIRAGE FLASH with drawings
* "An unusual feature was the occurrence of a green flash on the upper
* limb, while it was still well above the horizon."


I. C. McLennan
“(letter to the editor),”
Sky Tel. 29, 85 (1965).

* shorter version of the following report:
* Observation by Ian C.McLennan; this version published in Feb., the next
* in April:


I. C. McLennan
“An airborne observation of the green flash,”
J. Roy. Astr. Soc. Canada 59, 53–55 (1965).

* AIRPLANE FLASH from 35,000 feet
* N.B.: Minnaert's new translation has 39 kft in error
* "Its width was about half the apparent diameter of the solar disk."


M. Rowland-Hill
“Red and green flash at sunrise, North Atlantic Ocean,”
Marine Obs. 36, 62 (1966).

* Textbook green and red flashes
* "As the sun's upper limb appeared above the horizon, a very distinct
* green flash was seen . . . . When the sun had cleared the horizon it
* immediately disappeared behind the edge of the cloud sheet: a very marked
* red flash then appeared on the lower limb . . . ."
* "Air temp. 59 F, dew point 54, sea 62." [so GF was an Inf.-mir.]


D. Roberts
“Blue flash at moonset, off Muscat,”
Marine Obs. 36, 182 (1966).

* LUNAR BLUE flash
* "The atmosphere was exceptionally clear and dust free."


T. F. Gaskell
“The Empire of the Sun,” in The Explosion of Science: The Physical Universe , Sir Bernard Lovell and Tom Margerison, eds.
(Thames and Hudson, London, 1967), p. 47.

* The Vatican Observatory photo reproduced in this coffee-table book does
* not appear in O'Connell's book, so I suppose it had been taken since then.
* It shows a small but pure green mock-mirage flash, accompanied by the
* ``textbook'' explanation, which of course does not agree with the photo!
* Thanks to John Norris for mentioning this on Usenet!


C. H. Cotter
A History of Nautical Astronomy
(American Elsevier, New York, 1968), p. 267.

* A remarkable assertion: "SUGGESTED ON MANY OCCASIONS"
* "The method of finding longitude from an observation of the Green
* Flash which occurs in favourable meteorological conditions when the
* upper limb of the Sun sinks below the visible horizon has been suggested
* on many occasions during the present century." He considers it too
* imprecise to use "on account of the relatively long interval which the
* phenomenon may occupy"; but cites Simmons in J.Inst.Nav.4 (1951), who
* in turn cites Capt. Brett Hilder earlier in that volume. Evidently
* Ekman (1959) is another example, though not cited.
*      This book contains many errors; see
*             http://www.huxtable.u-net.com/cotter01.htm
* for a list of them.


M. Allen , Jr.
“Venus – colour changes, off S.W.Africa,”
Marine Obs. 38, 71 (1968).

* VENUS GF
* "At an altitude of approximately 5° the colour began to alternate
* between red and green . . . . At the moment of setting there was a vivid
* green flash in the shape of a triangle."


D. Patrickson and W. Cowan
“Green flash, North Atlantic Ocean,”
Marine Obs. 38, 72 (1968).

* 4 GFs in one sunset -- CLOUDS or blank strips?
* "At sunset, three narrow bands of cloud lay across the sun's disc.
* As the upper limb of the sun sank past the upper edge of each band there
* was a distinct pale emerald-green flash and, finally, a brilliant green
* flash as the top of the sun's disc disappeared below the horizon."


A. D. Thackeray
“An unusual view of the green flash,”
Mon. Notes Astron. Soc. South. Africa 27, 131 (1968).

* FLASH over VOORTREKKER MONUMENT (but none at horizon)


Ya. P. Koblents
“Usloviya poyavleniya zeleznogo lucha v Antarktike,”
Informats. Byull. Sov. Antarkt. Eksped. , No. 73, 57–61 (1969).

* an ordinary "emerald-green" sunset flash in ANTARCTICA
* Detailed meteorological conditions were recorded: slightly higher than
* average pressure and slightly lower than average humidity (53% at -20 C).
* From ship's position and time, the true altitude of the Sun's upper limb
* was found to be -0° 39' which indicates "normal conditions of
* refraction"
* Informatsionnii Byulleten' Sovetskoi Antarkticheskoi Ekspeditsii No.73


H. Miles
“The green flash,”
JBAA 79, 77 (1968).

* "a small green spot" photographed with (apparently) an ordinary 35mm camera


R. J. Livesey
“The green flash,”
JBAA 79, 77 (1968).

* GF seen over distant hills with binoculars


J. H. Taylor and B. T. Matthias
“Green flash from high altitude,”
Nature 222, 157 (1969).

* AIRPLANE FLASH
* NICE COLOR PHOTOS showing DISPERSION of HORIZON (red below).
* THANKS to Ros Austin for providing an actual reprint with the colored
* plate (filed separately in the "pictures" file)! -- Not to mention a
* first-hand account of the flight (he was there).
* ". . . no physiological causes need be considered."


(various)
“(report of meeting),”
JBAA 79, 262 (1969).

* random discussion of GF and color films -- useless
* Discussion begun with Smith's drawing (see his 1971 note, below).


C. Reeves
“The green flash,”
JBAA 79, 240–241 (1969).

* A grazing observation at 78 N, around local midnight. (Cf. Baxter, 1983)
* "During the course of the next 20 minutes the Sun disappeared and
* reappeared several times between the saw-tooth peaks of the Trollheimen
* . . . . On each occasion I observed a vivid green coloration . . . through
* binoculars for, I suppose, a second or two."


W. Viezee
“Optical Mirage,” in Ch.4 in "Scientific Study of Unidentified Flying Objects" , D. S. Gillmor, ed.
(E.P.Dutton, New York, 1969), pp. 598–654.

* VIEZEE in CONDON REPORT
* not 100% accurate, but many useful references
* "The refracted images of the setting sun computed by Wegener's model
* agree closely [!] with those photographed and described by D.J.K.O'Connell
* (1958) . . . "


W. G. Hunt and J. W. R. Daniels
“Green flash, English Channel,”
Marine Obs. 40, 106 (1970).

* A textbook inf.-mir. GF
* sounds like experienced observers:
* ". . . the atmospheric conditions prevailing seemed to indicate that a
* green flash could be expected at sunset and the setting sun was duly
* observed through binoculars with striking results."
* "Air temp. 59.5 F, wet bulb 52.6, sea 61.6. Wind NW, force 4."


A. J. Davies and S. Barton
“Lunar green flash,”
Marine Obs. 40, 107 (1970).

* MOON
* Report not clearly worded: what was seen?


B. H. D. Beresford
“``Green Sun'' observed in Cornwall,”
Weather 25, 133 (1970).

* probably inf.-mir. GF, not green Sun
* ". . . I was standing . . . about 15 feet above sea level."
* ". . . the solar disc changed suddenly to a distinct `spectral' green for
* a few seconds."


F. E. Dixon
“The green ray,”
Weather 25, 184 (1970).

* probably useless


F. H. W. Green
“The green ray,”
Weather 25, 288 (1970).

* Sunsets in CEYLON
* ". . . more often than not . . . ."


N. E. F. Clarke
“Green ray,”
Weather 25, 335 (1970).

* 2 SUNRISE flashes over hills
* Possible GREEN FOG ?
* ". . . the light appeared to flood the whole landscape, and to persist for
* some 2-3 seconds . . . ."


M. W. Bond
Far Afield in the Caribbean: Migratory Flights of a Naturalist's Wife
(Livingston Publishing Co., Wynnewood, Pa., 1971), pp. 93–94.

* MARY WICKHAM BOND's book
* "We had seen it before, in Grenada and St. Vincent . . . . To my eyes,
* it has never spread across the horizon, nor is it green but blue, like
* a brilliant spark from an electric wire."
* She here mis-cites Cain's 1959 chapter as a "book," but quotes the
* passage from it. (cf. her 1975 item in NYTimes)
* Thanks to Anna M. Stevens for finding this!


J. S. Grassick, D. Fox, and T. Seel
“Blue Flash, North Atlantic Ocean,”
Marine Observer 41, 21 (1971).

* NAKED EYE BLUE FLASH
* Color reversal: "Towards the end the blue became deeper and changed to a
* blue-green before fading away."
* Air here is reported 0.9 deg. warmer than sea, though description fits
* an Inf.-mir. flash.


J. R. Smith
“The green flash,”
JBAA 81, 230 (1971).

* Smith's letter to JBAA: probably one of Fraser's wave-flashes;
* the drawing is somewhat confusing.


J. R. Francis and B. T. Hernaman
“Green Flash, Eastern Pacific Ocean,”
Marine Observer 41, 102–103 (1971).

* VENUS colored limbs; not a flash. Nice sketch.
* The Editor's comments are a bit garbled: "When this happens the greater
* part of the orange/yellow range of colour will be removed by absorption
* due to invisible water vapour, while most of the blue/violet will be lost
* by scattering due to very small particles within the atmosphere."
* Where's the 3rd Baron Rayleigh when we need him?


C. M. Botley
“The green ray,”
Weather 26, 354–357 (1971).

* unreliable CICELY M. BOTLEY review -- many names misspelled;
* another LEGEND believer!


G. J. W. Oddie
“The green ray,”
Weather 26, 363 (1971).

* another MULTIPLE FLASH via HILLS


C. M. Botley
“The green flash,”
JBAA 81, 411 (1971).

* Botley's letter to JBAA, commenting on Smith: here she is correct.


R. Scorer
Clouds of the World : A Complete Colour Encyclopedia
(Lothian, Melbourne, 1972), p. 152.

* Richard Scorer's cloud atlas has a page on GFs
* Section 13.5.2 describes the low-Sun phenomena and GFs. There are
* several pages of fine pictures of atmospheric-optics phenomena in this
* chapter. Unfortunately, the supposed superior mirage in Fig. 13.5.1 is
* certainly a reflection in a curved window, not a mirage at all.


D. P. Slattery
“The green ray,”
Weather 27, 90 (1972).

* double AIRPLANE FLASH at 26,000 ft., 5 sec + 3 sec
* "There was a false horizon formed by the top of a layer of altostratus
* above which the air was very clear."


M. Seager
“The green ray,”
Weather 27, 90–91 (1972).

* another AIRPLANE FLASH


A. B. Fraser
“The green ray,”
Weather 27, 91 (1972).

* BLUE FLASH from Seattle; nutty explanation


M. V. Gavin
“Atmospheric phenomena and zodiacal light,”
JBAA 82, 353–356 (1972).

* 1 paragraph on 2nd page on GF: lone telescopic observation of green rim.


J. R. C. Young
“The green ray,”
Weather 27, 346 (1972).

* NO GF seen in Riyadh
* ?? can this be a color-blind observer?


C. M. Botley
“The green ray in Arabia,”
Weather 28, 43 (1973).

* Botley comments on Young's letter (above), getting the mirage wrong.


G. S. Hawkins
Beyond Stonehenge
(Harper & Row, New York, 1973), p. 39.

* Gerald Hawkins's passing comment:
* "On rare occasions the rim of the sun can shine a pale green for a few
* seconds. But this trick of refraction is with clear air over an open sea
* horizon. I knew there would be no green flash this morning, inland over
* rolling hills." Evidently he has never seen one.
* Thanks to Stephen Williams for turning this up.


A. H. Thompson
“The green ray,”
Weather 28, 174–175 (1973).

* flashes in Alaska "looked for, and usually observed" at Geophys.Inst.,
* Fairbanks.


G. E. Shaw
“Observations and theoretical reconstruction of the green flash,”
Pure Appl. Geophys. 102, 223–235 (1973).

* CHROMATICITY DIAGRAM, DOMINANT WAVELENGTH & PURITY tabulated


(various discussants)
“(account of meeting),”
JBAA 83, 430 (1973).

* minor mention of GF in meeting; no useful information


C. Smith
“The skies down here,”
JRASC 68, L5 (1974).

* GF routinely seen at Las Campanas
* evidently reprinted from the newsletter of the Toronto Centre.
* "I have seen the green flash at sunset only once in Canada, yet here it
* is easily seen three or four times a week."
* Thanks to ADS full-text search.


F. H. W. Green
“The green flash,”
Weather 29, 118 (1974).

* "electric BLUE" flash above alto-stratus
* ". . . visibility was remarkably good."


M. J. de F. Maunder
“(account of meeting),”
JBAA 84, 250 (1974).

* minor mention of GF in meeting; no useful information


A. B. Fraser
“The Green Flash and clear air turbulence,”
Atmosphere 13, 1–10 (1975).

* SPIKES -- GREEN FLASH -- WAVES (Mock Mirage?)
* "the green rim is magnified by the proper `mirage' conditions."
* [as already suggested by Evershed (1915, 1923, 1926, 1936) and seconded
* by Mercanton (1920), Visser (1921), and also others: e.g., Clarke (1930).]
*      He correctly says that inferior mirages over water "warmer than the
* overlying air" (p. 4) can work; but then proposes "Gravity Waves" as
* "the other way around the theorem". But he then assumes the inversion
* is "a kilometer or more above our eye" (p.6) to find the waves have
* ". . . wavelengths of between 200 m and 2 km." (p. 8)
*      This is where "Fraser's theorem" is proved [but not the first time].
* See White's more accurate treatment (1979) of waves on inversions.
*      Note: Atmosphere  became Atmosphere-Ocean  shortly after this, and
* seems never again to have published a GF paper.


M. W. Bond
“Encounter: in the Caribbean, an exploding emerald on the horizon,”
New York Times, section XX (Travel) , 9 (3 August, 1975).

* Rare bright GF photographed with a "small camera" (no focal length given)
* (MARY WICKHAM BOND was the wife of the ornithologist JAMES BOND,
* after whom Ian Fleming named agent 007.)
* This item was followed by 3 useless letters from writers who fit
* Havinga's condemnation, in the Aug.24 Travel section.
* NOTE: her reference to Cain's book gives chapter title, not book title


L. M. Starokadomskiy
in Charting the Russian Northern Sea Route , W. Barr, ed.
(Arctic Institute of North America, McGill-Queen's University Press, Montreal and London, 1976).

* Brief mentions of a few GF observations in the Arctic Ocean
* See pp. 112 and 182 [and note 8 on p. 293, citing Sharonov (1951)].
* There is a curious error on p. 229: "We saw the sun clearly for the first
* time after the arctic night on February 15. It rose at 1100 hours, and
* climbed to 18° above the horizon." [Obviously, 18' is intended.]
* (Thanks to David Burch for finding this reference!)


J. C. Bartholomew
“Double green flash over Western Isles,”
Weather 31, 30 (1976).

* 2 Mock Mirage flashes mistaken for "superior mirage"


A. B. Fraser
“So you think the sun is round?,”
Earth and Mineral Sciences 45, 49–52 (1976).

* Good photographs of SUNSET DISTORTIONS
* Believes, and even cites, Jules Verne for "LEGEND"


T. W. Edmunds
“Green flash from Venus, South Indian Ocean,”
Marine Obs. 46, 69 (1976).

* VENUS GF


P. S. E. Cave and G. Rudd
“Abnormal refraction, Great Australian Bight,”
Marine Obs. 47, 63–64 (1977).

* Distorted moonrise; seems to be an Inf.Mir.
* [filed here because of the following item on same sheet]


K. A. Stapleton
“Green flash, North Pacific Ocean,”
Marine Obs. 47, 65 (1977).

* Naked-eye Inf.-mir. flash
* Followed by a long quote from "The Meteorological Glossary" on GF,
* saying that "in a hazy atmosphere such differential scattering may not be
* appreciable and the flash may then appear blue or violet." This
* nonsense needs to be straightened out!


F. H. Stocking
“The green flash,”
UpCountry 6, No. 5, 8–10 (May, 1978).

* Eloquent eyewitness accounts of two sunrise flashes
* Fred H. Stocking was an English prof. at Williams College.
* This contains a few minor errors: seconds for minutes in
* longest duration; 25 for 35 minutes of the Byrd expedition.
* Note: though this is the May issue of UpCountry, it came with the
* 29 April issue of the Berkshire Eagle
* (Note that each issue is separately paginated, so month is required)


F. H. Stocking
“A split second in paradise,”
Reader's Digest 113, 124–125 (Sept., 1978).

* condensation of Stocking's GF article
* Color photo of inf.-mir. GF is BADLY reproduced
* (Note that each issue is separately paginated, so month is required)


R. White
“A new theory of the green flash,”
J. Meteorol. 4, 270–277 (1979).

* independent discovery of Sang/Meyer/Fraser THEOREM
* Badly confused about O'Connell's pictures
* Notes that OBLIQUE WAVES will produce "tilted" features
* This seems to be the only paper J. Met. ever published on the GF


T. Schlatter
“Weather queries? [answer actually provided by Alistair Fraser],”
Weatherwise 33, 173–174 (1980).

* Cover shows a barely visible green wisp -- filed in "color images" file
* Fraser's "photograph of the green flash on the cover is one of the most
* outstanding views ever captured on film." (Hardly true, even in 1980.)
* "Blue and purple [sic] light is scattered far more strongly than red
* light. For this reason, very little blue or purple light reaches the
* observer when the sun is near the horizon."
* "To enlarge the green rim so that it can be seen, requires a temperature
* profile that causes the atmosphere to act as a giant magnifying glass.
* There are at least three classes of temperature profiles that will do
* this; one with a superadiabatic lapse rate near the surface, and two in
* the form of lifted inversions."
* Minnaert, O'Connell, Shaw, and Fraser's 1975 paper are cited.
* August issue


M. Menat
“Atmospheric phenomena before and during sunset,”
Appl. Opt. 19, 3458–3468 (1980).

* a terribly oversimplified account -- poor
* But he does recognize (p.3466) that refraction does not scale with
* refractivity.


A. Urbańchik
“Zelenii luch [Green ray],”
Nauka i Zhizn , No. 7, 94–96 (1980).

* Andrzej Urbańczyk's observation
* (translated from the Polish original in Młody Technik, c. 1979?)
* He was captain of the "Morning Star", enroute from San Franciso to
* Polynesia, south of the Equator and west of Samoa. "One evening
* . . . I heard an agitated cry from the helmsman: 'Look! There! Look!
* Green Sun!' . . . I just looked at the setting Sun, . . . and suddenly
* the remaining gelatine-red piece, beginning at the Earth, emitted
* green like a tram light and disappeared."
* "The whole crew saw the green flash five times . . . ."
* The explanation starts out with the Ancient Egyptians, moves on to
* Jules Verne and "the well-known Soviet astronomer G. A. Tikhov", and
* "two French astronomers" -- all without specifics, but with extended
* quotations; but we know who they are.
*      The first observation appears to have been made in the summer of 1978,
* as he says at the end that he saw it again several times in the spring
* of 1979, including a cloud-top flash.
*      There is a photograph, credited to unnamed "French astronomers".
* (in Unicode: Andrzej Urbańczyk ; Młody Technik )
* In Russian, the reference is:
* А. Урбаньчик
* Зелёный луч
* Наука и Жизнь No.7,
* 94-96 (1980)


D. J. K. O'Connell
“The green flash,” in Atmospheric Phenomena , D. K. Lynch, ed.
(W.H.Freeman, San Francisco, 1980), pp. 91–97.

* O'Connell's 1960 Scientific American article reprinted


A. B. Fraser
“To see a dazzling festival of light, just raise your eyes,”
Smithsonian 11, 72–79 (Jan., 1981).

* Alistair Fraser's article on atmospheric optics in SMITHSONIAN
* with a good COLOR PHOTO of a nice Mock Mirage flash on p. 74;
* green flashes are discussed only in the final paragraph (where,
* again, we have: "Scottish legend assures us . . . .")
* Enough with the phony LEGEND, already!
* But this otherwise good article is too little known.
* Superb MIRAGE PHOTOS as well as the GF picture; other pretty stuff.


C. D. Spencer-Payne
“Green flash, Western North Atlantic,”
Marine Observer 51, 67 (1981).

* EXTINCTION comments -- good and bad!
* The observer notes that "On previous occasions such flashes had been
* either accompanied or replaced by an intense blue (topaz) flash, this
* phenomenon was not observed . . . , neither was the intensity of the flash
* so great as seen before." Fine. Then the Editor's comment claims that
* "In a hazy atmosphere . . . differential scattering may not be appreciable
* and the flash may then appear blue or violet," getting it all wrong.


R. Gerharz
“Observations of the green flash and slant range `seeing',”
Pure Appl. Geophys. 119, 998–1002 (1981).

* GERHARZ's Questar observations from 25 m
* GREEN AIRPLANES and CONTRAILS
* ". . . since O'Connell . . . any further analysis may have indeed become
* worthy of Sir Arthur Schuster paraphrasing this event . . . .
* However, despite these frequent assurances that everything optical under
* the sun has already been observed, recorded and analyzed, the
* interpretation of beautiful phenomena in nature must not remain restricted
* to the realm of science pundits."
* "For at least 10 minutes after sunset, and up to 5° elevation of the
* line of sight, green coloration . . . may still be observed on
* sun-illuminated, very distant airplanes in normal flight altitudes and on
* their contrails. . . ."


C. J. Hughes and J. G. Pearce
“Green flash, South Atlantic Ocean,”
Marine Observer 52, 28–29 (1982).

* 6 flashes in one sunset; BOTH INF.-MIR. and MOCK-MIRAGE (wave) flashes.
* Rather crude drawings illustrating the formation of mock-mirage flashes
* and the Omega form leading to the final inferior-mirage flash.
* "During the 28 seconds or so that it took the sun to disappear totally
* below the horizon, five separate green flashes were observed. These
* occurred when the upper limb of the sun broke away from the main body of
* the sun and formed a cigar shape approximately one-sixth of the diameter
* of the sun in length. This cigar shape almost immediately disappeared,
* turning a faint and rather watery green as it did so."
* . . . "The duration of these flashes was a split second each.
* The final and sixth flash, observed as the sun sank below the horizon
* was very pronounced. It appeared very slightly above the horizon and
* lasted approximately two seconds. A feature which the observers had not
* witnessed before was that in the centre of the green colouring (which was
* a bright emerald green) was a small circular area of a much paler green
* colour; this only occurred, however, in about the last half-second of the
* duration of the flash." [N.B.: the drawing shows the spot is
* elliptical, not circular.] (wind force 2).


E. Harrison
“Green flash, South Atlantic Ocean,”
Marine Observer 52, 139–140 (1982).

* Drawings look like an inf.-mir. flash, but description is odd:
* "The flash appeared after the sun had set and then collapsed into itself
* and disappeared." But it probably is a normal flash, as "the colour was
* a brilliant emerald green." (Certainly not a green ray.)


C. F. Bohren
“The Green Flash,”
Weatherwise 35, 271–275 (1982).

* Bohren believes Jules Verne's "LEGEND"!


A. Missira
“An unusual observation of the green flash,”
JBAA 92, 147–148 (1982).

* typical MM phenomena sketched from photos
* His slide (sent to ATY) shows a *yellow* flash on Kodachrome


G. Moyer
“The green flash,”
Griffith Observer 46, 2–4 (Nov., 1982).

* a fair popular summary. He has the mirage connection right, but says
* an inversion layer is "a condition in which a cold trough of air is
* sandwiched between two regions of warm air," which is nonsense. He also
* says the "orange and yellow light is dispelled [sic] by molecules of air
* in an effect known as Rayleigh scattering," which is also wrong. There is
* a nice drawing of a mock-mirage sequence, but the explanation is all
* wrong. There's also stuff about "lighting up the entire western sky."
* And he evidently confuses the 3rd Baron Rayleigh with the 4th. Still,
* a fairly good account, apart from these serious errors.
*      The "Lick" sunset is Chappell's, from Sept. 16, 1931.
* N.B.: Each issue is separately paginated, so the MONTH is essential!


R. Verseau
“Notre couverture – Le rayon vert,”
BSAF 97, 262 (Juin, 1983).

* COLOR PHOTO on cover
* Remarkable flash of appreciable dimensions recorded with 50mm lens
* (cf. Mary Bond's accomplishment)
* N.B.: author is not the photographer (Mlle.Danielle Jey).


E. Stone
“The green flash,”
Oceans 16, no. 5, 13 (Sept. /Oct., 1983).

* Nice color photograph of inf.mirage flash with red-outlined tropical cumuli
* text by Elizabeth Stone, photo by her husband David M. Stone
* from timed photo series, "the flash lasted at most, two thirds of a second."
* A color copy is in the colored-pictures file.


P. Baxter
“The green flash,”
JBAA 94, 36 (1983).

* MULTIPLE flashes of MIDNIGHT SUN (cf. Reeves, JBAA 1969)
* "As midnight approached the Sun sank towards the northerly peaks and was
* periodically eclipsed by them . . . . Just before the trailing limb of the
* Sun passed behind a peak the Green Flash was observed. . . . we saw the
* limb turn from yellow through green to a vivid blue over a period of about
* ten seconds. This phenomenon was repeated many times. . . . The effect was
* spectacular."


F. Schaaf
Wonders of the Sky: Observing Rainbows, Comets, Eclipses, the Stars and Other Phenomena
(Dover Publications, New York, 1984), pp. 54–57.

* Fred Schaaf's earlier book gives the GF several pages
* Here he still believes the "old Scottish legend". Otherwise, good.
* ISBN 0486244024; Google Book offers some sample pages.


C. A. Zapffe
“`Stopping the Sun' and its green flash,”
Speculations in Science and Technology , series 2, 7, 115–119 (1984).

* Not knowing the literature, Zapffe proposes many things already done.
* He also has some facts wrong, completely fabricating a story about Lord
* Kelvin, with a wrong date (1889) for Kelvin's first flash (1893), which
* was at sunset, not sunrise as stated by Z. [see S.P.Thompson, 1910]


P. Ford
“Sunsets, Twilights and Evening Skies [book review],”
JRASC 78, 259–260 (1984).

* Paul Ford reviews the Meinels' book, devoting a paragraph to the GF
* "Is the `green flash' purely an optical phenomenon or are there
* physiological effects that influence the brilliance or colour of the
* image?"


D. P. Cruikshank
“Sunsets, Twilights, and Evening Skies [book review],”
Icarus 59, 131 (1984).

* Dale Cruikshank reviews the Meinels' book
* ". . . an excellent chapter on the green flash, with a very clear
* explanation of the phenomenon and the reasons why it is not easily
* photographed. Astronomers would do well to commit parts of this chapter
* to memory in order to provide a concise explanation to those who are
* first introduced to this most spectacular of the low-sun phenomena."


A. Meinel and M. Meinel
“Rare Halos, Mirages, Anomalous Rainbows and Related Electro-magnetic Phenomena: A Catalog of Geophysical Anomalies [book review],”
Icarus 59, 131 (1984).

* Then the Meinels, in turn, review Corliss's book
* They have some useful remarks about second-hand reports:
* "The author often reproduces a sketch which he has redrawn . . . or
* occasionally apparently translates the word description in a cited
* reference into a drawing. While this latter procedure is useful in some
* cases, it may be deceptive in others. The weakness is that language is
* limited, and subtleties, difficult to put into words, can easily lead
* to a second-person sketch with profound differences from the real event."
*      Of the GF, they say: "The tropical [sic] green flash is an example of
* an anomalous phenomenon not yet fully or satisfactorily explained. . . .
* Gravity waves in the atmosphere have been offered as an explanation,
* but we believe that simple variations in refractive index in three
* [sic] dimensions are sufficient to cause the solar rays to be injected
* into and trapped in a ducting stratum and conveyed over the horizon to
* the observer." [Interesting both for their doubts about the textbook
* story, and for their belief that ducting is required. And, "tropical"
* to describe Fraser's flashes in Pennsylvania )(i.e., the "gravity-wave"
* idea? They don't see that 1 dimension suffices!]


A. Thom
“Halley's comet and observing the `green flash',”
JBAA 94, 137 (1984).

* Alexander Thom reports many green flashes
* "The last rays of the Sun's upper limb was often a brilliant green. It
* seemed to me to be such a regular phenomenon I did not think it worthwhile
* writing any description. . . ."


F. Vincent
“The green flash,”
JBAA 94, 138 (1984).

* Fiona Vincent confirms Thom's assertion that the GF is common, and
* comments on Baxter (1983):
* "I believe that the phenomenon can be observed, at any latitude, more
* often than is generally realized."


C. M. Botley
“The green flash,”
JBAA 94, 138 (1984).

* Botley also comments on Baxter


R. J. Livesey
“A double green flash seen from Devon,”
JBAA 96, 10 (1985).

* "CLOUD" seems to have been a blank strip (superior mirage);
* first GF above Wegener's BLANK STRIP, second GF at horizon:
* ". . . the sky was crystal clear without cloud or haze. . . . there was a
* very low thin band of cloud, not haze, with vertical columns between cloud
* and the Earth's surface . . . . [cf. d'Abbadie, 1849]
* This layer, together with the vertical columns, gave the effect of a
* road bridge and its piers, when backlit by the Sun's disc. I judged the
* thickness of the cloud band to be about one-twentieth of the vertical axis
* of the Sun's setting disc and the distance from the bottom of the band to
* ground level to be of a similar order.
* . . .      When the upper limb of the Sun sank to `deck' level of the bridge,
* there was a green flash on the top of the cloud layer, while the red disc
* continued to shine between the cloud and the ground. The top limb of the
* Sun then came down below the cloud layer, and as it approached the ground
* a green glow developed on the righthand side and spread leftwards along
* the edge of the limb . . . ."
* "Instrumentation was used to provide x7 magnification. . . ."


M. A. Armitage and C. Cavanagh
“`Green flashes', Indian Ocean,”
Marine Observer 55, 30–31 (1985).

* NOT a green flash at all, but green METEORS.
* A peculiar example of observers supposing they can estimate distances to
* remote objects: although the first one disappeared "behind low cloud at an
* altitude of 30°", "the distance from the ship did not appear to be
* great enough to be compatible with a meteor or other object entering the
* earth's atmosphere."


P. M. Swan and M. Holland
“Exceptional sunset, Red Sea,”
Marine Observer 55, 192–193 (1985).

* FOUR green flashes in one sunset with mountains 72 n. miles away
* The sun "constantly changed in appearance from that of an `upturned urn'
* to an `hour-glass'" (see DRAWINGS). "Before, during and after these
* observations, we were experiencing extreme radar ranges with ships' echoes
* being received from over 40 n. mile and strong land echoes at the maximum
* range of 48 n. mile . . . ."


C. M. R. Platt
“Book Reviews: Sunsets, Twilights and Evening Skies,”
Dynamics of Atmospheres and Oceans 9, 315–316 (1985).

* A bizarre review of the Meinels' book; 3 sentences mention the green flash
* He calls Aden Meinel "Eden" -- twice! Then there is ". . . not always
* scientifically accurate" with no supporting evidence; and such lapses
* as "Extinction of sunlight and it's [sic] effects is [sic] . . . ."
* Apparently this is the Platt of Paltridge and Platt -- also published by
* Elsevier. Strange. Who is at fault here, Platt or Elsevier?


Mme. Jay
“Le rayon vert,”
BSAF 100, 438 (Oct., 1986).

* COLOR PHOTO on cover
* mostly YELLOW FLASH in color on cover; some green


D. C. North
“The green flash in Antarctica, April 1985,”
Weather 42, 144–145 (1987).

* ANTARCTIC INFERIOR FLASH


K. C. Riddick
“Abnormal refraction, Arabian Sea,”
Marine Observer 58, 25–26 (1988).

* SUNRISE FLASH with both INF.-MIR. and MOCK MIRAGE features
* "ORANGE HORNS" and the Omega phase is described as like "a spherical
* buoy". No temperature data.


W. Bascom
The Crest of the Wave : Adventures in Oceanography
(Harper & Row, New York, 1988), p. 70.

* Willard Bascom's memoir
* "The reason the phenomenon is rarely seen from a densely inhabited
* coast is that the tiniest amount of haze or cloud will obscure the flash
* of green. However, it is often seen from ships well out at sea where
* the horizon is clear."


A. B. Meinel and M. P. Meinel
“At sunset,”
Optics News 14, No. 11, 6–13 (1988).

* MEINELS -- nonsense about GF, but showed that layers produce notches.
* [of O'Connell:] "While the pictures are excellent, some of the
* interpretation of the details of the origins of the phenomena need
* updating." (p.6)
* "Based on our siting [sic] of the green flash both in the Tucson desert
* and in Hawaii, we have come to the conclusion that there must be at least
* two different forms of the green flash: a ``green spot'' and an anomalous
* ``green flash.''" (p.9) [at this late date!]
* N.B.: November issue.


W. R. Corliss
“Beyond the rainbow; Unusual Natural Phenomena at Sea,”
Mariners Weather Log 32, No. 2, 22–23 (April-May-June, 1988).

* William R. Corliss's review for mariners
* He correctly concludes that the textbook explanation is inadequate.
*      Published by NOAA.
* The issue is marked "April-May-June" on the title page, but "Spring 1988"
* on the cover and in the footers.


J.-M. Malherbe
“Quelques phénomènes de l'optique atmosphérique,”
BSAF 102, 351–357 (1988).

* GF gets 1 paragraph on p.352.


L. de Witte
“Optical illusions of low-angle observing,”
Astronomy 16, 82–87 (Dec., 1988).

* 2 good COLOR PHOTOGRAPHS of flashes and a nice OMEGA photo


C. Leinert
“Atmosphärische Optik auf finnisch,”
Sterne Weltraum 28, 90–91 (1989).

* all COLOR photographs by PEKKA PARVIAINEN
* including one small GF and a fine early-stage OMEGA, and a
* near-rectangular Sun (Abb.4, 5, 6).
* Filed in sequence, as my color copy is not impressive.
* Text by Christoph Leinert; issue no.2


P. W. Kemp
“The elusive green flash,”
Pacific Discovery 42, No. 3, 16–21 (Summer, 1989).

* GOOD REVIEW from secondary sources; believes Verne's "LEGEND"
* good COLOR PHOTOS from Pekka, O'Connell, etc.


D. Overbeek
“The green flash by reflected light,”
Mon. Notes Astron. Soc. Southern Africa 48, C16 (1989).

* Nice account of GREEN ILLUMINATION of a BALLOON (cf. Seebold's contrails)


I. Howard-Duff
“Atmospheric Phenomena of the Antarctic,”
JBAA 100 2, (1990).

* Account of a report by Jonathan Shanklin of the British Antarctic Survey
* ". . . the green flash is occasionally seen, although difficult to
* photograph." [BAA Meeting Report]
* Thanks to ADS full-text search.


P. Eden
“Green flashes in beds,”
Weather 45, 66 (1990).

* 2 flashes with VISIBILITY = 50 km


B. E. Schaefer and W. Liller
“Refraction near the horizon,”
Pub. Astr. Soc. Pacific 102, 796–805 (1990).

* all sorts of nonsense, but a 14-second Green Flash reported
* Note that large variations in horizontal refraction have been known for
* several centuries; this is not a new discovery.
* Somebody ought to re-reduce these data, allowing for variations in dip.
*
* NOTE: in an e-mail dated Aug. 8, 2007, Bill Liller tells me his position
* at Viña del Mar is more accurately
*
*       Lat.  -32d 57' 28.1"       Long.  -71d 32' 45.3"       Height  120 m
*
* -- the values published in this paper should be corrected accordingly.
*
* See Stephen McCluskey's 2017 study of refraction at the apparent horizon
* (in the "variable refraction" file) for useful discussion. Also, his
* 2018 paper (in the "Terrestrial Refraction" file) that cites this.


P. L. Weiss
“Reflections on refraction,”
Science News 138, 236–237 (1990).

* mostly a puff piece about the above. The GF is mentioned in passing
* One of Pekka's GF photos is on the cover (Oct.13 issue)


T. Waters
“Green stuff,”
Discover 12, no. 7, 72–76 (July, 1991).

* Many errors of optics, as well as Verne's LEGEND


B. J. Miller
“Rain in Maine means slogging or shopping,”
St. Petersburg Times (City Times section) , 4 (Aug. 13, 1991).

* Betty Jean Miller's second GF item
* ". . . I talked about seeing `the green flash' as the sun set last
* weekend." A local biology teacher offers the after-image idea.
* The GF item follows the one in the title.


B. J. Miller
“No error here: Green flash is explained,”
St. Petersburg Times (City Times section) , 4 (Sept. 17, 1991).

* Betty Jean Miller's third GF item cites the first item (Aug. 3)
* Mentions the 1981 item in Smithsonian and the July Discover [above]


E. Overend
“Green flash,”
New Scientist 132, no. 1795, 58 (16 Nov., 1991).

* Writer asks about GF


M. Berry
“The Sun is green,”
New Scientist 132, no. 1797, 65 (30 Nov., 1991).

* Replies to the Overend query
* Michael Berry mentions O'Connell's book.


K. Durose
“The Sun is green,”
New Scientist 132, no. 1797, 65 (30 Nov., 1991).

* Replies to the Overend query
* Ken Durose cites Greenler's book.


J. Carroll
“The adventures of the green flash,”
San Francisco Chronicle , C 20 (Dec. 20, 1991).

* Explanation paraphrased (and embroidered!) from Bowditch
* Jon Carroll's column actually credits "American Practical Navigator".
* Apparently there was an earlier column in which he asked about the GF.


L. Dent
“Green flashes on the M62,”
Weather 47, 28 (1992).

* meteorological details given; sunset over hills


Chet Raymo
“In pursuit of the elusive, ephemeral green flash,”
Boston Globe , 26 (Jan. 13, 1992).

* "Night and day, the sky is an every-changing theater of optical wonders.
* Mostly, however, we go around with our eyes to the ground."


K. Bracher
“Echoes of the past: 90 years ago: the green flash,”
Mercury 21, 93 (1992).

* Katherine Bracher's historical notes turn up earliest PASP mention of GF
* (see PASP for June, 1902) -- this is the May/June issue.


C. B. Minnich
“Does the green flash really exist?,”
The Ensign 80, No. 6, 39 (June, 1992).

* Charles B. Minnich's ``ANCIENT NAVIGATOR'' columns
* The first shows the standard textbook model. Pretty much OK
* except for ". . . atmospheric refraction has little effect on the
* high-energy [sic] red portion of solar light so it streams off into the
* atmosphere. In contrast, the low-energy blue portion of solar light is
* refracted (bent) severely, so it's not seen."
* "The Ensign" is published by United States Power Squadrons, Raleigh, NC;
* thanks to Yvonne Hill, its editor, for these 2 items!


C. B. Minnich
“Photographing the green flash,”
The Ensign 80, No. 8, 37 (August, 1992).

* Charles B. Minnich's ``ANCIENT NAVIGATOR'' columns (#2)
* His advice not to use a focal length longer than 200mm is apparently
* intended for hand-held use. His suggestion to use the lens "a little
* less than wide open" and suggested exposure of a half second would
* produce greatly overexposed pictures. And: "Forget using a movie
* camera. The flash can occur between frames if your shutter speed is
* slow."


E. R. Cross
“Technifacts: green flashes,”
Skin Diver 41, no. 8, 34–40 (1992).

* A popular account based mostly on Bowditch (note the strange numbers)
* Incited by reader Howard R. Bird, who "saw a phenomenon called the green
* flash immediately following a sunset." Odd, how people get this notion.
* The GF treatment is only the first 2 pages of text. The advice is good,
* but the explanation is garbled, confusing inferior and superior mirages.


P. Candy
“Green flash da Viterbo,”
Nuovo Orione , no. 12, 16–19 (1993).

* Paolo Candy's mountain-wave flash
* The COLOR PHOTOGRAPHS show a few small flashes, and a good sunset
* series. The best example is enlarged on the cover.
* "Nuove Orione" is a popular magazine for amateur astronomers, much like
* "Astronomy". It does not seem to have volume numbers.


R. Silverberg
“Reflections,”
Amazing Stories , 5–8 (Sept., 1992).

* Bob Silverberg's popular account, as originally published
* He has only read O'Connell, it seems.


M. Anton
“Auf- und Untergänge,”
Sterne Weltraum 32, 642 (1993).

* see Robert Willmerdinger's tiny flash in color in Abb.2
* (filed in regular sequence, as the flash is so puny) This is part of
* a Xi-shaped Sun (corner of top line); the image is rather overexposed.
* issue no.8-9


P. Hechler
“Das Grün des Sonnenlichts,”
Beilage zur Wetterkarte des Deutschen Wetterdienstes , Nr. 114, (1994).

* PEER HECHLER reports his expedition's sighting of a GF near Shetland Is.
* The observation was made Sunday, Aug. 21, 1994. The 12 scientists found
* the display of what appears to have been a standard inferior-mirage
* flash very impressive: "`Geisterhaft' erschien uns diese optische
* Erscheinung insbesondere deswegen, weil die Farbe Grün am Himmel in
* Zusammenhang mit einem Sonnenuntergang nicht gerade die normale
* Erfahrung widerspiegelt." There is the ILLUSION of increasing
* brightness: ". . . vom gerade verschwindenden Rot über ein von der
* Intensität her zunehmendes Gelb in ein helles markantes Grün
* überging."
*      At the end he quotes a section from Meyers kleines Lexikon Meteorologie
* (1987) that makes the error of claiming that blue is not seen because
* it blends in with the color of the sky!
* Thanks to Prof. Dr. Kristian Schlegel for a copy of this item!


M. J. Coco
“Stalking the not-so elusive green flash.,”
Astron. Now 8, No. 11, 49–51 (Dec, 1994).

* Coco's flashes are all small MM-type flashes, probably due to Fraser's
* wave mechanism. I now have a color copy of the article. There is a
* nice RED FLASH that appears to be a MM on p.50.
* There are some errors: he thinks Swan's paper was the first; calls the
* MM flash "the green segment"; says never look at the Sun, etc.
* AAA062.082.031


M. Vollmer
“``Wenn das Licht in Farben sich erbricht . . . '',”
Physik in unserer Zeit 26, 106–115, 176–184 (1995).

* MICHAEL VOLLMER's nice 2-part review of atmospheric optics
* GFs get mentioned briefly in last paragraph of first column on p.182;
* as this is a small part of the content, I MOVED this to the Vollmer
* file.


W. Stefaniuk
“Green flash of the sun,”
Toronto Star , A7 (June 1, 1995).

* An unusual observation described in strangely impersonal terms
* in Walter Stefaniuk's "You Asked Us" column. Most of the GF explanation
* is quotes attributed to David Phillips of Environment Canada.
*
* I have talked to Walter Stefaniuk now about this on the phone. He says
* the sighting is his own: a "pencil of light" he saw overhead and to the
* east at sunset. He mentioned "misty" conditions, and that the weather
* had been cloudy; so I suppose this is a very rare anticrepuscular ray
* caused by an intense GF. The sunset itself was hidden from him by an
* island to the west (this was in Panama). The duration of a second or
* less is consistent with this interpretation, at least. [June, 2000]


B. McWilliams
“Weather eye: Greening of the sunset,”
Irish Times , 2 (Aug. 7, 1995).

* Brendan McWilliams begins his GF columns
* "People who have heard of it and havelooked for it and failed to find it
* often dismissed it as a fantasy. Others who have been fortunate enough
* to see it have thought it to be an optical illusion . . . ."
* Don't they have proofreaders in Ireland? His columns are full of typos.


B. Tobin
“Green sunset,”
Irish Times , 13 (Aug. 23, 1995).

* Beda Tobin's response to McWilliams reports an observation (not useful)


F. Sargeant
“Frank's tacklebox,”
Tampa (Fla.) Tribune (sports section) , 7 (Sept. 6, 1995).

* Frank Sargeant, the Tampa Tribune's outdoors editor, is skeptical
* But one of his correspondents is even worse: "The reason you can't see
* it in the Gulf is because the water is so dirty compared to the clear
* waters of the Caribbean." [Evidently, a through-the-waves believer.]
* (Apparently there was an earlier column on this topic, as this was "one
* of a number of readers who wrote" about it.)
* A second reader quoted from a Scientific American article.


K. Williams
Under an English Heaven --- The Life of George Alcock
(Genesis Publication Limited, Guildford, Surrey, England, 1996), pp. 156–157.

* Book publication of George Alcock's GREEN RAY observations:
* "Just after 8pm on 13th June [1964], George witnessed the phenomenon
* known as 'green flash': 'The sun went down behind a sharply defined belt
* of distant stratocumulus some 1.5 deg above the horizon. The last upper
* fringe of the disappearing limb turned a brilliant copper green.' The
* prevailing conditions -- good visibility, an unstable airstream behind a
* cold front -- had been as expected for such a display; yet George did not
* consider it to have been the genuine article, which he says he has seen
* only twice, on both occasions at sunrise. 'I saw it at Cape Trafalgar,
* Spain, on 17th November 1942, and in my garden on Christmas morning
* 1950. On those occasions the sun remained hidden by distant large cumulus
* before suddenly appearing behind the sharply defined moutain of cloud.
* At the moment the sun appeared, a brilliant copper-green crepuscular ray
* shot up from the cloud top to near the zenith. As the limb emerged vivid
* green, the ray vanished just as suddenly. The whole phenomenon lasted
* about 1 1/4 seconds -- a magnificent unforgettable spectacle, which I
* consider the true green flash'."
* It's notable that he explicitly says it was a CREPUSCULAR RAY.
*      Thanks to Eric Frappa for pointing this out!  It's a limited edition
* of 2000 copies, each signed by Alcock.


S. Howe
“Connoisseur's guide to fine sunsets,”
Backpacker 24, 66 (April, 1996).

* Short mention of GF in sidebar on p.66, with mistakes: "diffraction" !
* Main article "The fire that separates day from night", pp.58-66 by S.Howe


P. N. Spotts
“Ever wondered why?,”
Christian Science Monitor , 16 (April 30, 1996).

* Why is Leigh Sherman in La Jolla asking the C.S.M. about green flashes?
* Especially when there were several items in the local paper a few years
* earlier? Anyway, the answers are provided by Peter N. Spotts, on the
* "Home Forum" page; his column is evidently meant for the kiddies.


"Boston Globe"
“Science fare,”
Dallas Morning News , 8D (May 20, 1996).

* anonymously attributed to the Boston Globe
* Could this be the mystery ref. to Usha McFarlane?
* "Green flashes have inspired literary descriptions -- from Chekov [sic]
* to Jules Verne -- and a wealth of legends. The Scots claim that . . . ."
* O'Connell and Minnaert's book are cited. Sound observing advice.


N. A. Voss and A. Howes
“Blue flash, Bay of Bengal,”
Marine Observer 66, 115 (1996).

* Drawing shows "irradiation" according to R. White's comment following
* 2 unrelated GF reports are mentioned in the Editor's footnote (useless)


R. Jones
“Readers' wacky questions: `Green flash' at sunset hard to see in Colorado,”
Denver Rocky Mountain News (Spotlight section) , 2D (July 8, 1996).

* Rebecca Jones has an even wackier answer than the reader's question:
* Craig Bohren is cited, but misunderstood: "You need binoculars or a
* telescope to see it. . . . The light radiating from the sun comes in
* different wavelengths. . . . But when the sun sets, and the last few
* rays come over the horizon, all we're getting are the violet-blue ones.
* The atmosphere refracts those rays just a little, so to our eyes, they
* appear green.
* "And this is the green flash. It lasts just 5 - 10 seconds at this
* latitude, but can last a couple of hours in polar regions."
* But at least Craig is quoted as saying "There's no great risk" in
* looking at a "low horizon sun" through binoculars.


J. Klinkenberg
“Once in a green sun,”
St. Petersburg Times (Floridian section) , 1D–2D (Sept. 3, 1996).

* Jeff Klinkenberg's good article with a picture by Lu Rarogiewicz
* Quoting Rue Morgan: "It was like a green flash bulb going off, and it
* only lasted maybe a second, and it was incredible. I thought, `This is
* so amazing, it's going to be all over the news tonight.' I watched the
* TV that night, kept switching stations, but nobody reported anything."
* There is also much attention paid to the scoffers.
* The narrative describes an inf.-mir. flash, with "little notches" that
* "pinch off" a piece at the top: "The pinched-off part, a greenish version
* of the sun's disc, seems to float at the horizon."


P. Clinton
“The wild file (reply to letter from Frank King),”
Outside 21, 118 (Oct., 1996).

* Short reply to query about the reality of the GF


M. Frost
“Blue sky, red Sun, green flash,”
Astronomy Now 10, 54–55 (Nov., 1996).

* many small errors


Mark J. Coco
“Stalking the Green Flash,”
Weatherwise 49, no. 6, 31–34 (1996).

* popular article with good pictures by KENNETH D. LANGFORD
* but a few errors
* This is the (Dec.1996/Jan.1997) issue.


R. L. Speer
“Sun paints its fanciest canvasses on the Banks,”
The Carolina Coast (suppl. to Norfolk Virginian-Pilot) , 14 (Jan. 12, 1997).

* Ronald L. Speer (in Va.) thinks Florida sunsets are dull
* -- but he admits to never seeing a GF


L. Tarasov
“The green flash,”
Quantum 7, 38–39 (1997).

* article for schoolteachers, full of small errors; Jan/Feb 1997 issue
* Lev Tarasov says G.A.Tikhov was interested in the flash.


S. L. Knapp
“The green flash,”
Powder , 26 (Feb., 1997).

* A story about skier Glen Plake, who "told us it was good luck to see
* a green flash at sunset." No GF info.


P. Candy
“The green flash,”
Weather 52, 77–79, 81 (1997).

* another popularization, full of mistakes
* OK Omega photo, p.81; feeble GF, same page (March issue)


B. McWilliams
“Weather eye: Colourful reflections,”
Irish Times , 2 (March 11, 1997).

* Brendan McWilliams's second installment: the GF described
* Contains a short bio on O'Connell, citing his book


B. McWilliams
“Weather eye: Getting the green light,”
Irish Times , 2 (March 12, 1997).

* Brendan McWilliams's third installment: advice for observers
* The advice is generally sound, but he picked up O'Connell's error:
* "An unusual thermal structure in the upper air" is said to be required.
* Verne's "legend" is quoted in full (in translation).


C. DeLancey
“What exactly is a green flash? When is a good time to see one?,”
Oregon Coast , 18 (March/April, 1997).

* Yet another popular account, derivative and with some minor errors


L. Wilk
“Phenomena: the green flash,”
Discover Diving 15, no. 2, 23–25 (March/April, 1997).

* A fair but derivative article; author has seen 1 weak GF
* ". . . it was not the green explosion or backlit emerald that I'd been
* anticipating -- it was more subtle, a green glow that faded in and then
* abruptly vanished. . . .      I had watched the sun accelerate into the sea
* until it was nearly gone. Then, for the last ten seconds, I locked my
* gaze on the sun's rim and finally, there it was. When I saw the flash
* I turned excitedly to my wife and children, who were watching with me,
* but somehow they had missed it." [So, probably RETINAL BLEACHING.]
* Leslie Wilk has read the standard accounts, and repeats their errors,
* attributing the color to simultaneous contrast with the red sky,
* and mistakenly thinking the peak of the visual response is important.
* But he does recognize the importance of atmospheric structure.
* The publisher was bought in 1998 by Petersen Pubs, in turn bought the
* next year by emap.usa in England; but the editorial office is still in
* S.D.! (619-697-0703)
* The author's name is given on the contents page as Leslie Wilks; but as
* Dr. Les Wilk on the article. [I checked by e-mail: "Wilk" is correct.]
* By the way, he runs the "Physics Gearbag" Web site, one of my GF links.


M. Schirmer
“Aktuelle Hinweise für den Beobachter: Der grüne Blitz,”
Sterne und Weltraum 36, no. 4, 368 (1997).

* A SUNRISE FLASH photographed by Mischa Schirmer
* I have only a b/w photocopy, but the version on their Web site isn't
* very impressive; the flash is overexposed, due to use of automatic
* exposure setting. 4 stages from the line at the horizon to a very
* flattened Sun are shown.
* April issue


P. D. Davies, L. M. Butler, and E. Rosales
“Green flash, Mediterranean Sea,”
Marine Observer 67, 107 (1997).

* std. Inf.-mir. flash, but maybe longer lasting?
* "The remaining segment of the sun rapidly turned a very brilliant green
* which seemed to last for several seconds."


R. Silverberg
“The green flash,” in Reflections and Refractions
(Underwood Books, Grass Valley, 1997), pp. 124–127.

* Bob Silverberg's account, reprinted in hardcover anthology
* This is a popular account, based almost entirely on O'Connell's 1960
* article in Scientific American . It is remarkably accurate, except for
* "green being the color least affected by the atmospheric refraction."
* His own failure to see a flash is the common one, as betrayed by the
* words "The sun, yellow to the end, disappeared behind the hills."
* (see 1992 for the original publication.)


P. Candy
“Green flash follows a Mediterranean sunset (picture caption),”
Astronomy 25, 120 (1997).

* so-so COLOR PHOTO of inf.-mir.GF
* June, 1997


Anon.
“Ask the Old Farmer's Almanac,”
Deseret News , p.L–2, col.4 (July 13, 1997).

* Humphreys's couplet is quoted, in a reply by the editor of the Old
* Farmer's Almanac:
* Thanks to Jonathan Addington for pointing this out on Google News!


A. T. Young
“Sunset spectacular,”
Ocean Navigator , No. 83, 86–91 (July/August, 1997).

* ATY article on GF
* [actually FILED in "COLOR PHOTOS" file.]


M. Kobusch
“Grüne und blaue Blitze,”
Sterne und Weltraum 36, No. 10, 865 (1997).

* PHOTOGRAPHS with short text
* Abb.7 is completely muddied out on my b/w photocopy.
* The Web version of Abb.8 (the SUNRISE BLUE FLASH) in fact shows a
* small piece of blue rim; mostly this is overexposed. Both taken by
* Michael Kobusch. Oktober issue.


G. Lee
“Water colors,”
Washington Post (Travel section) , E1–E7 (Oct. 19, 1997).

* Entertaining first-hand account of a green-flash hunt in the Caribbean
* Gary Lee takes his color chart along. . . .


anonymous
“Take this, you green flash skeptics (in Flotsam & Jetsam Dept.),”
Aqua (Premier issue) 1, 22 (1997).

* Good short summary, with quotes from Alistair Fraser
* Nice Inf.-mir. GF COLOR PHOTO taken by Steven Businger
* This "Premier issue" apparently came out late in 1997; no month given.
* AQUA is the PADI Diving Society Magazine (Islands Publ. Co.)
* (PADI = Prof. Assoc. of Diving Instructors)
* [actually FILED in "COLOR PHOTOS" file.]


C. F. Bohren
“Le rayon vert,”
La Météorologie , series 8, , no. 20, 57–60 (Dec., 1997).

* French translation of Craig's Bohren's 1987 GF chapter from "Clouds . . . "
* Thanks to Didier Renaut for a photocopy!


A. Whitman
“At the eyepiece: scintillating wintertime half-hours,”
JRASC 91, 283–285 (1997).

* Alan Whitman's multiple GFs include a CLOUD-TOP flash
* Seen Jan. 22, 1983 from Queen Charlotte Islands. There are also
* accounts of chromatic scintillations of Sirius, Canopus ("mostly green,
* occasionally pure red, frequently both red and green. . . "), and the
* crescent Venus near the horizon.
* Thanks to the ADS full-text search, which revealed this; Dec. issue


P. Candy
Le Meraviglie del Cielo
(Il Castello, Collane Tecniche, Milano, 1997).

* Paolo Candy's book begins with a GF chapter


P. Candy
Le Meraviglie del Cielo, Seconda edizione riveduta e corretta
(Il Castello, Collane Tecniche, Milano, 1998).

* Thanks to Paolo Candy for supplying a copy of the revised edition!


C. Kitchin & R. W. Forrest
Seeing Stars: The Night Sky Through Small Telescopes
(Springer, London, 1998), p. 130.

* A short 1-paragraph mention of GF
* "At the time of the green flash, the red image of the Sun has set,
* and the blue image is absorbed by the atmosphere, leaving only the green
* image to be seen."


A. T. Young
“Green flash: sunset spectacular,”
Professional Mariner , No. 30, 79–82 (February/March, 1998).

* reprint of my Ocean Navigator article
* [actually FILED in "COLOR PHOTOS" file.]


Anon.
“Dining: Best Bet,”
Orange County Register (SHOW section) , 34 (April 3, 1998).

* This probably should be in the "folklore" file . . . .
* This is the little box at the bottom left corner of the page.
* "While no one in the group could recall actually witnessing the
* phenomenon, the consensus was that if they sat gazing at sunsets long
* enough, their chances of a sighting would increase.
* "Hence, an early-bird dinner and special cocktail were born."
* The dinner menu, and the recipe for the drink, are given.


A. T. Young
“The green flash,”
Weather 53, 189–190 (1998).

* ATY's 500 words on GF (filed in "pictures" file -- cover is my GF)
* The cover of this (June 1998) issue is my Jan.1996 GF.


A. T. Young
“Understanding green flashes,”
Bull. Amer. Astron. Soc. 30, 934–935 (1998).

* my AAS abstract


(unsigned report)
“In a flash,”
Economist 347, 95 (June 20, 1998).

* A badly garbled version of my press release at the AAS meeting
* No. 8073


C. Seife
“Don't let your eyes deceive you,”
New Scientist 158, 5 (20 June, 1998).

* nice summary of my press release and phone interview
* No. 2139


A. Whitman
“At the eyepiece: Eclipse-chasing perfection — the Caribbean,”
JRASC 92, 158–160 (1998).

* Cruise-ship sunset GF (p.160)
* ". . . a prolonged two to three second emerald green flash occurred! The
* dining salon erupted in cheers . . . ."
* [June issue]
* Thanks to ADS full-text search for turning this up!


W. Rossnagel
“Grüner Blitz bei Venus,”
Sterne Weltraum 37, 608–609 (1998).

* VENUS flash and HEIGHT EFFECT
* Thanks to Axel Quetz, editorial staff of SuW, for supplying the
* page number; I have only a photocopy that omits them. (July issue)


N. de G. Tyson
Just Visiting This Planet
(Doubleday, New York, 1998), p. 119.

* Neil de Grasse Tyson's book
* A simplified account of the textbook story: ". . . the atmosphere can
* act like a prism . . . ." (p. 119)
* He also touches on sunset eye safety on p. 124; and, though not as
* conservative as the extremists, is still overly cautious.
* Well-written, but (as Pasachoff notes below) prone to errors.


J. M. Pasachoff
“Book reviews: The FAQs of astronomy,”
Nature 394, 438 (1998).

* Jay Pasachoff reviews the Tyson book:
* "His explanation of the green flash which is sometimes visible at
* sunset is incomplete."
* (30 July 1998 issue)


N. Hey
“Successive green flashes,”
Sky & Tel. 96, 17 (Aug., 1998).

* Norman Hey's letter, cited by Harnish in the Nov. issue (below)
* In Palau, "We had three evenings in a row when . . . we saw a distinct
* green flash . . . ."      "Who might have seen more?"  There is a rare
* mention of YELLOW: ". . . the limb turned yellow then green . . . ."
* He also mentions "an apparent intensification just prior to the moment
* of disappearance." (This is a fairly common illusion.)


[Corliss]
“Some green flashes are yellow,”
Science Frontiers , No. 119, 3 (Sep.-Oct., 1998).

* a third-hand account, based on the New Scientist report
* (This is Corliss's newsletter)


Brendan McWilliams
“A flash of illusion in the blink of an eye,”
Irish Times , p.27 (13 Oct., 1998).

* seems to be based on the Economist's confused version of my work
* This regular column by the assistant head of the Irish Met Service
* is called "Weather Eye". No indication where he got it from.


M. Tinnesand
“The green flash,”
ChemMatters 16, No. 3, 12 (Oct., 1998).

* short article for high-school teachers, illustrated with my Jan.7 flash
* This mag is published by the ACS


anonymous
“The green flash,”
ChemMatters Teacher's Guide , 1 (Oct., 1998).

* supplemental info for the above item
* The questions on the last page don't allow a correct answer for
* what happens to red light, though.


M. Vollmer
“Gespiegelt in besondern Düften . . . ,”
Phys. Bl. 54, 903–909 (1998).

* GF treated in last section
* nice COLOR PHOTO of one of Pekka's green flashes (Abb.13)
* "Beliebt ist das Phänomen, weil es einerseits nur selten zu beobachten
* ist, so daß es immer noch etwas besonderes ist, den Strahl selbst
* gesehen zu haben. Zum anderen rankt sich um den grünen Sonnenstrahl
* Jules Verne zufolge die Legende . . . ."
* No. 10, so I suppose October issue.


T. Harnish
“Flying into the green flash,”
Sky Tel. 96, 14–16 (Nov., 1998).

* San Diego BIPLANE PILOT Tom Harnish reports seeing many a GF here
* and cites Norman Hey's letter in the August issue.
* Nov. issue (each month paginated separately)


S. Edwards
“Sunland Secrets: discovery,”
The Sunday Oregonian , T1–T3 (Nov. 8, 1998).

* This commercial travelogue treats the GF in its penultimate paragraph
* "Baja's unpolluted surroundings make it a perfect place to see a green
* flash. We saw several during the week." No details; sketchy description.
* This article is one of three under the "Sunland Secrets" head.
* "Steve Edwards is a staff writer for the Muskegon (Mich.) Chronicle"


[no author listed]
“Camera doesn't lie! Green flash is yellow,”
Current Science 84, p.14 (4 Dec., 1998).

* based on the AAS press release; slightly garbled
* Uses my inf-mir. GF photo


W. Galvani
“The green flash,”
48 Degrees North -- The Sailing Magazine 18, No. 6, 97 (Jan., 1999).

* William Galvani sees a flash in La Jolla, after 30 years of looking
* This is available on the magazine's website at
* http://www.48north.com/jan99/greenflash.htm
* but is accompanied by a most misleading animated graphic.
* Thanks to Greg Smart for the pointer!


C. Raymo
“Science musings: The quest for the flash,”
Boston Globe , C–2 (March 15, 1999).

* Chet Raymo finally sees a flash after 34 years
* "The atmosphere acts like a prism. . . ." And he mis-dates O'Connell's
* Scientific American article to 1965. Or does he mean he didn't see
* the article until 1965?
* Mentions the 1992 column, and one I don't have, in 1985.


A. T. Young
“Green flashes and mirages,”
Optics and Photonics News 10, no. 3, 31–37 (March, 1999).

* my OPN article; some COLOR PHOTOGRAPHS


T. von Foerster
“More green flash accounts,”
Optics and Photonics News 10, no. 6, 5 (June, 1999).

* letter commenting on my OPN article
* Mainly to point out the newer edition of Minnaert


K. Beevor
A Tuscan Childhood
(Pantheon, New York, 1999).

* A wrong idea popularized
* This memoir is more about Tuscany than about Kinta Beevor's childhood.
* But, alas, on p. 144, we have: "Sometimes from the beach at dusk we could
* see the `green flash'. The sky had to be perfectly clear, and just as the
* last tiny segment of the sun disappeared below the horizon, the streak of
* tangential light through the surface of the sea would produce this
* extraordinary optical effect." Extraordinary indeed!
* "Published in the United States by Pantheon Books, a division of Random
* House, Inc., New York. Originally published in Great Britain by Viking,
* a division of Penguin Books Ltd., London, in 1993." So this should
* really be moved back to 1993; but is kept here for the dangerous review
* (next below) by Jo Ann Hofheimer. Note that Kinta Beevor died in 1995.


J. A. Hofheimer
“An homage to the Tuscan way of life,”
The [Norfolk, Va.] Virginian-Pilot , E3 (July 18, 1999).

* A wrong idea popularized again!
* Jo Ann Hofheimer's unfortunate review of Kinta Beevor's book says
* "If you're interested in . . . what causes that mysterious green flash as
* the sun sets over the sea --- this is the book for you." Arrrghhh!!


A. T. Young
“De groene flits, hemelsverschijnsel tussen wal en schip,”
Zenit 26, 248–254 (1999).

* my Zenit article: GOOD COLOR PHOTOGRAPHS, so filed in "PICTURES" file.
* Includes the 4-flash sunset from Mt. Laguna.
* Very nicely translated into Dutch by editor Eddy Echternach.
* This is the June issue (no.6)


N. S. Alton
“Stellar performances,”
Frontier Magazine 2, no. 1, 9 (Sept.-Oct., 1999).

* the "70-word article" in Frontier Airlines's magazine
* The GF paragraph is the second part of Nancy Schatz Alton's column.
* My mock-mirage photo is mis-marked "inferior-mirage", but at least the
* correct advice for observing is given.


J. Kaiser
“Hot picks: Sunset strip,”
Science 285, 1455 (1999).

* Science 's "NetWatch" page picks up my GF Web site
* A pretty good 1-sentence summary, though "movies" is misleading.


C. Booy
“Groene flits (1),”
Zenit 26, 401 (1999).

* Letters to Zenit, responding to my GF article there:
* letter from Cor Booy about FEENSTRA KUIPER and his GF observations.
* Here is the "held van de dag" story!
* This is the Sept. issue (nr.9)


L. Huider
“Groene flits (2),”
Zenit 26, 401–402 (1999).

* Letters to Zenit, responding to my GF article there:
* letter from Lodi Huider, asking why Jules Verne wasn't mentioned.
* Both of these letters have responses from ATY (translated).
* This is the Sept. issue (nr.9)


Chr. Drösser
“Grüner Sonnenblitz,”
Die Zeit , Nr. 43, p.46, col.1 (21 Okt., 1999).

* Nice but short item in DIE ZEIT
* Christoph Drösser's reply to a query by Maria Blümel
* Succinctly put: "Bei bestimmten Schichtungen von warmer und kalter Luft
* kommt es aber nicht nur zu Brechungen, sondern auch zu Spiegelungen.
* Dann erscheint die Sonnenscheibe über dem Horizont eingekerbt und
* verzerrt. Unter diesen Bedingungen kann der grüne Rand im Moment des
* Sonnenuntergangs für kurze Zeit optisch in die Breite gezogen werden
* und wird für Sekundenbruchteile wie ein Blitz sichtbar."
* Evidently Stimmt's? is a regular column in the Wissen section.


F. Hirschmann
Alaska from the Air
(Graphic Arts Center Publishing, Portland, Oregon, 1999).

* Alaskan pilots' accounts of GFs and mirages, reported by Fred Hirschmann
* This is a big, glossy "coffee-table" book, with lots of pictures --
* but none of mirages or green flashes! The GF stories are on p. 28;
* mirages on p.27; and a good ball-lightning story (mis-labelled as St.
* Elmo's fire) on p.31. The GF explanation is a rudimentary version of
* the textbook account: "The earth's atmosphere acts as a giant prism,"
* blah, blah,blah. Also, in discussing latitude effects: ". . . the green
* flash occurs for a longer period of time in the Arctic. Some observers
* in northern Alaska have reported seeing green flashes that lasted for
* more than one second." Amazing, isn't it? The game of repeatedly
* displaying the same flash over and over by climbing and diving is also
* described. So is the trick of playing hide-and-seek with mountains and
* valleys.
* On the other hand, the mirages are accompanied by some quantitative data
* on inversions: a square Moon is described with an inversion of 60° F
* between the surface and 2000 ft. An inversion at 500 ft. gave mirages
* of an island 30 miles away, switching between erect and inverted images in
* 50 ft. of airplane elevation. Nice description of superior mirage:
* ". . . the tops of mountains go flat and appear boxlike." [TRUNCATION]


E. Schifano
“Hotline,”
Sarasota (Florida) Herald-Tribune , 2B (Nov. 2, 1999).

* Eileen Schifano's little gem, describing the flash clearly in 138 words


A. T. Young
“Chapter & Verse,”
Harvard Magazine 102, 34 (Dec., 1999).

* my appeal for source identifications


C. Day
“Web Watch,”
Physics Today 52, no. 12, 57 (Dec., 1999).

* Physics Today cites my GF Web site and shows Hank Hogan's composite photo


F. Deford
“Florida Keys: Paradise with attitude,”
National Geographic 196, 32–53 (Dec., 1999).

* Frank Deford obviously is dubious . . .
* "Or maybe it is just a Keysian Loch Ness monster."
* There is a follow-up to this in the November 2000 issue.


J. Schad
“Roam-O-Rama: A guide to unexpected San Diego,”
San Diego Reader , p.96 (16 Dec., 1999).

* Jerry Schad's good brief mention of green flashes and distorted sunsets.


B. Ansley
“See green,”
New Zealand Listener , 34 (18-24 Dec., 1999).

* Alan Gilmore tells me this story was largely based on my Web site
* They got some details right (the hyphen in Verne's title; ozone as the
* main orange absorber) and some wrong (the 1/40 second duration seems to
* be a simple error on the part of the reporter; believing Verne's "old
* Scottish legend" is another matter!). The phony illustration is a
* shame, though. (Filed with the other color illustrations, anyway.)
* The "Listener" is basically the radio and TV schedule for the Kiwis.


M. Viney
“Another life: A private wink from paradise,”
Irish Times, Weekend section , 17 (Feb. 19, 2000).

* Michael Viney's observation; books by Raymo and McWilliams named
* ". . . a brilliant, emerald flash of light. Yes -- emerald!"
* A little noise in here: wrong title for McWilliams's book; wrong date
* for O'Connell's work.


Anonymous [actually Didier Renaut]
“La photo du mois, février 2000: Le rayon vert,”
La Météorologie , series 8, , no. 30, 120 (juin, 2000).

* A couple of GOOD COLOR PHOTOS reproduced
* One is my April 19, 1998 mock-mirage flash from Alpine; the other was
* taken by Régis Tiercelin and shows a nice green rim. The descriptions
* are brief; the translation of Bohren's essay on GFs is cited.
* This is a special issue on numerical weather prediction. An item of
* special interest is on pp. 9-10, on numerical weather prediction in
* Potsdam; there is a fine color photograph of the Einstein tower!


Anonymous
“When and why the sun turns green,”
National Geographic 198, (Nov., 2000).

* A very insipid inferior-mirage flash; shows the Omega nicely, though
* Tim Laman's sunset sequence has barely a trace of green.
* (He tells me they failed to reproduce the frame that shows the flash
* best!)
* This is in the "Geographica" section of the un-numbered pages at the
* front of the issue.


A. T. Young
“Sunset science. III. Visual adaptation and green flashes,”
JOSA A 17, 2129–2139 (2000).

* My "visual effects" paper, mostly about retinal bleaching
* Sunset Paper III.


K. Burns
“Refraction in action: the bending of light beautifies the skies above San Diego County,”
North County Times , G–1 and G–3 (17 Dec., 2000).

* Katie Burns's newspaper column on refraction phenomena
* This came out quite well, though they failed to credit my photographs of
* green flashes.


G. E. Liston
“Green flash observations on 24/25 March 1983 at the South Pole, Antarctica,”
Weather 56, 2–3, 17 (2001).

* Glen Liston's report of South Pole flashes in 1983
* The photograph on p. 17 has been "digitally enhanced to more closely
* resemble the darker and brighter green colour that we witnessed."
* It clearly shows the flattened image at the top of a strongly-refracting
* (darker) layer.


A. Gulick
“What about: green flashes demystified,”
Dive Training 11, no. 2, 115–120 (Feb., 2001).

* Amy Gulick's article based largely on my website


P. Nichols
“The green ray,” in Tacita Dean
(Tate Gallery Pub., London, 2001), p. 62.

* Peter Nichols's apparent green-glow observation mentions Eric Hiscock
* "As the red upper rim vanished, a distinct, momentary, radium-green
* glow blinked and was gone." The facing page (63) shows an old German
* postcard colored by Tacita Dean in "the perfect radium shade" --
* actually, a rather watery, pale green.
*      This book is the catalogue for Tacita Dean's show at the Tate,
* 15 Feb. - 6 May, 2001. The copyright for the book is "The Tate
* Trustees" but the texts are copyright "the authors", and no author
* or editor is given for the book in the British Library catalog.


G. Beekman, L. Bruning, M. Kleinhans, J. Kuiper, J. Luyten, E. Echternach, E. Mathlener, and S. Mathlener
Zon, Zee en Sterren
(Stichting Universum, Utrecht, 2001), pp. 36–37.

* Brief mention of green flash in a handbook of phenomena for vacationers
* with one of my COLOR PHOTOs of an inferior-mirage flash.
* Standard textbook explanation, with use of term "groene segment".
* Co-publisher: ANWB bv, Den Haag.


D. Turner
“A Lamplighter moment: Hunting for the Green Flash ,”
JRASC 95, 101–102 (June, 2001).

* David Turner's BLUE SUNRISE flash in the mountains (Las Campanas)


J.-Y. Le Vourc'h, C. Fons, and M. Le Stum
Météorologie Générale et Maritime
(Meteo-France, Toulouse, 2001), p. 231.

* GF mentioned in a textbook for French mariners, with one of my photos


S. Dunlop
How to Identify Weather
(Collins, London, 2002), p. 131.

* Storm Dunlop's book
* GF is covered on p.131, under "Sunrise and sunset effects"


T. Dean
The Green Ray and Other Suns
(?, Serralves, 2002).

* Foldout catalogue produced for Tacita Dean's show at Museu Serralves
* in Portugal, 2002. (Cf. her movie, in the "GF in movies" section, and
* the 2004 book based on it, in sequence below.)
* I have not seen this. It is advertised at
* http://www.bookstorming.com/fiche.asp?idlivre=2147470343&page=liste.asp&np=1&nbr=1&ttcl=
* and elsewhere.


B. W. Brust
“Green flash,”
Quicksilver Magazine , 30–31 (Summer, 2002).

* Beth Brust's GF article
* Good 2-page treatment, with my photos


K. Morey
Kauai Trails, 2nd edition
(Wilderness Press, Berkeley, Calif., 2002).

* Kathy Morey's short mention
* This is a nice guidebook to one of the Hawaiian islands. Green flashes
* are mentioned in connection with a beach on the NW corner of the island.
* The somewhat inaccurate account on pp. 168-170 of the second (1997)
* edition has been replaced by a revised version on pp. 248-249 of the
* third (2002). There is an amusing account of ``The Tanqueray
* Flash'', attributed to her skeptical father.


J. A. Adam
Mathematics in Nature
(Princeton Univ. Press, Princeton, 2003).

* John A. Adam's book on mathematical models
* One paragraph on p. 75 is devoted to green flashes (textbook model).


C. L. Adler, J. A. Lock, J. Mulholland, B. Keating, and D. Ekelman
“Experimental observation of total-internal-reflection rainbows,”
Appl. Opt. 42, 406–411 (2003).

* from the Boulder meeting issue of AO
* One of their rainbows corresponds to the sub-duct flash, if you
* replace the light source (rainbow) with the observer (flash).


Anonymous
“Green Flash,”
Southern Boating , 110–111 (May, 2003).

* Hank Hogan's composite published again; 1 page of text
* Thanks to Hank for a color copy!


S. A. Ackerman and J. A. Knox
Meteorology: Understanding the Atmosphere
(Brooks/Cole---Thomson Learning, Pacific Grove, CA, 2003).

* Steve Ackerman's book has a short GF section
* Just gives the textbook explanation: ". . . a sliver of green appears for
* a second or two as the Sun disappears over the horizon."
* The 2-paragraph "Green Flash" section spans pp. 150-151.
* Hank Hogan's sunset composite is on p. 152, well reproduced in color.
* There is also a nice inferior mirage photo on p. 148.


H. Yizhaq
“Ha-Keren Ha-Yirokah: Ha-Polygraph shel Ha-Ahavah,”
Teva HaDvarim 104, 98–100 (June, 2004).

* Hezi Yizhaq's GF article in Hebrew
* Has a nice GF photo in color. This is a "National Geographic"-type
* mag, but with quarto page size.
* The title translates as "The green ray -- the polygraph of love".
* Thanks to Hezi Yizhaq for a copy, and Mark Stover for transliteration!


T. Dean
The Green Ray
(Verlag Der Buchhandlung Walther König, Köln, 2004).

* Tacita Dean's flip-book of frames from her video (ISBN: 3883756776)
* A rather marginal inferior-mirage flash. The film was (for my taste)
* overexposed about 1 stop, and the sky was very bright. Because of
* the combination of overexposure and excessive aerosol scattering,
* the flash is very washed-out looking; it shows, at best, a yellow-green
* color. This isn't helped by the low resolution of the film. It
* does convey well the naked-eye impression of an average flash.
*      The only printing in the flip book is on the inside cover, where
* Tacita Dean says, "At the end of last year, I made a 2 minute 16 mm
* film of the green ray in Madagascar. The green ray is an optical
* phenomenon that happens at the last moment of setting sun. It is
* quite rare to see from land and you usually see it when the sun sets
* over the sea when there is a 100% clear horizon." (dated 2002).
*      Apparently, from an interview with the artist at
*
*        http://www.bombsitebeta.com/issues/95/articles/2801 ,
*
* the use of a marginally-visible flash was intentional. On the
* other hand, I'm reminded of Havinga's (1934) remarks! Another
* interview with the artist was published in 2007 (below).
*      The flip-book is a cute idea; I'd have wished for a nicer flash.
* You can see, from the discontinuities in the waves, that about 1 frame
* per second was selected at first. Several consecutive frames show
* the flash itself. The overexposure makes the Sun white until the
* remaining segment is about 10' of arc wide.
* There seems to be a 2004 edition published by Distributed Art Pub Inc.


I. R. Schwab
“Better one or two?,”
British Journal of Ophthalmology 88, 733 (2004).

* A short treatment of the GF
* Accompanied by color images on the cover, which I have not seen.
* OK for GF, but unfortunately spreads the Galileo myth again.
* The reprint is available on the Web at
*             http://bjo.bmjjournals.com/cgi/reprint/88/6/733
* It shows an inferior-mirage flash (as the "one") and a nice pair of
* mock-mirage flashes (as the "two").


M. Richey
“The Green Flash,”
Flying Fish , No. 1, (2004).

* Mike Richey's brief summary
* This publication is the journal of the Ocean Cruising Club, a group
* of (mainly British) small-boat owners who enjoy long trips at sea.
*      This letter cites the Met. Office's Manual for marine observers,
* O'Connell's book, and Brett Hilder's observations in the 1950s for
* determining longitude by using GF times to mark the sunset.
*      A PDF is available at
* https://liveicomgrshot.blob.core.windows.net/occfiles/ffarticles/
* (look for article 643)
*      Thanks to Dick Morris for pointing out this obscure item.


R. R. de Freitas Mourão
“Le Rayon Vert: le roman comme agent stimulateur de l'observation scientifique,”
Revue Jules Verne , No. 19-20, 216–224 (2005).

* Ronaldo Régério de Freitas Mourão discusses Verne's book, and its effect
* The author is an astronomer in Brazil who is interested in history.
* Unfortunately this is marred by several careless errors: he says Back's
* observation was Antarctic (though he correctly cites the title with the
* word "Arctic" in it!); Treusch is claimed to be "le premier astronome à
* enregistrer les phénomènes qui entourent le rayon vert;" Rayleigh's
* name is misspelled (twice, in different ways), and he confuses the 3rd
* and the 4th Barons -- thus producing the absurdity of giving the name
* and dates of the 3rd Baron, who died in 1919, with the publication date
* (1934) of the 4th Baron's second paper; Keilin & Hartree (1950) are
* moved to 1952 (and Hartree comes out "Hartrel"), and falsely credited
* with suggesting that oxygen and ozone absorption are responsible; etc.
*      Thanks to Jacques Crovisier for pointing this out, and providing a
* photocopy. He says this "is from a contribution to one of the numerous
* colloquia organized to celebrate the Jules Verne year."


Editors of the Weather Calendar
Weather: The Ultimate Book of Meteorological Events
(Accord Publishing, Denver, 2008).

* Ken Langford says 2 of his GF photos are in here
* Scheduled for release Sept. 1, 2008 -- no editor named.
* Accord seems to be connected with Andrews McMeel Publishing, listed as
* "author" on some Web pages. Some familiar names are text contributors:
* Ed Darack, Fred Schaaf, etc.


J. A. Lock
“35 minute green flash observed at Little America on 16 October 1929: a retrospective study,”
Appl. Opt. 54, No. 4, B54–B63 (1 Feb., 2015).

* James Lock's analysis of the Byrd Expedition observations
* Much labored exposition of the positional astronomy of the circumstances,
* but a generally reasonable discussion of the observations. Both the
* author and his readers would have had an easier time if he had known
* to consult the Astronomical Ephemeris.


P. Lawrence
“The Green Flash,”
Physics World 27, No. 7, 30–31 (July, 2015).

* Pete Lawrence's pictures and visual observations
* He seems to think all GFs are due to inversions -- which is nearly true
* for his high observing sites. Includes a visual observation of a
* cloud-top flash, and a photograph of a long red line at the horizon.


T. ben Arous, S. Boulahjar, and S. G. Lipson
“Observing the green flash in the laboratory,”
Eur. J. Phys. 39, 015301 (2018).

* Tomer ben Arous, Saber Boulahjar, and Stephen G Lipson make a lab demo
* Another aquarium demo, using salt water; high-school students
* DOI: https://doi.org/10.1088/1361-6404/aa90f5



*** S+T FILE: articles & pictures from SKY & TELESCOPE and NIGHT SKY ***

T. S. Jacobsen
“The Green Flash at sunset and sunrise,”
Sky Tel. 12, 233–236 (1953).

*
* poor GREEN FLASH SPECTRUM and general discussion
* This is a re-hash of his JRASC paper in 1952.
* O'C #57


W. E. Howard, III, and and A. T. Young
“(letter to the editor),”
Sky & Tel. 17, 15 (1957).

* WEH III & ATY observe some GF phenomena, but don't understand them
* This was the first GF observation I ever made, completely mystifying to
* me at the time. The observations were made over Belmont Hill from the top
* of Building D at HCO; evidently the phenomena are the same ones discussed
* by Fraser in 1975. The cause is probably miniature mock mirages due to
* inversions bent up over the hill. These observations certainly took
* place when the Sun was a few degrees above the astronomical horizon.
* ". . . the gradual nature of the color and brightness changes rules out an
* explanation by eye fatigue."


W. A. Feibelman
“Sunset phenomena,”
Sky Tel. 18, 573 (1959).

* SUNSET PHOTOGRAPHS -- slight notching


R. H. Wilson , Jr.
“(letter to the editor),”
Sky Tel. 42, p.327, 351 (1971).

* full-spectrum flash: YELLOW, GREEN, BLUE, VIOLET
* "During the last few seconds of sunset, the remaining solar segment
* changed color through the whole visible spectrum: first more yellowish,
* then greenish, and finally blue and violet just before the last of the
* solar disk disappeared."


(editorial report)
“Green Flash of Venus,”
Sky Tel. 46, 413 (1973).

* GREEN INFERIOR MIRAGE OF VENUS
* Observations by Peter K. Nelson, Kevin Clarke, and James M. Roe
* on board the Canberra (eclipse cruise)


A. Boyko
“(letter to the editor),”
Sky Tel. 47, 85 (1974).

* GREEN INFERIOR MIRAGE OF VENUS explained correctly


(editorial summary)
“Observations of the Green Flash,”
Sky Tel. 48, 61–63 (1974).

* SUNSET PHOTOGRAPHS -- CLASSICAL INFERIOR-MIRAGE GREEN FLASH
* MOVIE FRAMES by Dennis di Cicco at Cape Velas, Costa Rica
* GREEN RIM photographed by George Ripley
* INFERIOR-MIRAGE GF photographed by Paul Travers at Puerto Vallarta, Mexico


[Observer's Page]
“Green Ray,”
Sky Tel. 48, 412–413 (1974).

* GREEN RAY observations
* Observations by Harold Hill in Italy (over Ligurian Sea)
* " . . . bright green ray shot up vertically from the sea."


(photographs taken by Richard J. Monda)
“Atmospheric distortion of the rising Moon,”
Sky Tel. 55, 362 (1978).

* DISTORTED MOONRISE -- features both compressed and expanded


[Observer's Notebook]
“Double Sun observed,”
Sky Tel. 60, 74–75 (1980).

* VERBAL DESCRIPTION of "DOUBLE SUN" -- cf. Hevelius, and Applegate (1929)
* ". . . since the lower image was the brighter they concluded that the
* upper image was the mock sun."


[Observer's Notebook]
Sky Tel. 71, 217 (1986).

* SUNSET PHOTOGRAPHS -- thistle shape; multiple layers
* photographed by Jim Baumgardt, Fremont Peak, Calif.


R. W. Sinnott
“Anomalous refraction low in the sky [box],”
Sky Tel. 72, 392 (1986).

* SUNSET PHOTOGRAPHS showing flatter top than bottom, and extinction in
* lower layer
* photographed by Claude Combes at Juniyah, Lebanon


D. diCicco
“Observer's Page: Sky photography near the Arctic Circle,”
Sky Tel. 73, 343–345 (1987).

* SUNSET PHOTOGRAPHS by PEKKA PARVIAINEN
* LUNAR MOCK MIRAGE; nice SOLAR OMEGA
* VENUS DISPERSED: self-portrait with Green Flash


(editorial summary)
“Bidding the day adieu,”
Sky Tel. 74, 680 (1987).

* SUNSET PHOTOGRAPHS + GREEN FLASHES by PEKKA PARVIAINEN and
* SUNSET PHOTOGRAPHS by Lee Coombs, Los Osos, CA (good HOURGLASS + extinction)


F. Schaaf
“A field guide to atmospheric optics,”
Sky Tel. 77, 254–259 (1989).

* General ATMOSPHERIC OPTICS with 2 GREEN FLASHES by Pekka, p. 258


G. L. Verschuur
“A green flash of Jupiter,”
Sky Tel. 77, 259 (1989).

* JUPITER flash


B. E. Schaefer
“The Green Flash,”
Sky Tel. 83, 200–203 (1992).

* SUNSET PHOTOGRAPH by PEKKA PARVIAINEN
* nice MOCK MIRAGE
* ". . . the green rim partially detached or even separated from the rest of
* the Sun . . . may be caused by stratified, horizontal air layers below
* the observer . . . ."


[Gallery]
Sky Tel. 83, 707–708 (1992).

* SUNSET PHOTOGRAPHS by PEKKA PARVIAINEN
* nice DOUBLE MOCK MIRAGE; POSSIBLE GENUINE BLANK STRIP


R. Sampson
“Novaya Zemlya: a solar mirage,”
Sky Tel. 85, No. 2, 96–97 (1993).

* SUNSET PHOTOGRAPH by PEKKA PARVIAINEN -- FINAL LINE
* also similar sunrise drawings by Russ Sampson, Edmonton, Alberta


[Observer's Notebook]
“The green and blue flash,”
Sky Tel. 87, No. 2, 110–111 (1994).

* CLASSICAL INFERIOR-MIRAGE GREEN FLASH and BLUE FLASH
* Observations by Kenneth A. Barbone at Pismo Beach and Rincon Point, CA
* MIRAGE plainly visible in first photo


R. W. Sinnott
“Sunrise and sunset: a challenge,”
Sky Tel. 88, No. 2, 84–85 (1994).

* SUNSET PHOTOGRAPH by PEKKA PARVIAINEN
* PEAR-SHAPED SUN; FLAT BOTTOM; 2 SMALL NOSES


[Observer's Notebook]
“Daylight Earthshine? / Airborne flashes,”
Sky Tel. 89, No. 1, 111 (1995).

* "GREEN DOT" and other green flashes
* Observations by Paul C. Soper
* See subhead: "Airborne flashes"


A. M. MacRobert
“Beating the seeing,”
Sky Tel. 89, No. 4, 40–43 (1995).

* SUNSET PHOTOGRAPH by Marc J. Coco -- green corners on small segment


M. Barlow Pepin
“Atmospheric symphonies,”
Sky Tel. 89, 100–104 (May, 1995).

* "SQUARE" SUN and GREEN STRIP above TRIANGLE by Eugene Brings
* This GF closely resembles my flash of 2 Feb., 1999, including the
* diagonal features due to waves on the inversion! (see p.102)
* Note that issues are paginated separately here.


B. A. Smith
“Prolonging the green flash.,”
Sky Telesc. 93, No. 5, 111–112 (May, 1997).

* copy in COLOR PHOTOS file, though Pekka's photos reproduced here are not
* very striking.
* AAA067.082.06


F. Schaaf
“Night of the Venus green flashes,”
Sky & Tel. 101, no. 2, 112 (Feb., 2001).

* Fred Schaaf's VENUS blue-green flash, seen with 7x50s on a roof
* "a few hundred yards" away; repeated a "few dozen" times by moving.


F. Schaaf
“The Sun, Moon, and planets in June,”
Sky & Tel. 101, No. 6, 95 (June, 2001).

* Dennis di Cicco's inferior-mirage flash sequence at top of p. 95
* (This is the same sunset published in S&T 48, 61, 1974)
* Thanks to Benji Myers for pointing this out!


J. Ryan
“SkyWise: green flash,”
Sky & Tel. 101, No. 6, 110 (June, 2001).

* The "textbook" story, badly presented in cartoons
* Thanks to Benji Myers for pointing this out!


F. Schaaf
“The near sky: Green flashes (Part 1),”
Sky & Tel. 102, No. 5, 104 (Nov., 2001).

* First installment of a small box on GFs, citing my Web pages
* This one mentions (but does not cite) my JOSA paper ("Part III.")


F. Schaaf
“The near sky: Green flashes (Part 2),”
Sky & Tel. 102, No. 6, 96 (Dec., 2001).

* Second installment of a small box on GFs, citing my Web pages
* This shows my Jan.7 GF, but hardly larger than a postage stamp.


A. Danielsen
“A flash of green,”
Sky & Tel. 108, No. 5, 137 (Nov., 2004).

* An overexposed picture of a mock-mirage flash


T. Flanders
“The green flash observed,”
Sky & Tel. 108, No. 6, 97–99 (Dec., 2004).

* a good inferior-mirage flash from Rome, and a very overexposed sunrise
* flash over mountains in New Mexico. There is an interesting discussion
* of Owen K. Garriott's report of a flash seen from several different decks
* of a ship.


F. Schaaf
“Catch the green flash!,”
Night Sky 2, 52–56 (Sept. /Oct., 2005).

* Good article by Fred Schaaf
* He even debunks the "legend"! Some nice color photographs here, including
* George Kaplan's "Omega" series. He concludes with a great line:
* ". . . more wondrous than even Jules Verne could ever hope to convey."
* ["Night Sky" is S&T's new attempt to compete with "Astronomy" mag.]



*** GF in LOCAL PAPERS FILE ***

J. Muncie
“News flash: Green at sunset isn't just a pigment of your imagination,”
San Diego Union-Tribune , Passport–13 (May 21, 1993).

*
* John Muncie's shaded sidebar from the U-T (reproduces badly from microfilm)
* This reply is attributed to William Nirenberg at Scripps


A. Salm
“No kidding: That flash of green is real,”
San Diego Union-Tribune , Night & Day–47 (5 Aug., 1993).

* Arthur Salm's "At Ease" column
* Remarkably, this newspaper story cites both Shaw's 1973 paper and
* Gerharz's 1981 paper, both in PAGeoph.


L. James
“Tourist eats: beach treats sans sand,”
San Diego Union-Tribune , Night & Day–44 (26 Aug., 1993).

* Restaurant review of Armando's Green Flash in P.B.
* Leslie James says "I happen to be among the non-believers."
* (Not too happy about the eatery, either.)


G. Ridge
“Zeroing in on the sun's green flash,”
Arizona Daily Star (Tucson) , 2H (Jan. 15, 1995).

* Tucson isn't quite local, but George Ridge's column fits best here
* He relies mainly on O'Connell's 1960 article in Scientific American .
* "As described by those who have seen it, the flash most resembles a
* green stem on the disappearing red apple of the sun."
* "For some reason, the flash is easier to see from a ship's upper deck or
* other high point." Generally good observing advice here, including
* binoculars.


Anonymous
“I didn't know that . . . ,”
Los Angeles Times , B–2 (18 Dec., 1997).

* The answer here is attributed to Sallie Baliunas


A. Bucholtz
“Sun's green flash caused by a prismatic effect,”
San Diego Union-Tribune , E–2 (24 Dec., 1997).

* Anthony Bucholtz's biweekly "Oceans Watch" column
* He gives Laplace his due: "The more atmosphere it goes through
* the more it is refracted." But then comes the textbook error:
* ". . . leaving only a green rim near the top of the sun. This is the
* green flash." So the variability has to be attributed to variable
* aerosol extinction: "Only when the atmosphere is fairly clean will the
* effect be seen. Since this is rarely the case, on most evenings you
* won't see the green flash." But he is one of the few to add that
* ". . . here in San Diego there are many days of the year when . . . chances
* are good that you'll see this beautiful effect."
* Thanks to Fred Talbert for first pointing this item out to me!


C. Raymo
“A trick of the eye or a real flash in the sky?,”
Los Angeles Times , F2 (26 April, 2005).

* Chet Raymo again
* This is in the "Outdoors" section of the Times, under the heading
* "Wild West". He still seems to think O'Connell's pictures were the
* first in color, and believes Groff's claims about the ancient Egyptians.
* The sunset photo on p. 1 shows a green artifact, not a GF.


E. Wendt-Kellar
“In search of the Green Flash,”
Naples Daily News, Neapolitan (Section D) , 1 (6 July, 2005).

* my picture gets a 5-column spread; the writeup is good
* Reports of green flashes seen from the Naples Princess, a local
* sightseeing boat.
* Naples, Florida is where this comes from.


R. Krier
“Rare green streak is there and gone in a flash,”
San Diego Union-Tribune, Quest (Section E) , E1 (17 July, 2008).

* Mila Zinkova's GF photo illustrates our local paper's article
* Good treatment of GFs by Robert Krier. This article accompanies 2
* others by him on sunsets and clouds.


R. Krier
“SDSU professor shares finer points of how to see sunset's green flash,”
San Diego Union-Tribune, Quest (Section E) , E1 (14 August, 2008).

* A follow-up to the above, with a well-reproduced GF by Jim Grant
* The column is headed "Weather Watch".



*** O'CONNELL FILE ***

D. J. K. O'Connell
The Green Flash and Other Low Sun Phenomena
(North Holland, Amsterdam, 1958).

*
* Here we have the citation of O'Connell's book, and REVIEWS of it.
* It's incredible that the book sold for a mere $6 in 1958.
*
* (Originally this was of interest to me only for SUNSET OBSERVATIONS.)
* See
*             https://aty.sdsu.edu/explain/observations/OConnell.html
*
* for detailed discussion of the phenomena in the photographs.
* Note that the phrase "low Sun phenomena" was coined by W.J.Fisher and
* used in the titles of several of his papers.


P. Darnell
“D.J.K.O'Connell, S.J.: The Green Flash . . . ,”
Nordisk Astronomisk Tidsskrift 39, 142–143 (1958).

* "At Specola Vaticana the Sun goes down sometimes over land, sometimes
* over the Adriatic Sea . . . "
* Yeah, right. So it isn't just Americans who don't know geography.


L. Searle
“Review of publications: The Green Flash and Other Low Sun Phenomena,”
J. Roy. Astron. Soc. Canada 53, 47 (1959).

* ". . . this book will be an inspiration to amateur astronomers in showing
* how colour photography with a telescope can be applied to the study of
* fascinating and often ill-understood meteorological phenomena."


J. Paton
“The green flash,”
Nature 183, 423 (1959).

* Feb.14 issue
* James Paton parrots the Rayleigh party line: "It occurs when refraction
* in the atmosphere close to the Earth's surface is abnormally great, that
* is, when the density decreases rapidly with height."


"P. S."
“Review: The Green Flash and Other Low Sun Phenomena,”
J. Astron. Soc. Victoria 12, 28 (1959).

* About a half-page summary with few comments, except:
* "The whole subject actually belongs to the field of Meteorological
* Optics, but -- as the author says -- it has been widely dealt with by
* astronomers, and valuable observational material can only be obtained by
* astronomical equipment." Nonsense!
* "Victoria" appears to be the Australian one. April issue.


C. H. Smiley
“The Green Flash and Other Low Sun Phenomena,”
Science 129, 1218–1219 (1959).

* a one-column review by Charles H. Smiley
* "The color photographs of the green flash are particularly impressive
* when one realizes that, on the average, the phenomenon is visible only a
* few times a month and then only for a second or so. I have seen the
* green flash many times in the last 20 years . . . ."
* "Sea captains, retired after half a century or more of service, have
* told me that it was only after retirement that they had heard of the
* green flash and had observed it."
* This review provoked some discussion: see the letter by Schwarz,
* and Smiley's reply.
* May 1 issue


(editorial notice of new books)
“The Green Flash and Other Low Sun Phenomena,”
Sky & Telescope 18, 162 (1959).

* 3-sentence announcement in Jan. issue of S&T
* "Astronomical telescopes that could be pointed to the horizon were used
* to procure this unprecedented series of pictures. . . ."


S. P. Wyatt , Jr.
“Books and the sky: The Green Flash and Other Low Sun Phenomena,”
Sky & Telescope 18, 457–458 (1959).

* S&T review by Stanley P. Wyatt, Jr. in the June issue
* "The book is surely the authoritative work on the green flash,
* containing, in addition to the photographs, data on simultaneous visual
* observations and meteorological conditions, a very complete bibliography,
* and a good account of the history and qualitative theory of the flash."
* "The photographs include a remarkable collection showing how varying
* atmospheric conditions distort the solar disk at the horizon. Perhaps the
* most impressive feature of these weird shapes is their symmetry around a
* vertical axis, indicating that small-scale stratification in the
* atmosphere occurs in essentially horizontal layers."
* One of the few mentions of the lack of a QUANTITATIVE theory:
* "Perhaps better balance would be achieved, and the book's utility as a
* complete and compact summary would be enhanced, if the story of the theory
* of the green flash were accompanied by a quantitative presentation. . . .
* For it is always satisfying to know that theory and observation are in
* accord."


M. A. Ellison
“Reviews: The Green Flash and Other Low Sun Phenomena,”
Observatory 79, 115–116 (1959).

* Obs. review by M.A.Ellison, an old scintillation observer:
* "The study of meteorological optics has been under a cloud for many
* years; this work by an astronomer will do much to initiate a revival of
* interest in the field." [cf. the review in QJRMS, below!]
* "There is also a fine bibliography of 313 entries, being an extension of
* the earlier lists of papers and observations compiled by Fisher and
* Mulder."
* in June issue


D. H. McIntosh
“Book reviews: Meteorology,”
Endeavour 18, 163 (1959).

* ". . . perhaps the most striking of all atmospheric optical phenomena."
* "The chief remaining doubt is the precise meteorological conditions
* which favour the appearance of the effect. Its notorious capriciousness
* suggests the need for atmospheric super-refraction (as when an air stream
* is cooled from below); the suggestion is strongly supported by the
* radiosonde temperature data quoted in the book but it is not supported to
* a significant degree by the measure of refraction afforded by a comparison
* of actual and theoretical sunset times on occasions of the green flash.
* It is rather disappointing that there is only scanty discussion of this
* aspect of the phenomenon."
* July issue


R. E. G. Simmons
“Reviews: The Green Flash,”
J. Inst. Navigation (London) 12, 337–338 (1959).

* Simmons, who published his own short review of this subject in 1951,
* makes several relevant remarks:
* "It is remarkable to think that a phenomenon as common as the Green
* Flash should daily pass almost unnoticed."
* "Although many observations of the Green Flash have been made, it is by
* no means certain that all the causative factors are known."
* "There are indeed many variations of the so-called Green flash . . . . On
* rare occasions the last segment of the Sun turns red just before the
* appearance of the Green Flash; this has been very clearly shown in at
* least three photographs. No concrete explanation is given for this
* unusual phenomenon and it certainly does not correlate with the main
* causes of the Green Flash."
* "Detailed meteorological data have been appended to some photographs but
* correlation between the two is not clearly explained, nor is it evident
* to the novice!"
* N.B.: There are two things called "Journal of the Institute of
* Navigation." This one (called "Journal of Navigation" since vol.25, 1972)
* is published in London by the Royal Institute of Navigation. The other
* (now called simply "Navigation") was published in Los Angeles at UCLA and
* was produced in Washington, DC, from 1960 to 1992.


R. A. Buchanan
“Book Reviews: The Green Flash and Other Low Sun Phenomena,”
Irish Astronomical Journal 5, 157 (1959).

* Another complaint about TERMINOLOGY:
* "The author and many other observers of the phenomenon known in English
* as ``the green flash'' are unhappy about nomenclature. . . . Both
* ``flash'' and ``ray'' are poor, even wrong, descriptions. Would ``flare''
* be a more appropriate term?"
* "Weather data are given for some of the occasions that are illustrated
* by photographs. Here the standard of exactness, so evident in the
* photographic work, has fallen. Some of the synoptic weather maps are
* badly drawn and a few have serious errors. A number of radiosonde ascents
* are tabulated but nowhere are we told the units of wind speed. These are
* unfortunate lapses, all the more so as it was unnecessary to print these
* data since no attempt is made to use them to illustrate the causes of the
* phenomena."


A. C. Menzies
“Reviews of Books: The Green Flash and Other Low Sun Phenomena,”
Proc. Phys. Soc. Lond. 74, 226–227 (1959).

* a short paragraph endorsing the textbook explanation
* "edited by D.J.K.O'Connell."


T. S. Jacobsen
“Reviews: The Green Flash and Other Low Sun Phenomena,”
Pub. Astron. Soc. Pacific 71, 251–252 (1959).

* Jacobsen in PASP
* "The work differs distinctly from all other treatises so far published
* on this borderline subject between astronomy and meteorology in
* containing, for the first time, color photographs of
* the actual flash itself -- all other published color pictures known to
* this reviewer being at best photographs of the green or blue upper fringe
* of the solar image preceding the flash."
* "There are no new or strikingly unexpected phenomena described, as every
* type of sunset and flash has been drawn, photographed (though not in
* color), or mentioned before by observers using low-power telescopes . . . ."
* "Forms like ``lamp shades,'' ``mushrooms,'' ``harmonicas,'' etc.,
* reminiscent of J. F. Chappell's photographs in the December 1933 issue of
* these Publications , are reproduced in great profusion. They show the
* detailed development of the solar limb as it passes inversion layers in
* the atmosphere . . . ."
* "With this magnificent material one can see what is visible in a small
* telescope at the exact moment of sunset, a spectacle that so far few
* persons have bothered to look at directly."


L. H. Aller
“Announcements and News: Book Reviews. The Green Flash and Other Low Sun Phenomena,”
Am. J. Phys. 27, 432–433 (1959).

* ALLER explicitly credits mirages
* "Atmospheric dispersion, refraction, mirages, and inversion layers
* all combine to create a class of phenomena that rank among the most
* beautiful in nature." He also mentions absorption of yellow and orange
* (though without saying "water vapor"); but credits Jacobsen for "a mirage
* condition or reflection from an inversion layer".
* Remarkably, he "has never seen a green flash".
* Sept. issue


H. Elsässer
“Besprechungen: O'Connell, D.J.K.: The Green Flash and Other Low Sun Phenomena,”
Naturwissenschaften 46, 659 (1959).

* a good, short, one-paragraph summary


B. C. V. O[ddie]
“Reviews: The Green Flash and Other Low Sun Phenomena,”
Q. J. Roy. Met. Soc. 87, 264 (1961).

* Some trenchant remarks:
* "Most of the coloured photographs show very clearly the green upper rim
* of the sun . . . . The author claims by implication that these photographs
* are proof of the objectivity of the Green Flash, but one may doubt whether
* the case is sound. Nobody doubted that the upper rim of a heavenly body
* near the horizon was green --- this can be seen on any clear evening with
* a small telescope. What the opponents of the objective theory said was
* the green fringe was too narrow to be perceptible to the naked eye, and
* certainly too narrow to cause a striking flash, and it is hard to counter
* this argument with photographs taken through powerful telescopes."
* "The book reproduces radiosonde ascents and synoptic charts . . . and, as
* it were, invites the reader to interpret the sun's appearance in terms of
* meteorological conditions: but the author does not attempt to do so
* himself."
* "There is an adequate index and a bibliography of about 300 papers.
* Alas, not one of them appeared in the Quarterly Journal , and few in any
* meteorological periodical." [N.B.: we now know this is due to O'Connell's
* oversight, not to lack of meteorological papers!] "Perhaps this book may
* persuade meteorologists that there is still meat on the carcass of
* meteorological optics."


Anon.
“The scientists' bookshelf: The Green flash and Other Low Sun Phenomena,”
American Scientist 50, 62A (1962).

* A belated and slightly erroneous unsigned review in American Scientist
* "Joule's own observations of the flash are recorded by Winstanley."
* "The skill of the Vatican observers . . . makes it certain that the
* green flash is objective, its appearance explainable by the ordinary
* laws of optics." (Explainable, yes; explained, no.)
*      The subtitle of the column says "By Hugh Taylor, the Associate Editors,
* and Guest Reviewers." No hint as to who was responsible here.


B. R. Wilkins
“Book Reviews: The Green Flash and Other Low Sun Phenomena,”
Medical and Biological Illustration 15, 135 (1965).

* A SCOFFER relents:
* ". . . we saw no such event, and our informant was accused of pulling our
* legs. Until seeing this book I thought no more about the matter, but it
* now seems that we had been unjust to our informant, and in spite of the
* time elapsed since publication this annotation is offered."



*** GF in MOVIES FILE ***

G. Lucas
THX 1138
(American Zoetrope, San Francisco, 1971).

*
* There is a small mock-mirage flash in the final scene of THX 1138
* Thanks to Robert Roosen for pointing this out!


E. Rohmer
Le Rayon Vert / Summer
(Les Films du Losange, Paris?, 1986).

* Eric Rohmer's film "Le Rayon Vert" ("Summer") has a REAL GF!
* The sunsets were photographed by Philippe Demard; his inferior-mirage
* flash is perfectly exposed.
* There is also an Omega-type sunset earlier in the film, with no GF.
* The Jules Verne novel is described, along with the standard textbook
* explanation of the GF, in the middle of the film.
* "Green is the color of hope," says someone in the film. Is this French
* folklore? The "legend" is not mentioned; its content, though, is
* attributed to Verne. This would actually be an acceptable
* introduction to the subject.
* Distributed with English subtitles as "Summer" by Orion Classics, and
* on videotape by Pacific Arts videos. The tape is copyrighted 1986,
* though some references give 1985 as the film's date.


C. Huisking
“Screen Gems (Although some are in the rough),”
Sarasota (Florida) Herald-Tribune , 1G–3G (June 30, 1996).

* Charlie Huisking's column about movies made in Sarasota, Florida
* John D. MacDonald's "A Flash of Green" ". . . was turned into a motion
* picture in 1983 by independent Tallahassee filmmaker Victor Nunez." . . .
*      "Nunez's cameras captured evocative images of the mythic Florida --
* great stretches of isolated beach, herons gliding above the water, and
* the green flash of the film's title -- that brief, brilliant illumination
* that sometimes occurs just as the sun dips into the Gulf."
*
* But, alas, I have seen the movie; the "green flash" is a clumsy special
* effect that bears no resemblance to any green flash ever described by
* any eye-witness -- the setting Sun is optically superimposed on a scene,
* and a green filter over the lens fakes something the movie makers
* imagined. (Apart from this, the movie is a faithful adaptation of the
* book.) The movie was made for the PBS series "American Playhouse",
* which I suppose accounts for the cheapness of the effect used.
*
* [in the "Arts & Travel" section]


C. Taylor
“Glum in the Sun,”
Salon. com, [website] , (June 21, 1999).

* Charles Taylor's extended movie review of Eric Rohmer's 1986 film
* published by salon.com in "Arts & Entertainment" on June 21, 1999 at URL
*
* http://www.salon.com/ent/col/tayl/1999/06/21/summer/index.html
*
* and still there as of July, 2001.
* The film originally was "Le Rayon Vert"; "Summer" is the American title.
* This is Taylor's "Home Movies" column for videos; the film is
* available on tape. The interesting part for us here is:
* "Rohmer banked the entire movie on the off chance that he would be able
* to capture the green ray on film. He filmed sunsets for months."
* The sunsets were photographed by Philippe Demard; he tells me they got
* the nice GF sunset (in the Canary Islands) the very first evening they
* tried!


T. Dean
Green Ray on Madagascar, [movie] , (2001).

* Tacita Dean's sunset movie
* Tacita Dean is an artist with an interest in green flashes.
* Evidently she was one of the tourists who went to Madagascar for the
* solar eclipse; cf. Paolo Candy's GF taken at that time.
* Supposedly this runs 2 min 30 sec -- just the duration of the sunset.
* A short 16mm movie. I have not seen this.


J. Eugenides
“Tacita Dean,”
Bomb Magazine , No. 95, 32–37 (Spring, 2006).

* Interview with Tacita Dean about her GF movie, etc.
* Mainly useful for Tacita Dean's acount of her CLOUD-TOP FLASH seen
* from an airliner.
*      Her quoted remarks contain some nonsense about green flashes, and
* a strange claim that Eric Rohmer "faked it! It looks fake. . . ."
* -- which confirms my impression that her experience of green flashes
* is very limited. The interview appears on the magazine's website at
*
*        http://www.bombsitebeta.com/issues/95/articles/2801
*
* P. 32 shows 2 frames of the GF movie, discussed on pp. 32-33.


R. Fortnum
Contemporary British Women Artists
(I.B.Tauris, London, 2007), pp. 94–103.

* Another Tacita Dean interview, published later but probably done
* earlier than the above, as she says "I've just made this little film"
* (about the GF). Her 5 GF observations are described on p. 102.



*** GF in MUSIC FILE ***

M. Castelnuovo-Tedesco
Il Raggio Verde, per pianoforte [op.9]
(A.Forlivesi, Firenze, 1916).

*
* Mario Castelnuovo-Tedesco's piano piece
* Reprinted in 1994 by Masters Music, Boca Raton, Fla.
* Thanks to Paolo Candy for turning this up!


G. M. Gatti
“Four composers of present-day Italy,”
The Musical Quarterly 12, 449–471 (1926).

* A critical appreciation of the works of Castelnuovo, and others
* "One of the compositions that fill us with a most bountiful sense of
* this tranquil emotion in the presence of Nature is Il Raggio Verde
* (The Green Ray), technically one of the most finished of Castelnuovo's
* works and, in its inspiration, one of the freest. Here the musician is
* alone with his own emotion. . . .      It is said that the sun, when sinking
* into the sea, sends out a final green ray; it was, therefore, a sunset
* that the musician had in mind to describe. . . ." (p. 450)


S. Tepper and R. C. Bennett
Forty Nine Shades of Green
(George Paxton Corp., New York, 1956).

* 49 SHADES OF GREEN
* From musicdiv@nypl.org Wed Sep 25 10:52:34 1996:
*
*      According to the Library of Congress's "Catalog of Copyright Entries,"
*      "Forty-Nine Shades of Green" was copyrighted 11 September 1956
*      (EP102142).  The entry states only, "Words and music by Sid
*      Tepper and Roy C. Bennett."  We regret that we did not find a listing
*      for the song in our collections and so cannot check the lyrics for you.
*
* ASCAP says: by Roy C. Bennett and Sid Tepper
* recorded by the Ames Brothers, with Hugo Winterhalter's orchestra
* ". . . the greenest green you've ever seen. . . ." (as aty recalls)
* OK, so it doesn't have anything to do with green flashes; it's still
* a great line!



*** GF in LITERATURE FILE ***

A. R. Hope Moncrieff
Bonnie Scotland
(A.& C.Black, London, 1905), pp. 199–204.

* (see Jules Verne & F.A.Steel refs. in main GF file)
*
* A Scotsman complains about Verne's treatment of Scottish places
* ". . . let me borrow from the ingenious M. Jules Verne, who in
* his Rayon-Vert gives a remarkable account of this region and its
* inhabitants. It is always well to see ourselves as others see us,
* especially through the eyes of a famous story-teller. This story of his
* is intended to be amusing, and he appears to succeed in being funnier
* than he knew by reading up Sir Walter Scott and other works of fiction,
* then `combining his information.'" Our native guide points out the
* various errors committed by Verne, while summarizing the plot of
* his novel. "All of which, if one skips the guide-book passages, makes
* a very striking account of Scottish manners and customs, but prompts
* some doubt of the author's accuracy when he comes to deal with such
* more remote regions as the moon or the bottom of the sea." Remarkably,
* not a word is said about the supposed "ancient legend."
*      The copy I saw said "Published November 1904 / Reprinted with slight
* alterations November 1905" on the back of the title page.


L. van der Post
The Face Beside the Fire
(Hogarth Press, London, 1953).

* Laurens van der Post's description of a green ray
* "Then the sun disappeared. For a second the sea caught its breath at so
* great a loss of light, the horizon went dark with anguish -- and then
* it happened. From below the horizon, from the other side of the gulf a
* tremendous flash of bright, emerald green light shot up across the sky
* in the most solemn, urgent, majestic, and defiant wave of farewell. It
* came right over the edge of the sea like a flight of burning arrows shot
* straight at the breast of the advancing night by an army marching not
* in defeat, but victoriously homewards." [p. 231]
* Well, a bit overwrought; but probably based on somebody's observation.
* In the same year, Morrow, in New York, published an American edition.
* Thanks to Alison Ford for pointing this out!


J. D. MacDonald
A Flash of Green
(Fawcett, New York, 1962).

* JOHN D. MACDONALD's novel
* This is the modern work that has done most to popularize the GF.
* Unfortunately, it's apparent MacDonald had neither seen a GF himself nor
* talked to anyone who had; the description on p. 173 is most unrealistic.
* Interestingly, this is the only fictional account to associate seeing a
* flash with the making of a wish. Did he get it from some old Cajun?
* The ILL Team in Venice, Fla., says this is "loosely based on an actual
* event of criminal history."


H. Wouk
Don't Stop the Carnival
(Doubleday & Co., New York, 1965), pp. 279–281.

* HERMAN WOUK's NOVEL
* minor mention, but correctly described


J. Rhys
Wide Sargasso Sea
(Deutsch, London, 1966).

* JEAN RHYS uses ``EMERALD DROP'' in passing
* "And when she said, `Look! The Emerald Drop! That brings good fortune.'
* Yes, for a moment the sky was green -- a bright green sunset. Strange.
* But not half so strange as saying it brought good fortune."
* (This phrase first appeared in the English Mechanic in 1889.)
* [This is on p. 561 of the 1985 Norton "Complete Novels".]
* Thanks to Charles Freehling for pointing out this usage.


J. Aiken
The Green Flash
(Holt, Rinehart and Winston, New York, 1971), pp. 146–163.

* short story, republished


A. Waugh
The Fatal Gift: A Novel
(Farrar,Straus and Giroux, New York, 1973), p. 94.

* GF mentioned in Alec Waugh's semi-autobiographical novel
* (The writer was Evelyn Waugh's older brother.)
* The characters don't see a GF, but talk about it, and look for one.
* A nice touch: another character says to the writer, "In how many of
* your stories have you made your lovers look for that," and he replies,
* "More often than I've seen it myself."
* Apparently it was released simultaneously in England by W. H. Allen.


T. Jones
Adrift
(Macmillan, New York, 1980).

* GREEN FOG or just ADAPTATION?
* IMPROBABLE that this guy spent so much time at sea and only saw 3 GFs
* ". . . just a split second after the sun's upper tip sinks below the
* horizon, and the sun shines through the sea, the whole sky shimmers in a
* pulsing deep-emerald glow. . . . The colors all about -- the sea the clouds,
* the boat itself, my skin -- all glowed brilliant green."
* This guy is known for his exaggerations and embroidery of stories . . .


L. Dufour
“Le rayon vert dans la littérature française,”
Ciel et Terre 98, 122–123 (1982).

* A very brief bibliography of GFs in French literature
* "La formation du rayon vert dépend de tant de facteurs qu'il n'est
* surprenant que son apparition semble capricieuse." Verne's book
* ". . . semble avoir élargi l'intérêt porté à ce photométéore par
* les hommes de science, du moins si l'on en juge par le nombre d'article
* consacrés au rayon vert la parution de cet ouvrage. Cet exemple
* relativement rare, pour ne pas dire exceptionnel, d'une influence probable
* de la littérature sur la science mérite d'être noté."
*      After quoting Verne's description, he then quotes passages from
* Simenon's Maigret et la vielle dame and four less-famous authors,
* who all give only a passing mention, with no description. Then,
* surprisingly, we find:
*      "Selon un vieux dicton écossais, le rayon vert est un signe de beau
* temps:
*                          « Glimpse you ever the green ray
*                                Count to morrow a fine day. »
*
* And then, of course, ". . . suivant une légende écossaise . . . ."


W. Graham
A Green Flash
(Random House, New York, 1987).

* Winston Graham wrote the popular "Poldark" historical novels, as well
* as "Marnie" (made into a movie by Hitchcock). Here he pays a curious
* sort of homage to Jules Verne: though the flash is mentioned only
* briefly a few times in the middle of the book, its use in the title
* evidently is a reference to Verne's phony "legend" -- and the lovers
* here never see the flash, even in Barbados (much less in Scotland, where
* some of the action is set.)
* The flash is introduced on p.170 of this 383-page book. On pp.173-175
* it is (in passing) dismissed as an illusion. After brief mentions of
* its failure to be seen, on pp. 180 and 211, it appears the final time
* on p.242, where one remarks, "I was talking about it to someone in Paris
* not long ago, and he said it was an accepted natural phenomenon, not an
* optical illusion or a subjective fantasy." "Like love," replies the
* other.
* Oddly, some editions of this are entitled "A Green Flash" and others
* "The Green Flash".


D. Poyer
The Med
(St. Martin's Press, New York, 1988).

* VIVID DESCRIPTION of a inf.-mir. sunrise; but the characters look for a
* green flash at the END of it instead of the beginning. This has been
* corrected in the seventh printing (1999) of the paperback, which now
* (correctly) mentions the red flash as the Sun leaves the horizon.
* Mentions Bowditch. See pp. 201-203 of this revised edition (which still
* bears the 1989 copyright for St. Martin's Paperbacks).
* Thanks to Robert Roosen for pointing out this interesting book!
* David Poyer


J. M. G. Le Clézio
Onitsha
(Gallimard, Paris, 1991).

* (see 1997 for the English translation, below)
* ". . . tandis qu'à la proue, au point où le ciel tombe à la mer, comme
* un doigt entrant par les les pupilles et touchant le fond de la tête,
* éclatait le rayon vert!" (p.16)


R. W. White
The Heat Islands
(St. Martin's Press, New York, 1992).

* Randy Wayne White's murder novel set in South Florida
* A minor character in this uninspired potboiler sees a green flash (but
* off-camera, so to speak). The author, evidently, has not: "Like a green
* flashbulb had gone off. I mean it was bright!" (p. 64) The
* know-it-all hero asserts that "It has something to do with the distance
* sunlight travels at the earth's horizon. The light travels farther,
* something like that. The distance bends and separates the light, makes
* the sun seem visible after it has already sunk below the horizon. If
* conditions are just right, the yellow of the sun mixes with the blue of
* the sea, and it's like a chemical reaction." (pp. 66-67) The character
* recalls it as "Great big sun ball. Yellow . . . red . . . orange . . .
* oily purple, then -- poof! -- green . (p. 138) Yuk. Well, what can
* you expect from a part of the world where the food is so bad?
* Passing references occur on pp. 90, 203, and 229 as well.
* Thanks to Christine Francescani for pointing this out.


K. Beevor
A Tuscan Childhood
(Viking, London, 1993).

* A wrong idea popularized
* This memoir is more about Tuscany than about Kinta Beevor's childhood.
* But, alas, on p. 144, we have: "Sometimes from the beach at dusk we could
* see the `green flash'. The sky had to be perfectly clear, and just as the
* last tiny segment of the sun disappeared below the horizon, the streak of
* tangential light through the surface of the sea would produce this
* extraordinary optical effect." Extraordinary indeed!
* "Published in the United States by Pantheon Books, a division of Random
* House, Inc., New York. Originally published in Great Britain by Viking,
* a division of Penguin Books Ltd., London, in 1993." This entry is here
* for the original English edition; see the 1999 Pantheon reprint in the
* main GF file.      Note that Kinta Beevor died in 1995.


I. Allende
Paula
(HarperCollins, New York, 1995), p. 44.

* Isabel Allende's memoir records the "make a wish" folklore
* "Every evening, my mother took my hand and walked with me to the rocks
* to watch the sunset. We waited to make a wish on the last ray, which
* sparks green fire at the precise instant the sun sinks below the horizon."


S. Martini
The List
(G.P.Putnam's Sons, New York, 1997).

* passing mention in Steve Martini's thriller set in Puerto Rico
* "Maybe catch the setting sun, the green spark as it flashes on the
* horizon." (p.317)
* Thanks to Hank Hogan for pointing this out!


J. M. G. Le Clézio
Onitsha
(U.of Nebraska Press, Lincoln, 1997).

* Alison Anderson's translation of Le Clézio
* ". . . while at the bow, where the sky drops into the sea, like a finger
* through a pupil to probe the depths of the head, the green flash exploded
* in sudden brilliance." (p.5) [not copied, as this is the only GF use.]


A. Anderson
“Translating J. M. G. Le Clézio,”
World Literature Today 71, no. 4, 695–702 (Autumn, 1997).

* Alison Anderson explains the difficulty of translating the GF passage:
* "This was perhaps the most difficult paragraph in the novel. . . . Finding
* the translation, initially, for `rayon vert' was quite difficult, as I was
* not familiar with the expression in English."


C. Campbell
“Green Flash,”
Christian Science Monitor , 18 (3 March, 1999).

* Mention of GF in a poem rates the "Literature" file, though it's from
* The C.S.M., and mostly about jellyfish.
* "The orb we see / is merely phenomenal.
* The sun as noumenon has already sunk. . . .
* "By hugging that globe with our eyes as it plunges,
* we hope for a vision of spurting green." Etc. Sounds as if
* Colin Campbell understood refraction, but hadn't seen a flash.


C. Wolper
The Cigarette Girl
(Riverhead Books, New York, 1999).

* Carol Wolper's novel about sex and Hollywood
* The passages of interest here are on p. 47, where screenwriter
* Elizabeth West and her friend Andrew are in an art gallery "in front of
* a large canvas . . .      entitled Green Light .
* `It's the green flash created when the setting sun hits the ocean,'
* Andrew explained.
* `It is? How come I've never noticed that?'
*  `It's out there,' he said."      CUT TO: p. 271, where they are at the
* beach, on the penultimate page of the book:
* "The sun had just hit the water, and for a second it was as if a
* horizontal band of green light was drawn across the horizon."
* So it's like Jules Verne all over again, though the GF hasn't played
* any visible part in between. (Or Dorothy being told she can go back to
* Kansas any time she wants.)
* "Riverhead Books / a member of Penguin Putnam Inc."


J. Verne
[Hebrew translation of "Le Rayon-Vert" by Hezi Yizhaq]
(Ofarim Publishers, Kfar Monash, Israel, 2001).

* Hezi Yizhaq's translation of Jules Verne, with my 1997 flash on cover
* The original illustrations are reproduced in this well-produced volume.
* This website is mentioned at the bottom of p.10.
* ISBN 0 04340001574 8.


D. Lee
Yellow: stories
(Norton, New York, 2001).

* Don Lee's stories set in Southern California use the GF for local color
* Thanks to Kathryn Neal of the SDSU Library for pointing this out!


P. Murphy
Adventures in Time and Space with Max Merriwell
(Tom Doherty Associates, New York, 2001).

* Pat Murphy's physics lessons, disguised as fiction; Verne would have approved
* The GF page is 237; cites Bowditch. No useful details.


J. Verne
Jules Verne's Magellania
(Welcome Rain, New York, 2002).

* JULES VERNE's last mention of GF
* This is the English translation of Verne's unpublished manuscript.
* The GF appears on the last 2 pages, as part of the climactic scene
* (pp. 186-187). This is the 3rd time the GF appears in Verne's works
* -- always as a symbol of hope for the future, so I suppose that is
* how he felt about it.
* "Originally published in France as En Magellanie . . . 1998."
* Translated by Benjamin Ivry. Thanks to Hezi Yizhaq for finding this!


J. Verne, P.-J. Hetzel, O. Dumas, P. G. della Riva, and V. Dehs
Correspondance inédite de Jules Verne et de Pierre-Jules Hetzel (1863-1886), Tome III (1879-1886)
(Slatkine, Genève, 2002), p. 140.

* The true origin of the "old Scottish legend" revealed
* in letter 535 from Hetzel to Verne (pp. 139-143).
*      Olivier Dumas, Piero Gondolo della Riva & Volker Dehs, the editors
* of Jules Verne's unpublished correspondence with his editor Pierre-Jules
* Hetzel, have uncovered the actual facts: Hetzel invented the "legend",
* and Verne adopted almost the exact wording that Hetzel proposed.
*      The phrase "rayon vert" appears without hyphenation in their early
* letters; it is not until the text is almost ready for the printer that
* we find Verne writing it as "Rayon-Vert" (p. 153).
*      Some library catalogs list only Verne as the author here; others
* list Hetzel as well; WorldCat lists the editors also. Olivier Dumas
* seems to be the main editor; he signed the introduction. Most of
* Hetzel's letters to Verne were collected by della Riva.
*      Many thanks to Eric Frappa for telling me about this!


Bob Guess
Waiting for the Green Flash
(iUniverse, New York, 2005).

* A local writer features the GF and related San Diego attractions


É. Frappa
“Jules Verne et le mystère du Rayon Vert,”
Bulletin de la Société Jules Verne , No. 198, 77–89 (May, 2019).

* Éric Frappa shows how Verne probably learned of the Green Ray
*      "Avec Le Rayon-Vert , Jules Verne nomme  pour la première fois le
* phénomène, qui acquiert ainsi un statut d'objet scientifique à part
* entière et attise la curiosité des férus de nature et de science."
* But how did Verne learn of this phenomenon? The few published reports
* before 1877 (when the flash first appeared in Verne's writings) were
* in English or Italian, neither of which Verne could read.
*      "Ainsi, pendant longtemps, l'origine de la connaissance précoce du
* rayon vert par Jules Verne est restée un mystère . . . ."
*      The link appears to have been Winstanley's 1873 report, which was
* translated in a Sept. 1874 article by Abbé Moigno in Cosmos-Les Mondes ,`
* a journal readily available to Verne -- who is known to have read it.
* Furthermore, Moigno was the Paris correspondent of The Chemical News ,
* which had reprinted Winstanley's report only a month after Winstanley
* had read it to the Manchester Literary and Philosophical Society.
* However, Moigno used the French translation of the Chemical News report
* that had appeared in L'Institut in July, 1874; in this process,
* Winstanley's name was garbled by a typo, and other errors were
* introduced. (As often happens with refraction phenomena, the effect
* of these errors was to make the phenomenon seem much more spectacular
* than it really is.)
*      However, because the descriptions of green flashes in Verne's
* 1882 novel go beyond the brief and misleading French translation of
* Winstanley's report, it seems likely that Verne obtained additional
* information about them from seamen, or from friends in the Yacht-Club
* de France. In particular, in his 1877 novel Les Indes-Noires , he
* describes the flash as visible both morning and evening, while both
* Joule and Winstanley mention only sunset observations.
*      Indeed, there are hints that Verne might himself have seen a green
* flash or two. He describes the "Etruscan vase" shape typical of an
* inferior-mirage sunset in his 1882 novel. And he recorded seeing
* the green of a green flash (but not in an actual flash) in a notebook
* entry dated 19 June 1881. These are tantalizing indications, but not
* conclusive evidence.
*      However, it seems very likely that the French translation of
* Winstanley's report really is what got Jules Verne interested in green
* flashes: "La découverte, pour la première fois, d'un article sur le rayon
* vert en français qui précède Les Indes-Noires, dans une revue lue par
* Jules Verne, fournit une explication plausible à la prise de connaissance
* du phénomène par l'écrivain."



*** GF in FOLKLORE FILE ***

W. R. Manley
“A green Sun in India,”
Nature 28, 576–577 (1883).

*
* Possible reference to GF in Indian astronomy or astrology?
* Just a passing reference in a long letter on the Krakatoa Green Sun:
* "The native astronomers say that there is a planet wholly absorbed in
* the sun, and that if it leaves the sun a green light will appear. Or,
* according to others, if Venus comes in contact with the sun, which,
* according to their calendars, is the case now, a green light will be
* seen."


W. J. Humphreys
Weather Proverbs and Paradoxes
(Williams & Wilkins, Baltimore, 1923), pp. 14–16.

* HUMPHREYS (who believes the "LEGEND" as well!)
* ". . . according to Highland legend . . . "
* "In proverb form:
*
*             Glimpse you e'er the green ray,
*             Count the morrow a fine day."
*
* I suspect he made this up himself.
*      According to Dean Newman, this couplet also is quoted by a character
* in some novel -- but which one??? If a reference before 1923 could
* be found, it would disprove my assumption that Humphreys invented this
* "proverb".


W. W. Gill
“The green flash,”
Times (Lond.) , p. 8 (30 Aug., 1929).

* Here are the actual letters to The Times that set off Botley and a
* host of others:
*
* Hints of the legend:
* "In the Isle of Man a belief existed formerly, and is not yet quite
* forgotten, that a momentary gleam or tincture of the light from the
* rising sun, of a special and significant character, occurred at rare
* intervals -- once perhaps in two or three years."
* "Literary use made of the actual phenomenon, as by Jules Verne and
* William Black, belongs to a different category."
* QUERY: What did William Black write about the GF?


M. Douglas
“The green flash,”
Times (Lond.) , p.10 (10 Sept., 1929).

* DETAILS of the SOILSHEY-BIO story:
* ". . . something like the green flash appears occasionally in Manx
* folklore. The old Manx name for it was soilshey-bio , or `living light';
* and I have gathered the impression, without having been actually told so,
* that it was thought to be an emanation of the sun's life . . . ."
* "In several fragments taken down by me from Manx fisherfolk, the `flash'
* was seen at sunrise on the morning preceding the wreck of one or more
* boats . . . ."
* ". . . the `flash' certainly also had its beneficial side in popular
* belief . . . . I had this belief directly from a very old man who was, I
* should think, about the last of the `charmers,' . . . . if any person could
* find what he called `the herb of lifé at the moment when it was touched
* by the soilshey-bio , death would never touch him or anyone to whom he
* gave a portion of the herb to eat."
* (Mona Douglas was a well-known authority on Manx folklore.)


F. E. Whitman
A Determination of the Weather Proverbs which are true or false in terms of scientific principles
(B.U.School of Education, Boston, 1948), p. 32.

* FRANCES ELLA WHITMAN attributes the green-ray couplet to Humphreys
* in her Master's thesis from Boston U.


L. C. Wimberly
Folklore in the English & Scottish Ballads
(Dover, New York, 1965).

* "The association of green with the dead and with witches, and the
* familiar superstition that green is unlucky. . . " (p.176)
* ". . . green is a fairy color and of ill omen, and is, moreover,
* associated with witches and the dead. . . " (p.178)
* "In British folksong the color green is occasionally associated with the
* dead or with death." (p.240)
* ". . . the ill omen that in general attaches to green." (p.241)
* Dover reprint of U. of Chicago Press, 1928 edition:


G. Douglas
“Green ray, green rain,”
The Islander: Daily Colonist Magazine , p.2, 4 (March 7, 1971).

* "GLIMPSE YOU EVER THE GREEN RAY, count the morrow a fine day."
* Thanks to Dean Newman for alerting me to this phrase!
* Contains 2 not very useful GF observations, but more on folklore,
* including both the verse and that "whatever you wish on the green ray
* will come true." (cf. J.D.MacDonald's "A Touch of Green".)
* This column by Gilean Douglas has about 8 column-inches on GF in the
* Sunday supplement to the Victoria Daily Colonist .


H. Beck
Folklore and the Sea
(Wesleyan University Press, Middletown CT, 1973), pp. 236–237.

* suggests the GF is connected with the "kelpie" that vanishes in a blue flame
* (According to Admiral W. H. Smyth's "Sailor's Word-Book", a kelpie is
* "A mischievous sea-sprite, supposed to haunt the fords and ferries of
* the northern coasts of Great Britain, especially in storms.")


A. Lee
Weather Wisdom
(Doubleday, Garden City, New York, 1976), pp. 77–78.

* Another fool fooled by Jules Verne's "LEGEND"
* ". . . it has also become a part of folk legend. The Scottish
* Highlanders, for example, say . . . ."
* Also quotes Humphreys's verse, without attribution.
* Thanks to Keith Heidorn, "the Weather Doctor", for this reference!


J. G. Ford
“Book Reviews: Science and Society in Prehistoric Britain. By Euan W. Mackie,”
Technology and Culture 20, 356–359 (1979).

* J. Glyn Ford's strange book review, placed here for its odd notions
* The book reviewed leans heavily on A. Thom's now largely-discredited
* claims of extreme sophistication and accuracy in Stonehenge (and related)
* alignments. That's urban-folklore enough in itself; but now read this:
* "The major objections concern the solar alignments, for it is charged
* [?? by whom ??] that observations of solar risings and settings would be
* rendered impossible by the dazzle." (Obvious nonsense to anyone who has
* ever observed sunsets!)
* Then the weirdness really sets in: "One solution which would overcome
* the problem of dazzle is that Neolithic observers were looking for the
* phenomena [sic] of `green flash.' These phenomena occur due to the
* atmospheric dispersion of sunlight when only a minute segment of the sun
* is above the horizon. Under ideal conditions this segment is observed
* to change in color from orange to green so that the final glimpse of the
* sun is a flash of green. . . . J.H.Mathers (`The Green Flash,' Hermes 13
* [1966]: 112-14) has suggested that some Celtic tales indicate that these
* phenomena were observed. Therefore, this seems to provide a possible
* answer to the critics." A far-fetched "solution" to a far-fetched
* "problem" is crazy!



*** W. H. JULIUS FILE ***

W. H. Julius
“Sonnenphänomene als Folgen anomaler Dispersion des Lichtes betrachtet,”
A. N. 153, No. 3672, 433–446 (1900).

*
* Some of W. H. Julius's nutty papers on anomalous dispersion are here
*
* The beginning: note that this precedes the 1901 eclipse expedition,
* despite Minnaert's assertion in the DSB.
* The paper is dated 1900 August; the issue closed on 15 Nov.
* But it seems to be a German translation of Julius's paper in the
* proceedings of the Kon.Akad.v.Wetenschappen te Amsterdam 8, 510-523
* (24 Feb.1900)
* He mentions Schmidt's theory, and cites Wiener's 1893 mirage review.
* Already here in col. 444 there is the confusion about ir/radiance,
* couched in the tell-tale language of "rays", when he tries to explain
* why sunspots are dark.


W. H. Julius
“Solar phenomena considered in connection with anomalous dispersion of light,”
Astrophys. J. 12, 185–200 (1900).

* The English version of the same paper:
* [According to J.Hartmann, whose 1907 AN paper is in the GF file, this
* also appeared in Dutch, and in Physik. Zs.!]


W. H. Julius
Proc. Roy. Acad. Amst. 12, 273 (1909).

* The revised sunspot proposal


W. H. Julius
Physik. Z. 11, 62 (1910).

* . . . and its German translation


W. H. Julius
“On the interpretation of photospheric phenomena,”
Astrophys. J. 38, 129–140 (1913).

* And now the English version (though now the sunspot story is put off)
* This version has some weasel-wording: ". . . explanations . . . on which
* we shall not now insist." And: ". . . must be deferred to a separate
* paper." Looks as if the Editor or a referee leaned on him here.


W. H. Julius
“Über dir Brechung des Lichts beim Durchlaufen wirbelnder Gasmassen und über Sonnenflecken,”
Phys. Z. 15, 48–54 (1914).

* In this paper, the ir/radiance confusion is obvious
* "Wegen ihrer schliefen Einfallrichtung haben diese Strahlen geringe
* Intensität; sie entsprechen dem Kernschatten."
* (Lecture-demonstration given at the 4th meeting of the International
* Solar Union at Bonn, 4. Aug. 1913)


W. H. Julius
“Anomalous dispersion and Fraunhofer lines,”
Astrophys. J. 43, 43–66 (1916).

* Now Julius has become a full-fledged crank: no equations, just wild
* stuff. Here he is fighting not only Anderson, but St. John, and
* Adams and Burwell, and others.


K. Hentschel
“Julius und die anomale Dispersion: Facetten der Geschichte eines gescheiterten Forschungsprogrammes,”
Studies aus dem Philosophischen Seminar 3, Heft 6, (April, 1991).

* Klaus Hentschel's review of Julius's folly
*      Julius was a student of Buys Ballot, and the thesis advisor of
* Minnaert (in his second Ph.D.!) and van Cittert. He founded the
* solar-physics laboratory and program in Utrecht, in an attempt to find
* support for his bizarre theories.
*      This has a complete list of Julius's publications; but beware:
* Hentschel is a social scientist, and doesn't understand any of the science
* involved. So he fails to see why everyone who knew anything about solar
* physics regarded Julius as a crank, or nearly so. This, despite the
* fact that he notices something odd about Julius's presentation, and so
* has a whole section devoted to Julius's rhetoric. Hentschel seems to
* think Julius's explanations were as plausible as the solar astronomers'
* at the time; his arguments are as qualitative as Julius's were. So there
* is no discussion of the quantitative side of the dispersion relation;
* no mention that many of the effects Julius was "explaining" were lost
* in the errors of measurement at the time; no awareness of the role of
* polarization in the discovery of Zeemann splitting in the sunspot lines
* -- or, for that matter, the recognition (from line ratios of neutral
* and ionized states of the same element, and the presence of molecular
* absorptions) of spectroscopic evidence for the lower temperature in
* sunspots than in the photosphere.
*      Hentschel has missed several comments on Julius's GF theory, and adds
* no new references; so I didn't make a copy of this 192-page item.



*** MISCELLANEOUS FILE ***

B. Cavalieri
Trigonometria Plana, et Sphærica, Linearis, & Logarithmica
(Typis Hæridis Victorij Benatij, Bononiæ, 1643).

*
* BONAVENTURA CAVALIERI's trig and log tables
*      This is most likely what Cassini used to compute his refractions,
* as it was published in Bologna just a few years before he began working
* for Malvasia, and is reputed to be the book that introduced logarithms
* into Italy. I'd think Malvasia would have bought himself a copy for his
* own library and observatory.
*      There is an elaborate title page, too complicated to simulate here; see
* either Google Books or the better (color) copy available at the Swiss
* electronic library, at e-rara.ch (part of E-lib.ch.) The author is
*
*                                    FR. BONAVENTURA CAVALERIO
*                                                MEDIOLANENSI
*                          Ordinis Iesuatorum Sanctti Hieronymi
*       Ac in Almo Bononiensi Gymnasio Primario Matbematicarum
*
* NOTE: G.D.Cassini was Cavalieri's successor to the professorship of
* mathematics and astronomy at the U. of Bologna after Cavalieri died.


Maraldi
“Experiences du barometre, faites sur diverses Montagnes de la France,”
Mem. Acad. Roy. Sci. 1703, 229–237 (1720).

* MARALDI's invention of the "refractive medium"
*      From observed heights of the mercury column at several places with known
* heights (supposedly, from surveys), he decides that the mercury column
* is one line lower at 60 feet above sea level, and that the increment in
* height to produce the next line drop in column height is 61 feet, and so
* on. This arithmetic progression makes the heights a parabolic function
* of the pressures, which allows him to calculate that the pressure goes
* to zero at a height of 12796 toises, or 6½ leagues!
*      As this is much larger than the height determined from astronomical
* refractions, he says the discrepancy "donnerent lieu de conjecturer
* qu'il pourroit y avoir quelque matiere fluide répandue dans la partie
* inférieure de l'air, & peu élevée sur les plus hautes montagnes de
* ll terre, qui fut la cause principale des réfractions des Astres."
*      So, from two wrong estimates of the height of the atmosphere, he
* infers that the refracting material is different from air???


J.-D. Cassini
Mémoires pour servir a l'histoire des sciences et a celle de l'Observatoire royal de Paris
(Chez Bleuet, successeur de Jombert, Paris, 1810).

* The history of the Paris Observatory, with Cassini's autobiography
*
*
*      This is Jean-Dominique Cassini's account of the Paris Observatory; but
* it includes the autobiographical memoir of Jean Dominique Cassini (his
* great-grandfather, or "Cassini I"), which contains some recollections
* of the construction of the San Petronio meridian/heliometer. There are
* also accounts of his trip to England to see Herschel's telescope, and
* other papers relevant to the instrumentation and finances of the Paris
* Observatory in the early post-Revolutionary Republic. I was bemused
* at seeing the correspondence about the secret of making flint-glass,
* and a mention of Bouguer's binocular heliometer.
*      The title page rambles on and on, with "suivis de la vie de J.-D.
* Cassini, écrite par lui - même, et des éloges de plusieurs académiciens
* morts pendant la révolution", including J.-D. Maraldi (the nephew of
* J.-P. Maraldi who observed looming and mirages), and Le Gentil.
*      The title is often truncated at "sciences".
*      Note: Hachette republished this in 2016.


Anonymous
“Longitude by chronometer at sun-rise or sun-set. – Weston's method.,”
Nautical Mag. (Lond.) 17, 620 (1848).

* First mention of using sunrise/sunset to determine LONGITUDE
* "Captain Weston has proposed that the opportunity afforded by the
* glorious appearance of the setting sun, shall be made use of for obtaining
* ship time, and thence with a chronometer shewing Greenwich time, to get
* the longitude! . . . The tables are preparing for publication by the
* Admiralty,. . . . Capt. Weston has been rewarded by the Admiralty for his
* ingenuity . . . ."


G. Buist
“Notices of the most remarkable Meteors in India of the fall of which accounts have been published,”
Transactions of the Bombay Geographical Society 9, 197–230 (1850).

* Visual estimates of altitude good to a degree or two
* Buist's collection of published accounts of meteorite falls in India
* includes Capt. Shortrede's provocative statement from the Journal
* of the Asiatic Society of Bengal , Part II, vol. xi, pp.959-962
* (1842?):
*      "The observations themselves are very easily made when a person
* knows exactly what he has to do, and does not allow himself to be
* distracted by attempting too much. Besides general attention, the most
* useful qualification I believe to be, the ability readily to estimate
* altitudes at sight. I know by experience, that persons in the habit of
* such observations may train themselves to estimate altitudes at sight
* within 2° of the truth, for I have practised it along with another
* person, proving our estimates by an altitude and azimuth instrument."
* (reprinted by "G. Buist, LL.D., F.R.S.L. and E. &c." on p. 204)
* NOTE: Captain Shortrede was 1st Assistant, Grand Trigonometrical
* Survey of India.
*      Buist notes in his introduction: "I found as I proceeded, that by
* causing notices of meteors to be inserted in the Bombay Times ,
* gentlemen were induced to write accounts of such as they had seen, who
* otherwise might have remained silent ; and the multitudes described
* during the two past years compared to the small number of notices we
* have anteriorly to this, sufficiently indicate the conveniency of the
* practice, and its adaptation for eliciting intelligence."


J. Janssen
“Remarques sur le spectre de la vapeur d'eau, à l'occasion du voyage aérostatique de MM. Crocé-Spinelli et Sivel,”
C. R. Acad. Sci. 78, 995–998 (1874).

* Janssen's sunset spectroscopy and visible-IR report
* In his 1868 passage through the Red Sea, he took advantage of the
* high dew-points (26 to 30° C) to observe water bands at sunrise and
* sunset with a special low-dispersion spectroscope:
*      "Observant avec cet instrument les levers et les couchers du Soleil
* dans cette mer, j'ai été surpris de voir que ma vision s'entendait
* loin dans la région obscure, au delà de A, et je vis alors les bandes
* obscures Y, Z de Brewster, extraordinairement accusées; ce qui montre
* bien qu'elles sont dues à la vapeur aqueuse; car dans les circonstances
* atmosphériques ordinaires, ces bandes sont bien difficilement
* perceptibles."
*      NOTE: Brewster's Z is the clump of water lines at 8228 Å ,
* according to the Rubber Bible; and Y is another group at 8990.


Alan D. Fiala and Steven J. DIck (editors)
Proceedings, Nautical Almanac Office Sesquicentennial Symposium, U. S. Naval Observatory, March 3-4, 1999
(U.S. Naval Observatory, Washington, D.C., 1999).

* HISTORY of the ALMANACs, biographical notes on everybody at USNO and RGO,
* an account of Wallace Eckert (1902-1971) and computing and . . . !!!!
*      Everybody involved with the Almanac is here: the heads of the US and
* HM NAOs; the people involved on both sides with refraction calculations
* (Myles Standish, Catherine Hohenkerk) or star catalogs (Dorrit Hoffleit);
* George Kaplan and modern instrumentation; computing (T.J.Watson Sr. and
* the IBM 650); Simon Newcomb, E.W.Brown and G. W. Hill, Bessel's
* refraction table, etc. are all mentioned in this 400-page book.
*      This SESQUICENTENNIAL SYMPOSIUM is full of good stuff.  See the Table
* of Contents (pp. ix - xi) for a fascinating look at the recent past.
*      Available at  https://apps.dtic.mil/sti/tr/pdf/ADA470556.pdf


P. Ray, D. S. Monzú, R. Presl, J. A. Butt, and A. Wieser
“Refractivity corrected distance measurement using the intermode beats derived from a supercontinuum,”
Optics Express 32, no. 7, 12667–12681 (2024).

* Pabitro Ray, David Salido Monzú, Robert Presl, Jemil Avers Butt,Andreas Wieser
*      A good modern review of 2-color methods.  Errors of a few parts in 107
* are demonstrated. References to other modern papers.
* DOI: 10.1364/oe.514997



*** OBITUARY + BIOGRAPHIES FILE ***

J. B. Biot
“Une anecdote relative a M. Laplace,”
Journal des Savants , 65–71 (1850).

*      [see also Cassini's memoir, published by his great-grandson namesake]
*
* Biot's story about LAPLACE
* This tells how he became Laplace's proofreader, and "il est aisé de
* voir." But the main point is the anecdote about his discovery in
* analysis, and Laplace's responses to it.
*      This was reprinted in Biot's  Mélanges Scientifiques et Littéraires
* (M. Lévy, Paris, 1858), pp. 1-9.
* [This may be vol. 212; dated Fev. 1850]


?
“Claude Louis Mathieu,”
M. N. 36, 158–161 (1876).

* CLAUDE LOUIS MATHIEU (1783-1875)
* (Not to be confused with the mathematician Émile Mathieu, of the
* eponymous functions.) Mathieu was a carpenter's son, but managed to
* acquire an education, and the ambition of attending the École
* Polytechnique. Mathieu lived in Delambre's observatory as a student,
* in 1801. He and Delambre became friends, and Delambre left him the
* History of Astronomy in the 18th Century to complete. He met Arago
* at the École Polytechnique, and later married Arago's sister; their
* daughter in turn married Laughier. When Arago died, Mathieu took over
* the supervision of the Connaissance des Temps and the Annuaire
* of the Bureau des Longitudes. When he died in 1875 at the age of 92,
* he was the last living link with the founding of the metric system,
* having served as Biot's assistant in the Dunkirk survey.
* [See also the notes in C.R. 80, 581-583 (1875).]


F. W. Bessel
Briefwechsel zwischen W. Olbers und F. W. Bessel
(A. Erman, Leipzig, 1852).

* FRIEDRICH WILHELM BESSEL (1784-1846)
* An English translation of Heinz Klaus Strick's biography of Bessel
*
*        https://www.spektrum.de/wissen/friedrich-wilhelm-bessel-1784-1846/999405
*
* is available at the St. Andrews website:
*
* https://mathshistory.st-andrews.ac.uk/Strick/Bessel.pdf
*
*      A longer article at
*
* https://en.wikipedia.org/wiki/Friedrich_Bessel
*
* as well as Strick's short account is evidently based on Bessel's own
* short memoir, which is cited in his obituary in Astronomische Nachrichten.
*
* https://adsabs.harvard.edu/full/1919AN. . . .210..161R
*
*      Bessel's "Kurze Erinnerungen an Momente meines Lebens" was published in
*
* "Briefwechsel zwischen W. Olbers und F. W. Bessel" (A. Erman, Leipzig, 1852)
* which is available on the Web at
*
* https://www.digitale-sammlungen.de/de/view/bsb10061073?page=13
*
* An English translation is available at
*
* http://www.probabilityandfinance.com/sheynin/098_bessel.pdf
*


C. Leah Devlin
“William Scoresby as an Arctic physical oceanographer,”
Archives of Natural History 46, No. 1, 33–43 (2019).

* WILLIAM SCORESBY (1789-1857)
* Contains a short biography of Scoresby, and a summary of his work.
*      Available at
* https://www.euppublishing.com/doi/pdfplus/10.3366/anh.2019.0551


?
“Friedrich Wilhelm August Argelander,”
M. N. 36, 151–155 (1876).

* FRIEDRICH WILHELM AUGUST ARGELANDER (1799-1875)
* Argelander's father was Finnish, but his mother was German. The German
* royal family stayed in their house after the battle of Jena. After
* Gymnasium at Elbing, Argelander attended the University of Königsberg,
* where he was attracted to astronomy by Bessel's lectures. He asked to be
* allowed to do some work for Bessel, who was so pleased by the results that
* he called him "one of his most distinguished pupils." He became Bessel's
* regular assistant Oct. 1, 1820, and made the refraction observations
* at low altitude early in 1821. In 1823 he became the director of the
* new observatory at Abo, which was moved to Helsingfors after the fire
* of 1827. In 1837 he became director of the new observatory at Bonn,
* where, beginning in 1852, he undertook "that great Durchmusterung
* . . . with which his name will be for ever associated."
* [based on a longer obit. by Schönfeld in VJS AG 10, part 3.]


F. Groff
“Notice Biographique de William N. Groff (1857-1901),” in Œuvres Égyptologiques de William N. Groff
(Ernest Leroux, Paris, 1908), pp. I–IV.

* This is the notice by William Groff's sister, Florence Groff, in his
* French collected works. She concentrates on his Biblical studies, and
* does not mention his GF work.


J. L. Hunt
“James Glaisher FRS (1809-1903),”
Q. J. R. Astr. Soc. 37, 315–347 (1996).

* JAMES GLAISHER (1809-1903)
* A detailed biography of James Glaisher by "a grandson of Glaisher's
* only daughter". Though he "did not receive much formal education,"
* Glaisher became both an FRS and a FRAS; he was "the first President of
* the Royal Microscopical Society, President of the Royal Photographical
* Society for more than 20 years, and a member of the Council of the Royal
* Aeronautical Society from its foundation in 1866 until his death."
*      A friend of the family with connections at the RGO got Glaisher
* training in astronomical instruments while John Pond was A.R. After 2
* years' work with the Ordnance Survey in Ireland, Glaisher became an
* assistant to Airy at Cambridge in 1833. When Airy became A.R., he "made
* arrangements for Glaisher, then his First Assistant, to transfer . . . to
* the Royal Observatory at Greenwich." [Impressive that the finicky Airy
* was so pleased with Glaisher's work!]
*      "In 1840 Airy appointed Glaisher Superintendant of the Magnetical
* and Meteorological Department on its formation, a post he was to retain
* for 34 years."
*      Glaisher's discovery of the stratosphere is mentioned, but not his
* affirmation of nocturnal inversions.


A. Bravais
Notice des travaux scientifiques de M. A. Bravais
(Mallet-Bachelier, Paris, 1854).

* AUGUSTE BRAVAIS (1811-1863) references
*      This is his own annotated bibliography, which was used to support his
* application for membership in the Académie des Sciences
*
* [See
*             Maurice Crosland
*             Assessment by Peers in Nineteenth-century France: The Manuscript
*                  Reports on Candidates for Election to the Académie des Sciences
*             Minerva, Vol. 24, No. 4, pp. 413-432 (December 1986)
*
* which is available at Stable URL: https://www.jstor.org/stable/41820664
* for an explanation of such "Notes". There, Bravais is discussed on
* pp. 419-420.]
*
*      Bravais began his career as a sailor, and was sent as a naturalist on
* several expeditions. This required him to study botany; a study of the
* symmetries of flowers and leaves led him into the study of minerals and
* crystals. His work in navigation clearly stimulated his study of
* refraction. [I am reminded of the career of Minnaert, who went from
* photobiology to solar physics, with excursions into atmospheric optics.]
*      Bravais was a co-founder and first President of the Société
* Météorologique; he presided at its first meeting, on 14 Dec. 1852.
* This "Notice" outlines his most productive years.
*
* He discusses his interest in atmospheric optics on p. 8 of this Notice,
* beginning with rainbows and halos. The mirage publication is described on
* p. 10, where he summarizes it as follows:
*      "Je passe en revue toutes les anciennes observations venues à ma
* connaissance ; je rappelle les travaux de Woltmann , de Wollaston ,
* de M. Gergonne et de M. Biot .
*      "Mirage inférieur .  -- Rôle important de la caustique. -- Rapport de
* grandeur des deux images . -- Explication du mirage inférieur . -- Cas de
* la caustique rectiligne . -- Cause de la moindre étendue de l'image
* inférieure dans le sens vertical. -- Effet de la courbure de la terre.
*      "Mirage avec simple élévation des objets. -- Il ne peut y avoir de
* caustique dans ce cas .       Couche dont la densité fictive est un minimum .
*      "Mirage supérieur. -- Cas des trois images. -- Cause de la disparition
* fréquente de l'image supérieure. -- Cas où l'image moyenne disparaît .
*      "Mirage latéral. Mirage multiple. --  Combinaison des deux espèces de
* mirage. -- Phénomène rare ; ce phénomène a été vu par M. Bravais dans le
* nord de l'Europe.
*      "Depuis cette époque , j'ai fait, à Royan (Charente-Inférieure), de
* nombreuses observations sur le mirage observé à l'horizon de la mer ; ces
* observations ne sont point encore publiées ; elles sont accompagnées de
* plusieurs dessins, représentant l'apparence de la rive gauche de la
* Gironde, et celle de navires entrant dans le fleuve ou en sortant."
*
* Then comes the reference to his paper on the horizontal ray:
*      "Explication théorique du relèvement des trajectoires lumineuses dans
*      le mirage ."
* The footnote here cites his abstract in "L'Institut" 21, p. 193. His
* interesting comment is:
*      "Ce phénomène paraît avoir embarrassé les géomètres, et en a conduit
* plusieurs à admettre la réflexion totale. Je montre qu'il n'y a point de
* réflexion totale , et que le relèvement des trajectoires est une
* conséquence naturelle de l'application de la théorie des ondes à la
* marche du rayon ."
* (That paper was not published until 1856.)
*
* Bravais's "Notice" is available at Google Books, at URL:
*
* https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=Bravais+Notice+Travaux&btnG=
*      and at  HathiTrust.
*


F. W. D[yson]
“Mathieu-Prosper Henry,”
M. N. 64, 296–298 (1904).

* PROSPER HENRY (1849-1903)


H. Blanc
“Le professeur D^r François Alphonse Forel,”
Actes de la Société Helvétique des Sciences Naturelles 95, 110–148 (1912).

* FRANÇOIS-ALPHONSE FOREL (1841-1912)
* Prof. Dr. Henri Blanc's long obituary of Forel
* NOTE: the obituaries are paginated separately from the main part of
* the volume. To get this, tell your librarian that the pages you need
* are in the "Annexe" or "Anhang" that contains the obituaries.
*      Although the long bibliography was compiled by Forel himself, it is
* not complete, and contains many errors.


[unsigned]
“Prof. F. A. Forel,”
Nature 89, No. 2234, 638–639 (Aug. 22, 1912).

* FRANÇOIS-ALPHONSE FOREL (1841-1912)


F. D. C. Forel
Forel et le Léman: Aux Sources de la Limnologie
(Presses Polytechniques et Universitaires Romandes, Lausanne, 2012).

* FRANÇOIS-ALPHONSE FOREL (1841-1912)
*      This contains Forel's autobiography, written for his grandchildren;
* it lay unpublished in the family archives for a century, before being
* transcribed from his scribbly handwriting and published in 2012.
*      The section of interest here is pp.146-154, which cover the refraction
* phenomena. Unfortunately, there is an error of transcription in the
* description of inferior mirages: in the 3rd line from the bottom of
* p.148, "au-dessus" should be "au-dessous". [see the correct (and
* similar) wording on p. 475 of Forel's 1911 lecture on the Fata Morgana,
* or pp. 523 and 525 of his 1895 monograph.]
*      Thanks to Eric Frappa for useful discussion of this book.


A. Watt
“Robert Traill Omond, LL.D.,”
J. Scottish Met. Soc. 16, 293–302 (1914?).

* ROBERT TRAILL OMOND (1858-1914)
* Omond seems to have been the first person to use the phrase
* "green flash" in print. He was a student of Tait's but did not earn a
* degree (his LL.D. was honorary).
* Many thanks to Marjory G. Roy, Hon Secretary, Scottish Centre,
* Royal Met Soc, for the reference to this item!


B. Monterosso
“Prof. Annibale Riccò,”
Boll. Bimens. Soc. Met. Ital. 38, 28–30 (1919).

* ANNIBALE RICCÒ (1844 -1919)
* not very informative


H. F. N[ewall]
“Annibale Riccò,”
M. N. 80, 365–367 (1920).

* ANNIBALE RICCÒ (1844 -1919)
* Much better! He began life as an architect; his work at the
* Agricultural Station at Modena involved meteorology; in 1872 he became
* assistant at the observatory there. Most of his work after 1879
* involved solar observations. He became co-editor of the Memorie degli
* Spettroscopisti Italiani with Tacchini in 1899.
*      See the JHA article by Nali (2022) for another biography.


Anonymous
“Mr.C. T. Whitmell,”
Nature 104, 398 (1919).

* CHARLES THOMAS WHITMELL (1849-1919)
* "Mr. C. T. Whitmell, the well-known amateur astronomer . . . ."
* "His interests lay in the mathematical rather than in the observational
* side of astronomy, though his long series of observations of the
* phenomenon known as the ``green flash'' are almost unique."
* Whitmell died Dec. 10; this paragraph appeared in the Dec. 18 issue!


J. R. Mozley
“Charles Thomas Whitmell,”
JBAA 30, 98–99 (1919).

* CHARLES THOMAS WHITMELL (1849-1919)


H. P. Hollis
“Charles Thomas Whitmell,”
Leeds Astron. Soc. Journal & Trans. 27, 20–22 (1919).

* CHARLES THOMAS WHITMELL (1849-1919)
* "In 1897 he was transferred to Leeds, where he lived for the remainder
* of his life.
*      "When he settled in Leeds, Mr. Whitmell found several opportunities
* for scientific occupation. . . . There had been a Leeds Astronomical
* Society 30 or 40 years earlier, established under the honorary
* presidency of Sir George Airy, to whose proceedings Sir John Herschel
* had contributed a remarkable essay: `The Yard, the Pendulum and the
* Metré; but this society had not fulfilled expectations, and did not
* endure, but had been revived in 1892 . . . . Mr. Whitmell joined this new
* society in March, 1897 . . . . He was elected President at the end of the
* year, and held that office until 1900. He joined the British
* Astronomical Association in 1897, and was a member of its Council for
* some years. . . . Mr. Whitmell was elected a Fellow of the Royal
* Astronomical Society in December, 1898."
* Thanks to Ray Emery for supplying this! -- On the back is a title page
* for the journal, for the next year (1920).


A. C. D. C[rommelin]
“Charles Thomas Whitmell,”
M. N. 80, 359–360 (1920).

* CHARLES THOMAS WHITMELL (1849-1919)
* "He was held in the highest respect and esteem . . . for his courtesy,
* considerateness, and charm of manner."
* ". . . the patient, careful manner in which he dealt with the difficulties
* of inquirers in the columns of the English Mechanic .
* "Phenomena of colour greatly interested him, and he wrote several notes
* in explanation of the green flash at sunset . . . ." as well as ". . . his
* useful handbook on colour, published in 1888."


Anonymous
“Charles Michie Smith,”
M. N. 83, 245–246 (1923).

* CHARLES MICHIE SMITH (1854-1922)
* Smith succeeded Pogson at Madras; founded the Kodaikánal Observatory
* near there; and was succeeded by John Evershed on his retirement in 1911.
* See Report of Kodaikánal & Madras Observatories, MN 72,286(1913)
* Note that Evershed, his successor, always refers to him as
* "Michie-Smith" (hyphenated) in his autobiographical note in Vistas.


W. M. H. G[reaves]
“Arthur Alcock Rambaut,”
M. N. 84, 220–221 (1924).

* ARTHUR ALCOCK RAMBAUT (1859-1923)
* Rambaut became Radcliffe Observer in 1897, soon after publishing his
* big 1895 paper on atmospheric dispersion, which must have influenced
* his choice as the author to review the Green Flash -- as well as his
* mental model for it! His main work was the attempt to measure parallaxes
* from simple direct photographs -- enshrined in vol.53 of the
* Radcliffe Observations -- but this was largely a failure.


Anonymous
“Captain Alfred Carpenter,R.N., D.S.O.,”
JBAA 35, 241–242 (1925).

* CAPTAIN ALFRED CARPENTER (1847-1925)


Anonymous
“Colonel Ernest Elliott Markwick, C.B., C.B.E.,”
JBAA 35, 311–315 (1925).

* Colonel ERNEST ELLIOTT MARKWICK, C.B., C.B.E. (1853-1925)
* This long obit is prefaced with a fine portrait of Col. Markwick.
* He was interested in solar work, which may have given him his
* introduction to green flashes. His main astronomical accomplishment
* was to organize the Variable Star Section of the BAA, after which
* (his biographer here claims) the AAVSO and other like organizations
* were patterned. "In 1879 he became a Fellow of the Royal Astronomical
* Society and in October, 1912, he was elected President of the B.A.A."
* He discovered T Cen and RY Sgr, the latter an R Cor Bor star, using
* only the charts of Gould's Uranometria Argentina and binoculars,
* while stationed in Gibraltar.


A. Einstein
“W.H.Julius, 1860-1925,”
Ap. J. 63, 196–198 (1926).

* WILLEM HENRI JULIUS (1860-1925)
* Einstein's obituary, "written with the hope that his views on taking
* refraction into account in explaining solar phenomena may not be
* temporarily forgotten by oversight," refers to him as an "old friend".
* ". . . in 1891, a work of A. Schmidt . . . turned his attention to the
* field of solar physics, to which he thereafter devoted his entire life."
* His treatment of Julius's explanation of "the distribution of intensity
* in sun-spots", as due "to refraction of light from the photosphere",
* indicates that Einstein, like many others, did not understand the
* distinction between radiance and irradiance. Fortunately, he excuses
* himself by saying "I am not competent to render judgment on the reach of
* Julius' ideas . . . ."


M. G. J. Minnaert
“Julius, Willem Henri,”
Dictionary of Scientific Biography 7, 186–187 (1973).

* WILLEM HENRI JULIUS (1860-1925)
* Minnaert's biography of Julius in the DSB:
* "His observation of the solar eclipse of 1901 was the turning point in
* Julius's activity" . . . "The darkness of sunspots was explained by
* regular refraction. In these conceptions the importance of refraction
* was vastly exaggerated."
* So Minnaert, too, seems not to have realized the physical impossibility
* of Julius's ideas about sunspots.
* The DSB was edited by C.C.Gillespie and published by Scribner's, New York.


F. R. H. Smit
“Marten Edsge Mulder,” in 400 Jaar Groninger Veenkoloniën in Biografische Schetsen , J. D. R. van Dijk and W. R. Foorthuis, eds.
(Regioproject, Groningen, 1994), pp. 165–168.

* MARTEN EDSGE MULDER (1847-1928)
* Mulder, who had been a student of Donders and Snellen (inventor of the
* familiar E / F P / T O Z / . . . eye chart) in Utrecht, founded the 4th
* eye clinic in the Netherlands in 1879, where he treated over 50,000
* patients. His pride was the library which he managed himself, and whose
* catalog he published. He resigned from his professorship at the
* University of Groningen in 1913, an unusual step at the time, to devote
* himself to travel and his interests in the natural sciences. [Note that
* the GF articles in Kosmos that provoked his interest appeared just at
* this time.] He and his wife then moved to the Hague, and he published a
* series of works on popular science.
* Many thanks to Dieneke de Vries for sending a photocopy!


E. Kleinschmidt
“August v. Schmidt,”
Gerlands Beiträge zur Geophysik 22, 233–238 (1929).

* CARL AUGUST von SCHMIDT (1840-1929)
* Includes a COMPLETE BIBLIOGRAPHY of Schmidt's publications.
* Schmidt's papers cover a wide range: geophysics, meteorology, astronomy.
* His principal field seems to have been geophysics and seismology.
* He spent 32 years teaching at the Realgymnasium in Stuttgart, where he
* taught physics, chemistry, and mathematics. This career as what we
* would call a high-school science teacher was followed by several years
* as head of the Stuttgart weather office. Though he is primarily
* remembered for his work in seismology, we are concerned here with his
* papers on refraction in the atmospheres of the Earth and (supposedly)
* the Sun.
* Note: p. 238 is numbered 338 in error.


E. Kleinschmidt
“August von Schmidt,”
Met. Z. 46, 265–267 (1929).

* CARL AUGUST von SCHMIDT (1840-1929)
* Kleinschmidt's other obituary of Schmidt. This one is shorter, but
* seems to recognize more of Schmidt's errors; it mentions his value
* of 14K/km for the adiabatic lapse rate, for example -- and says
* "Die nach ihm benannte Sonnenhypothese -- scherzhaft wurde er oft der
* ``Sonnenschmidt'' genannt -- . . . ."
* On the other hand, here he's introduced as "Geh. Hofrat Prof. Dr."


E. van Everdingen
“Alfred Wegener,”
Hemel en Dampkring 29, 185–187 (1931).

* ALFRED WEGENER


A. Amerio
“ANTONIO GARBASSO,”
Memorie della Società Astronomia Italiana, Vol. 7, 211 (1933).

* ANTONIO GARBASSO (1871-1933)
* Garbasso was a physicist who studied under Heinrich Hertz at Bonn.
* He worked at Turin, and later at Florence, in both mathematical and
* experimental physics, primarily connected with the electromagnetic theory
* of light, such as circular polarization, birefringence, and spectroscopy.
* Later, he was President of the Italian Physical Society.
* PDF available at ADS.


A. Meder
“Prof. Dr. Karl Reinhold Kupffer,”
Korrespondenzblatt des Naturforschenden Vereins zu Riga 62, 1–19 (1937).

* KARL REINHOLD KUPFFER (1872-1935)
* Kupffer was a colleague of Rudolf Meyer's; his obituary gives some
* insight into the German community in Riga, as the plunder of the library
* after the Bolshevik Revolution and disquieting effects of the German
* occupation during WW I are alluded to.
* Kupffer is a minor figure in our story. Still, he is an interesting
* character; and his complete bibliography at the end of the obituary is
* remarkable for its breadth. The obituary gives the German and current
* names of places; some of Kupffer's publications are pleas to preserve the
* German place-names.


M. S. Drower
Flinders Petrie: a life in archaeology
(Gollancz, London, 1985).

* Sir W. M. FLINDERS PETRIE (1853-1942)
* (knighted in 1923, at age 70)
* [This book is in the library: DT 76.9 P4 D7 1985]
* He is a minor figure in our story, but a major figure in archaeology;
* his measures of the Great Pyramid showed that Piazzi Smyth was a crank.
* He also wrote an autobiography, ``Seventy years in Archaeology'' (1931).
* Margaret Drower's book will tell you more than you want to know about him.


A. C. Egerton
“Lord Rayleigh. 1875-1947,”
Obituary Notices of Fellows of the Royal Society 6, No. 18, 502–538 (1949).

* ROBERT JOHN STRUTT, 4th BARON RAYLEIGH (1875-1947)
* Contains a useful anecdote about the 1929 trip to South Africa that
* aroused his interest in green flashes (p.525): "The writer remembers
* one evening when Rutherford saw it on the deck above and we who were
* standing just below did not see it. Rayleigh . . . came to the conclusion
* that `everything depends on the location' of the observer."
* There is also a quote (from where???) about reactions to Rayleigh's
* GF papers. (p. 526)


R. T. Zoch and R. G. Stone
“William Jackson Humphreys (1862-1949),”
Bull. Am. Met. Soc. 31, 142–144 (1950).

* WILLIAM JACKSON HUMPHREYS (1862-1949)
* Humphreys was President of the AMS in 1928-29, and served in many other
* offices both there and in the AAS, of which he was one of the founders
* (though you can't find that here). He served on the Councils of both
* societies. He took an oddly simplistic view of both ball lightning,
* which he thought did not exist, and the GF, and was conned by Jules Verne.
* He studied under Rowland at Johns Hopkins; his most notable student was
* E.W.Woolard. Meteorologists remember him for his work in understanding
* the stratosphere; astronomers have forgotten him.


D. Sc. Obituaries: Hugh Robert Mill and LL. D.
Met. Mag. 79, 180–182 (1950).

* H. R. MILL (1861-1950)
* Mill became editor of Met. Mag. from 1901 to 1919, after G. J. Symons
* died in 1900. He was a distinguished meteorologist and geographer:
* President of the RMS in 1907 and 1908; v.p. of the Royal Geographical
* Soc. in 1927-31; author of many books. This obit. is a good summary.
* He was also Shackleton's biographer. For a review of his
* autobiography, see QJRMS 78, 117 (1952). (cf. Who's Who as well.)
* Followed by a brief mention of Humphreys's death.


E. Römer
“In Memoriam, Gustav Schröder,”
Deutsche Hydrog. Z. 11, 258–259 (1958).

* OBIT for GUSTAV SCHROEDER, with publication list
* Dated 1958, though it reports his death on Jan.10, 1959


G. Bomford
“James de Graaff-Hunter (1881-1967),” in Biographical Memoirs of Fellows of the Royal Society 13,pp.78-88 (Nov., 1967)
(Elmar B.V., Rijswijk, 1998).

* JAMES DE GRAAFF-HUNTER (1881-1967)
* Contains an extensive (but incomplete) list of his publications.
* A much shorter version of this appeared in QJRAS 8, 292-293 (1967);
* very similar versions of it were in J.of Geodesy 41, 83-84 (1967)
* and Geographical Journal 133, 282-283 (1967).
* MARCEL MINNAERT (1893-1970)
* Memorial brochure produced for the dedication of the Minnaert building.
* Leo Molenaar's very attractive brochure, commissioned by Utrecht
* University for the opening of the Minnaert building on 5 March 1998.
* Contains a short biography of Marcel Minnaert, and reminiscences of him
* (all in Dutch) by various people he worked with.
* P. 27 has a nice photo of Minnaert "in action" with the inferior-mirage
* ray drawn on the blackboard behind him. P. 30 reproduces the GF drawings
* from his book, with the original Dutch captions. The back cover shows
* the Taylor-Matthias flash sequence.
* Nicely illustrated with photos of and drawings by Minnaert, and the
* covers of his many publications.
* Many thanks to Leo Molenaar for providing a copy!


L. Molenaar
Marcel Minnaert Astrofysicus 1893-1970
(Balans, Amsterdam, 2003).

* Leo Molenaar's monumental tribute to Minnaert
* At slightly over 600 pp., this tells you all you want to know about
* Minnaert. There is an Appendix that explains how Minnaert fell under
* the influence of Julius, and outlines Julius's crazy anomalous-dispersion
* theory of solar phenomena. Green flashes get a paragraph on pp. 255-256;
* a footnote mentions my Zenit article. There are numerous references,
* and a name-index, but no subject index.
* Thanks to Steven M. van Roode for pointing this out!


S. Gulev
“Distinguished Air-Sea Interface Explorer Lutz Hasse (1930–2016),”
Boundary-Layer Meteorol. 162, 203–205 (2017).

* LUTZ HASSE (1930-2016) obituary
* Lists his major accomplishments, but no bibliography.
* DOI 10.1007/s10546-016-0197-y



*** O4 FILE ***

H. Salow and W. Steiner
“Die durch Wechselwirkungskräfte bedingten Absorptionsspektra des Sauerstoffes,”
Zs. f. Physik 99, 137–158 (1936).

*
*
* ABSORPTION COEFFICIENTS and BAND PROFILES in LIQUID and GAS


J. Dufay
“Notes sur l'absorption sélective dans l'atmosphère terrestre. I - Description de spectre du soleil couchant, de 4600 a 6900 A,”
Ann. d'Ap. 5, 93–113 (1942).

* LOW-SUN SPECTRA with good resolution
* but only down to 3 degrees altitude
* Ignores refraction in estimating airmasses!
* O'C #29


D. Keilin and E. F. Hartree
“Absorption spectrum of oxygen,”
Nature 165, 543–544 (1950).

* LIQUID O2


D. Perner and U. Platt
“Absorption of light in the atmosphere by collision pairs of (O2)2,”
Geophys. Res. Lett. 7, 1053–1056 (1980).

* (O2)2 seen in ATMOSPHERE


G. D. Greenblatt, J. J. Orlando, J. B. Burkholder, and A. R. Ravishankara
“Absorption measurements of oxygen between 330 and 1140 nm,”
J. Geophys. Res. D 95, 18577–18582 (1990).

* GOOD ABSORPTION DATA


H. Naus and W. Ubachs
“Visible absorption bands of the (O2)2 collision complex at pressures below 760 Torr,”
Appl. Opt. 38, 3423–3428 (1999).

* more ABSORPTION DATA



*** RICCÒ & ARCTOWSKI FILE ***

Ricco
“Image réfléchie du Soleil à l'horizon marin,”
C. R. Acad. Sci. 107, 590–594 (1888).

*
* (SEE ALSO his 1887 Nature paper in GF file)
*
* (SEE ALSO the Hunt (1863) and Budde (1885) papers in Mirage File)
*
* Riccò's first mention of OMEGA shape
* INFERIOR MIRAGE OF SUN
* H.Faye presented the paper of A.Riccò, so this is occasionally
* mis-attributed to Faye.
* A German summary is in Naturwiss. Rundschau 3, 632 (1888).


C. Wolf
“Sur la déformation des images des astres vus par réflexion à la surface de la mer,”
C. R. Acad. Sci. 107, 605–606 (1888).

* WOLF calculates the image flattening in response to Ricco's paper
* He does a parametric calculation as a function of the position of the
* reflecting point on the sea, and produces a table showing that the
* flattening is extreme at the horizon and rapidly diminishes.
* Note that this connection had been made empirically by Bravais in 1853!


A. Riccò
“Immagine del sole riflessa nel mare, prova della rotondità della terra,”
Mem. Soc. Spett. Ital. 17, 203–219 (1888).

* Followup to above; REFLECTION in sea claimed
* See Whitmell's reprise of this in JBAA, 1905 (filed in GF file).
*      See the figure captions on p. 220, and the corresponding Plates,
* Tav. CCXXIV and CCXXV.
* Mem.Soc.Spett. was actually printed (according to the title page)
* in the year after the one conventionally assigned. Evidently the
* papers were given at meetings in the previous year, at the end of which
* they were all printed.
* A.Riccò
* O'C #115


A. Venturi
“Sulla formazione delle immagini di oggetti celesti o terrestri sulle grandi superfici liquide della terra,”
Mem. Soc. Spett. Ital. 18, 23–36 (1889).

* Followup to above; REFLECTION in sea
* Adolfo Venturi models the reflection in the sea, including standard
* terrestrial refraction, and finds less contraction of the image than
* observed by Riccò and Forel. He thus concludes that the additional
* contraction of the image is due to the waves on the water; here he
* adopts a very small slope (2.5 minutes of arc!) for the typical wave
* slope, which of course pushes the reflection of the Sun's upper limb
* toward the horizon -- assuming it is at the near face of the wave.
* He finds that refraction decreases the image reduction [as one could
* have seen more easily by adopting the point of view that refraction
* increases the effective radius of curvature of the Earth].
* Venturi was Professor of Geodesy at Palermo.
* N.B.: printed in 1890.


A. Riccò
“Considerazioni sui risultati degli studi delle immagini riflesse dalle acque,”
Mem. Soc. Spett. Ital. 18, 45–47 (1889).

* Riccò replies to Venturi
* Riccò summarizes the principal points, noting that the refraction is
* uncertain because the water "in general has a temperature different from
* that of the air." He thinks the tops of the waves are flat and should
* give the same image as a flat sea, as only the very tops can be seen
* near the horizon. Otherwise, the waves would make a broken-up image,
* which is not observed. He thinks his observations are due to the
* "celebrated calmness of the water of the Gulf of Palermo".
*      [This argument is partly correct: actual reflections on waves are
* broken up; so the "reflection" here must be an inferior mirage.]
* N.B.: printed in 1890.


V. Cerulli
“Sull'immagine marina del sole,”
Mem. Soc. Spett. Ital. 18, 57–60 (1889).

* A simpler derivation, neglecting refraction.
* N.B.: printed in 1890.


A. Venturi
“Sulla formazione delle immagini sulle grandi superfici liquide della terra,”
Mem. Soc. Spett. Ital. 18, 104–105 (1889).

* Venturi replies to Riccò
* Refraction and curvature don't suffice to explain the observed image
* contraction; therefore it has to be the waves, even though an exact
* analysis is difficult. . . .


A. Riccò
“Sulla variazioni della rifrazione atmosferica,”
Mem. Soc. Spett. Ital. 18, 204–213 (1889).

* Preliminary note on DIP
* A.Ricco


A. Riccò
“Sopra un modo facile di studiare la rifrazione atmosferica,”
Rend. della R. Accad. dei Lincei , series 4, 6, 13–17 (1890).

* DIP and diurnal variations; horizon highest during sirocco
* A.Ricco (actually filed in DIP file; see followups there)


C. Flammarion
“Nouvelle preuve de la sphéricité de la terre,”
L'Astronomie 10, 241–244 (1891).

* FLAMMARION's note on sunset flattening and Earth curvature
* He attributes it to Riccò (see above entries), accepting the "surface
* tranquille de la mer" idea. He also refers to Forel's drawings of the
* shrunken reflections of ships' sails on Lake Geneva, as well as
* Ch. Dufour's predictions in 1874.
*      The whole argument is faulty, not only because the inferior mirage is
* the "reflector", but also because terrestrial refraction of the
* "reflected" rays is neglected.


A. Riccò
“Deformazione del disco solare all'orizzonte,”
Mem. Soc. Spett. Ital. 30, 96–110 (1901).

* SUNSET DEFORMATIONS; drawings & photographs; cites Colton
* Many GREEN FLASHES at sunrise; good account of photographic difficulties
* several DOUBLE HORIZONS; ". . . FOG or MIRAGE . . . "
* Note the additional observations made by T. Zona, pp. 102-103.
* A.Ricco
* Fisher #127; O'C #117


P. F. Nali
“Annibale Riccò and the catoptric proof of the Earth’s curvature,”
Journal for the History of Astronomy 53, no. 1, 88–119 (2022).

* Pier Franco Nali's recent discussion of Riccò's work, Earth curvature, etc.
*      This is mostly about the supposed "reflection" from the sea surface.
* He mentions the various works above, and discusses the attempts by all
* the players to force a reflection to fit the facts.
*      Alfred Russel Wallace and his fight with Hampden get mentioned, and
* the Bedford Level story; but not the lawsuit: "Wallace won the wager."
* Some hollow-Earth fanatics also appear; but no mention of Symmes.
*      There is an interesting discussion of Ch. Dufour's reduced images
* of sailboats and Forel's confirmation of them, in connection with the
* curvature question. The appearance of these images is associated with a
* calm lake surface, but without realizing that it is the calm air that
* allows a thermal inversion to modify the images.
*      Even Bravais and Woltman are cited; but the details of atmospheric
* refraction are largely passed by. So the differences seen over water and
* land surfaces are mentioned, but not attributed to different roughness
* lengths.
*      The difficulties of photographing the Sun at the horizon with
* 19th-Century means are vaguely mentioned, but not explained. The
* compressed image beneath the low Sun is supposedly justified by a
* deeply saturated digital-camera image (Fig. 2), with no awareness of the
* artifacts of digital cameras, charge spill, etc. The partly hidden feet
* of an Omega at the edge of an island are shown as evidence that Riccò
* was correct, without realizing that the perspective that applies to the
* inverted image (which is "seen" from beneath the sea) greatly modifies
* the effective profile of the island.
*      Venturi's mistaken notion that the reflected Sun is due to the wave
* facets facing the observer is mentioned without objection. This leads
* into a discussion of the reflections from waves, where a 1968 textbook
* is cited. But there's no direct mention of Cox & Munk, nor any reference
* to Shoulejkin. The glitter problem is treated as if it were separate
* from the average reflectance of the water. (No mention of Fresnel
* reflection, either.) And the lowest parts of the glitter pattern
* are attributed to the surface elements "more slanting toward the
* observer". (p. 108) The closely related issue of the variation of
* brightness over the sky and the brightness and color of the sea
* surface is not mentioned.
*      Near the end of the text, Wegener's mirage model is described as
* "standard"; but the modern treatment by Kattawar and Bruton is missing.
* No mention of classic works like Pernter & Exner, or Humphreys, or
* the many works on low-altitude refraction, like Fletcher's review. . . .
*      So, much interesting detail; but odd omissions and errors as well.
* The discussion is mostly qualitative, and often physically off the mark.
* In particular, the complexity of refraction phenomena makes the
* simplistic arguments advanced by the observers (and the author here)
* often misleading or wrong. Still, the details of the exchanges among
* Riccò and his critics are interesting to read, and go well beyond the
* references I have included in this bibliography. And the biographical
* note on Riccò at the end is very welcome.
*      Thanks very much to Pier Franco Nali for a PDF of his paper!


H. Arctowski
“Phénomènes optiques de l'atmosphère, Journal des observations de météorologie optique faites à bord de la 'Belgicá,” in Résultats du Voyage du S. Y. Belgica en 1897 - 1898 - 1899
(J.E.Buschmann, Anvers, 1902).

* Henryk ARCTOWSKI
* Distorted Sun drawings (cf. Colton/Chappell/Fisher file)
* The "Belgica" was the first ship to winter over in the Antarctic pack
* ice, at about -71 degrees latitude.
* SCINTILLATION:
* "Pourtant, je crois pouvoir dire que, dans la région de notre hivernage,
* la scintillation des étoiles est relativement très faible toutes les fois
* que le ciel est dépourvu de nuages et qu'il n'y a pas de brume à
* l'horizon." p.19
* also 2 GREEN FLASH reports (p. 26)
* Fisher #3a


H. Arctowski
“Notice sur les déformations apparentes des astres a l'horizon, observées a bord de la 'Belgicá,”
Bull. Soc. belge d'Astron. 7, 72–87 (1902).

* extract from the memoir, full illustrations
* Many references to thin "CLOUD LAYERS" near the horizon,
* correlated with solar distortions.
* O'C #2
* Fisher #3b


H. Arctowski
“Déformations apparentes des astres a l'horizon, observées a bord de la "Belgica",”
Mem. Soc. Spett. Ital. 31, 191–197 (1902).

* extract from the memoir, fewer illustrations
* O'C #3
* Fisher #3c


Dr. Baer
“Reise- und Bädernachrichten: Ein Sonnenuntergang in der Nordsee,”
Schlesische Zeitung , Nr. 627, (6 Sept., 1904).

* Dr. BAER's first report: EARLY RECOGNITION of MIRAGE involvement
* From his verbal description, I would have made this sunset a simple
* inferior mirage; but his drawings in Met. Z. (1905) show it to be
* quite otherwise. Part of this is excerpted in the Met. Z. report,
* which includes a mock-mirage sunrise as well.
*      Two features are notable: (a) the smallness of the waves (``das Meer
* machte nur ganz kleine Wellen''), mentioned twice (``Das Wasser war von
* leichten Wellen bewegt,'' -- not reprinted in the Met. Z. paper); and
* (b) his firm suggestion that mirage phenomena were involved: ``. . . der
* Auffassung, als handele es sich um Spiegelungserscheinungen auf der
* Meeresoberfläche, möchte ich vornherein entgegentreten. Das Wasser
* war von leichten Wellen bewegt, aber das untere Sonnenbild hatte
* nichts Schwankendes, Unbestimmtes, sondern ebenso scharfe Konturen wie
* das obere, und es stand in jeder Phase ganz symmetrisch zu ihm; nur war
* es zuerst viel kleiner, schmaler wie das obere, um erst am Schlusse
* breiter zu werden. Nach meiner Meinung hat sich der ganze optische
* Vorgang in der Luft abgespielt.''
* THANKS to Kristian Schlegel for sending a copy!


Dr. Baer
“Merkwürdige Refraktionserscheinungen,”
Met. Z. 22, 128–129 (1905).

* BAER's early DRAWINGS of Mock Mirage, and perhaps a sub-duct sunset:
* "Das ganze Schauspiel war so sonderbar, so merkwürdig, dass ich sofort
* seine einzelnen Phasen in meinem Taschenbuch aufzeichnete. Aber allen
* Personen, die ich in den nächsten Tagen auf die Erscheinung anredete,
* selbst gebildeten autochthonen Borkumern, war sie unbekannt. Der Wärter
* auf dem Leuchtturme, dem ich ein Interesse an allen meteorologischen
* Erscheinungen zutraute, hatte sie gar nicht beachtet and erklärte mir,
* um Sonnenuntergänge bekümmere er sich nicht; das hätte ja gar keinen
* Nutzen."
* He mentions "meine Mitteilung in der Schlesischen Zeitung." After
* reporting (and drawing) a mock mirage at sunrise, he adds:
*      "Um gleich dem Einwande zu begegnen, daß meinerseits eine
* physische oder optische Täuschung bei diesen Beobachtungen vorliegen
* könne, bemerke ich, daß ich Temperenzler bin, also alkoholischen oder
* sonstigen narkotischen Einflüssen nicht unterstehe, und daß ich zwei
* gesunde, emmetropische (normalsichtige) Augen mit etwa 5/3, also
* übernormaler Sehschärfe besitze. Ich kann demnach mit bestem Gewissen
* die Wahrheit der hier mitgeteilten Tatsachen bekräftigen."
* Here Dr. Baer's address is given as ``Hirschberg i. Schlesien''.
* O'C #6 -- but NO GF reported.



*** Colton/Chappell/FISHER etc. (DISTORTED SUNSETS FILE) ***

Diodorus Siculus
Diodorus of Sicily: The Library of History, Books II.35 - IV.58, with an English translation by C. H. Oldfather
(Harvard Univ. Press, Cambridge, 1933), pp. 233–235.

*
* See also Agatharchides near beginning of file.
* See also Rogers in DIP file, 1926.
* See also Weidefeld in Refraction Observations file, 1904.
*
* DIODORUS SICULUS again, with early distorted sunsets
* Speaking of Arabia Felix, he says of the sun:
* ". . . when out of the midst of the sea, as they say, it comes into view,
* it resembles a fiery red ball of charcoal which discharges huge sparks,
* and its shape does not look like a cone [footnote: `Agatharchides says
* "discus-shaped" '], as is the impression we have of it, but it has the
* shape of a column which has the appearance of being slightly thicker at
* the top; . . . ."
*      This is from Book III.48; perhaps it is what Lalande (1792; sect.2247)
* had in mind, though he says "Diodore de Sicile parle avec étonnement
* d'un pays du nord où le Soleil ne paroît point rond (liv. III,
* ch. 19); on croit que ce fait étoit emprunté d'Agatharchides."
* But nothing else in Diodorus seems to come close.


J. Kepler
Optics: Paralipomena to Witelo & Optical Part of Astronomy
(Green Lion Press, Santa Fe, N.M., 2000).

* KEPLER's calculation of solar flattening at horizon (1604)
* This is translated from Kepler's "Ad Vitellionem paralipomena" (p. 131)
* by William H. Donahue (p. 144 of his translation):
* "Thus the refracted figures acquire an oval figure, like that of a coin
* thrown into water, if viewed from a very oblique angle. . . . Let it be that
* the lower edge of the Sun graze the horizon: its refraction will be 34'.
* But the refraction of something higher, such as has an altitude of half
* a degree, will be 29'. Thus, in place of the Sun's diameter, 30', there
* will be seen a quantity of 25 minutes, while the transverse diameter,
* or that parallel to the horizon, will be 30'."


Chr. Scheiner
Sol ellipticus : hoc est, novum et perpetuum Solis contrahi soliti phænomenon quod noviter inventum . . .
(typis Christophori Magii, Augustæ Vindelicorum, 1615).

* CHRISTOPH SCHEINER remarks on solar flattening
* Strange that he does not acknowledge Kepler's earlier work, though he
* cites it. He claims to have discovered the elliptical Sun for the
* first time in 1612.
* We have this only on P-10.


F. Daxecker
Christoph Scheiners ``Sol ellipticus''
(Leopold-Franzens-Universität, Innsbruck, 1998).

* German translation of Scheiner's book [so, placed here out of order]
* P.2 reproduces Scheiner's title page.
* The volume bears a full-page ad for the Hypo Bank on the back cover.
* This is Veröffentlichungen der Universität Innsbruck, Band 226.


E. Reeves and A. Van Helden
On Sunspots
(University of Chicago, Chicago, 2010).

* English translations of both Galileo and Scheiner
*      Only the "sunspot letters", the Rosa Ursina , and Scheiner's 1612
* note on sunspots are provided here -- not the "Sol Ellipticus". A
* mirage is mentioned on p. 13, and "Sol Ellipticus" is briefly mentioned
* on p. 311.


R. Hooke
Micrographia
(Dover, New York, 1961).

* ROBERT HOOKE describes seeing, scintillation, and low-Sun distortions
* in his MICROGRAPHIA (1665), correctly attributing all these effects to
* the varying density of the air!
* DISTORTIONS at the horizon: "Since the invention (and perfecting in
* some measure) of Telescopes , it has been observ'd by several, that the
* Sun and Moon neer the horizon, are disfigur'd (losing that
* exactly-smooth terminating circular limb, which they are observ'd to
* have when situated neerer the Zenith) and are bounded with an edge every
* way (especially upon the right and left sides) ragged and indented like
* a Saw: which inequality of their limbs, I have further observ'd, not to
* remain always the same, but to be continually chang'd by a kind of
* fluctuating motion, not unlike that of the waves of the Sea; so as that
* part of the limb, which was but even now nick'd or indented in, is now
* protuberant, and will presently be sinking again; neither is this all,
* but the whole body of the Luminaries, do in the Telescope , seem to be
* depress'd and flatted, the upper, and more especially the under side
* appearing neerer to the middle then really they are, and the right and
* left appearing more remote: whence the whole Area seems to be
* terminated by a kind of Oval." (pp. 217-218)
* He discovers empirically the consequence of Laplace's extinction
* theorem: ". . . I have always mark'd that the more the limb is flatted or
* ovalled, the more red does the body appear, though not always the
* contrary." (p. 218)
* Astronomical and terrestrial REFRACTION, and MIRAGES: "It has been
* observ'd and confirm'd by the accuratest Observations of the best of our
* modern Astronomers, that all the Luminous bodies appear above the
* Horizon, when they really are below it. So that the Sun and Moon have
* both been seen above the Horizon, whil'st the Moon has been in an
* Eclipse. I shall not here instance in the great refractions, that the
* tops of high mountains, seen at a distance, have been found to have; all
* which seem to argue the Horizontal refraction, much greater then it is
* hitherto generally believ'd." (pp. 218-219)
*      "I have further taken notice, that not onely the Sun, Moon and
* Starrs, and high tops of mountains have suffer'd these kinds of
* refraction, but Trees, and several bright Objects on the ground: I have
* often taken notice of the twinkling of the reflections of the Sun from a
* Glass-window at a good distance, and of a Candle in the night . . . .
* and upon the whole, I find much reason to think, that the true cause
* of all these Phænomena is from the inflection , or
* multiplicate refraction of those Rays of light within the body of the
* Atmosphere , and that it does not proceed from a refraction caus'd by
* any terminating superficies of the Air above, nor from any such
* exactly defin'd superficies within the body of the Atmosphere ." (p.219)
* He then demonstrates the phenomena by using two liquids of different
* densities in a rectangular glass tank, just as Wollaston did 135 years
* later, and many others since then; and also mentions (p. 221) "The
* veins of Glass, nay, of melted Crystal , found, and much complained
* of by Glass-grinders, might sufficiently demonstrate the truth of it to
* any diligent Observator. . . . It remains therefore to shew, that there
* is such a property in the Air, and that it is sufficient to produce all
* the above mentioned Phænomena , and therefore may be the principal,
* if not the only cause of them." He does this on the following pages,
* using several elegant and simple laboratory experiments to demonstrate
* the relation between the density and the refraction of air. And, as
* the density seems to be inversely proportional to the pressure,
* ". . . there is a continual increase of rarity in the parts of the Air,
* the further they are removed from the surface of the Earth: It will
* hence necessarily follow, that (as in the Experiment of the salt and
* fresh Water) the ray of Light passing obliquely through the Air also,
* which is of very different density, will be continually, and infinitely
* inflected, or bended, from a streight, or direct motion." (p. 228)
*      Using Tycho's refraction table (p. 230), he shows that the
* FLATTENING of the Sun at the horizon is due to the differential
* refraction of upper and lower limbs, so that "the apparent refracted
* perpendicular Diameter of the Sun, will be . . . consequently six or seven
* minutes shorter then the unrefracted apparent Diameter."
*      "I shall . . .  proceed to shew, that the mass of Air neer the surface
* of the Earth, consists, or is made up, of parcels, which do very much
* differ from one another in point of density and rarity; and consequently
* the Rays of light that pass through them will be variously inflected,
* here one way, and there another, according as they pass so or so
* through those differing parts; and those parts being always in motion,
* . . . they do by this their motion inflect the Rays, now this way, and
* presently that way.
*      "This irregular, unequal and unconstant inflection of the Rays of
* light, is the reason why the limb of the Sun , Moon , Jupiter ,
* Saturn , Mars , and Venus , appear to wave or dance; and why the body
* of the Starrs appear to tremulate or twinkle, their bodies, by this
* means, being sometimes magnify'd, and sometimes diminish'd . . . ." (p.231)
*      "And that there is such a property or unequal distribution of parts,
* is manifest from the various degrees of heat and cold that are found in
* the Air; from whence will follow a differing density and rarity, both as
* to quantity and refraction . . . ." The thermal effects are also shown
* experimentally.
* Then (p.234) he asks "Whether the disparity between the upper and
* under Air be not sometimes so great, as to make a reflecting
* superficies; I have had several Observations which seem to have
* proceeded from some such cause, but it would be too long to relate and
* examine them." (Perhaps he had seen some superior mirages?) "An
* Experiment,also somewhat analogous to this, I have made with Salt-water
* and Fresh, which two liquors, in most Positions, seem'd the same, and
* not to be separated by any determinate superficies, which separating
* surface yet in some other Positions did plainly appear."
*      On p. 236 he takes up LOOMING: "Whether the appearance of the Pike
* of Tenerif , and several other high mountains, at so much greater a
* distance then seems to agree with their respective heights, be not
* attributed to the Curvature of the visual Ray . . . . I think it is very
* rational to suppose, that the greatest Curvature of the Rays is made
* nearest the Earth, and that the inflection of the Rays, above 3. or 4.
* miles upwards, is very inconsiderable. . . . Whence, I suppose, proceeds
* the reason of the exceedingly differing Opinions and Assertions of
* several Authors, about the height of several very high Hills."
* The Dover edition is a facsimile of the original 1665 edition, published
* by Martin and Allestry, London.


Mr. Cassini
“Observations astronomiques faites dans les voyages de France et d'Italie, en 1694, 1695, & 1696,”
Histoire de l'Academie royale des sciences, T. VII, Seconde Partie , 17–22 (1733).

* JACQUES CASSINI's OMEGA SUNRISE, with drawings, 7 Dec. 1694
*      This has to be Cassini II, as he begins by speaking of "le Voyage
* que j'ai fait avec mon Pere en Italie, d'y faire des Observations pour
* contribuer à la perfection de l'Astronomie & de la Géographie. . . .
* Nous partîmes de Paris le 23 Septembre de l'année 1694. . . ."
* They began observing in early December:
*      "Nous allâmes le 6 sur les Montagnes qui environnent le Port,
* pour voir la Mer. Le Mesco, qui est une petite Isle à l'embouchure de
* Porto Venete, se voyoit de la Montagne de S. Giorgio en forme de Navire,
* plus étroit en bas qu'au milieu, & élevé sur la surface de la Mer.
*      "Le 7 au matin le vent parut favorable. . . .  A 7h 30' étant à
* la hauteur de Chiavari, le Soleil parut se lever à la pointe du Cap de
* Mesco; il avoit la figure d'une colomne de feu, arrondie par le haut . . . ."
* (pp. 18-19) He then describes the Omega-shaped sunrise, complete with
* crude drawings of the various stages. On pp. 19-21 he describes his
* interpretation of the inverted image as being a reflection by ". . . la
* surface de la Mer, qui étoit alors tranquille. . . ." (p. 20)
* The problem that the sea horizon itself was not seen at the image-fold
* line is arm-waved away: the eye "ne la voit pas distinctement jusqu'à
* l'horizon sensible, où arrivent les rayons visuels qui la touchent,
* mais seulement jusqu'à un certain terme . . . au-delà duquel, l'eau
* faisant l'effet d'une glace de miroir disparoît à la vûë, & fait
* voir à la place où elle devroit paroître par la réfraction, le Ciel
* & les objets élevez, où les rayons visuels . . . réfléchissent & se
* terminent. L'on peut expliquer par cette raison l'apparence de l'Isle
* de Mesco, que l'on voyoit élevée sur la surface de la Mer, de même
* que nous l'avions remarqué le jour précédent de la Montagne de S.
* Giorgio . . . ." On p. 21, he cites Picard's Voyage d'Uranibourg for
* similar observations.
* Thanks to Luc Dettwiller for a copy of this!


MM. Cassini
“Observations astronomiques faites dans les voyages de France et d'Italie, en 1694, 1695, & 1696,”
Histoire de l'Academie royale des sciences, T. VII, Partie II , 465–533 (1729).

* The details of Jacques Cassini's Omega sunrise (again)
* This is the version provided by Gallica. As this has the earlier date
* of publication, it must be the original, and the previous entry, a reprint.
* Occasional footers say neither Hist. nor Mem., but Rec. de l'Ac., Tom.VII.
* In this version, the report is on pp. 483-487.
* Note that both Cassinis are credited here in the Table des Matieres .


de Mairan
“Observations du Soleil vu elliptique a environ 10 degrés de hauteur sur l'horison, le 28.e Juin 1733,”
Mem. Acad. Roy. Sci., Ann. M. DCCXXXIII , 329–330 (1733).

* DE MAIRAN's anomalous flattening observation
* A naked-eye observation through strongly reddening haze (probably smoke):
* "Je l'avois jugée auparavant telle que le diametre horisontal pouvoit
* avoir sur sept à huit parties, une partie de plus que le vertical."
* Cites Scheiner's Solis Elliptici Phænomenon .
* Actually published in 1735.


Anonymous
“Soleil vû Elliptique à une hauteur considérable sur l'Horizon,”
Hist. Acad. Roy. Sci. [1741] , 134 (1744).

* A similar observation, at 17 or 18° altitude
* This first-person account has no signature. I suppose it was written
* by the perpetual secretary himself, whoever it was. The curious way
* of estimating the flattening does not sound like an astronomer.
* De Mairan's observation is cited, in the Hist.


Le Gentil
Voyage dans les mers de l'Inde,Vol.1
(Impr.royale, Paris, 1779), pp. 393–415.

* LE GENTIL's 1769 observations at Isle de France [Mauritius] and Pondicherry
* Here are his observations of the effects of INFERIOR MIRAGE:
*      ". . .  je parle des réfractions horizontales pendant l'été & pendant
* l'hiver dans la Zone torride, & d'une inégalité que j'ai en même
* temps remarquée dans le lever du Soleil; inégalité qu'on ne peut bien
* observer que sur le bord de la mer." (p. 394)
*      "On avoit long-temps pensé, avant que l'expérience le confirmât,
* que vers l'Équateur les réfractions étoient différentes de ce
* qu'elles sont en France; . . . on croyoit même la réfraction horizontale
* aux environs du pôle, double de ce qu'elle est en France; on se fondoit
* principalement sur les observations de Spole & de Bilberg, faites en
* Lapponie en 1695 . . . ." (p. 394)
*      He also cites Maupertuis's book on the figure of the Earth;
* "Mais M. de Maupertuis . . . ne rapporte que des observations faites à
* deux degrés de hauteur au-dessus de l'horizon; or, à cette hauteur les
* réfractions commencent à n'être plus si inégales. C'est à
* l'horizon que se font remarquer les grandes variations; & dès que
* le Soleil est élevé de deux degrés, ces grandes variations & les
* différences ne se font presque plus sentir, même d'une saison à
* l'autre . . . ." (p. 395) [VARIATIONS CONFINED to 2° interval]
*      ". . .  j'ai constamment trouvé, à Pondichéry, par mes observations,
* la réfraction au lever du Soleil, sur le bord se la mer, d'environ deux
* minutes plus grande en été qu'en hiver . . . .
*      "J'avois commencé, des l'Isle-de-France . . .  or, en faisant ces
* observations, je remarquerai, que quoiqu'il fît le plus beau temps,
* quoique le ciel fût sans nuages, que l'horizon fût de la plus grande
* netteté, je remarquerai, dis-je, que le Soleil qui, à la vue simple,
* m'avoit toujours paru se plonger dans l'horizon de la mer, se plongeoit
* réellement dans un horizon élevé au-dessus de celui de la mer, d'une
* quantité assez considérable . . . ; cette quantité . . . pouvoit aller à
* quatre ou cinq minutes: ce phénomène me surprit beaucoup la première
* fois que je l'observai . . . ." (p. 396)
*      "Qui pourroit décrire le beauté du ciel, à Pondichéry, pendant
* les mois de Janvier & Février? . . . malgré ce beau ciel, qui n'a rien
* de comparable, sans un seul petit nuage, un horizon superbe : le Soleil,
* pendant tout l'hiver, n'a pas paru se lever une seule fois à l'horizon
* de la mer, mais toujours au-dessus, d'une quantité même assez
* considérable : l'effet en étoit très-singulier, comme on va le voir
* dans le détail des observations.
*      "Et au contraire pendant les mois de Juin & de Juillet, qui sont à
* Pondichéry le temps des grandes chaleurs, pendant lequel temps le ciel
* n'est plus à beaucoup près si beau ; que l'air au contraire est
* toujours rempli de vapeurs, le Soleil se lève constamment à l'horizon
* de la mer . . . ." (p. 397) To this he adds that in winter he could
* view the Sun directly up to an altitude of a degree, while in summer he
* had to use a smoked glass as soon as it rose. (cf. pp. 406-407)
* [?? Perhaps this explains why he reported no green flashes??]
* In summer the upper limb took 59 seconds to reach the astronomical
* horizon after its appearance, while in winter it took only 35 seconds,
* the difference representing the difference in altitude of the effective
* horizons.
*      He then gives several examples taken from his journal of
* observations. Some descriptions are of interest:
*      7 Jan. 1769: "J'attendois le Soleil à l'horizon de la mer que je
* voyois fort distinctement; mais lorsque cet astre a commencé à
* pointer, il a paru au-dessus de l'horizon de la mer, chose assez
* singulière & que j'avois déjà remarquée à l'Isle-de-France.
* Lorsque le Soleil a été à moité levé, l'horizon de la mer s'est
* abaissé, & a paru moins élevé qu'auparavant d'environ les trois
* quarts des 50 secondes trouvées avant le lever du Soleil,
* c'est-à-dire, de 36 secondes environ : le centre du Soleil étant
* tout-à-fait levé, le bord supérieur a paru refluer des deux côtés
* de l'horizon de la mer, & former comme le haut d'une urne : enfin le
* bord inférieur a quitté l'horizon bien au-dessus de la horizon de la
* mer. L'effet en a été singulier : il m'a semblé qu'une partie du
* haut de l'urne est rentrée sous l'horizon, & que le reste s'est joint
* au Soleil comme deux morceaux qu'on auroit détachés avec le ciseau."
* (pp. 399-400) So here is the EARLIEST DESCRIPTION using the URN image,
* as well as the rest of the OMEGA shape!
*      9 Jan.: "Le quart-de-cercle ayant été placé comme le 7, j'ai
* trouvé comme ce jour-là, l'horizon de la mer abaissé de 10' 50''.
*      "Le Soleil a pointé beaucoup au-dessus de l'horizon à 6h 5' 58''
* 30''' ; à mesure que le Soleil paroissoit monter, l'horizon de la mer
* s'abaissoit de façon qu'il s'est trouvé moins élevé d'environ le
* quart des 50 secondes trouvées ci-dessus ; c'est-à-dire, de 12 ou 13
* secondes : enfin le second bord du Soleil s'est dégagé de l'horizon
* bien au-dessus de l'horizon de la mer à 6h 8' 25'' ½ ; ce qui a
* produit l'effet de deux soleils qui se détachoient & se quitoient, dont
* l'un retournoit du côté de l'horizon & n'a disparu que 5 à 6 secondes
* après s'être détaché du véritable." (p. 401) (So what he is
* calling the "horizon" at sunrise is really the fold-line between the
* erect and inverted images of the inferior mirage.)
*      14 July: "Le Soleil a paru subitement & précisément à l'horizon
* de la mer, c'est-à-dire, que j'ai aperc,u un petit trait ou filet de
* lumière qui a doré l'horizon ; & ce filet étoit le Soleil." (p. 406)
* So, as noted by Fisher (1921), the summer sunrises were of Type B, and
* the winter ones of type A.
*      He cites and discusses the horizontal refractions found by Bouguer
* in Peru (p. 414); and, as Bouguer's values are appreciably less than his
* own, adds: "J'aurois desiré que M. Bouguer nous eût donné le détail
* de ses observations, & non pas seulement des résultats comme il a
* fait."
* Title of section:
*      Article Troisième
* Observations sur les Réfractions horizontales au bord de la mer,
* à 46 pieds au-dessus de son niveau ; avec quelques Remarques sur
* l'Observation des Hollandois dans la nouvelle Zemble.
* (The latter part is pp. 416-426.)
* This section bears the note: "Ces Observations ont été lûes à
* l'Académie Royale des Sciences, dans son assemblée du 27 Novembre
* 1774."      [See Mirage File and General Refr. file for other sections]


J. B. J. Delambre
Astronomie Théorique et Pratique, Tome Premier
(Courcier, Paris, 1814), p. 326.

* DELAMBRE -- [more in Simpson/Bradley/Mayer file]
* This was the standard textbook at the time. He goes through the
* standard exercise of comparing the refractions at the upper and lower
* limbs of the Sun at the horizon, and finds a reduction of the vertical
* diameter of 4' 17", or about 1 part in 8; so "le disque du soleil
* déformé par la réfraction, est sensiblement elliptique; et c'est
* ainsi que je l'ai vu très-souvent, surtout lorsque d'une tour ou d'une
* montagne élevée je le voyais se lever à l'horizon de la mer ou s'y
* coucher. Souvent même la demi-ellipse inférieure m'a semblé plus
* aplatie que la supérieure. Quelquefois la supérieure seule paraissait
* elliptique et l'inférieure était singulièrement défigurée, ce qui
* indiquait des réfractions très-irrégulières pour les différens
* points du bord inférieur; mais cet effet cesse dès que le soleil est
* sorti des vapeurs de l'horizon."


Dangos
“Beobachtungen über die irdische Strahlenbrechung, angestellt auf der Insel Malta,”
Gilb. Ann. Physik 47, 442–446 (1814).

* German translation of Dangos's 1806 paper with early OMEGA report
* The main part of this report is about the looming of Aetna as seen from
* Malta, so that it looked like an island. The last paragraph describes
* the Omega at sunrise.
* [I have put the original French version in the Mirage File.]


H. Salt
A Voyage to Abyssinia
(F.C. & J.Rivington, London, 1814).

* Henry Salt's observation (cf. Agatharchides)
* "In the evening, we observed the sun before it set put on a very unusual
* appearance. At the moment of emerging from a dark cloud, when its disk
* touched the horizon, it seemed to expand beyond its natural dimensions,
* became of a palish red hue, and assumed a form greatly resembling a
* portion of a column. This is one of the many singular effects produced
* by the refraction of the atmosphere common in this part of the world;
* and something of the same kind may have given rise to the extraordinary
* appearances of the heavenly bodies mentioned by Agatharchides, to have
* occurred at the mouth of the Red Sea [he quotes the original passage in
* Greek] which have been too hastily discredited by succeeding writers.
* Our latitude at noon was 4° 53' 30" N., long. 49° 0' . . . ."
*      No doubt this reference to Agatharchides explains Burstein's citation.
* (The copy I have seen is the American reprint of 1816 by M.Carey,
* Philadelphia; but I suppose it is identical to the original.)


G. W. Jordan
“On the apparent Changes of Place, Colour, Size, and Figure of the Heavenly Bodies,”
Quarterly J. of Science (Royal Institution) 10, 9–25 (1821).

* Absolutely CRANK paper by an F.R.S.!
* Surely even in 1821 this must have been regarded as absurd.
* He correctly notes the reddening and deformation of the Sun and Moon at
* the horizon, including the greater flattening of the lower limb, and
* its "considerable fluctuations, and variations of outline, contracting
* and enlarging in different points at the same time." But then . . .
* He finds the atmospheric heights of 40 to 75 miles found from twilight
* observations "exceed all reasonable estimate." He supposes that
* because air is "one continuous body," there "are in fact no atmospheric
* refractions" (and denies there is any refraction where crown and flint
* glasses, optically contacted, meet!) He believes the Moon illusion is
* not an illusion but a real effect due to "inflections": "The principal
* phaenomena of inflections, more than thirty years ago, I observed and
* explained, correcting some very important errors of great authority,
* . . . ." Right. The astronomers are all wrong in supposing that
* refraction takes place in the vertical plane, and have brainwashed the
* observers into faking their data to agree with this mistaken theory:
* "Such are the defects of the astronomical schools on this subject."
* The Moon illusion is bigger for the Sun than for the Moon because of
* "the weaker marginal light of the moon being extinguished, and her size
* more reduced by the atmosphere through which she appears, than that of
* the sun." The width of the rainbow at the horizon is greater than high
* in the sky "in consequence of the increased sizes of the united drops."
* The atmosphere extends only a little above the summit of Mont Blanc,
* about 3 miles. And "he who can continue to believe that the apparent
* increase of size of the sun and moon, in the horizon, is a deception . . .
* may ascribe all the other concurrent appearances and changes, change of
* colour, change of place, change of figure, undulatory changes of limb
* and outline, to delusions, not only ocular but mental . . . ."


Peytier
“Sur les formes extraordinaires que paraît prendre le soleil en se couchant derrière l'horizon de la mer,”
C. R. 45, 23 (1857).

* Wish this had been published with his figures!
* He cites Biot's Astronomie Physique for plates.


J. Janssen
“Sur l'application de la photographie à la Météorologie,”
C. R. 105, 1164–1167 (1887).

* Jules Janssen's early sunset photographs (not reproduced, of course)
* "Les photographies nos 7 et 11 montrent des effets très intéressants
* de coucher de Soleil." (p. 1166)
* These might be the EARLIEST PHOTOGRAPHS of sunset distortions?
* Or are they merely images of crepuscular rays?


F. Křifka
“Refraktionserscheinungen der aufgehenden Sonne,”
Meteorologische Zeitschrift 8, 101–102 (1891).

* KRIFKA with hacek over the r
* colored drawings in Tafel III -- cf. Pernter & Exner
* O'C #73


É. Daguin
“Aspect du Soleil se couchant au-dessus de la mer,”
l'Astronomie 10, 155 (1891).

* Drawing of Omega-shaped sunset
* This was *before* l'Astronomie merged with B.S.A.F.


F.-A. Mavrogordato
“Déformation du Soleil,”
l'Astronomie 10, 194–195 (1891).

* Crude drawings of Omega-shaped sunset, with oval stage
* There is a curious error in the Omega stages: he draws the horizon at
* the notch, instead of under the feet -- i.e., what he thinks he sees.
* But the final blob correctly is drawn floating above the horizon.
* Refers to Daguin's paper in April issue
* This was *before* l'Astronomie merged with B.S.A.F.


E.-M. Antoniadi
“Curieuses déformations du soleil couchant,”
l'Astronomie 12, 35 (1893).

* ANTONIADI's distorted sunset drawings, seen near Constantinople
* "Les figures n'ont rien d'exagéré et représentent fidèlement ce
* que j'ai observé." A textbook example; cited by Galli (1908).
*      This is the old  l'Astronomie, *before* it merged with BSAF.
* The LC number for this is QB 1.A5; the other (BSAF) is QB 1.S58.


A. L. Colton
“Eigentümliche Refraktionserscheinungen bei Sonnenuntergang,”
Himmel und Erde 7, 222–227 (1895).

* COLTON
* Explicitly associates the distorted sunsets with the hot weather of
* August. "Nebelstreifen":
* ". . . am 8. Juli was einer dieser Streifen so undurchsichtig, dass er die
* Sonne in zwei scharf begrenzte Teile schied; am 8. und 9. August is die
* Sonne durch Refraktion aus den oben erwähnten unsichtbaren
* Wolkenschichten vollständig geteilt."
* O'C #19


A. L. Colton
“Sunsets at Mount Hamilton, some curious effects of refraction,”
Lick Contr. 5, 71–80 (1895).

* COLTON
* O'C #17


A. L. Colton
“Photographs of the setting Sun,”
P. A. S. P. 7, 285 (1895).

* O'C #18


M. F. Beuer
“Sonnenuntergangs-Phasen, beobachtet von der Jeschkenkoppe aus, am 13. Januar 1900,”
Jahrbuch des deutschen Gebirgsvereines für das Jeschken- und Isergebirge 11, 85–86 (1901).

* M. F. Beuer's distorted sunset
* "An diesem Tage was es wohl kalt aber ausnehmend ruhig, so dass man
* sehr wohl im Freien zubringen und sich einmal ordentlich satt sehen
* konnte. . . . Besonders aber fesselte mich diesmal der Untergang der
* Sonne, den ich in der Zeit von etwa ½5 bis ¾5 Uhr verfolgte und
* in 16 verschiedenen Phasen aufgezeichnet habe. . . . Überraschend
* und sonderbar genug sind die durch die Strahlenbrechung erzeugten
* Formen, jedoch ganz naturtreu."
* The figure shows the Sun setting through 2 or 3 inversions; the
* drawings keep features that should be at constant altitude nearly so;
* so I believe the drawings are fairly accurate.
* Beuer is listed as "Bürgerschullehrer (Reichenberg)".
* Thanks to Kristian Schlegel for a copy of the text AND the figures!


T. Zona
“Deformazioni del Sole all'Orizzonte,”
Atti R. Accad. Palermo , series 3, 6, 1–7 (1902).

* Nice drawings of classical inversion-layer shapes, including MMs
* "The phenomenon was so striking and constant that every evening near
* sunset my children begged me to be taken to see the grimaces of the
* Sun."
* "The figure of the Plate represents the matter perfectly: the Sun
* at first, approaching the horizon, assumes the well-known elliptical
* shape; then from below an appendage emerges, which elongates and widens,
* and then the whole Sun is squeezed and widens, assuming hundreds of
* symmetrical forms, rapidly and continually varying, of which the plate
* represents but the principal ones, as they were drawn during the
* phenomena by me and the assistant Mr. Sartorio Gaetano at Monte Cuccio;
* every day the phenomena undergo the same phases."
* NOTE: Monte Cuccio is about 8 km west of the Palermo harbor. Measured
* coordinates from the 1943 U.S. military maps (1:50,000) of the area put
* the summit at about +38 06' 50'' N, 13 15' 54'' E of Greenwich.
* The height is marked as 1050 m. There are several lower peaks and
* ridges to the west that prevent observations from much lower down.
* NOTE: The "Atti" are all separately paginated, but not numbered.
* Full title: Atti della Reale Accademia di Scienze, Lettere e Belle Arti
* di Palermo, Terza Serie (Anno 1900-1901)
* This paper is dated 18 Nov. 1900, and is the first in the volume.


H. A(rctowski?)
“Déformations du Soleil et de la Lune au moment du lever et du coucher de ces astres au-dessus de nappes de vapeurs,”
Bull. Soc. Belge Astron. 8, 363–364 (1903).

* Arctowski (?) suggests comparing the "Belgica" obsns. with Tissandier's
* The Tissandier ref. is back in 1878, but seems useless.


W. Krebs
“Verzerrungsformen der aufgehenden Sonne,”
Ann. Hydrog. u. Maritimen Meteorol. 32, 158–161 (1904).

* COPIES OF KRIFKA's drawings
* BLACK LINE or "schwarze Strich": (cf. his paper in Weltall later in 1904)
* "Diese pflegt, entsprechend der Entscheinung des `schwarzen Strichs', im
* allgemeinem zu etwa 1000 m Meereshöhe angenommen zu werden."
* See his further details of green edges in Phys.Z.11, 645-648 (1910).


K. Graff
“Spiegelungs- und Refraktionserscheinungen an der See,”
Ann. Hydrog. 34, 181–182 (1906).

* MUSHROOM-shaped sunset, as well as a FINAL LINE lasting 3 min. or more
* also some drawings of mirages -- see Tafel 10 (good DRAWINGS)
* The claimed LATERAL MIRAGE is probably towering of distant low coastline


L. Rudaux
“Déformations du soleil a l'horizon,”
Bull. Soc. Astron. Française (l'Astronomie) 20, 283–285 (1906).

* EARLY PHOTOGRAPHS of distorted forms
* O'C #123


E. D. Roe , Jr.
“On the appearance of sunset at sea,”
Pop. Astron. 14, 444–445 (1906).

* Fairly good drawings of a Type B sunset, probably with a small mock mirage
* from "the Hamburg American Line steamer Belgravia".
* O'C #119


J. Krčmář
“Deformation der Sonnescheibe beim Sonnenaufgang,”
Met. Z. 23, 461–463 (1906).

* Nice DRAWINGS of distorted sunrises from 203.5 m height
* First is a classical bi-lobed mushroom; second also shows inversion
* features. Note haceks and accent over the a in Krcmar.


Prof. Dr. Doss
[Beobachtungen bizarrer Formen der untergehenden Sonne]
Korrespondenzblatt des Naturforschenden Vereins zu Riga 50, 262–264 (1907).

* DRAWINGS of a classic DISTORTED SUNSET
* This is an account of discussion at a meeting. The comments by RUDOLF
* MEYER are particularly interesting, and much longer than Doss's short
* paragraph. "Assistent Cand. R. Meyer" first points out the similarity to
* the drawings in a recent issue of Met.Z. (presumably the previous item,
* but could be Baer's paper in 1905).
* ". . . man erkläre es durch anormale Refraktionsverhältnisse, die . . .
* wichtige Schlüsse über die Temperaturverteilung in der Atmosphäre
* zulassen. . . . Verzerrungen des Sonnenrandes sind nicht ganz selten. In
* der ersten Woche dieses Jahres, während des starken Frostes, konnten sie
* mehrere Tage nacheinander beobachtet werden. Die Annahme einer
* horizontalen Schichtung der Atmosphäre hat für die Erklärung der
* Erscheinungen mehr Wahrscheinlichkeit für sich, als andere Hypothesen; die
* erwähnten Beobachtungen . . . haben bei windstillem Wetter stattgefunden."
* After suggesting that the vertical sides might be related to ice-crystal
* sun-columns: "Es scheint auch nicht ausgeschlossen, dass die
* Geradlinigkeit der Seiten des Sonnenbildes zum Teil auf einer optischen
* Täuschung beruhe."
* Prof. Pflaum points out the similarity to "sehr ähnliche Zeichnungen in
* derselben Aufeinanderfolge in Pernters Meteorologischen Optik II (S.133)
* vom Jahre 1902 . . . und dort ebenfalls auf Luftspiegelung zurückgeführt
* werden." Then there is a long and largely erroneous attempt by "Direktor
* Schweder" to explain the details with known mirages (the final drawing
* shows a double MOCK MIRAGE -- quite an EARLY EXAMPLE.)
* Curiously, the dates are given in both Old and New Styles.
* This must be one of the earliest appearances of RUDOLF MEYER in print!


Prof. Dr. B. Doss
“Beobachtung bizarrer Formverzerrungen der untergehenden Sonne,”
Met. Z. 24, 573 (1907).

* Formal publication of Doss's sketches
* Here he explicitly states that the Met.Z. drawings he had been apprised
* of in the Riga meeting were those of Krcmar, Met.Z.,23,461 (1906).
* But he finds the resemblance closer to Arctowski's drawings from the
* Belgica (as reproduced in Pernter's M.O., S.133 (1902).
* (No mention of Meyer.)


Dr. Chant
J. Roy. Astron. Soc. Canada 1, 324 (1907).

* SKETCHES of distorted sunsets
* Account of paper at RASC meeting by "Dr. Chant" (probably C.A.Chant)
* (no mention of Colton)
* The Frontispiece of the Sept.-Oct. issue, facing p.273, shows
* "Forms of the setting sun as seen from the summit of Mount Hamilton, Cal."
* dated June 27, June 29, and July3, 1907


I. Galli
“Sulla duplicazione e deformazione dell'immagine solare e sui recenti crepuscoli colorati,”
Atti della Pontificia Accademia Romana dei Nuovi Lincei 61, 51–56 (1908).

* IGNAZIO GALLI's review article -- many good refs.
* Observer was deceived by optical illusions, supposing the image became
* wider when distorted. The shapes drawn appear overly geometric and
* simplified.
*      Cites Antoniadi, Daguin, Scheiner, Payer, and Fontenay-le-Comte.
* Mentions Biot & Matthieu [sic -- no reference; probably Mathieu's
* edition of Delambre's 18th-Century Hist.]
* "Sessione IIa del 19 Gennaio 1908"
* THANKS to Gerardo E. Milesi for providing a lead to this!


W. Wetekamp
“Eigentümlicher Sonnenuntergang am Wattenmeere,”
Weltall (Berlin) 9, no. 9, 141–142 (1908).

* Nice DISTORTED-SUNSET DRAWINGS much like Krifka's
* This would have been put in the green-flash file for its opening
* sentence: [the "HANGING DROP"]
* "Ich hatte wiederholt auf Seereisen Gelegenheit, sowohl den `hängenden
* Tropfen' wie den `grünen Strahl' zu beobachten." The footnote says:
* "Wenn die Sonne am Meereshorizont bei völlig klarem Himmel untergeht,
* so hat man kurz vor der Berührung des Sonnenrandes mit dem Horizonte
* den Eindruck, daß plötzlich ein glühender Tropfen den Sonnenrand
* mit dem Horizont verbände. Der letzte Strahl der verschwindenden Sonne
* erscheint in wunderbar smaragdgrünem Lichte."
* Despite this GF mention, it belongs here in DISTORTED SUNSETS because of
* Meyer's reply, below.
* He was 3m above the water, but "mein Sohn beobachtete dieselben
* Erscheinungen direkt vom Strande aus."
* "Die Zeichnungen sind sofort nach Untergang der Sonne aus dem
* Gedächtnis angefertigt. Eine Vergleichung von mir und meinem Sohne
* (Primaner) ergab ziemlich genaue Übereinstimmung." I take this as
* evidence for an internal boundary layer.
* The image below the apparent horizon is almost surely a reflection on
* the shallow water, as Meyer suggests -- one of very few such cases.
* "Von Realgymnasial-Direktor Prof. W. Wetekamp"


R. Meyer
“Erklärung des eigentümlichen Sonnenunterganges am Wattenmeer,”
Weltall (Berlin) 10, 19–21 (1909).

* MEYER explains Wetekamp's sunset in Weltall 9, no.9
* This is a SPLENDID article, showing great understanding of sunset
* effects at a remarkably early time! Too much good stuff to quote!
* His main weakness is that, not knowing of the mock mirage, he finds
* some sunsets inexplicable, and then blames time-dependent refraction.
* Also, he neglects curvature of Earth. Still, he recognizes that the
* effects are due to "Lichtbrechungsverhältnisse der unteren
* Luftschichten", in contrast to O'Connell. . . .
* "Von Rud. Meyer, Dozent am Rigaschen Polytechnikum"


A. Wegener
“Drachen- und Fesselballonaufstiege,”
Meddelelser om Grønland 42, No. 1, 1–76 (1909).

* Alfred WEGENER's 1906-1908 observations in GREENLAND (part I)
*      These reports are in the 42nd volume of the Danish journal
* "Meddelelser om Grønland", which is available at BHL, as a PDF.
* Supposedly the scans are from the New York Botanical Garden; but the
* images show library stamps and a barcode from Woods Hole.
*      This item is Wegener's 76-page account of the kite and captive-balloon
* ascents, dated 1909. It has a hair-raising account of the expedition's
* difficulties and narrow escapes, with photographs of their primitive
* equipment. Our main interest here is in section III, "Diskussion der
* Beobachtungen" -- specifically, the subsection "Temperaturschichtung
* bei Refraktionsstörungen" that begins on p. 60, and particularly the
* temperature profiles ("Zustandskurven bei Luftspiegelungen") on p.65.
* The detailed descriptions of the mirage displays are in Part IV, which
* was published two years later (see next bibliography entry).
*      The temperature profiles are discussed in the next subsection, "Die
* Höhe der Föhnwolken" (p. 64), where Wegener connects the wiggles in the
* profiles with the layers in the clouds: "Bemerkenswert ist der Aufstieg
* vom Oktober 13 (1907). Hier wurde beim Aufstieg eine Inversion um
* 0.9° zwischen 1250 und 1400 m gefunden, beim Abstieg aber war diese in
* 6 allerdings sehr kleine Teilinversionen zerlegt. Diese blätterige
* Temperaturschichtung dürfte der Eigentümlichkeit der Föhnwolken
* entsprechen, bisweilen in mehreren, dicht über einander liegenden
* Etagen aufzutreten, wodurch sie bei der ihnen eigentümlichen Form den
* Anblick einer Reihe auf einander gestellter Kugelsegmente darbieten
* (siehe Abbildung)." (p.66) Here he identifies the upper edge of the
* clouds with "eine typische Diskontinuitätsfläche". On the next page,
* he identifies these clouds as standing waves.
*      In the next subsection (on fog), he notes that the mean height
* of the top of the fog is 225 m, the same height where a temperature
* increase was found, on average. The structure of the fog over the ice
* was seen as the ship was leaving on 31 July 1908: "Beim Austritt aus dem
* Eise plötzliches Ansteigen der Temperatur um 4° (siehe Thermogramm).
* Gleichzeitig verschwindet dar Nebel. Von aussen sah man dann den Nebel
* (nur ca. 100 m hoch) über dem Eise liegen, nach dessen Aussenkante hin
* flacher und flacher werdend." (see sketch, p. 68)
*      The subsection "Der Zustand der Atmosphäre bei Föhn" on p. 69 discusses
* specific offshore and mountain flows.


A. Wegener
“Meteorologische Terminbeobachtungen am Danmarks-Havn,”
Meddelelser om Grønland 42, 125–356 (1911).

* Alfred WEGENER's 1906-1908 observations in GREENLAND (parts 2-8)
*      These reports are in the 42nd volume of the Danish journal
* "Meddelelser om Grønland", which is available at BHL, as a PDF of
* the copy at New York Botanical Garden (though I see a library stamp on
* p.157 that says "Marine Biological Laboratory, Woods Hole". This chunk
* is numbers 2-8, dated 1914 on the cover. (Part I is Wegener's 76-page
* account of the kite and captive-balloon ascents, dated 1909.)
*
*      This is Parts 2 - 8 of Vol. 42; it has the subtitle (on BHL image 11):
*
*             D A N M A R K - E K S P E D I T I O N E N
*
*                  TIL GRØNLANDS NORDØSTKYST 1906--1908
*
*                                    under ledelse af
*
*                                L. MYLIUS-ERICHSEN
*
*
*                                           BIND II
*
*
*      See the table of contents on image 13, which tells which chapters
* have associated "Tavle" and the "Kort" ("cut"). Here we have Wegener's
*
* III. Meteorologische Beobachtungen während der Seereise 1906 und 1908
*                              (dated 1911)                                                                         pp.113-124
*
* IV. Meteorologische Terminbeobachtungen am Danmarks-Havn
*                              (dated 1911)                                                                         pp.125-356
*
* VI. Meteorologische Beobachtungen der Station Pustervig (with W.Brand)
*                              (dated 1912)                                                                         pp.447-562
*
*
*      PDF image 73 shows a translucent overlay identifying features of the
* photograph on image 75 (showing that printed books still have superior
* multimedia features not available on Web and PDF pages!)
*
*      In the weather journal (p. 202), three periods each day are denoted:
*              I       8 am
*             II       2 pm
*            III       9 pm
* These are used in the daily records.
*
*      There are numerous references to both distorted images of the low Sun,
* and mirages and/or looming of mountains on the horizon. Search the PDF
* for "Sonne" or "Refraktion" (usually in "Refraktionsanomalie".)
*      Section 3, "Wetterjournal" begins on p.202 and describes the daily
* phenomena in detail. It has several figures that show the temperature
* and pressure recordings during events of interest.
*      P.224: Feb.15, 1907: "Vormittags wurden am südlichen Horizont starke
* Luftspiegelungen nach oben gesehen, bisweilen auch nur Vertikalverzerrung.
* Am deutlichsten erschien die Spiegelung, wenn man etwa 10 m über dem
* Meereise stand, sie verschwand aber fast ganz, wenn man auf das Meereis
* hinunterging."
*      P.226:  "beim Sonnenaufgang (9" 5) wird eine eigentümliche
* Refraktionsanomalie beobachtet: Der Oberrand der Sonne tauchte zuerst
* über dem oberen Horizont (dem Spiegelbilde) auf, verschwand etwa nach
* ½ -- 1m wieder vollständig, tauchte ungefähr nach einer gleichen Pause
* am wahren Horizont auf, verschwand wiederum vollständig und tauchte
* --- wieder nach einer ähnlichen Pause --- nun definitiv gleichzeitig
* über dem 'doppelten' und dem wahren Horizont auf, 2 parallele Striche
* bildend. Das Bild war sehr beweglich,  eine      Zeitlang konnten sogar
* 3 solche parallelen Striche gesehen werden, von denen der mittlere
* erheblich kürzer war als die andern beiden [entsprechend dem häufig
* auftretenden 3-fachen Horizont]. Besonders verblüffend wirkte das
* zweimalige langsame Wiederverschwinden, das täuschend dem wirklichen
* langsamen Sonnenuntergang glich." (BHL image 174)
*      P.230: 1907 Mar. 10: "Solange das Licht es zulässt, werden
* Luftspiegelungen (meist doppelter Horizont) beobachtet, welche wohl ebenso
* wie die Temperatur- schwankungen auf eine Inversion zurückzuführen sind."
*      P.230: 1907 Mar. 11: "starke Luftspiegelung . . .      Charakteristisch
* ist das Verschwinden der Luftspiegelungen beim Anstieg der Temperatur
* (vergl. Fig. 25). Bei den schnellen Schwingungen der Temperatur gibt
* das Stations-psychrometer heute mitunter ganz sinnlose Werte: Um 8a
* steht das Eisthermometer um 1.1°, um 2p um 0.9° höher als das
* trockene Thermometer!"
*      P.237; 1907 Jul. 5:  Fig. 29 is a nice drawing of the superior mirage
* with multiple images and flattening of Koldeway Island, seen from 132 m.
* "Die Spiegelung machte dem normalen Bilde Platz, als der Beobachter 25 m
* vom Gipfel abgestiegen war. Das Thermogramm zeigt mehrmals an diesem Tage
* Schwankungen zwischen 2 bestimmten Werten (vergl. Fig. 30). Anscheinend
* ist also eine Inversion vorhanden, welche in geringer Höhe liegt
* und bisweilen die Station passiert, so dass diese abwechselnd in
* die untere (kalte) und in die obere (warme) Schicht versetzt wird.
* Diese Schichtgrenze durfte auch die Ursache der Luftspiegelungen sein."
*      P.240; July 17: Inversion with strong temperature swings.  "Gegen 3
* Uhr nachmittags, als die Station nach dem Thermogramm ausgesprochen im
* Bereich der kälteren unteren Schicht lag, wurden auch Luftspiegelungen
* nach oben am südlichen Ende der grossen Koldewey-Insel gesehen, wobei
* aber der untere Teil des Berges ungestört sichtbar war, und die Störung
* nur die oberen Teile desselben betraf. Dies scheint darauf hinzudeuten,
* dass die Schichtgrenze in grösserer Höhe über dem Boden lag, und damit
* stimmt überein, dass um 3p nur noch eine Inversion um 1.1° bis zur
* Ausguckstonne gemessen wurde, während um 1p, als die Schichtgrenze
* offenbar noch niedriger lag, eine solche von 5.6° vorhanden war. ---
* Gleichzeitig wurde weiter östlich am Kap Bismarck ein 3-facher Horizont
* über dem Meereise gesehen."
*      July 24: "Abends wird eine interessante Luftspiegelung nach oben
* an der grossen Koldewey-Insel gesehen; die wechselnden Formen konnten
* durch Zeichnungen festgehalten werden (Fig. 36). Von besonderem Interesse
* ist es, dass die Spiegelung hier unmittelbar über der Oberfläche des
* Nebels erschien; sie ist offenbar durch die hier herrschende Inversion
* hervorgerufen. Wegen der Einzelheiten sei auf die Notizen bei den
* Zeichnungen verwiesen."
*      P.241: series of commented drawings of the island miraged on July 24.
*      P.250, Sept. 14: Drawings of inferior mirages.
*      Tafel VIII, IX, and X (between pp. 252 and 253) show photographs of
* inferior mirages. See p. 253 for descriptions. [Wegener thinks these
* might be "die ersten Photographien von Luftspiegelungen überhaupt";
* but R.W.Wood published a mirage photograph in 1898.] He used a weak
* yellow filter to cut the haze.
*      P.256: several mirages in October, including inf. and sup. mirages
* simulataneously on the 21st; "Die Breite des spiegelnden Streifens
* wurde mit dem Pulfrich'schen Kimmtiefenmesser zu 4 Bogenminuten
* gemessen." [This may be the first appearance of that term!] And a
* drawing of the inferior mirage that day. "Von 9 oder 10 Uhr ab wurde
* gleichzeitig auch eine Spiegelung nach oben an der grossen Koldewey-Insel
* gesehen; der fernste (südlichste) Teil der Insel erschien stark gehoben,
* wobei er mit dem normalen Bilde durch Vertikalzerrung verbunden war. Der
* obere Rand der Insel erschien ausgefranst und war in ständiger Bewegung,
* wobei er oft Brücken bildete. Auch direkt unter dieser Spiegelung
* oder Hebung, aber durch einen Streifen mit normaler Refraktion von
* ihr getrennt, war der spiegelnde Streifen der 'Spiegelung nach unten'
* zu erkennen, wenn auch hier wegen des Fehlens des Himmels weniger
* deutlich. Auf Tafel XI und XII ist einerseits der normale Anblick und
* andererseits die Hebung bezw. Spiegelung der grossen Koldewey-Insel nach
* einem Aquarell von Achton Friis wiedergegeben. Ein mittags ausgeführter
* Drachenaufstieg bis 930 m Höhe zeigte, dass bis zu dieser Höhe eine
* Temperaturumkehr um mehr als 13° herrschte, was offenbar die Ursache
* der Spiegelung nach oben bezw. Hebung war. Nachmittags wurde der
* nordwestliche Wind stärker mit föhnähnlicher Erwärmung (vergl. das
* Thermogramm Fig. 56), gleichzeitig traten auch Föhnwolken auf. Offenbar
* bedeutete diese Temperatursteigerung die Wegräumung der untersten
* kalten Luftschicht." (Ending on p.257.)
*      The two colored plates named in the paragraph above nicely illustrate
* the looming.
*      The mirages continued on the 23rd: "Mit den tiefen Temperaturen
* (vergl. Fig. 56) hat sich sogleich wieder die Luftspiegelung nach unten
* eingestellt. Bei der Morgenablesung konnte festgestellt werden, dass
* diese Spiegelung am deutlichsten war, wenn der Beobachter sich auf dem
* Meereise befand, während sie in dem Masse abnahm, wie er auf das Land
* hinaufging. Von 5 m Seehöhe aus verschwand sie gänzlich." Inferior
* mirages continued the next 3 or 4 days, accompanied by heavy
* hoarfrost formation. On the 28th, "Die Luftspiegelung nach unten
* ist verschwunden, statt dessen wird eine stark wogende Bewegung
* aller Objekte, namentlich der kleinen Koldewey-Insel, beobachtet.
* Ein Drachenaufstieg zeigt starke Temperaturumkehr." (p. 260)
*      These October, 1907, mirages are discussed further in Wegener's
* discussion of the temperature profiles in issue No.1 (see the
* previous bibliography entry). The two should be read together.
*      P. 266: Drawings of "Hebung und Spiegelung nach oben", Nov. 26.
*      P. 286, Feb.15, 1908: "eine Luftspiegelung nach oben an der Schäre
* und der kleinen Koldewey-Insel gesehen die grosse Koldewey-Insel ist
* ohne Störung."
*      Feb. 17: "Starke Luftspiegelung nach oben.  Schon vormittags werden
* Spiegelungen nach oben an relativ nahen und niedrigen Objekten, wie der
* Schäre und der kleinen Koldewey-Insel beobachtet, die sich durch starke
* Unruhe auszeichnen. Mittags ist der Wind erheblich stärker geworden, es
* herrscht dauernd Schneetreiben, und das ganze Landschaftsbild ist in stark
* flimmernder Bewegung. Die Flimmerwellen laufen mit dem Winde. Deutlich zu
* erkennen ist noch die Vertikalverzerrung an dem nördlicheren Teil der
* kleinen Koldewey-Insel, auch die Schäre zeigt meist einen Steilabfall,
* der nicht existiert; aber die Bilder sind in beständiger schneller
* Bewegung und werden auch noch durch das Schneetreiben, das aus der
* Entfernung als Dunst erscheint, undeutlich gemacht. Die Konturen aller
* Objekte zeigen eine wilde Wellenbewegung mit zeitweiligem Emporschlagen
* einzelner Wellen. Auch die grosse Koldewey-Insel zeigt diese
* Erscheinung, es liegt also der seltene Fall vor, dass die Erscheinung
* sich gleichartig an den niedrigeren und höheren Objekten zeigt, und dass
* auch verhältnismässig sehr nahe Gegenstände diese flimmernde Bewegung
* zeigen. Die grosse Koldewey-Insel ist ausserdem noch gehoben und zeigt
* älinliche Bilder, wie früher beschrieben, nur schneller wechselnd. Bei
* der Schäre kann man bisweilen Andeutungen einer regulären Spiegelung
* nach oben sehen, meist sieht man aber nur ein Chaos von mit dem Winde
* dahinstürmenden Wellen, aus dem man nur entnehmen kann, dass jedenfalls
* die Verlikalerstreckung des Bildes grösser als normal ist." (p.287)
*      Feb. 21: ". . .  es wurden starke Luftspiegelungen sichtbar.  Um 12 Uhr
* mittags wurde eine Photographie der Vertikalverzerrung an der mittleren
* Partie der kleinen Koldewey- Insel erhalten (siehe Tafel XIV). Um 2p
* wurde das südöstliche Ende der kleinen Koldewey-Insel stark entstellt
* beobachtet, wovon die Skizze Fig. 78 ein Bild gibt. Diese Abbildung
* zeigt nur denjenigen Teil der Insel, welcher von der Station gesehen
* links von der höchsten Erhebung liegt. Die letztere selber sowie der
* dahinter liegende Teil der grossen Koldewey-Insel ist in der Skizze
* Fig. 79 dargestellt. Bemerkenswert ist dabei, dass auch die grosse
* Koldewey-Insel nach oben spiegelt, ohne wie sonst dabei gehoben zu sein.
* Das über der höchsten Erhebung der kleinen Koldewey-Insel schwebende
* Spiegelbild variierte stark, wenn auch verhältnismässig langsam;
* zuerst glich es einer auf dem Felskopf stehenden dicken Säule, dann
* bekam diese Saule ein Kapitäl und wurde zugleich dünner und dünner,
* bis sie einen ganz feinen senkrechten Verbindungsstrich zwischen Objekt
* und Spiegelung darstellte, der dann schliesslich verschwand, so dass die
* Spiegelung frei in der Luft schwebte. Bisweilen traten auch rechteckige
* Abflachungen auf, wie sie besonders schön an der Insel Maroushia
* beobachtet wurden, von der Fig. 80 zwei Zerrbilder gibt." (p. 288)
*      Feb. 22: "Spiegelung nach oben und nach unten; . . .  Sehr merkwürdig
* ist das heutige Auftreten der Luftspiegelung nach unten, von welcher eine
* Skizze (Fig. 82, nächste Seite) erhalten wurde. Bald nach Anfertigung
* derselben trat zu der vorhandenen Spiegelung noch Vertikalverzerrung,
* die aber zwischen sich und der Spiegelung einen ziemlich breiten Streifen
* des direkten Bildes liess, so dass nur eine Überhöhung des oberen
* Teiles der Insel resultierte. Ausserdem traten am Oberrande des
* überhöhten Streifens auch bisweilen kurze Ansätze einer Spiegelung
* nach oben auf. Während die Vertikalzerrung und Spiegelung nach oben
* ziemlich schnell variierten, war die Spiegelung nach unten die ganze
* Zeit über, wo das Licht eine Beobachtung zuliess, vollkommen konstant."
*      P. 289, Feb. 25: "Den ganzen Tag über schöne Luftspiegelungen
* nach oben, vormittags bei Windstille mehr an der kleinen Koldewey-Insel
* (hiervon, freilich nicht während der stärksten Phase, wurde die
* auf Tafel XV wiedergegebene Photographie erhalten), nachmittags bei
* Schneetreiben mehr an der grossen. Bisweilen wurde an der kleinen
* Koldewey-Insel ausser der Spiegelung nach oben gleichzeitig auch die
* nach unten gesehen (auf der Photographie nicht vorhanden), die nur einen
* ganz schmalen Streifen am Fuss der Insel bildete. Nach oben schloss sich
* daran ein breiter Streifen mit Vertikalverzerrung, und darüber erschienen
* wieder die in Fig. 78 -- 80 dargestellten überhöhten Stufenkonturen,
* Ansätze zu umgekehrten Spiegelbildern u. s. w. Der schmale Streifen mit
* Spiegelung nach unten war nur vom Meereise aus sichtbar und verschwand,
* wenn man am Lande um einige Dekameter emporstieg; dagegen war die
* Spiegelung nach oben von etwa 10 m Seehöhe aus mindestens ebenso schön
* ausgebildet wie vom Meereise aus." (p.290)


W. Brand and A. Wegener
“VI. Meteorologische Beobachtungen der Station Pustervig,”
Meddelelser om Grønland 42, 447–562 (1912).

* WEGENER and BRAND report meteorology at the Pustervig station
*      Many reports of mirages, and occasional MULTIPLE HORIZONS:
* Superior mirages on pp. 518-521; inferior mirages on pp.523-524,
* and a superior mirage again on p.524, and a strong superior mirage and
* thermal inversion on 525. P.577 reports double horizons on 2 days,
* one with a very strong inversion, and a triple horizon, p.579.


W. Brand
“Die Temperatur in der Ausguckstonne am Grossmast der ,,Danmark",”
Meddelelser om Grønland 42, 563–592 (1912).

* BRAND reports temperatures (and mirages) from the crow's nest:
* P.577 reports double horizons on 2 days, one with a very strong
* inversion, and a triple horizon, p.579. P.580: inferior mirages,
* one with a simultaneous superior mirage, "separated by a strip of
* normal refraction", with a 13° inversion. On April 16, the wind was
* calm, followed by light variable winds; "Die Feuchtigkeit war dauernd
* gering. Mit einer Ausnahme ist zu allen Zeiten Inversion vorhanden, deren
* maximaler Wert 4.9° beträgt, während ihr durchschnittlicher Wert 1.8
* ist. Am 17. um 8a wurden schwache Luftspiegelungen nach oben beobachtet."
*      In June, 1908, "Auch ist stets Inversion vorhanden, die
* durchschnittlich einen etwas grösseren Betrag als im gleichen Monat des
* Vorjahres erreicht. Wiederholt herrscht eine Inversion von 4° zwischen
* Eis und Tonne. Gleichzeitig wurden wieder Refraktionsanomalien und
* Spiegelung beobachtet. Ein am Abend des 15. ausgeführter Ballonaufstieg
* ergab ebenfalls Inversion in den untersten 200 m." (p. 582)
*      There is a discussion of inversions, p. 587, and of mirages, p. 591.
* The general conclusion is that the lowest 300 meters are normally
* inverted.


E. S. Bruce
“Curious mirage of the sun seen at Ostend, September 1907,”
Q. J. R. Met. Soc. 40, 73 (1914).

* HAT-shaped sunset (but no drawings!) and comments on mirages
* ". . . at Ostend on or about September 20, 1907 . . . I was on the sea
* parade near sunset time, and suddenly heard a group of men shouting out
* `Un chapeau, un chapeau.' Looking towards the sea I saw on the horizon
* the sun in the decided shape of a hat with a large brim."
* Cites Nansen, and refers to "The South African Pilot" for mirages along
* the coast of western Africa, and recurrent Fata Morganas at Cape St. John.


H. Henning
“Die besonderen funktionen der roten Strahlen bei der scheinbaren Grösse von Sonne und Mond am Horizont, ihr Zusammenhang mit dem Aubert-Försterschen und Kosterschen Phänomen und verwandte Beleuchtungsprobleme,”
Z. f. Sinnesphysiol. 50, 275–310 (1919).

* HANS HENNING's curious paper, with DRAWINGS by his brother
* This is mostly about the MOON ILLUSION, so has been FILED SEPARATELY
* with those papers.
*      The distorted-sunset drawings begin on p. 293; those are not
* attributed. The ones on p. 294 are by his brother, Georg Henning, and
* made in a 500-m high hill near Samaria, looking out over the Saron plain.
* He describes the mock mirages in Fig. 7 as "Erhöhungen der
* untergehenden Sonne mit Aufsatz" -- that is, "headpiece". The drawings
* are very schematic; and as some of his other sunset drawings, purporting
* to show a tree 50 km away (which would make the tree 250 m high!) are
* incredible, I don't put much stock in these drawings.
*      I have 2 really bad copies, apparently from the same torn original.
* The full journal title is: Zeitschrift für Psychologie und Physiologie
* der Sinnesorgane. 2. Abteilung, Zeitschrift für Sinnesphysiologie".
* Thanks to Helen Ross for pointing out this reference in her book!


W. J. Fisher
“Low-Sun phenomena in Luzon III. Marine sunsets and the duration of sunset on Manila Bay and the China Sea,”
Philippine J. Sci. 17, 607–614 (1920).

* Comments on "COLTON PHENOMENA"; TYPE A and Type B sunsets; MIRAGES noted
* "Type A occurs always when mirage is perceptible . . . . As the descending
* sun, vertically compressed by atmospheric refraction, approaches the sea
* horizon, a protuberance . . . grows out below, and almost simultaneously a
* line of light appears in the sea horizon, which lengthens horizontally and
* thickens upward till the protuberance and the line join . . . . For about
* half the duration of sunset the sun presents the appearance of an inverted
* fish globe, whose mouth widens to the sun's diameter; from then on the
* vanishing disk looks like an ellipse much flattened below, and vanishes as
* a small elliptical spot. . . . This spot does not sink below the horizon; it
* `goes out.'"
*      Type B never occurs simultaneously with a perceptible mirage. . . .  The
* descending sun flattens below as it approaches the horizon, which is not
* easy to see under it, being comparatively dark. The corners of the disk
* as it passes below the horizon are rounded, instead of projecting like the
* rim of a fish globe, until about midsunset; then the remaining half-disk
* begins to show a rim, so that it looks for a time not unlike the `tin hat'
* or trench helmet of the American Expeditionary Force. This flattens down
* in the middle faster than it shortens horizontally, becomes a line of
* light, and disappears in dots and dashes among the waves, if the horizon
* is near. The disappearance is slow, not like the vanishing of the spot at
* the end as in type A.''


W. J. Fisher
“Mirage at sea,”
Science 53, 236 (1921).

* Fisher's appeal for info about Janssen's 1875 report to Brit. Ass.
* "In the Sections reports of the meeting of the B. A. A. S., Bristol,
* 1875, p. 26, M. J. Janssen gave a brief summary of his observations and
* conclusions with regard to mirage at sea. As this happens to connect
* with a phase of low sun phenomena in which I am interested . . . ."
* (No. 1367, 11 March 1921)


W. J. Fisher
“Duration of sunset,”
JBAA 32, 209 (1922).

* Fisher's papers reported in JBAA


W. J. Fisher
“Low-Sun phenomena — IV. The `Green Flash',”
Pop. Astron. 29, 251–265, 382–392 (1921).

* GREEN FLASH HISTORY and BIBLIOGRAPHY
* Type A and B now more succinctly described:
* "Type A occurs always when mirage is perceptible . . . . As the
* descending sun, vertically compressed by atmospheric refraction,
* approaches the sea horizon, a protuberance . . . grows out below, and
* almost simultaneously a line of light appears in the sea horizon, which
* lengthens horizontally and thickens upward till the protuberance and the
* thickened line join . . . . For about half the duration of sunset the sun
* presents the appearance of an inverted fish globe, whose mouth widens to
* the sun's diameter; from then on the vanishing disk looks like an
* ellipse much flattened below, and vanishes as a small oval spot. . . .
* This spot does not sink below the horizon; it `goes out,' above it.
*      Type B never occurs simultaneously with a perceptible mirage.  The
* descending sun flattens below as it approaches the horizon, which is not
* easy to see under it, being comparatively dark. The corners of the disk
* as it passes below the horizon are rounded, instead of projecting, until
* about midsunset; then the remaining segment begins to show a rim, so
* that it looks for a time not unlike the `tin hat' or trench helmet of
* the American Expeditionary Force. This flattens down in the middle
* faster than it shortens horizontally, becomes a line of light and
* disappears in dots and dashes among the waves, if the horizon is near.
* The disappearance is slow, not like the vanishing of the spot at the end
* of type A."
* "Not the least argument against the contrast theory arises from its
* [i.e., the flash's] ill understood capriciousness." (p.263)
* ". . . the psychological explanation seems much more convincing to persons
* who have seen the sun's departing flash only once or twice, or who have
* only read about it.
* The simple dispersion explanation is accepted, nearly as it was first
* put forward by Winstanley . . . , by W.J.Humphreys . . . and by A.A.Rambaut . . . ,
* as explaining the green flash. F.M.Exner, however, holds that the
* phenomenon is not yet completely explained. Some of its difficulties are
* variable duration, capriciousness, appearance on a cloud but not at a
* clear sea horizon below, and occasional lack of color." (p.265)
*      Note that the final installment appeared in 1922.
* O'C #34


W. J. Fisher
“The duration of sunrise and sunset,”
Nature 108, 211–212 (1921).

* FISHER's summary in Nature, with DRAWINGS of the 2 types
* "While the sun is the source of light in such observations, and the
* Nautical Almanac and four-place logarithms have to be used in computing,
* the subject is not astronomical but meteorological, and, I believe, has to
* do with temperature distribution in the atmosphere. We have here one of
* those residual phenomena the study of which may lead to the discovery of
* interesting facts and which can be forwarded by amateur observers, the
* more and the more widely scattered the better."


(editorial)
“The duration of sunrise and sunset,”
Met. Mag. 56, 333–334 (1921).

* editorial report of the Nature paper, with DRAWINGS reproduced.
* (See also Fisher, 1926 PASP, in GF)


W. J. Fisher
“Table for the duration of sunset,”
Nature 108, 433–434 (1921).

* Fisher's table of SUNSET DURATIONS
* ". . . for any year there are two maxima about the solstices and two
* minima about the equinoxes. The maxima are sharper than the minima. In
* low latitudes the summer maximum is less than the winter, due to the
* smaller semi-diameter of the sun; but in high latitudes, beginning above
* N. 52°, this is reversed, due to the unsymmetrical and exaggerated
* effect of refraction, which makes the sines of summer solstice hour-angles
* less than those of the winter solstice."
* "Elevation above sea-level would have an effect like refraction."


W. J. Fisher
“Old observations bearing on the duration of sunrise,”
Nature 108, 531–532 (1921).

* Fisher discovers Le Gentil's work, and classifies his observations as
* Type A ("which is a mirage type") or B


W. Fisher
“Low Sun phenomena,”
JBAA 32, 209–210 (1922).

* Fisher's papers reported in JBAA (on same page as the previous, so filed
* before the P.A. paper, though noted here, after it.)
* Described as "a very comprehensive and suggestive summary" by JBAA
* "He promises a more detailed memoir, but there is sufficient in this one
* to give much food for thought."


W. J. Fisher
“The duration of sunrise and sunset,”
Pop. Astr. 30, 213–216 (1922).

* A summary paper, repeating much of the previous:
* This appears to be mostly a reprint of the first 2 papers in Nature.


W. J. Fisher
“Old observations bearing on the duration of sunrise and sunset,”
J. Roy. Astron. Soc. Canada 16, 261–262 (1922).

* Fisher's detailed reduction of Le Gentil's observations, and of Colton's
* (Sept.-Oct.1922 issue)


W. J. Fisher
“Low Sun Phenomena: the duration of sunset and sunrise,”
Ann. Astron. Obs. Harvard Coll. 86, 39–45 (1922).

* FISHER's important H.A. paper, with "79 cases, including those observed
* in Luzon, with corrections and additions. . . ."
* Here are important details about instruments, timing, and calculations.
* Also an extract of a letter from W.W.Campbell (Director at Lick):
* ". . . on midsummer evening, what we call the cigar form of the setting
* sun . . . ." [i.e., Chappell's final long line]
* ". . . type B was often not as brilliant as type A." [airmass effect.]
* also a Prefatory Note by Alexander McAdie, p.38


M. P. Hurand
“Optique atmosphérique,”
BSAF 44, 156 (1930).

* Drawings showing effects of 2 or 3 inversions; SQUARE SUN
* "Le temps était ce jour-là, tres beau, sans nuages et sans vent."


R. L. Holdstock
“Abnormal refraction at sunset. Spencer Gulf, South Australia.,”
Marine Observer 8, 251 (1931).

* Very schematic drawings of the geometrical phases
* Dec. issue


J. F. Chappell
“Apparent distortions of the setting Sun,”
Pub. Astr. Soc. Pacific 45, 281–282 (1933).

* SUNSET OBSERVATIONS
* ". . . the final singular long line, which oddly enough is substituted
* for the small tip of light that could reasonably be expected as the
* final glimpse of a bright descending sphere."
* O'C #16


W. A. Owen
“An unusual sunset,”
Met. Mag. 69, 146 (1934).

* typical distortions from an inversion above observer, with DRAWINGS
* "I cannot recall the exact details of the change from the `mushroom'
* shape of figs.2-4, to the `Bowler Hat' shape of the later phases."


R. Moss
“Atmospheric optical phenomena in North East Land,”
Q. J. R. Met. Soc. 64, 451–458 (1938).

* SUNSET DISTORTIONS with RECTANGLE and HOURGLASS
* Also, possible INFERIOR MIRAGE of 22-deg.HALO (Fig.3)


J. S. Dines
“A remarkable sunset,”
Q. J. R. Met. Soc. 68, 236 (1942).

* fair DRAWINGS of a rather typical Type B sunset from 50 ft. above sea level
* "The bright spot . . . below the main portion of the sun and detached
* from it was very striking, but short lived, as it rapidly expanded to form
* a `mushroom stalk' reaching from the sun to the horizon." (Mock mirage)
* "This finally degenerated into a faint red line on the horizon which
* persisted for perhaps 30 sec. before disappearing."


H. H. Lamb
“Strange moonrise in the Antarctic,”
Marine Obs. 17, 98–100 (1947).

* Distorted moonrise and sunset; DRAWINGS
* Possible GREEN RAY 1 minute long at sunset?
* "The sun was greatly distorted at sunset on that day, being accompanied
* during the last minute or so before it disappeared by a greenish-yellow
* drapery immediately above the orb . . . . This greenish-yellow curtain of
* light set below the horizon a few minutes after the sun."


D. Ewan
“Abnormal Refraction, off coast of Portugal,”
Marine Observer 21, 80 (1951).

* DISTORTED SUNRISE


J. Ballantyne
“Abnormal Refraction, North Atlantic Ocean,”
Marine Observer 26, 82–83 (1956).

* Possible DARK LINES in sky ("cloud")


W. C. Loughlin
“Abnormal Refraction, Persian Gulf,”
Marine Observer 26, 83–84 (1956).

* DISTORTED SUNSET ending with small GREEN FLASH


C. A. F[ederer]
“Notes on a convention in Miami,”
Sky & Tel. 15, 485–488 (Sept., 1956).

* Photographs of an extreme OMEGA sunrise
* This is Charles A. Federer's account of the 1956 Astronomical League
* (amateur astronomers') convention.
* The pictures (reproduced in b/w) extend across the top of the first page.
* The caption says, "The strking mirage as caused by a temperature
* difference of 28° Fahrenheit between the atmosphere and the air close
* to the warm ocean water."
* "Most dramatic was the presentation . . . of colored sunrise motion
* pictures by Matt F. Taggart, of Ft. Lauderdale. He has recorded
* little-known mirage phenomena associated with dawn; when the temperature
* difference between the cold air and the warm water is greatest, these
* effects are particularly striking." (p. 485)
*      Thanks to Jim Mosher for pointing this out!
* Note that volumes and years do not come out even at this period in S&T.


N. Johnson
“Abnormal refraction, English Channel,”
Marine Observer 27, 13 (1957).

* Classical OMEGA sunrise roughly sketched


R. Jackson
“Refracted sunrise, South African waters,”
Marine Obs. 39, 178–179 (1969).

* Apparently (from the DRAWING) a narrow BLANK STRIP
* This is an amusing example of the MOON ILLUSION at sunrise;
* the text says "two images visible, one on the horizon and one 2-3°
* above." But the drawing shows the second image only about 2/3 solar
* diameter, or 1/3 degree, above the horizon!
* The drawing is crude but a reasonable basis for a simulation.


I. E. Brady
“Abnormal refraction, Southern North Atlantic,”
Marine Obs. 44, 22–23 (1974).

* MYSTERIOUS UNEXPLAINED PHENOMENON, or else bad description
* Drawing unfortunately shows circular Sun images
* ". . . a `double sun' with the `lower sun' being semi-transparent in that
* the waves could be seen through it. The two `suns' kept the same position
* relative to each other."
* [Editorial comment that this "is due to a strong temperature lapse rate
* in the vertical, as confirmed by the presence of cumulus cloud" is
* nonsense.]
* Sounds like a ghost reflection in window or glasses???


P. N. Mendes
“Abnormal refraction, Persian Gulf,”
Marine Obs. 45, 67 (1975).

* MYSTERIOUS UNEXPLAINED PHENOMENON, or else bad description
* Again drawing is all arcs of circles, so unreliable. Sounds vaguely
* like a mock mirage, but description doesn't fit.


L. Aerts
“Ω-vorm van de zon,”
Zenit 9, 237 (1982).

* Nice but small OMEGA PHOTOGRAPH
* "On 31 July 1981 Leo Aerts (Heist-op-den-Berg, Belgium) took the setting
* sun from the Belgian coast. The temperature of the sea-water was higher
* than the air temperature. Thus the horizon looked notched rather than
* rectilinear. At the same time there appeared a mirage, which caused the
* omega-form of the setting sun."
* cites Zenit 8, 70 (1981)


A. Nagel and B. Zwart
“Resultaten fotowedstrijd: Fig. 6 (Ruud Keller),”
Zenit 15, 5–9 (1988).

* An OMEGA with large temperature difference and large inverted portion
* Ruud Keller won the "optical phenomena" category in the photo contest:
* "Travelling on the motor ship Leliegracht on 27 January 1985, he
* made a number of photos of a remarkable sunset over the Gulf of Bothnia
* near the Swedish port of Vaija (fig. 6). As the sun approached the
* horizon, while coming out from behind a cloud bank, its mirror image
* rose up! Sun and mirror image approached one another and then formed a
* sort of hour-glass (omega-form). The photos give a clear example of a
* sun reflected on a (relatively) warm layer of air above a water surface.
* The air temperature lay between -20 and -25 C; the seawater temperature
* at about -1 C. The sea was partly covered with ice . . . "
* Jan. 1988 issue; the pictures are on p. 7 and the text on p.8.


B. Vrancken
“Omegavormige zon,”
Zenit 16, 116 (1989).

* photographs of an OMEGA-shaped sunset
* ". . . taken on 5 November 1988, with cold and quite clear weather
* conditions."
* Cites Floor's Zenit 8, 72 (1981) paper.


H. Keizer
“(photograph of setting Sun),”
Zenit 20, 179 (1993).

* Fine example of OMEGA SUNSET, with cloud across middle
* Photographed with 600mm telescope
* April 1993 issue


T. Damme
“Ein ungewöhnlicher Sonnenuntergang,”
Sterne Weltraum 33, 881–882 (1994).

* TEXTBOOK EXAMPLE of OMEGA SUNSET [N.B.: actually filed in COLOR file]
* Photographed by Torsten Damme at 1400mm f.l.
* This is probably the finest Omega sunset ever photographed -- and in
* color, too. The maximum extinction at or just below the fold-line
* is particularly striking. There is also a curious pseudo-reflection of
* the inverted image on the water. . .
* Abb. 6 a-f: Sonnenuntergang über der Wesermündung in Bremerhaven . . .
* issue No. 12 (Dez.)


R. G. C. Noble
“Abnormal refraction, Mediterranean Sea,”
Marine Obs. 65, 70 (1995).

* Observer draws what he *thinks* is there (not a realistic drawing)
* but does mention ``a sort of hourglass appearance''. -- i.e., OMEGA.
* This is clearly an Inf.-mir. sunrise:
* "air temperature 10.0, wet bulb 8.6, dew-point 7.1, sea 13.5, . . .
* wind NW'ly, force 4."


Z. Néda and S. Volkán-Kacsó
“Flatness of the setting Sun,”
Am. J. Phys. 71, 379–385 (2003).

* Two Romanian physicists observe and model flattened sunsets
* The calculations are the crude ones typical of physicists. No info
* on the photographic equipment used, but looks like short focal lengths
* were used.
* Dip of the horizon was not taken into account in the Indiana observations;
* but the discrepancies between theory and observation are mostly due to
* adopting the Standard Atmosphere's lapse rate (Biot not mentioned).
* The "textbook" GF is briefly mentioned. O'Connell's book is cited, but
* his name is misspelled. Pretty typical Am.J.Phys. effort.
* [see Siebren van der Werf et al.'s Novaya Zemlya paper (2003) for a
* much better treatment of the same problem.]


S. N. Kivalov and A. T. Young
“Horizontal magnification of finite-sized celestial objects,”
Appl. Opt. 49, 2720–2727 (2010).

* Sergey Kivalov and I bring Biot and Chauvenet up to date
* This expands on Biot's magnification theorem, as well as dealing with
* the effects of the convergence or divergence of the vertical circles
* near the horizon.


S. J. O'Meara
“Tropical Novaya Zemlya effects,”
Astronomy 52, No. 3, 14 (2024).

* Stephen J. O'Meara's ducted Botswana sunrise
*      Unfortunately, what looks like good photographs of a DISTORTED SUNRISE
* turns out to be just an artist's drawing based on naked-eye observation.
* Apparently, waves on an inversion made the Sun appear and disappear;
* the refraction was unusually large.
*       Though the title refers to the N.Z. effect, I don't think the
* refraction was really big enough to deserve that name. The nocturnal
* inversion in a dry desert salt pan is the obvious cause, in any case.
*      Thanks to Mila Zinkova for bringing this interesting observation to
* my attention! For a somewhat similar low-Sun display, see her video of a
* prolonged ducted sunset at https://www.youtube.com/watch?v=5fwGs-bP68w .
* Thanks, too, to Stephen O'Meara for explaining to me that the images are
* not really photographs; the editors "created their own caption" without
* telling him.
*      Available at
* https://www.astronomy.com/observing/secret-sky-tropical-novaya-zemlya-effects/



*** SCHNIPPEL FILE ***

E. Schnippel
“Ein Sonnenuntergang in Verbindung mit Luftspiegelung,”
Das Wetter 18, 193–201 (1901).

*
* Emil Schnippel
* SUPERIOR MIRAGES with SUNSET drawings
* best seen 3 m above the sea, not from the slopes or heights of the dunes
* BRIGHT STRIP, looks like FOG
* This is probably the most complex sunset display on record! Many
* interesting features.



*** DIP FILE ***

Raymond P. Mercier
“Geodesy,” in Cartography in the Traditional Islamic and South Asian Societies , J. B. Harley and D. Woodward, eds.
(University of Chicago, Chicago, 1992), pp. 175–188.

*
* (See also Shackleton, 1962, in Novaya Zemlya file.)
* (See also Wales, 1770; Huddart, 1797; Reinecke, 1800; and Kelly, 1846,
* in Mirage file; and de Vanssay de Blavous, 1944 in modern Refraction.)
*
* DIP of the horizon seen from a mountain used to measure the Earth
*      According to this history of geodesy, this method was invented by
* Al-Biruni (see p. 182) c. 1017
*      This is Chapter 8, "Geodesy", in Part 1, "Islamic Cartography", of
* Book 1, "Cartography in the Traditional Islamic and South Asian Societies",
* in Volume 2 of "The History of Cartography"


E. Wright
Certaine Errors in Navigation, Arising either of the ordinarie erroneous making or vsing of the sea Chart, Compasse, Crosse staffe, and Tables of declination of the Sunne, and fixed Starres detected and corrected
(Valentine Sims, London, 1599).

* The FIRST DIP TABLE is supposed to be the one by EDWARD WRIGHT
* This is the original edition (1599). The table is given to minutes
* only, for every 5 ft. of height. The basis of the calculation is
* not explained. The pages are not numbered; the dip table appears on
* folio O, verso: "For the higher the eye is aboue the water, the
* greater is the angle intercepted betwixt the two visual lines, whereof
* one toucheth the conuex superficies of the sea, the other passeth on
* to the sun or starres : And the lower the eye is, the lesser is the
* foresayd angle : and then onely it sheweth the true altitude, when the
* center of the sight is in the same line of leuell with the superficies
* of the water. But if the eye be higher then the water, that angle is
* greater then the true altitude, and therefore subtraction must bee made
* accordingly, that you may haue the true altitude. For this purpose I
* haue made this table here adioyned, the vse whereof is this: when you
* obserue the heigth of the sunne or starres at sea with the crosse staffe,
* you shall also find out how many foot high your eye is aboue the water
* with a plumb-line or otherwise : seeke that heigth of the eye in the
* first columne of this Table : and in the same line in the second column
* (intituled Minutes to bee subtracted ) you shall find what number of
* minutes are to be subtracted from the apparent heigth of the sunne or
* starres . . . ."
*      This is immediately followed by a curious table of the solar parallax.
* From his praise of Tycho, I assumed it would be Tycho's table, based
* on a horizontal parallax of 3'; but instead, it is 2' 59" at the horizon.
*      After that, one finds: "Hereunto some do also adioine the fourth
* cause of errour by reason of refraction of the beames of the sunne or
* starres through thickness of the ayre : which for aught I can finde
* by obseruation with large instruments is little to be regarded in anie
* meridian altitude of the Sunne heere at London : But in the starres I
* haue many times found it to be some thing, especially when they come
* neere the horizon, and sometimes scarce any thing being but a few
* degrees aboue the horizon. So as I think it not greatly needefull at
* this time to trouble the mariners conceipt herewith any more, for whose
* sake especially this labour was vndertaken."
*      Concerning Tycho, he is copiously cited as an authority in the Preface
* as ". . . that magnificall Tycho in his Vraniburg . . . ", and that
* ". . . Astronomie hath much aduauncement by Tycho Brahe alone, who
* for his deserued renowne cannot be too oft named." (Preface, fol. 3r)
*      The state of the art in his day is shown by reference to "large and
* exact instruments, wherin both minutes and half minutes might be easily
* discerned." (Preface, fol. 2r)
*
*      I have seen only the 1974 facsimile reprint edition:
*
*                    Edward Wright
*                    Certaine Errors in Navigation: . . .
*                    (Theatrum Orbis Terrarum, Ltd., Amsterdam, 1974)
*
* co-published by Walter J. Johnson, Inc., Norwood,N.J. This is Number
* 703 of "The English Experience -- its record in early printed books
* published in facsimile". It reprints the original title page:


Edw. Wright
Certain Errors in Navigation. Detected and Corrected by Edw. Wright (3rd Ed.)
(Joseph Moxon, London, 1657).

* Wright's revised dip table appears on p. 96 of the 3rd edition
* The title page shows the instruments of the day, with a curiously
* formed map of the world: "America" is the southern one only (the northern
* continent, "Virginia", subsumes Canada); California is an island near the
* longitude of Texas; China and India are small peninsulas; "Nova Zelandia"
* is 2 hours east of its true place; etc.
*      Item 7 in the list of "Additions To this Edition that were not in the
* former" is the table of dips; item 8 is Tycho's refraction table.
* [However, Bob Graham tells me the 1599 edition did have a dip table.]
*      Wright deduces the size of the Earth from the dip measured from Mount
* Edgecombe, 375 ft. high, and finds a radius of some 18.3 million ft.
* or about 5582 km; so the dips are a bit too large. He calls them
* "the angle of dipping", and I suppose this must be the first use of the
* term in English.
*      It appears that Wright's measurement was first published by Richard
* Norwood in "The Seaman's Practice" in 1637.
*      The "refraction of the Beams of the Sun or Stars" is "by reason of the
* Vaporous thickness of the ayre that is betwixt us and them, especially
* when they are neer the Horizon."
*      There is also a table of solar parallaxes, based on 3' at the horizon.


F. Arago
“Sur les dépressions de l'horizon de la mer,” in Connaissance des Temps pour l'an 1827
(Bureau des Longitudes, Paris, 1827), pp. 316–323.

* 3 series of DIP and TEMPERATURE DIFFERENCES
* ". . . l'observateur le plus exercé et muni des meilleurs instrumens, peut
* se tromper en plus ou en moins d'une minute, sans que les circonstances
* météorologiques puissent lui fournir ne les moyens de calculer l'erreur,
* ni même lui faire présumer dans quel sens elle a eu lieu."
* ". . . la seule conséquence qu'on puisse déduire de l'ensemble de ces
* déterminations, est celle-ci: l'erreur de la dépression calculée ne
* sera positive dans nos climats, qu'autant que la température de l'air
* surpassera celle de l'eau."
*      Reprinted in: Œuvres Complètes de François Arago, Tome Onzième
* (Gide, Paris, 1859) pp. 662-670 [which is available at Gallica].


H. Atkinson
“On the fluctuations of the atmosphere near the earth's surface; and On the effect of such fluctuations upon the refraction at the horizon, and at very low altitudes, especially on the dip of the horizon at sea,”
Mon. Not. Roy. Astr. Soc. 1, 192–193 (1830).

* REFRACTION AND DIP
* "..the late Mr. Henry Atkinson . . . proposed to himself to demonstrate,
*      1st, That the fluctuations in the state of the atmosphere near the
* surface of the earth are not only fully adequate to account for the very
* great variations which have been observed in the horizontal refraction,
* but even for still greater variations.
*      2dly, That the variations of the dip of the horizon at sea are caused
* by the fluctuations of the atmosphere, and can be calculated when the
* latter are known."
* ". . . draws the conclusion, that the variation of refraction arising from
* any conceivable derangement if this middle portion will be inconsiderable,
* compared with that which may be produced by changes in the lowest portion
* [the bottom 50 feet]."


H. Atkinson
“Of the fluctuations of the atmosphere near the earth's surface; and of their effects upon the refraction at very low altitudes. With an Appendix on the dip of the horizon,”
Mem. Roy. Astr. Soc. 4, 517–530 (1831).

* Here is Henry Atkinson's incomplete paper:
* In the Appendix he says: "To estimate the effect of refraction on the
* dip, I have shewn, in my former paper, that the small portion of the curve
* AEF, described by a ray of light in the problem under consideration, does
* not sensibly differ from a circular arc." He then employs a diagram
* similar to Wegener's.


J. H. Bell
“On the dip of the horizon, and mirages of the Gulf and River of St. Lawrence,”
The American Merchant 2, 271–274 (March, 1859).

* Short note connecting DIP and MIRAGES, copied from Kelly (1846)
* "Every one who is acquainted with nautical astronomy is aware that some
* uncertainty always attends observations made with the natural horizon,
* from the varying amount of the dip occasioned by terrestrial refraction.
* The cause of these variations is very obscure. The best authorities seem
* to regard differences of temperature in the air and water as the sole
* cause of the irregular density of the lower strata of the atmosphere on
* which the varieties of the dip depend. It is known that in general, when
* the water is warmer than the air, the dip is greater than that given in
* the nautical tables; and that when the water is colder than the air, the
* dip is less. But cases occur where the deviations from the tables are
* found to bear little relation, at least in amount, to the relative
* temperatures of the air and water. Some other property of the atmosphere
* must therefore be sought after, by the influence of which the effects of
* temperature are modified." (p.271) [He thinks it is the humidity.]
* "We know of no place where the dip is more affected or mirages more
* frequent and extraordinary than on the northeastern part of this
* continent, in the Gulf and River St. Lawrence. These phenomena are of two
* kinds. In one (the mirage of arctic regions), the horizon is elevated, the
* forms of objects distorted and inverted, sometimes two, three, and even as
* many as five mirages of the same object are seen, alternately erect and
* inverted —— the lowest always being erect. This kind of mirage is only seen
* when the water is colder than the air. In the other kind of mirage (the
* mirage of the desert), the horizon is depressed, distant points of land
* seem raised into the air, the form of objects is seldom materially
* changed, there are never more than two images of an object, and when a
* second is seen, the lower is inverted and the upper erect. When this kind
* of mirage is seen, the water is usually warmer than the air." (p. 272)
* "The mirage is constantly seen with a depressed horizon, when the water
* is warmer than the air. . . . The occurrence of either form of mirage, and
* its intensity, seem to be affected by other circumstances besides the
* relative temperature of the air and surface of the water, and the
* hygrometric state of the air." (p. 272)
* "Either the elevation or the depression is comparatively greater in a
* calm and less in a breeze." (p. 273)
* ". . . it is pretty plain that the elevation or depression of the horizon
* is chiefly influenced by the relative temperature of the air and surface
* water, and only in a minor degree and perhaps less regularly by the
* hygrometric state of the air, and either elevation or depression is the
* greater in calms." (p.274)
*      All of this is copied nearly verbatim from Kelly's article in the Nautical
* Magazine 15,p. 393 (Aug. 1846).
*
* Capt. John H. Bell ran the "Nautical Department" of this magazine.
* This is item 3 of 6 short notes in his column for March, 1859.
* Google Books has Vols. 1 and 2 together; not copied.


E. Kayser
“Beobachtungen über Refraction des Seehorizontes und Leuchtthurmes von Hela angestellt auf dem Observatorium der naturforschenden Gesellschaft zu Danzig,”
Schriften der naturforschenden Gesellschaft zu Danzig (n. F.) 4, No. 2, (1877).

* VARIABLE DIP and TERRESTRIAL REFRACTION
*      This could as well have been filed under "Terrestrial refraction" or
* "Variable refraction", but is here because of the dip data.
*      This 50-page paper has 2 Tafeln  at the end, showing the observing
* geometry, figures for the derivations, and the instrument used. About
* the first 20 pages give observations of apparent depressions to the
* nearest second of arc. While the weather data are provided, there are
* no estimates of water temperature, so the data are not very useful
* today.
*      Perhaps the most interesting result is that the dip of the apparent
* sea horizon was more than twice as variable as that of the lighthouse.
* There is also a useful discussion of theory, in which he shows that the
* formula given by Delambre assumes that k2 can be neglected, which is
* by no means true. Not surprisingly, he finds that objects (such as
* the shoreline at the base of the lighthouse) that should be invisible
* occasionally appear, and that the sea ``horizon'' is occasionally above
* the astronomical one. [NEGATIVE DIP] (Cf. McCluskey 2018; Tschudin 2019)
*      The light was about 30 km, or very nearly 16' of arc, from the
* observer. Heights are given in Rhenish feet and inches; the observer
* was 78 ft. above the sea, the light about 130 Rheinl. Fuss. Evidently
* it is the penetration of the visual ray into the surface layer that
* makes the dip of the horizon more variable than that of the light.
* (The light typically appears some 4' above the apparent horizon.)
*      There is the promise that "Die Discussion  a l l e r  Beobachtungen
* hinsichts des Zusammenhanges zwischen dem jährlichen und täglichen
* Gange der Refraction und den atmosphärischen Zuständen soll in einem
* zweiten Theile erfolgen, so bald das genauere Datum der Höhe des
* Heláer Leuchtthurmes über der See durch die neuen Pegel-beobachtungen
* der Admiralität bekannt geworden ist," but this seems never to have
* happened.
*      These "Hefte" are separately paginated; this one has 50 pp of text,
* plus 2 Tafeln, and is available at
*      https://www.biodiversitylibrary.org/item/50937#page/333/mode/1up
*      Mentioned, but not cited, by Forel in his 1899 C.R. note.
* NOTE: Friedrich Ernst Kayser: 27 Mar. 1830 - 12 July 1907.
* A detailed biography is in the Schriften (N.F.) vol.12, No.2, pp.58-70,
* (1908), followed by a complete bibliography of his publications.


A. Riccò
“Sopra un modo facile di studiare la rifrazione atmosferica,”
Rend. della R. Accad. dei Lincei , series 4, 6, 13–17 (1890).

* DIP and diurnal variations; horizon highest during sirocco
* A.Ricco (in DIP file)


G. Saija
“Sulla variazioni della rifrazione atmosferica,”
Mem. Soc. Spett. Ital. 28, 245–253 (1899).

* Continuation of similar measures by SAIJA at Catania


V. E. Boccara
“Sulla variazioni diurne della rifrazione atmosferica,”
Mem. Soc. Spett. Ital. 30, 162–177 (1901).

* Continuation of similar measures by BOCCARA at Catania


(editors of De Zee)
“Kimduiking,”
De Zee 22, 278–282 (1900).

* PREVIEW of VERUDELLA


K. Koss and E. Graf Thun-Hohenstein
“Kimmtiefen-Beobachtungen zu Verudella,”
Denkschr. der kaiserl. Akad. Wiss. (Wien), math.-naturwiss. Cl. 70, 347–428 (1901).

* VERUDELLA
* DIP depends on DIFFERENCE between AIR and WATER TEMPERATURES
* Karl Koss, k.und k. Linienschiffs-Lieutenant
* Emerich Graf Thun-Hohenstein
* ``. . . ein sehr merkwürdiger Fall'' on 17 March 1899, when the dip changed
* from 6'6" below the true horizon to 1'7" above it, between 1:03 pm and 4:57.
* On this day, ``Sonne im Untergehen (6h10m) stark flach gedrükt.''
* FLATTENED SUNSET; WAVY HORIZON
* ``4½h sieht man mit freiem Auge die Kimm gewellt . . . und diese Wellen
* wandernd.'' (p. 395)
*
* footnote, p.364:
* "Es ist hier der Platz, eine Bemerkung über solche abnorme Hebung der
* Kimm zu besprechen, nämlich die Frage: Wieso kommt es, dass man von
* solchen Fällen (Hebung über den Augeshorizont), die sich ja doch
* öfters ereignen müssten, noch nie etwas gehört hat? Die Antwort ist
* die, dass wohl schon mancher Navigationsofficier hin und wieder aus einer
* Höhenbeobachtung eine augenscheinlich um 10 -- 15' irrige Position
* erhalten hat, dass er aber in einem solchen Falle eher eine grobe Irrung
* im Ablesen oder Aufschreiben angenommen hat als einen Fehler in der
* Kimmtiefe, zu dessen Feststellung er zudem keine Zeit gehabt hätte,
* überdies auch keine Mittel. Dass sich bei den vorliegenden
* Beobachtungen nur zwei solche Fälle ergeben haben, wiewohl sie ein Jahr
* umfassen, ist eben dem örtlichen Wetter zuzuschreiben, das im
* Winterhalbjahre entweder südlichen oder Nordwestwind, im Sommer zumeist
* Nordwest bringt, und dem Zufalle, der von 48 Beobachtungstagen des Jahres
* eben nur zwei so ausgezeichnet hat. Von Kimmfehlern bis zu 5' berichten
* übrigens R a p e r, Practice of Navigation und M a g n a g h i, Gli
* strumenti a riflessione." (p.364) [cf. Cornelis, 1924; Ramforth, 1973!]
* [see also Reinicke, 1903; Havinga, 1905; Baker, 1922).]
*
* (Wind was from the NW this day, they say.)
*


J. B. Messerschmitt
“Resultate neuerer Kimmtiefenbeobachtungen und ihre Verwerthung in der Navigation,”
Annalen der Hydrographie und Maritimen Meteorologie 29, 162–167 (April, 1901).

* Dr. J.B.Messerschmitt's review, including Koss
* including many references: Helmert, Th.v.Oppolzer, Budde, Forel, etc.
*      But Forel's results can't be directly compared with those of Koss,
* because "die Temperaturverhältnisse über einem Binnensee komplicirter
* als am offenen Meere sind. . . ."
*      The historical background that led up to the "Pola" project is
* summarized, and the results discussed. The physical description
* is remarkably modern, considering that this pre-dates the concept of
* a boundary layer; the increased lapse rate due to heat exchange over
* water warmer than the air, and its reduction over colder water, are
* plainly stated.
*      Revised dip formulae and tables are presented; but "Dabei ist
* vorausgesetzt, daß die Luft gut durchmischt ist, also eine Briese
* von mindestens der Stärke 2 bis 3 weht. Bei schwächerem Winde kann
* sogenannte Temperaturumkehr eintreten, wobei sich warme Luft in der
* Höhe sammelt, ohne daß der Wind sie mit der unteren kälteren zu
* durchmischen vermöchte. Dadurch entsteht eine . . . starke Hebung der
* Kimm bis auf 3' über die durchs Auge gedachte Horizontalebene, also
* eine Hebung der Kimm um 10'." Then the temperatures must be measured
* with the best instruments; the air temperature "mit einem Aspirations-
* oder mit einem Schleuder-thermometer." In this connection, notice the
* complete neglect of "der Korrektion der Kimmtiefe wegen des Seeganges"
* which can exceed 20" when the wave height between crest and trough exceeds
* 2 m, which can limit the accuracy of altitudes measured at sea to 2'.
* [Note: corrections for the sea state were not introduced until 1960.]
*      Therefore the use of a gyroscopic sextant or "Libellensextanten"
* (apparently an early bubble sextant) is recommended, to make the
* determination of the dip superfluous; or to measure the dip directly
* with any of a variety of instruments named: Steinheil prism circle,
* Troughton's dip sector, Pistor & Martin's reflecting circle, Amici-Magnaghi
* prism circle) which all assume the refraction conditions are the same on
* opposite sides of the horizon -- which is certainly not always the case.
*      Auxiliary tables are included to correct for the temperature
* difference. There is a special table for near-calm conditions, assuming
* that in addition to measuring the temperature of the water surface,
* the air temperature is measured just above the water as well as at eye
* height. "Auf die Messung der Temperaturen ist dabei besondere Sorgfalt
* zu verwenden."
*      This volume of Ann. Hydrog. is available at Google Books.


T. Ferguson
“Eenige opmerkingen betreffende de Kimduiking in verband met de temperatuur van zee en lucht,”
De Zee 24, 357–361 (1902).

* TEMPERATURE DIFFERENCE and DIP
* "Even when neither land nor ships are in sight, the miraging can be
* determined by the unique moving appearance of the horizon seen through a
* telescope. The water seems to wave unnaturally and seems to flicker
* like flames along the upper surface. It does this with a strongly
* increased dip. I have never been able to see the least miraging so long
* as the ``extra dip'' remained under 30"." [This agrees well with Havinga's
* 1 deg.C] " . . . the ``boiling'' horizon." [cf. Forel, 1890. Forel has
* a nice drawing of the wave effect on p. 520 of his 1895 monograph.]
*
* "The danger is the greater because such cases [cold sea and warm air]
* generally seem to go together with a clear sharp horizon, from which one
* should never expect anything abnormal." (So much for Hornstein et al.!)
*


J. B. Blish
“The navigator's prism,”
Proc. U. S. Naval Institute 29, 175–184 (1903).

* Lieut.-Commander JOHN B. BLISH and his PRISM, with measurements
* The observations are off the coasts of the Californias in October,
* 1901 (Santa Ana season!), and show the Table to be wrong by from +7' 08"
* to -3' 18" -- a range of 10' 26". The large positive value is noted as
* being seen in "cloudless and hot" conditions -- typical Santa Ana.
* The positive value had air 5° F warmer than surface water; the
* negative one, 4° colder. All just as expected! (But, alas, no
* info on sea state or wind.) The photographs of the mustachioed gent
* taking observations are quite charming.
* Thanks to George Huxtable for a copy, originally from Brenda Corbin!
* Whole number 105, dated March, 1903.


G. Reinicke
“Durch Luftspiegelung veränderte Kimmtiefe,”
Ann. Hydrograph. Maritim. Met. 31, 511–512 (1903).

* DIP and REFRACTION (cf. Havinga's dip review)
*
* Here we have a horizon 8' or 9' above the dip of 5' calculated from
* the measured water and air temperatures, using Koss's formula.
* Evidently this is a case of Hasse's "Kimmfläche" -- i.e., the observer
* is *in* a duct. In this case, it must be caused by a strong inversion
* overhead, out of reach of the air-temperature measurements.
*      Comments on the occurrence of these phenomena:  ". . .  recht oft
* mögen wegen gehoben erscheinender Kimm falsch gemessene Kimm-
* abstände zu Ergebnissen geführt haben, die man auf
* Stromversetzungen, Änderungen der Deviation oder dergl., wenn nicht
* gar auf Unachtsamkeit geschoben hat. Wie im vorliegenden Falle, so wird
* man allerdings in vielen anderen Fällen erkennen können, sei es
* durch irgend welche verzerrt erscheinenden Objekte, sei es auch nur
* durch auffällig ausgezackt scheinende Kimm, daß
* außergewöhnliche optische Verhältnisse herrschen." . . .
*      "Auch in den deutschen Gewässern kommen Luftspiegelungen oder doch
* gehobene Kimm gar nicht so selten vor, wie sich aus den meteorologischen
* Tagebüchern der Normalbeobachtungsstation der Deutschen Seewarte zu
* Neufahrwasser ergibt; . . . ."
* See p. 568 for a correction to one sentence.


E. Kohlschütter
“Folgerungen aus den Koßchen Kimmtiefenbeobachtungen zu Verudella,”
Ann. Hydrograph. Maritim. Met. 31, 533–554 (1903).

* uses temperature gradient info -- see Freiesleben (1948) for update
* Note the formula for distance to the horizon on p. 543, which he relates
* to the dip variations and surveyors' k (refraction coefficient).
* On the next page, he considers the possibility of seeing infinitely far:
* ". . . das heißt der Lichtstrahl behält diese Höhe bei, soweit er auch
* läuft; daraus ergibt sich, daß man in dieser Höhe h' unendlich weit
* sehen kann und daß Punkte, die über oder unter dieser Höhe liegen,
* überhaupt keinen Kimmstrahl haben." This might count as a
* prefiguration of Hasse's Kimmfläche, except that he continues:
* "Da dies Resultat von der Erfahrung aber nicht bestätigt wird, . . . ."


E. Kohlschütter
“Kimmprisma,”
Ann. Hydrograph. Maritim. Met. 32, 84–85 (1904).

* another instrument


(editorial?)
“Kimduiking,”
De Zee 26, 187–194 (1904).

* DIP REVIEW; mentions Kohlschütter's instrument and others
* "Different researches and theoretical demonstrations have led to the
* conclusion that difference in temperature between the water surface
* and the height of the observer's eye has a great influence. . . .
* "The observation of the temperature difference . . . still does not give
* complete certainty. The following case may serve as an example, which
* was published in the German 'Annalen' of December 1903, p.511. . . .
* [That would be Reinicke, above.]
* All these heights must thus have been too small by 8' or 9'. Every 4
* hours the temperatures of air and water were taken, the greatest was at
* 4 p.m. 1.0 degree and at noon it reached 0.6 deg. . . .
* "Between 12 and 1:30 in the afternoon there was an explanation of the
* phenomenon, when on the north side several ships came into view, whose
* forms were seen distorted in the most grotesque ways by mirage."
* (cited in Havinga's 1934 paper)


E. Havinga
“Kimduiking,”
De Zee 27, 330–331 (1905).

* Havinga's DIP and TEMPERATURE data
* "A remarkable case, which can well serve as an example, occurred the 19
* April in the Gulf of Suez. A strong mirage was visible, so that one saw
* inverted images above land, towers, ships and other objects. . . . Two
* hours later . . . while still always at the horizon, where no other objects
* were found, there was nothing unusual to see. The measurements showed,
* however, that there was no more dip, but an elevation of the horizon of
* 7'0".
*      Had one at that moment taken an altitude, then one on almost all
* ships, making use of the usual tables, would have subtracted 6' for the
* dip, while one really should have added 7' and thus would have made an
* error of 13' in altitude."
* N.B.: this change from 4'40" to -7' dip occurred with only 0.3 degree
* change in the air-water temperature difference! So, the inversion here
* was well above eye level.


von Schrötter
“Der Einfluß der irdischen Strahlenbrechung auf die Navigierung,”
Ann. Hydrog. Maritim. Met. 33, 158–166 (1905).

* A fine tutorial article on refraction and dip; much on mirages as well
* He distinguishes among Luftspiegelung, Hebung, and Senkung.
* Many specific examples, as well as naming places where mirages are
* common (e.g., Newfoundland bank, water warmer than air by 13 deg or more
* in winter; west coast of Africa, air warmer by 16 deg or more.)
* At the end is an extended extract from Woltmann.
* April, 1905


F. Lauffer
“Ein Kimm-Diagramm,”
Mitteilungen aus dem Gebiete des Seewesens (Pola) 33, 700–704 (1905).

* a nice NOMOGRAM to make use of Koss's formulae


A. Bemporad
“La depressione dell'orizzonte all'osservatorio etneo (Nota preliminare),”
Bollettino delle sedute della Accademia Gioenia di Scienze Naturali in Catania 93, 14–15 (1907).

* Bemporad finds the dip should differ at Etna by 15" from meridian to
* prime vertical, owing to shape of ellipsoid (AZIMUTH EFFECT)
* Cites Riccò in Mem.Soc.Spett.18, p.210 in the 204-213 (1899) paper.
* A fuller account of observations from Etna is promised in Mem.Soc.Spett.


von Schrötter
“Hebung der Kimm und Luftspiegelungen in der Nordsee,”
Ann. Hydrog. Maritim. Met. 36, 490–497 (1908).

* Remarkably large NEGATIVE DIP (Wegener's strip occulting horizon)
* A fine example of Lutz Hasse's Kimmfläche, years before its invention.
* Much space devoted to instrumentation for measuring air temperatures
* accurately at sea. The case reported here (27' elevation of the
* apparent horizon above the real one!) is unusual; it is backed up by
* temperature data.
* "FOG": "Diese wogende Luftschicht über dem Wasser machte den Eindruck
* einer weißlich gelben Dunstmasse, die von der darüber befindlichen
* `kälteren' Luftschicht durch eine flimmernde Linie getrennt erschien."
* The thickness of the disturbed layer seems to have been 4 meters above
* the surface.
* [Note observation of CONCAVE surface.]
* Contains useful refs. to earlier papers in Ann.Hydrog., usw.
* The article ends with good ADVICE to observers: what to record.
* Kapitän Frhr. v. Schrötter


K. Brehmer
“Beitrag zur atmosphärischen Refraktion über Wasserflächen,”
Ann. Hydrog. Maritim. Met. 37, 306–324 (1909).

* nice LITERATURE REVIEW; looks like a student's thesis
* Mostly about dip, but contains some survey reductions
* and a useless lab experiment based on the assumption of a
* constant temperature gradient.
* Attempts to decide between Koss and Kohlschütter. Unfortunately, the
* field measurements between Neuwerk and Helgoland were complicated by both
* instrumental problems with a heliotrope, and the different heat-transfer
* properties over the "Wattenmeer von 1 meter Tiefe, welches zur Ebbezeit
* stundenlang trocken liegt. Da nun die Wärmeabgabe des Sandes eine
* andere als die des Wassers ist, so ändert sich das Temperaturgefälle
* der Luft gegen Eintritt des Niedrigwassers beträchtlich . . . ." (p. 321)
*      So (p. 322) Kohlschütter's model works only for a wind of at
* least force 2; "geringe Windstärken oder gar Windstille bringen
* außerordentliche Abweichungen hervor."
*      There are many good historical references on dip measurements in the
* introduction. At the end is a fairly comprehensive list (6) of dip-
* measuring instruments. (p. 323)
*      An appendix tabulates the measurements from 1878 of observed zenith
* distances on the sight-line Helgoland-Neuwerk, for which Kohlschütter's
* method fails because of small wind speed.


D. W. Horner
“Refraction as affecting dip of the horizon,”
Nautical Mag. (Glasgow) 98, 267–268 (1917).

* a somewhat confused presentation of dip, based on Chauvenet's treatment
* Thinks there is no refraction for an isothermal atmosphere.
* ". . . when the temperature increases upwards at the rate of 0.066 ° F.
* per foot the dip is zero. For more rapid increase of temperature the sea
* surface will appear concave , and there will be no true horizon."
* [This wording is lifted verbatim from de Graaff Hunter, 1913 -- who got
* it from Professor Everett (1873)!]
* [Note observation of CONCAVE surface.]
* Donald W. Horner, F.R.Met.Soc.


W. J. Peters
“Results of dip-of-horizon measurements made on the Galilee and Carnegie, 1907–1917,”
Terr. Magnetism Atmos. Electricity 23, 47–60 (1918).

* DATA DO NOT FIT KOSS FORMULA
* Good comparison of instruments for observing dip directly
* [The smaller variations here must be due to the higher waves at sea.]


E. Havinga
“Kimduiking,”
Hemel en Dampkring 19, 166 (1922).

* Havinga's chastising people who mis-use "dip":


J. C. Kelly Rogers
“Refraction. On the Cape Route.,”
Marine Obs. 3, 42 (1926).

* DOUBLE HORIZON and DOUBLE SUNSET
* "The double horizon was not uniform all round the compass. At some
* parts only the lower one was visible, and at others gradually merged into
* the upper one, this merging showing up as two clearly defined horizons.
*      At sundown the sun assumed some very grotesque shapes, but a peculiar
* feature of its setting was that it completely set on the upper horizon
* first, then reappeared on the lower one and proceeded to set there."
* Separation of horizons was "ten to fifteen minutes of arc at its greatest."
* N.B.: land "was distant some 40 miles."


J. C. Kelly Rogers
“Two sunsets on one day,”
Met. Mag. 61, 15 (1926).

* DOUBLE HORIZON and separate sunsets at each
* Summary of March Marine Observer report


T. Y. Baker
“On the refraction of electro-magnetic waves in a spherically stratified medium,”
Phil. Mag. , series 7, 4, 955–980 (1927).

* Instructor-Captain Thomas Yeomans Baker, R.N. (ret.)
* FIRST discussion of DUCTING?
* shows a DIP DIAGRAM, with axes interchanged: Figs. 3, 4, 5, 7, etc.
* There is also a clear discussion of the resulting "triple horizon";
* see Fig. 9 (p.977), where "the true horizontal appears half-way between
* the lines" that mark the lower erect and (middle) inverted horizon
* images. "The phenomenon of the triple horizon is well known to anyone
* who has had to take astronomical observations for navigation purposes.
* It is generally referred to as mirage without any very satisfactory
* explanation of how it is caused. Not infrequently the navigator assumes
* that the detached strip of sea is a layer of low-lying haze or cloud."
*      "As the point X [in Fig. 8, p.976 -- where the horizon rays cross]
* moves upwards towards B [where the observer is] the two [lower] horizons
* merge into one another and at the point B have just disappeared. It is
* therefore wrong to say, as was done above, that the observer at B sees
* the earth as flat. He sees it hollow, the line dividing sea from sky
* being . . . the indistinct line coming from the extreme range of visibility.
* As the observer goes higher still he ultimately reaches a height at which
* he is at the culminating point of an inclined ray which started from the
* extreme range of visibility. He then has a 'dip' value of zero and for
* greater heights the sea-horizon is depressed below the horizontal."
* (p. 978) So the observer in the inversion sees only a false horizon;
* the duct here extends to the surface, but the inversion does not.
* [Note observation of CONCAVE surface.]
*
* Much of the paper is concerned with radio-wave propagation; that part
* is obsolete, and he did not know about the fast phase speed in ionized
* media (there is much discussion of the Heaviside layer).


S. Ogura
“On the dip of sea horizon,”
Hydrographic Review 8, 101–111 (1931).

* Comparisons of various dip tables with observations
* H.R. was published by International Hydrographic Bureau in Monaco


E. Moll
“Measurement of the dip of the horizon,”
Hydrographic Review 8, 209–220 (1931).

* GOOD REVIEW of DIP with many citations of earlier papers
* He finds the Pulfrich instrument much better than Blish's prism.


C. Prüfer
“Das Kimmtiefenproblem,”
Ann. Hydrog. Maritim. Met. 71, 171–174 (1943).

* MANY GOOD QUOTES: recognizes the BOUNDARY LAYER as important.
* Explains how Freiesleben got into this business.
* "Es gibt Geophysiker, die behaupten, die Theorie habe immer recht."
* "Aber die Frage, wie man diesen Temperaturgradienten bestimmt, die
* so harmlos erscheint, blieb mehrere Jahrzehnte lang ungelöst."
* "Diese Schicht ist als Prandtlsche Grenzschicht mit laminarer Strömung
* aufzufassen."


H. C. Freiesleben
“Die Berechnung der Kimmtiefe,”
Deutsche Hydrographische Zeitschrift 1, 26–29 (1948).

* DIP FORMULA
* Hans Christian Freiesleben
* Note his use of the unusual term "geodätische Kimmtiefe"
*
* NOTE: DHZ was the successor to Ann.Hydrog.; this is its first volume.
* After 2000, it became "Ocean Dynamics".


H. C. Freiesleben
“Geophysikalische Folgerungen aus Kimmtiefenbeobachtungen,”
Deutsche Hydrographische Zeitschrift 2, 78–82 (1949).

* "surface" is about 0.5 m above WAVES, comparable to 0.4m WAVE HEIGHT


G. G. Pegler
“Mirage, Cape Town, South Africa,”
Marine Observer 19, 10–12 (1949).

* BEAUTIFUL PHOTOGRAPHS of DOUBLE HORIZON with "FOG" in between,
* and large-scale structure ("crest") along the upper horizon
* Alas, no useful supporting data! The Editor comments on the "fog".


J. Tattersall
“Mirages, Mediterranean Sea,”
Marine Observer 19, 186 (1949).

* DRAWINGS of MIRAGES
* This report is flanked by several other mirage reports.
* FOG reported:
* "A bank of mist appeared to lie around the whole horizon. . . . The
* phenomenon lasted until about 1530, when the mist cleared and objects
* resumed their normal appearance."
* Air was 4 F warmer than sea.


J. B. McGowan and R. Mattingley
“Mirages, Australian waters,”
Marine Observer 19, 187 (1949).

* GOOD DRAWINGS of DOUBLE HORIZON and WAVY HORIZON
* This report is flanked by several other mirage reports.
* Air was 7 F warmer than sea.


H. C. Freiesleben
“Investigations into the dip of the horizon,”
J. Inst. Navigation (London) 3, 270–279 (1950).

* Freiesleben's fine REVIEW article
* Several classic references are discussed; the treatment is excellent.
* But his Fig. 3 shows he does not understand double horizons; clearly
* the notion of "Kimmfläche" was not in his head at all.
* He concludes that the effective "surface" layer of air is less than
* a meter above the water, and "As it is impossible to obtain accurate
* measurements of temperature at such low heights, it is impossible for
* practical navigators to compute reliably the dip of the horizon from
* measurements of temperature."
*
* N.B.: There are two things called "Journal of the Institute of
* Navigation." This one (called "Journal of Navigation" since vol.25, 1972)
* is published in London by the Royal Institute of Navigation. The other
* (now called simply "Navigation") was published in Los Angeles at UCLA and
* was produced in Washington, DC, from 1960 to 1992.


H. C. Freiesleben
“Die Strahlenbrechung in geringer Höhe über Wasseroberflächen,”
Deutsche Hydrographische Zeitschrift 4, 29–44 (1951).

* DOUBLE HORIZON TRANSITION
* notes "the sensitivity to variations of the temperature gradients";
* "Hence, it is practically impossible to compute the course of a ray of light
* with precision from temperature measurements; one may, however, be able to
* obtain an insight into the thermical structure of the lowest atmospheric
* layers by optical measurements."
* [Cf. Kurzyńska, 1987.]


K. Brocks
“Bemerkungen zu H. C. Freiesleben, Die Strahlenbrechung in geringer Höhe über Wasseroberflächen,”
Deutsche Hydrographische Zeitschrift 4, 121–122 (1951).

* BROCKS COMMENTS on Freiesleben's paper
* He supplies the missing factor of α before T in the denominator
* of F.'s equation for the refractivity gradient, and adds the effects of
* the water-vapor gradient. He promises there will soon be a full report
* on the importance of the water-vapor gradient.


H. C. Freiesleben
“The dip of the horizon,”
J. Inst. Navigation 4, 8–9 (March, 1954).

* Hans Christian Freiesleben has by now found the other "Navigation"
* journal. This is a one-page summary of his 1952 empirical study:
* mostly just the formulae for the results.
* N.B.: There are two things called "Journal of the Institute of
* Navigation." One (called "Journal of Navigation" since vol.25, 1972) is
* published in London by the Royal Institute of Navigation. The other
* (now called simply "Navigation") was published in Los Angeles at UCLA and
* was produced in Washington, DC, from 1960 to 1992. Yet another "Navigation"
* is published in Paris!
* This is the LOS ANGELES version.


B. M. Cwilong
“Anomalous atmospheric refraction at sea,”
Nature 181, 181 (1958).

* TIME-VARYING DIP
* "24 per cent of sight points deviate by 2 min. of arc or more, and ½
* per cent by 5 min. of arc or more, from interpolated curves."
* ". . . there is often change of sign of deviation . . . when the azimuth
* changes very quickly and the telescope sweeps over large stretches of the
* horizon between two consecutive sights."
* "Morning sights show the lowest deviation frequency. . . ."


L. Hasse
“Über den Zusammenhang der Kimmtiefe mit meteorologischen Größen,”
Deutsche Hydrographische Zeitschrift 13, 181–197 (1960).

* NICE WORK on effects of WAVES and SUPER-REFRACTION for log profiles
* introduces concept of the Kimmfläche, where ray curvature = Earth's
* Uses Koss & Graf Thun-Hohenstein as first example
* Note: DHZ became Ocean Dynamics in 2001


L. Hasse
“Temperature-difference corrections for the dip of the horizon,”
J. Inst. Nav. (London) 17, 50–56 (1964).

* shorter English version of Lutz Hasse's thesis, placed here out of order:


H. H. Shufeldt
“Precision Celestial Navigation,”
J. Inst. Nav. (London) 15, 301–324 (1962).

* Shufeldt's paper on DIP measured with a dip-meter and high magnification
* Notable for the Prefatory Note and the Discussion, both by D. H. Sadler,
* Superintendent of H.M. Nautical Almanac Office.
*      "During the study, it became increasingly evident that the great
* accuracy achieved by the high-powered telescopes in measuring the
* altitude of a body above the horizon made it most desirable to determine
* the value of the dip accurately and consistently, which is not possible
* with the tables available at present. Even when the height of the eye
* was accurately established, anomalies in the value of the dip were
* encountered, although full allowance was made for barometric pressure,
* and air and water temperatures." (p. 303)
*      The dip-meter used was Gavrisheff's; see his patent for details.
*      "The depression of the visible horizon below the horizontal at the
* eye of observer can readily be calculated. However, the line of sight
* from the observer to the horizon is affected by terrestrial refraction;
* the amount of this effect varies with changing weather conditions.
* Differences in air temperature along the line of sigh from the observer
* to the horizon seem to be the chief cause of this variation. Where the
* water temperature differs from that of the mass of air above, the air
* immediately adjacent to the water is cooled or warmed. The effect of
* this difference is usually particularly strong on a calm wind-less day.
*      "Many attempts have been made to establish a direct relationship
* between the difference of temperature of air and sea and the value for
* the correction for dip; however, the results obtained by different
* investigators differed so greatly that no definite conclusions can
* be drawn." (p. 306)
*      [Hasse's English summary would not appear for another 2 years.]
*      ". . .  Considerable differences between sea and air temperatures were
* encountered, and had a marked, but by no means consistent, effect on
* the dip. Such celestial observations as could be obtained during this
* period, when corrected for dip as obtained by the dip-meter, always
* resulted in lines of position lying much closer to Loran fixes than
* those corrected by means of the dip tables." (p. 306)
*      "Using the value of the dip as obtained by dip-meter in correcting
* the altitudes, the mean distance from the known position was 0.115
* miles; when the tabulated value of the dip, corrected for barometric
* pressure and temperature was employed, the mean distance was 0.85 miles.
* These anomalies in the value of the dip are particularly interesting
* as the winds were extremely strong (up to 65 knots) during much of
* this period, and because many of the dip measurements were made with a
* height of eye of over 80 ft. Both these factors theoretically reduce
* any anomalies in the dip at sea." (p. 307)
*      Capt. Henry H. Shufeldt was one of the editors of the 12th Ed. of Dutton.
* Note: Cover of the issue reads:
*                   The Journal of the Institute of Navigation
* Available on Cambridge Journals website.


A. M. Sinzi, N. Owaki, and H. Suzuki
“Vertical deflection from dip observations,”
Int. Hydrogr. Rev. 45, 129–148 (1968).

* DIP


D. V. Anderson
“The horizon as an indicator of atmospheric stability over lakes,”
Bulletin of the International Association of Scientific Hydrology 14, No. 3, 117–118 (1969).

* DIP over LAKES (cites Forel and Minnaert)
* ". . . sightings of the horizon were made with a laboratory cathetometer
* . . . on Lake Huron near Kincardine." It was mounted on "a concrete pier
* on the shore six feet above the water line. . . ."
*      "An unexpected but regular feature came from small, but significant
* changes in the morning and the evening." (A few points are graphed.)


Y. Takenouti, M. Hyuga, and Y. Sakamoto
“Measurements of vertical air temperature gradients with dipmeter,”
J. Oceanographical Society of Japan 26, No. 4, 226–232 (August, 1970).

* Yositada TAKENOUTI, Masaaki HYUGA and Yurin SAKAMOTO use a Pulfrich dipmeter
* to determine thermal structure
*      Data are shown for two ocean cruises spanning a large range in latitude.
*      Cf. Johnson & Roberts (1925) in "Terrestrial refraction" file.


D. Rawlins
“Doubling your sunsets or how anyone can measure the earth's size with wristwatch and meter stick,”
Am. J. Phys. 47, no. 2, 126–128 (1979).

* Dip and Earth radius
* Historian-of-science Dennis Rawlins seems unaware that dip was once
* used to determine the radius (cf. Edw. Wright, 1657; also Al-Biruni).
* Despite the title, he used a stopwatch. Notable for mentioning the GF
* as a timing marker; cf. Brett Hilder (1951).
*      "All you have to do is sit for the first sunset and then stand up to
* view a repeat performance." [Too bad Brad Smith (1997) hadn't read this.]
*      Contains a useful estimate of the WAVE HEIGHT off San Diego (0.6 m),
* and convenient tables to allow for latitude and solar-declination
* effects. However, the treatment of refraction is simplistic and not
* very accurate. He is aware that "if the setting solar disc exhibits a
* visibly stratified shape (obviously indicating density gradient
* discontinuities [sic]), then it will be naive to assume that the
* correction b refraction factor is a constant . . . .", but does not
* realize that the absence of these features usually implies a convective
* surface layer and hence subnormal refraction -- especially below eye
* level. (The variation of ray curvature with height further spoils the
* method, in the real world.)
*      There is a good short discussion of azimuth effects on the geoid;
* he adopts 6386 km as a good average radius of curvature. But he fails
* to point out that the radius of curvature enters into the corrections,
* which in practice should be applied iteratively, to avoid a circular
* argument.


A. T. Young and G. W. Kattawar
“Sunset science. II. A useful diagram,”
Appl. Opt. 37, 3785–3792 (1998).

* SUNSET Paper II (the DIP DIAGRAM)


S. Y. van der Werf and I. Shokaryev
“Wave height and horizon dip,”
Navigation: Journal of The Institute of Navigation 62, No. 2, 161–169 (Summer, 2015).

* Siebren's 2015 dip paper
* Makes no mention of temperature effects; but there are good references
* to the navigation literature, and a discussion of wave heights.


M. E. Tschudin
“Refraction near the horizon – an empirical approach. Part 1: terrestrial refraction of the dip,”
Appl. Opt. 55, No. 12, 3104–3115 (April 20, 2016).

* Marcel Tschudin's dip analysis
* Nice re-working of old observations, as well as adding many new ones.
* Uses Siebren's wave correction.



*** OCEAN WAVES FILE ***

Was. Shoulejkin
“A new method of investigating sea waves,”
Nature 114, 498–499 (1924).

*
* See also Lutz Hasse (1960, 1964); Freiesleben (1949);
*       Franklin-Adams (1901) and de Graaff-Hunter (1913) for wave effects;
*       also Siebren's 2015 dip paper.
*
* GLITTER patterns analyzed long before Cox & Munk
* Glitter is relevant to the Smiley-Clemence fight, as the glitter path
* might contribute to irradiation at moderate solar altitudes, but not
* the last few degrees at the horizon.
* Thanks to George Golitsyn for mentioning this!



*** DISTANCE TO HORIZON FILE ***

T. W. Backhouse
“Distance of the visible horizon,”
Nature 92, 96 (1913).

*
* 1913 NATURE series
*
* Meteorologist Backhouse requests a general formula
* Sept.25 issue


T. H. Tizard
“Distance of the visible horizon,”
Nature 92, 96–97 (1913).

* Tizard replies that "Atmospheric refraction is such a varying quantity
* that no rule respecting it can be laid down applicable in all
* circumstances; as in cases of mirage, for instance . . . ."
* He cites Parry, mentions Biot, and gives empirical examples from the
* 1871 survey of the Gulf of Suez.
* Sept.25 issue


J. Ball
“Distance of the visible horizon,”
Nature 92, 344 (1913).

* John Ball cites various textbooks of surveying, including Jordan
* "It is not temperature per se which affects refraction, so much as the
* vertical temperature-gradient in the air . . . ."
* "It is easy nowadays to measure the vertical angles well within 5" of
* the truth . . . ."
* Nov. 20 issue


T. H. Tizard
“Distance of the visible horizon,”
Nature 92, 344–345 (1913).

* Tizard refers to Gillespie's California data on diurnal variations
* Nov. 20 issue


R. Langton Cole
“Distance of the visible horizon,”
Nature 92, 425 (1913).

* R. Langton Cole offers a simple formula
* Dec. 11 issue


A. P. French
“How far away is the horizon?,”
Am. J. Phys. 50, 795–799 (1982).

* SIMPLISTIC TREATMENT by a physicist -- exponential atmosphere assumed
* Curiously, section IV of this is also called "Distance of the visible
* horizon"!


Голицын Г. С.
“Рефракция в приземном слое воздуха,”
Изв. АН СССР, Физика атмосферы и океана 18, No. 12, 1282–1288 (1982).

* REALISTIC treatment by GOLITSYN (what a contrast with French's paper!)
* Golitsyn's first paper on distance to the horizon for Venera pictures.
* Useful for reference [10], the first known application of Monin-Obukhov
* theory to refraction. Notice that the integrals start at z0 -- this
* assumes that the observer can see down to this level.


G. S. Golitsyn
“Refraction in the atmospheric surface layer,”
Izvestiya, Atmospheric and Oceanic Physics 18, No. 12, 988–992 (1982).

* The translation of that paper:
* A clear explanation of the use of Monin-Obukhov scaling for convective
* and near-stable conditions. The z0 business is briefly discussed in
* the paragraph following Eq. (4.1) on p. 990:
*      "We will take as the reference level the roughness height z0 . . .
* since the universal functions of the surface layer in Eq. (2.10) are
* defined only to this level. The height z0 is proportional (it amounts
* to some fraction, usually ~0.1) to the height of obstacles on the
* surface. We will see below that the range to the horizon l is
* very slightly dependent on the exact value of z0."
* Note that the page numbering differs from that of the Russian original.


G. S. Golitsyn
“Some problems of Venus' atmospheric dynamics,”
Icarus 60, 289–306 (1984).

* REALISTIC treatment by GOLITSYN (what a contrast with French's paper!)
* Remarkably, this is buried in a little section near the end, starting
* on p. 300. He applies Monin-Obukhov theory, and gets reasonable
* results. Cites his fuller treatment in Izv. Atmos. Ocean. Phys. 18, 1282
* (1982) but I file this here because of the emphasis on the closed-form
* solution for the distance to the horizon -- a neat trick -- using
* confluent hypergeometric functions. [Note that due to translation
* from English to Russian and back again, they appear here as "degenerate"
* rather than "confluent" hypergeometric fcns. There are some typos as
* well, most of them obvious.]
* Thanks to George Golitsyn for pointing this paper out to me!



*** VARIABLE REFRACTION FILE ***

J. J. T. Chabot
“Der sogenannte Sonnenuntergang und das optische Verhalten der Atmosphäre nach den jüngsten Aeusserungen vulkanischer Thätigkeit in Mittelamerika,”
Met. Zs. 19, 520–522 (1902).

*
* See also Perrault (1674), Huygens (1690), Jacques Cassini, 1714;
* Maraldi (1722/24), Nettleton (1725), Bessel (1823), Bauernfeind, etc.
*
* CHABOT shows pictures of discrepant sunsets in a nice COLOR PLATE
* showing the solstice Sun setting on different sides of a distant church
* in different years.
* (See Tafel 2 at end of Nov. issue)


C. J. Hudson
“Irregularities in refraction,”
Pubs. Allegheny Obs. 6, No. 1, 1–8 (1929).

* Finds quasi-periodic motions of equatorial stars (Z.D. about 41°)
* with periods of a few minutes of time and peak-to-peak amplitudes of
* about one second of arc, in agreement with Schlesinger (vol.3, 1916).
* Cf. Fletcher's 1952 discussion, below; and Fraser's 1975 paper.
* Date uncertain; I first adopted 1926, but ADS says 1929.
* THANKS to Shaun Hardy for this reference!


S. T. S. Lecky
Wrinkles in Practical Navigation (22nd edition)
(George Philip & Son, London, 1947).

* LECKY -- "WRINKLES"
* DIP variations:
*      ". . .  owing to the uncertainty of the effects of refraction, the
* apparent position of the sea horizon can never be depended upon. It is
* found to be sometimes above its normal place, and at others below it.
* The rule seems to be, that when the sea is warmer than the air, the
* horizon appears below its mean place; and when the sea is colder
* than the air, the horizon appears above its mean place. The known
* capriciousness of terrestrial refraction has prevented the formation of
* a table of values in connection with this subject."
* [Marginal note: "Sea horizon not reliable." -- p. 81 of 19th edition,
* revised and enlarged by William Allingham (1918)]
*
* cites errors in limits of lighthouses of 14 and 17 miles (=minutes of
* arc), in and before 1881; pp. 681, 682


F. R. Gossett
Manual of Geodetic Triangulation (U.S. Dept. of Commerce Special Pub.No.247)
(Government Printing Office, Washington, DC, 1950), pp. 135–136.

* HORIZONTAL REFRACTION (in the sense of "lateral") discussed
* (cf. Fletcher, 1952, below)
* This is a textbook for geodesists. Refraction in the horizontal
* direction is discussed in about a page:
*      "The errors caused by horizontal refraction may be of considerable
* size. Night observations have occasionally been found to be in error
* by five or six seconds because of horizontal refraction and daylight
* observations by two or three times that amount." (p. 136)


C. H. Smiley
“Atmospheric refraction at low angular altitudes in the tropics,”
Navigation (Los Angeles) 2, 110–113 (1950).

* BEGIN SMILEY - CLEMENCE dispute
* Smiley's first paper -- Suggestion that std. tables are wrong:
* N.B.: There are two things called "Journal of the Institute of
* Navigation." One (called "Journal of Navigation" since vol.25, 1972)
* is published in London by the Royal Institute of Navigation. The other
* (now called simply "Navigation") was published in Los Angeles at UCLA
* and was produced in Washington, DC, from 1960 to 1992.
* This is the latter, sometimes called "Navigation (Los Angeles)".


G. M. Clemence
“Astronomical refraction at great zenith distance,”
A. J. 56, 123–124 (1951).

* Smiley's claim refuted by Clemence:
* abstract


G. M. Clemence
“Remarks on suggested improvements in sunrise-sunset-twilight tables,”
Pop. Astr. 59, 358–361 (1951).

* Clemence's full article:
* ". . . the indeterminacy is a geometrical one, and the refraction at any
* instant may differ by several minutes of arc from the most accurate value
* that can be calculated."


C. H. Smiley
“Atmospheric refraction at low angular altitudes in the temperate zones,”
Navigation (Los Angeles) 3, 33–36 (1951).

* Smiley's SECOND paper (Temperate zones) . . .


G. M. Clemence
“Refraction near the horizon,”
Navigation (Los Angeles) 3, 36–41 (1951).

* . . . Smiley is immediately refuted by Clemence . . .
* "Smiley's results disagree with both the theory and the observations,
* and I conclude that they are subject to such large systematic errors as
* to be valueless . . . ."
* This is the paper in which Clemence says the upper-limb discrepancies
* are due to irradiation (a term apparently invented by Plateau -- see
*       http://www.mhsgent.ugent.be/engl-plat8.html )


R. C. Willems
“Low altitude refraction correction,”
Navigation (Los Angeles) 3, 41–45 (1951).

* . . . and Clemence is immediately followed by Willems:
* Captain Raleigh C. Willems is concerned about tables for use in the
* Air Almanac, where even surface temperatures are not available. He
* seems largely ignorant of the theoretical side: "Most formulae for
* computing astronomical refraction are based on the work of Lord
* Rayleigh. . . ." (p. 42)


C. H. Smiley
“Atmospheric refraction at low angular altitudes in the polar regions,”
Navigation (Los Angeles) 3, 81–84 (1952).

* Smiley's THIRD paper (POLAR regions).
* Note change of year within volume!


R. W. Byerly
“Suggestion for measurement of refraction,”
Navigation (Los Angeles) 3, 169–171 (1952).

* A proposal to test the Smiley-Clemence arguments with stellar
* separations measured at night, to avoid irradiation problems.
* [Immediately followed by short notes from both Smiley and Clemence.]
* (Sept. 1952)


A. Fletcher
“Astronomical refraction at low altitudes in marine navigation,”
J. Inst. Navigation (London) 5, 307–330 (1952).

* FLETCHER's great review article -- really EXCELLENT !!
* This really belongs in the General Refraction file, but is here for
* its extensive discussion of the Smiley-Clemence controversy.
*      This SUPERB review article does everything right: it mentions the
* increasing importance of temperature gradients near the horizon, gives
* lots of numerical values, points out that refraction can be abnormally
* large but not very small; it even discusses TILTED layers, pointing out
* that "a tilt of the layers by 6' would alter refractions near the zenith
* by about 0."1. It seems fairly certain that the effect cannot be much
* larger than this under normal weather conditions. In the first place the
* standard deviation of the effective tilt in one coordinate can hardly be
* as much as 2', or the standard deviation of the irregularities in
* refraction would be more from this cause alone than it is found to
* be from all causes. . . . Secondly, in observing stars near the zenith
* with the photographic zenith tube . . . the zenith distance residuals are
* small enough to rule out refraction anomalies . . . much greater than 0."1.
* Thirdly, the sort of meteorological information contained in an ordinary
* synoptic chart rarely suggests tilts of more than one or two minutes of
* arc, except under extremely violent conditions.
*      "Thus it seems that tilt is normally less than what at first sight may
* seem the rather small value of 0.°1. But it must be remembered that
* refraction changes with zenith distance nearly a thousand times faster
* near the horizon than at the zenith (at the rate of about 14', instead of
* about 1", per degree). Thus variations of one or two minutes of arc in
* the horizontal refraction are perhaps indicated, although it cannot be
* very accurate to reckon so simply at low altitudes." (pp. 320-321)
* [cf. Hudson's 1926 paper, and Gossett (1950), above.]
*      He also points out the latitude and azimuth effects due to the geoid;
* that measurements made over land may not apply at sea; that diurnal and
* seasonal variations are large (giving numbers and citing references).
* Dispersion, humidity, and wind are given their due. (Oct. 1952)
*      There is a section on dip, citing Freiesleben's paper in this Journal.
* Cites Varnum (1922); but Sugawa's work is not mentioned.
*      This is now called the "Journal of Navigation" and is published on
* behalf of the Royal Institute of Navigation by Cambridge U. Press; see
* https://www.cambridge.org/core/journals/journal-of-navigation/all-issues


B. Hilder
“Refraction at sea,”
J. Inst. Navigation (London) 6, 314–320 (1953).

* Captain Brett Hilder gives the results of his proposal to use GFs.
* [This paper is mostly about refraction at the horizon, with comments
* on the Smiley-Clemence argument and on Fletcher's review. In turn,
* there are extensive replies by both Fletcher and Clemence interpolated
* in the present very interesting note.]
* The 103 sights were all in the SW Pacific at low latitude, so we can
* argue that the water was generally warmer than the air. [If these were
* (nearly) all Type A events, the disappearance is at the mirage level
* and not the geometric horizon; this probably accounts for the 2.8-minute
* mean discrepancy (which Hilder supposes is an error in the tabulated
* refraction), as well as the agreement of upper and lower limbs.]
* The larger discrepancy with land in sight is explained by coastal
* effects on refraction, by about 1'. As there is a smaller difference
* with the tables at sunset, the apparent refractions being less than the
* tabular ones, he decides "there is more refraction at sunset than at
* sunrise (as attributed to Delambre by Dr. Fletcher)".
* He specifically discusses variability of refraction (p.316), and
* recalls errors of 15' and even 30' at a storm front; Fletcher comments
* that these must be due to dip rather than refraction errors.
* Hilder points out that Clemence's "irradiation" explanation must be
* wrong; Clemence replies that the systematic error (though not really
* explained) is in the data and so the correction should be in the
* Almanac, whatever its cause.


I. Greenbaum
“Observed and theoretical values of astronomical refraction at low altitudes,”
A. J. 59, 17–19 (1954).

* Greenbaum's observations in Clearwater, Florida, July - Aug., 1951
* The mean temperature was 80° F but no correction seems to have been
* made for humidity! (Or wavelength.) Only 7 nights of data.
* "The observations fully support the modified Garfinkel theory . . .
* The value [2' larger at 3.5° altitude] found by Smiley is not
* substantiated."
* The claim is that observations were made down to 0.5° altitude; but
* as Fig.1 does not show this, and "one was rejected", it appears the lowest
* point did not fit.


G. Wallerstein
“Refraction observations on the Greenland icecap,”
Navigation (Los Angeles) 5, 138–140 (1956).

* George Wallerstein's secret past as a positional astronomer is revealed!
* Unfortunately, he mistakes Clemence's "irradiation" for "irradiance".
* The method of observing was to determine latitude from Noon altitude
* of the Sun, then use lower culmination to find refraction. A Wild T-2
* theodolite was used, and individual observations are given to 1"
* precision.
* "These results agree with Garfinkel's theoretical table quite well down
* to 2°. However the effect that Smiley has observed, of differences
* changing from positive to negative as the horizon is approached is
* confirmed by this investigation."
* Cites both Smiley and Clemence.
*
* NOTE: I was able to discuss this work with George Wallerstein himself
* at the Jan. 2001 AAS meeting here in San Diego. He says he himself
* made all the measurements, which were referred to the astronomical (not
* the apparent) horizon, using the theodolite. A 25-second systematic
* error in the measurements was never explained; but this is negligible
* compared to the effects under discussion.


D. H. Sadler and W. A. Scott
“Refraction at low altitudes,”
J. Inst. Navigation (London) 13, 139–147 (1960).

* Mostly a check on the Smiley-Clemence controversy, confirming Clemence
* This contains summaries of data sent in from ships, based on sextant
* observations -- so dip errors are included. The observations between 5
* and 10° altitude were used to correct for position errors.
* No data on water temperatures or wave heights.
* Conditions of unusual refraction were probably eliminated by rejecting
* data with large runs of residuals between 5 and 10°: "Only 42 sets
* out of the original 76 were retained in the main analysis." (Censored
* data.) So the confirmation of the Almanac values is not surprising!


H. Exton
“A fresh analysis of some recent data on atmospheric refraction near the horizon with implications in archaeoastronomy,”
J. History Astronomy 23, S57–S58 (1992).

* SCHAEFER & LILLER REFUTED
* See Stephen McCluskey's 2017 study of refraction at the apparent horizon
* (in the "variable refraction" file) for useful discussion.
* N.B.: Archaeoastronomy no.17 = JHA 23, special section


R. D. Sampson
Atmospheric Refraction and its Effects on Sunrise and Sunset
(Dept. of Geography, Edmonton, Alberta, 1994).

* RUSS SAMPSON's M.S. thesis (filed separately, but belongs here)
* A nice independent rediscovery of the main features of horizontal
* refraction through careful observations and analysis of sunrise/sunset
* timings. This is a fine piece of work; it should be a model for other
* graduate students! The presentation is clear; the graphs are easy on the
* eye; the work is well done. And the data are all neatly tabulated.
* 244 sunrises (!) plus 125 sunsets.
*      There is a nice drawing of LOOMING of the distant horizon on Jan. 14,
* 1993, in Fig. 2.5.3 on p.18: the surface was raised by a low-level
* thermal inversion, while the astronomical refraction was increased
* even more, making the apparent sunset occur at a more northerly azimuth.
*      Ch.4 is on applications to archaeoastronomy; cf. McCluskey (2017).


R. D. Sampson
“Astronomical refraction and the equinox sunrise,”
JRASC 94, 26–29 (Feb., 2000).

* Sampson points out the effects of variable refraction on the "equinox
* sunrise" azimuth


G. de Donà
“Misure della rifrazione atmosferica all'orizzonte,”
Astronomia , no. 1, 4–11 (2003).

* Giuseppe de Donà's observations of sunset times
* The presentation of "formulas" for refraction is superficial and
* useless; the value of this article is in the 17 sunset observations,
* and the nice photos of DISTORTED SUNSETS (could have been filed there,
* but is so similar to Russ Sampson's work that I put it here). 10 of the
* observations have (p,T) values as well. The observed refractions at the
* sea horizon vary from 29' 59'' to 49' 43''; mean, 36.65'. A nice touch is
* the flattening observed when the lower limb touched the apparent horizon.
* The individual observations are tabulated. Good photo sequence of an
* OMEGA sunset on p. 5; interesting comments on distortions.
* "Astronomia, la rivista dell'Unione Astrofili Italiani" seems not to
* use volume numbers. This is "n.1 gennaio/febbraio 2003".
* Thanks to Katia Alboresi for providing a copy through ILL!


R. D. Sampson, E. P. Lozowski, and A. E. Peterson
“Comparison of modeled and observed astronomical refraction of the setting Sun,”
Appl. Opt. 42, 342–353 (2003).

* More Sampson
* Here he compares the observed refractions with model calculations based
* on radiosonde profiles. ". . . the inverse solution (i.e., extracting
* the temperature profile from refraction measurements) may produce
* no improvement on U.S. Standard Atmosphere adjusted to the surface
* conditions." (But no mention of Fraser & Hemler.) However, the
* comparison really shows that this simple adjusted model fits the
* refractions better than the noisy radiosonde data, which are useless.
* (They keep the tropospheric lapse rate fixed.)
* 20 Jan. issue


R. D. Sampson, E. P. Lozowski, A. E. Peterson, and D. P. Hube
“Variability in the astronomical refraction of the rising and setting Sun,”
PASP 115, 1256–1261 (2003).

* Further analysis of Sampson's observations
* Contains good evidence of seasonal and DIURNAL (sunrise vs. sunset)
* variations: "variable but not at all random." Lapse rates are even
* mentioned. About 3% of the data show refraction over a degree. The
* large sunrise refraction in June & July is surprising.


R. D. Sampson, E. P. Lozowski, and H. G. Machel
“Variability of observed low-altitude astronomical refraction (LAAR) from different geographic locations: progress toward a global map of LAAR variability,”
Appl. Opt. 44, 5652–5657 (2005).

* Russ is still at it. . . .
* ". . . it seems reasonable that the standard deviation of the surface
* vertical temperature gradient may be used as a climate proxy for the
* standard deviation in the LAAR."


S. C. McCluskey
“Archaeoastronomy and refraction near the earth's surface,”
Journal for the History of Astronomy 48, No. 3, 329–345 (2017).

* Stephen C. McCluskey's study of refraction at the apparent horizon
* He explains the effects of refraction on rising and setting times
* more clearly than the Explanatory Supplement does, and shows that
* refraction in the surface layer *at* the apparent horizon is
* significant, even for elevated horizons at distant mountain ridges.
* This effect is much larger for level-surface horizons (plains and seas),
* which explains why much larger variations are observed in rising and
* setting times (and azimuths) there than at elevated horizons.
*      A good list of references from the literatures of geodesy,
* meterorology, and navigation.



*** FOREL & DUFOURs FILE -- N.B.: Louis & Charles Dufour were brothers. ***

Ch. Dufour
“Séance du 23 avril 1851,”
Bull. Soc. Vaud. 3, 71–72 (1854).

*
* Most of their publications were in
* Bulletin des séances de la Société Vaudoise des
* Sciences Naturelles [usually just "Bull.Soc.Vaud."]
*      Many volumes are available at the HathiTrust:
*        https://catalog.hathitrust.org/Record/000504901
*
* Charles Dufour's "non-symmetrical mirage" is probably similar to my
* own observation of the boundary layer of a mountain just after sunset.
* He supposes it to be a lateral mirage; the Sun had not yet risen.
* (A letter from him, read by R.Blanchet at a meeting of the society.)
* [This is also reported in C.R. 33, 121-122 (1851).]
* Available at HathiTrust:
*       https://babel.hathitrust.org/cgi/pt?id=uc1.b3085875;view=1up;seq=79
* Bulletin No. 23


C. Dufour
“Mirages et réfractions anormales sur le Lac Léman,”
Bull. Soc. Vaud. 4, 129–138 (1854).

* Charles Dufour's identification of the miraged objects
*      He begins with the visible effects of the Earth's curvature, seen
* across the lake. "Cependant cette espèce de dépression
* mathématique causée par la rondeur du sphéroïde terrestre,
* est singulièrement modifiée par les réfractions et les
* réflexions anormales éprouvées par les rayons lumineux qui
* passent près de la surface du lac."
*      His account of the Fata Morgana displays begins on p. 130, after
* discussing the inferior mirage, "un mirage tout à fait analogue à celui
* que l’on observe dans les plaines d'Egypte. Ce mirage a lieu toutes
* les fois que l'eau est plus chaude que l'air et c’est ce qui arrive
* presque constamment pendant les mois d'octobre, novembre et décembre;
* le plus souvent pendant les mois de septembre, de janvier et de février,
* et presque toujours quelques heures dans la matinée pendant les autres
* mois de l'année."
*      Now comes the more interesting part:
* "Cependant, dans les circonstances où sur le lac on ne peut voir
* que des mirages, les observations n’ont rien de frappant. Il serait
* sans doute intéressant de mesurer la grandeur de ces mirages et noter en
* même temps la température de l’air et celle de l'eau. Mais j’avoue
* que pendant la dernière année, je n’ai pas spécialement porté mon
* attention sur ce point. J’ai plutôt observé dans les moments où
* les mirages avaient cessé. Alors les phénomènes qui se présentaient
* étaient bien plus variés et bien plus compliqués, et c’est surtout
* sur ceux-là que je me propose d’appeler ici l’attention.
*      "Plaçons-nous à Morges par un beau jour du printemps ou de
* l’été. Mettons l’œil à 3 ou 4 mètres au-dessus du niveau du lac,
* et suivons du matin au soir, l’apparence que présentent soit la côte
* savoyarde, soit surtout le voisinage de Vevey, avec les villages et les
* maisons du cercle de Montreux.
*      "En général le matin, il y a un mirage qui cesse vers 9 ou l0
* heures. Dès lors jusqu’à midi ou une heure, les objets paraissent
* demeurer à peu près à la même hauteur au-dessus du lac, mais il
* y a souvent une agitation des couches d'air, qui rend le pointé et les
* mesures angulaires bien difficiles.
*      "Depuis une heure après midi, suivons spécialement la localité
* de Montreux et les villages voisins (distance de Morges 32 à 34
* kilomètres). Toute cette contrée ne tarde pas à sortir de l'eau. Il
* semble presque à certains jours qu’il y a une puissance magique qui,
* avec un cordon, soulève tout ce territoire.
*      "Ce mouvement ascensionnel, d’abord assez lent, devient fort rapide
* vers 3 1/2 heures ou 4 heures, Dès lors il se ralentit de plus en plus et
* dure quelquefois jusqu'à l'approche de la nuit. D'autres fois, depuis
* 6 heures du soir, les objets paraissent retomber un peu dans l’eau
* jusqu’au coucher du soleil. Mais dans tous les cas, depuis ce moment,
* l'obscurité est telle que tout ne tarde pas à disparaître. Pour cette
* raison, je ne sais pas à quelle heure de la nuit et en combien de temps
* ces objets, ainsi soulevés dans l'après-midi, retombent à leur place,
* pour paraître le lendemain sortir encore du lac et donner ainsi tous
* les jours la même apparence avec la même régularité.
*      "Ce grand mouvement est accompagné de déformations apparentes
* assez considérables de tous les objets qui paraissent ainsi déplacés.
*      "La première fois que je remarquai ces déformations, je fus
* étonné, en arrivant à une heure après midi au lieu ordinaire
* d’observation, de voir du côté du Chatelard, une ville magnifique qui
* paraissait sortir du sein des eaux. C'étaient des palais, des édifices,
* des monuments superbes, remarquables surtout par leur hauteur. Tous ces
* objets, beaucoup moins brillants que ceux qui étaient plus élevés,
* paraissaient ainsi dans un demi-jour, qui ne faisait que réhausser leur
* éclat grandiose.
*      "Malheureusement, toutes ces belles images n’étaient pas de
* longue durée; elles changeaient plus ou moins rapidement, mais elles
* conservaient, en général, l'aspect que je viens de décrire. Cependant
* leur forme était tellement étrange qu’il me fut impossible de
* reconnaître là aucune des localités de la contrée. En prenant avec
* soin la direction de ces objets agrandis, et en la rapportant sur la
* carte fédérale, je pus me convaincre que ces palais, ces édifices,
* ces monuments nouveaux n’étaient autre chose que la Tour-de-Peilz,
* dont les bâtiments, qui en réalité n’ont rien d’extraordinaire,
* prenaient ainsi une apparence féerique sous l’influence des
* circonstances météorologiques dans lesquelles j’étais placé.
*      "Mais les objets un peu plus élevés au-dessus du niveau du lac
* avaient un aspect fort différent. Bien loin d’être amplifiés dans le
* sens vertical et de n’être que faiblement éclairés, ils éprouvaient
* au contraire une dépression considérable, et ils étaient en même temps
* extrêmement brillants. Il en était de même pour des objets tels que
* les maisons de Montreux et de Veytaux, qui paraissaient au niveau du lac,
* mais qui en réalité en sont plus éloignées que celles de la Tour, et
* qui ne semblent être aussi bas qu’à cause de la rondeur de la terre
* et de la plus grande distance qui les sépare de Morges. --- Cependant, il
* est arrivé quelquefois que les maisons de Veytaux et de Montreux m’ont
* aussi paru amplifiées dans le sens vertical, mais ce fait n’a jamais
* été de longue durée. Je citerai comme exemple, la pension Henchoz à
* Montreux, qui, le 7 mai 1854, à 3 heures 50 minutes, me présentait une
* hauteur angulaire de 3’ 10". A 6 heures du soir, elle n’avait plus
* que 30". Et en ne supposant aucune réfraction anormale d’après sa
* hauteur et d'après sa distance de Morges, cette maison devrait avoir 56".
*      "Je pourrais multiplier les citations d’observations analogues,
* et pour m'assurer qu’il n’y avait ni erreur de l'instrument que
* j'employais, ni inhabileté dans la manière de m'en servir, j'ai à
* diverses reprises mesuré la largeur de plusieurs bâtiments dans le
* sens horizontal (largeur qui n’éprouvait aucune variation), et j’ai
* toujours trouvé, à 2 ou 3" près, une même valeur, qui s’accordait
* avec la détermination trigonométrique." [pp. 130-132]
*      P. 134: in discussing the Fata Morgana, he makes the usual mistake
* about RADIANCE and IRRADIANCE: "On comprend très-bien que les
* objets ainsi agrandis paraissent plus sombres, puisque la lumière
* s’y distribue sur un plus grand espace, et par la raison inverse,
* on comprend de même que les objets déprimés dans le sens
* vertical paraissent aussi plus lumi-. . . " [missing line, it seems.]
*      "Chacun sait que les Italiens nomment Fata morgana, des images
* fort bizarres, qui de temps en temps apparaissent en mer près du
* rivage de Messine. On voit des colonnades, des monuments, des palais
* faiblement éclairés, et qui paraissent changer de forme d’un instant
* à l'autre. On les attribue généralement à l’existence de ruines
* placées au loin sur les bords de la mer. Mais je ne sache pas que l’on
* ait jamais montré pourquoi ces ruines qui ordinairement doivent être
* presque invisibles par leur petitesse et presque cachées par la rondeur
* de la terre, apparaissent ainsi de temps en temps, pourquoi elles ne sont
* quà moitié éclairées, pourquoi elles sont agrandies, enfin pourquoi
* elles changent ainsi de forme d’un instant à l’autre. Il me semble
* que ce phénomène est peut-être analogue à celui que j’ai constaté
* depuis Morges, quand la ville de la Tour-de-Peilz, qui ordinairement
* est presque invisible, apparaît comme une ville magnifique, et je crois
* que la même explication pourrait être admise."
* (cited by Forel, p. 545)
* The title page of the volume says it contains the years 1853 - 1855, and
* gives the date of publication as 1856. This paper is in No. 34, which
* begins on p. 97, with the annual meeting held on 22 juin 1854. The
* Google scan is available at the HathiTrust website:
*      https://babel.hathitrust.org/cgi/pt?id=uc1.b3085876;view=1up;seq=149


L. Dufour
“Observation d'un mirage non symétrique,”
Bull. Soc. Vaud. 4, 279 (1855).

* Louis Dufour's paper on a "non-symmetrical mirage"
* Again, it seems an image of the boundary layer, not really a mirage.
* (Bulletin No. 36; meeting of 3 Jan. 1855)


C. Dufour
Bull. Soc. Vaud. 4, 344 (1855).

* His brother's comment on the above item in "Procès-verbaux":
*      "Mr C. Dufour ajoute, à l'occasion de la communication de
* Mr son frère, que les phénomènes du mirage sont bien connus
* des pêcheurs et qu'ils les expliquent en disant que ce cas
* l'eau trouble l'air."
* (Bulletin No. 37; meeting of 5 Dec., 1855)


L. Dufour
“Des températures de l'air et des mirages a la surface du Lac Léman,”
Bull. Soc. Vaud. Sc. Nat. 4, 388–398 (1856).

* good discussion of INFERIOR MIRAGE over WATER, and how to
* distinguish the mirage from the REFLECTION on water (cf. Floor, and Bravais)
* First observations of REFLECTIONS on water after Büsch?
*      Notice his use of the phrase "ligne de partage" for the fold line.
* He got this term from Bravais (1853), who is cited on p.391.
* This is No. 37, containing memoirs for 1855: "Séance du 4 juillet 1855."
*      Available at the HathiTrust:
*      https://babel.hathitrust.org/cgi/pt?id=uc1.b3085876;view=1up;seq=418
* My copy has "1857" written on it -- probably the date it was received.


L. Dufour
“Des températures de l'air et des mirages à la surface du Lac Léman,”
Bull. Soc. Vaud. Sc. Nat. 5, 26–47 (1858).

* TEMPERATURE PROFILES for INFERIOR MIRAGES over WATER
* This paper is the continuation of his previous paper. It has the
* TEMPERATURE measurements.
*      He is aware of the difficulties: "La recherche des températures de
* l'air est toujours une opération difficile. . . . " (p. 26)
*      "Les recherches que j'ai faites au-dessus du Léman avaient pour objet
* la connaissance de la température de l'air à diverses hauteurs au-dessus
* de la surface jusqu'à une distance de 1m50 à 2m. Les difficultés sont
* ici nombreuses et variées. Il s'agit d'avoir un instrument assez
* sensible pour apprécier facilement des différences ne s'élevant qu'à
* quelques dixièmes de degré; observer au-dessus de l'eau à une distance
* assez considérable du rivage; se garantir autant que possible des effets
* de rayonnement; agiter le thermomètre dans l'air en demeurant pourtant
* dans une même couche sensiblement horizontale et enfin prendre la
* température aussi près que possible d'une nappe d'eau qui n'est que bien
* rarement tout à fait immobile.
*      "Je me transportais avec un petit bateau un peu au large et je me
* servais d'un thermomètre Fastré à graduation arbitraire. Chaque
* division, de la longueur de 5/9 millimètre, équivalait à 0°,1816. Le
* thermomètre, suspendu par une ficelle à l'extrémité d'un bâton, était
* alors suspendu dans l'air à une certaine distance du bateau et à des
* hauteurs variables au-dessus de l'eau. Enfin, par un léger mouvement
* communiqué au bâton, que je tenais le bras étendu comme un pêcheur
* tient la ligne, je faisais décrire à la ficelle et au thermomètre
* une oscillation conique, de manière que l'instrument agité dans l'air
* demeurait cependant dans une même couche horizontale. Une règle
* graduée servait à mesurer la hauteur de cette couche au-dessus de
* la surface de l'eau." (p. 27)
*      So the measurements ought to be fairly reliable.  And, indeed,
* the temperature and density plots in the plates seem quite plausible.
* His "surface" data in the tables correspond to about 5 cm above the
* water surface.
*      Furthermore, his discussion of the temperature data (pp. 31-32)
* leads him to reject both Biot's parabolic profile and the exponential
* suggested by Bravais; and he decides that "Il est à remarquer que la
* variation des densités est en général rapide près de la surface, puis
* beaucoup plus lente à une certaine hauteur. . . .      En d'autres termes,
* la vitesse du décroissement des densités, qui est une certaine fonction
* de la hauteur, décroit en même temps que cette hauteur augmente. Il
* faut donc que l'équation qui représente des variations de la densité
* soit telle que sa différentielle, prise par rapport à la hauteur,
* décroisse en même temps que la hauteur augmente, ou bien que la
* différentielle seconde soit négative.
*      "D'après cela, le cas qui apparaît le plus simple est celui où
* l'équation différentielle serait de la forme :
*
*                               dδ/dz = b + c/z
*
* b et c étant des constantes. En intégrant, on trouve :
*
*                               δ = bz + c. l. z
*
* . . . ." (p. 32)
* -- in other words, he discovers the correct log-linear law for
* convective boundary layers! But, unfortunately, he rejects it, because
* of its large residuals when compared to some of his data. (This poor
* fit seems to be due to the low-lying lake inversion on some days.)
*      On p.36 he offers the first suggestion to derive temperature profiles
* from optical measurements:
*      "Les observations optiques peuvent se faire avec beaucoup plus de
* précision et de certitude que celles de la tempèrature et c'est ici un
* de ces cas où les faits d'un certain ordre peuvent être plus sûrement
* et plus exactement connus en les abordant d'une manière indirecte et
* par leurs conséquences, qu'en cherchant á les examiner eux-mêmes et
* indépendamment de leurs effets. Avec un théodolite ou une lunette de
* Rochon, on apprendra à connaitre les variations de la température de
* l'air, suivant la hauteur, beaucoup mieux qu'on ne pourrait le faire
* avec le thermomètre le plus irréprochable."
*      On p.36, he describes his method of measuring the "size" of the
* inferior mirage.
*      P.37: he comments on the "lack of sharpness of the apparent horizon.
* One sees a line which, most of the time, is not very sharp; it is a sort
* of serrated ridge, with mobile and oscillating summit, presenting
* elevations and depressions that move and change at every instant. One
* would say that waves of great size collide and clash on this crest.
* This lack of sharpness on the line of the horizon is the greatest
* obstacle to observations of the mirage."
*      Vol. V contains the years 1856 and 1857.  This is available at the
* HathiTrust website:
*      https://babel.hathitrust.org/cgi/pt?id=uc1.b3085877;view=1up;seq=44


L. Dufour
“Note sur les images par réfraction a la surface du Lac Léman,”
Bull. Soc. Vaud. Sc. Nat. 5, 217–220 (1858).

* Louis Dufour compares his measurements with Bravais's formula
* Presented at the 4 Feb. 1857 meeting.
* at HathiTrust:
*       https://babel.hathitrust.org/cgi/pt?id=uc1.b3085877;view=1up;seq=265


Charles-Th. Gaudin
“Phénomènes de mirages,”
Bull. Soc. Vaud. Sc. Nat. 6, 33–37 (1858).

* Charles-Th. Gaudin's mirage drawings
* This is a letter sent from Palermo in Feb. 1858. There is a nice plate,
* with numerous drawings of inferior mirages, some showing the
* contraction of the inverted image.
* No. 43.


Ch. Dufour
“De l'altération des images par reflexion sur la surface des eaux,”
Bull. Soc. Vaudoise Sci. Nat. 13, 303–309 (1874).

* Early observations of "REFLECTIONS" on water
* (has the diagram reproduced by Riccò (1888))
*      This may be the earliest calculation of the expected size of the
* shrunken image produced by reflection on a convex surface with the Earth's
* radius of curvature; the effect was already mentioned by Bravais (1853)
* for the inferior mirage. Dufour mentions the observation of the effect
* by "mon ami" Forel on a sunny afternoon; it is surely the inferior mirage
* and not the reflection on the water itself. In the numerical example,
* Dufour assumes the observer at Morges is 20 m above the water, and
* calculates a reduction factor of 3.5.
* [cf. Büsch, 1783/1800, for an early observation of this mirage.]
*      Reprinted in Arch. Sci. Phys. Nat. (Ser.2) 53, 131-137 (1875).
* See Whitmell's reprise of this in JBAA, 1905 (filed in GF file).


Ch. Dufour
“Preuve sensible de la rondeur de la Terre,”
l'Astronomie 5, 354–355 (1886).

* Charles DuFour describes the reflection clearly in l'Astronomie:
* ". . . les images ne se font pas sur un plan, mais sur une
* surface convexe , à cause de la rondeur de la Terre . . . ."
* Refers to "moe ami M. Forel" as having called his attention to it.
* This was *before* l'Astronomie merged with B.S.A.F.


F.-A. Forel
“Images réfléchies sur la nappe sphéroidale des eaux de lac Léman,”
C. R. 107, 650–651 (1888).

* Forel replies to Riccò's note in C.R. (see RICCO file)
* Note that he has the wrong volume for Riccò's note.
* "La seule erreur possible serait une confusion avec des faits de mirage
* dans le cas de réfractions anormales. Mais nos études sur ces
* derniers phénomènes nous ont assez bien fait connaître toutes les
* possibilités du mirage, pour que nous soyons assurés de distinguer avec
* certitude les deux indices d'apparitions; et cela d'autant mieux que, sur
* une nappe d'eau aussi bien limitée que notre lac, les conditions
* thermiques et hygrométriques sont assez simples pour que nous puissions,
* dans chaque circonstance, prévoir d'avance quel type de mirage nous
* devons avoir devant nous. Les images de réflexion ainsi déformées
* ne sont nettes et précises qu'en l'absence de toute espèce de mirage."


J.-L. Soret
“Sur divers phénomènes de mirage,”
Arch. Sci. Phys. Nat. 20, 302–304 (1888).

* Abstract on mirages -- probably DUCTING and FATA MORGANA
* With air much warmer (25 C) than water (12 C), he observed strong
* towering or Fata Morgana from a steamboat: "Les rives, réellement
* basses apparaissaient comme se terminant par des falaises élevées; mais
* ce phénomène présentait une grande variabilité d'un instant à
* l'autre."
* Cites Ch.Dufour (1854) for a DARK BAND in the image: ". . . en regardent
* une chaloupe . . . on voyait nettement les voiles supérieures, très
* blanches et d'un grand éclat; au-dessous les voiles inférieures
* paraissaient déformées, allongées dans le sens vertical, sombres et
* donnant l'impression de deux images confuses superposées."
* WHITE FOG or "smoke": "Mais l'apparence qui a le plus frappé M.Soret,
* parce que, à sa connaissance, elle n'a pas encore été signalée, est
* . . . on voyait du côté du golfe d'Anthy, comme des fumées blanches
* dont les bouffées juxtaposées se seraient rapidement transportées vers
* le sud-est, sous l'impulsion du vent." He connects this with the
* mirage, and suggests that the appearance of "le mirage ordinaire" when the
* water is colder than the air might be "rattache à l'état hygrométrique
* de l'air." (and mentions Forel in particular as having seen this.)
* Cited by Forel (below)
* Evidently part of the minutes of a meeting of Soc.Phys.Hist.Nat.Genève;
* the meeting must have been in July, as it is followed by the 2 Aug. one.


F.-A. Forel
Arch. Sci. Phys. Nat. 22, 278–279 (1889).

* Abstract on mirages
* Very insistent that the air can be up to 7° above the water and still
* have an inferior mirage, but with very compressed inverted image.
* Also: "Dans ce cas de mirages anormaux, l'image inférieure est souvent
* très fortement déprimée, tellement qu'elle apparaît plus brillante
* que l'objet réel." Which is nonsense.
* Cites Soret.
* Evidently part of the minutes of a meeting of Soc.Helv.Sci.Nat.


F.-A. Forel
“Mirages d'hiver sur le lac Léman,”
Bull. Soc. Vaud. 25, XII–XIII (1890).

* Meeting abstract on inferior mirages and WAVES on the apparent horizon
* THINNESS of the mirage layer measured: "Les mirages sont encore
* parfaitement développés à 10 centim., à 5 cm., 2 cm. au-dessus de la
* nappe des eaux; à 1 cm., M. Forel croit les avoir vus; à un ½ cm.,
* l'observation lui a échappé, le lac n'ayant par été assez calme pour
* le miroir ne fût pas mouillé par quelque vague à cette très petite
* distance du plan de l'eau."
* Perhaps the most interesting part: "M. Forel donne ensuite
* l'explication des dentelures des vagues à l'horizon en cas de mirage
* d'hiver. Ces dentelures sont à leur maximum de développement quand
* l'air est le plus calme: point n'est besoin que les vagues soient fortes
* ou aiguës; la vague de refoulement d'un bateau à vapeur donne peut-être
* la plus belle apparition du phénomène. . . . le rayon visuel, parti de
* la crête de la vague, est moins réfracté que celui du cercle de
* l'horizon et le sommet de la vague apparaît ainsi comme un point suspendu
* en l'air. Un plan de réflexion en dessous du plan de partage transforme
* l'image de ce point en un losange à grand axe vertical qui est
* l'apparition parfaite des dentelures en question." [cf. Ferguson, 1902]


F.-A. Forel
“L'intensité des mirages. . . ,”
Bull. Soc. Vaud. 26, IX–X (1891).

* Forel tries to estimate the strength of an inferior mirage with a ratio
* I don't understand. . . .
* He also remarks on the rapidity with which the surface layer assumes the
* water temperature, in the offshore flow (8 to 20 seconds).
* under "Procès-Verbaux: Communications Scientifiques"


F.-A. Forel
“Fata Morgana,”
Arch. Sci. Phys. Nat. 32, 295–296 (1894).

* Abstract on Fata Morgana
*      This is all about the striated zone -- maybe its first mention by Forel?
* Evidently part of the minutes of a meeting of Soc.Helv.Sci.Nat.


F.-A. Forel
Le Léman, tome second
(F.Rouge, Lausanne, 1895).

* Léman
* Limnological monograph in 3 volumes on Lake Geneva
* (republished by Slatkine Reprints, Genève, 1969)
* "Déformation de l'image réfléchie sur la surface sphéroïdale du lac.
* Images de Charles Dufour." (pp.509-511)
* "Réfractions normales et anormales dans l'air atmosphérique en contact
* avec le lac." (pp.514-559) (extensive mirage & Fata Morgana observations)
*      On p. 520 he has a drawing of the waves at the inferior-mirage
* apparent horizon; cf. Forel (1890), and Ferguson (1902).
*      On p. 526, he points out the lack of waves on the apparent reflecting
* surface of the inferior mirage; cf. Büsch (1800) & Abbott (1854).
*      P. 532: an account of inferior mirage over ice; cf. Greenler's photo.
*      Note his remarks on the concave appearance (p. 541) of the lake, in
* refractions over cold water; cf. Brandes (1806), Everett (1873), and
* Thompson (1916).      Forel notes the negative dip, and the recession
* of the apparent horizon. "La réfraction n'arrive cependant pas à
* éloigner indéfiniment le cercle de l'horizon. Par les plus belles
* réfractions du printemps, nous ne voyons pas la grève à vingt ou
* trente kilomètres de distance, et le corps d'une barque qui navigue
* dans ces régions éloignées reste masqué à notre vue, alors même
* que la nappe du lac nous semble concave et parait se relever jusqu'à
* la rive de la côte opposée."  (p. 541)      Furthermore (p. 542),
* "Les objets situés sur l'eau en dedans du cercle de l'horizon
* apparent sont déprime's. Le corps d'une barque ou d'un bateau est
* réduit en hauteur; souvent il ne parait plus qu'un trait horizontal,
* presque sans épaisseur."
*      Then comes the historical anecdote about the visibility of the
* château de Chillon in 1851, which drew Charles Dufour into the matter.
* This leads to the discussion of the Fata-morgana (pp. 543-544); notice
* that he says it is "Le phénomène le plus fréquent" of those seen
* over cold water.
*      The striated zone "est très remarquable et son aspect est
* caractéristique. Elle est limitée en bas par le plan du lac qui ferme
* sa ligne inférieure, en haut par une ligne plus ou moins bien dessinée,
* généralement horizontale." Its width is 2 to 5 "et même 10 minutes"
* of arc.
*      On p. 546, he twice remarks that the concave appearance of the lake
* is usual for these apparitions.
* [Note observation of CONCAVE surface.]
*      Pp. 551-553 describe the Fata-brumosa.
*      Notice that on pp. 561-565, he carefully examines the "lateral-mirage"
* story of Soret and Jurine. I fully agree with his conclusion.
*
* Now available from Google Books, at:
*
*            http://books.google.com/books?id=LMNZAAAAQAAJ
* or
*            https://books.google.com/books?id=LuMPhZFIhCAC
*


K. Hutter, I. P. Chubarenko, and Y. Wang
Physics of Lakes: Volume 3: Methods of Understanding Lakes as Components of the Geophysical Environment (Advances in Geophysical and Environmental Mechanics and Mathematics)
(Springer Science and Business Media, Cham, 2014).

* There is a photograph of Forel on p. 246 of the book at
* https://books.google.com/books?id=Nou4BAAAQBAJ&dq=%22Physics+of+Lakes
* with a brief biog. note, and account of his invention of "Limnology".
* authors: Kolumban Hutter, Irina P. Chubarenko, Yongqi Wang


F.-A. Forel
“Réfractions et mirages observés sur le Léman,”
C. R. 123, 161–162 (1896).

* Further details of Lake Geneva mirages and refraction over warm/cold water
* ". . . le fait encore inexpliqué du mirage sur eau froide , lequel
* se montre quand la température de l'air s'élève progressivement
* au-dessus de la température de l'eau. Le mirage sur eau froide a les
* mêmes caractères que le mirage des réfractions sur eau chaude, sauf
* que l'image inférieure n'est pas symétrique; elle est bien opposée à
* l'image réelle, mais elle est fort réduite dans ses dimensions
* verticales; souvent elle n'a pas le tiers de la hauteur de l'image
* réelle."
* "Je crois avoir constaté que l'apparition des palais de la fée Morgane
* n'a lieu dans toute sa beauté que lorsqu'une brise légère passe sur le
* lac, après une matinée de grand calme."
*      Perhaps his "mirage over cold water" is an inferior mirage in the
* residual layer, confined by a very low capping inversion?


F.-A. Forel
“Réfractions, mirages et Fata morgana sur le lac Léman,”
La Nature 25:1, No. 1228, 19–20 (1896-7).

* Forel's popular summary in La Nature
* He begins with a useful remark:
*      "Les réfractions et mirages sont d'apparition très fréquente,
* car il est rare que le sol ou l'eau soit de même température que
* l'air sous-jacent; on les reconnaît aisément quand on a appris à les
* observer. L'observation en est le plus facile sur une nappe liquide,
* celle-ci ne présentant pas les irrégularités d'une plaine terrestre;
* sur un lac, elle est plus instructive que sur la mer, car les distances
* de la côte opposée d'un lac sont connues, tandis que l'éloignement
* d'un navire qui passe au delà de l'horizon marin est indéterminé."
*      Accompanied by his standard drawings of the 4 types, showing their
* effects on sailboat sails: "Voici la suite des phénomènes qui se
* développent successivement sous nos yeux; pour en illustrer la narration,
* je représente dans une série de croquis A B C D les mêmes deux barques
* marchandes, aux voiles latines, qui sont censées naviguer sur le lac
* au delà de la ligne d'horizon apparent, disons à 10 kilomètres de
* distance."
*      NOTE: John Tyndall has a very similar drawing of miraged sails at
* Lake Geneva in his "Glaciers of the Alps", pp.31-34.
*      Finally: "La Fata morgana  se déplace dans le sens de la brise
* régnante; quand elle a parcouru tout le cercle de l'horizon, il ne reste
* plus que l'apparition des réfractions sur eau froide, caractérisées
* par l'éloignement du cercle de l'horizon, l'apparence de surface
* à concavité supérieure que prend la nappe sphéroïdale du lac,
* le soulèvement de l'horizon apparent, l'apparition d'objets très
* éloignés masqués en réalité par la rotondité de la terre, enfin la
* compression verticale des objets bas sur l'eau, à grande distance. En
* D, se trouvent les voiles latines des barques réduites à l'état de
* triangles tellement surbaissés qu'elles sont presque méconnaissables."
*      The issue is dated 12 Dec. 1896; but the reference is often cited as 1897.
* (available at Google Books, and at
* http://cnum.cnam.fr/CGI/fpage.cgi?4KY28.48/23/100/536/0/0 .)


F.-A. Forel
“Refractions et mirages: passage d'un type a l'autre sur Le Léman,”
Bull. Soc. vaud. sc. nat. 32, No. 122, 271–277 (1896).

* another summary of the mirage phenomena on Lake Geneva
* Good drawing of the peculiar horizon with inferior mirages, reprinted
* from his monograph.
*      Dated 1896 on p. 167; but sometimes cited as 1898.
* Cites the La Nature paper (above).


A. Delebecque
“Réfractions extraordinaires connues sous le nom de Fata morgana,”
La Nature 25:1, No. 1237, 163–164 (1897).

* Delebecque's reprinted comments on Forel's C.R. paper
* With a reproduction of an obviously faked "mirage" photograph!
* "Nous reproduisons dans la figure ci-jointe une photographie qui a été
* faite par MM. Picard, de la Chaux-de-Fonds, à la fin de 1896, et qui
* nous montre un effet de mirage obtenu avec une barque sur le lac Léman.
* On remarquera la dissemblance des voiles du vrai bateau et de son image."
* Indeed! (The sails are set quite differently in the two images of the
* boat.) And the perspective indicated by the waves on the water, and the
* mountains in the background, would put the "mirage" 10 degrees or so
* above the horizon. . . . (No inverted image appears in the "mirage"
* picture, by the way.)
*      Apart from the inserted sentences quoted above that describe the
* "mirage" picture, and the omission of the phrase "de l'Académie"
* from the first sentence, which would have given away the true source,
* the text is a word-for-word reprint of his 1896 C.R. note. Is this
* self-plagiarism, or entirely due to the editor? This reprint appears
* to be a comment on Forel's note in the 12 Dec. 1896 issue; but it was
* in fact a comment on Forel's note in C.R. 123, p. 161, (1896). Who was
* responsible for this deception?
* Thanks to Eric Frappa for calling my attention to this.
*      The issue is dated 13 Fév. 1897.


A. Delebecque
“Correspondance,”
La Nature 25:1, No. 1240, 222 (1897).

* The fake photo explained as a double exposure
* Here, André Delbecque disavows the inserted image, acknowledges that
* his text had already been published in C.R., and says:
*      "La photographie paraît, à première vue, représenter un effet de
* mirage sur le Léman ; mais ce mirage est imaginaire, et d'après ce que
* m'écrit mon ami le professeur Forel, très versé dans ces questions
* d'optique, la double image du bateau résulte simplement d'un accident
* photographique qui doit être produit pendant l'overture de l'obturateur."
*      The editor ("H. de P.") says:  "Par suite d’une transposition, on a
* effectivement placé dans le texte de M. A. Delebecque plusieurs lignes
* qui auraient dû venir en note à part et qui servaient d’explication à la
* photographie que nous a envoyée M. Picard, de la Chaux-de-fonds. Cette
* photographie, comme nous l’écrit de son côté M. Picard, et ainsi
* qu’il l’a reconnu après coup, résulte d’un double déclenchement
* de l’obturateur. D’où les deux images superposées. L’épreuve
* de M. Picard offre un curieux exemple de double impression et de faux
* mirage."
* Found on the Web (with some typos) at
*      http://www.gloubik.info/sciences/spip.php?article878#nb2
*      The issue is dated 6 Mar. 1897.


F.-A. Forel
[procès-verbaux, 2 déc.1896]
Bull. Soc. vaud. sc. nat. 33, No. 123, v (1897).

* Forel comments on Delebecque's double exposure, and his forthcoming
* work on changes in mirages


Ch. Dufour
[procès-verbaux, 20 juin]
Bull. Soc. vaud. sc. nat. 32, No. 122, xxxv–xxxvi (1896).

* Charles Dufour reports a Fata morgana seen at Morges
* "Le 2 juin 1896, vers les quatre heures du soir, à Morges, j'ai vu
* sur le lac un mirage supérieur fort remarquable. L'air était calme,
* et l'on voyait une belle Fata morgana sur tout le littoral d'Evian
* à Villeneuve." [Meeting of 20 juin 1896]
*      A steamboat about 10 km from Morges appeared to be only 3 or 4 km
* away. With a telescope he saw an inverted image above it, joined
* at the mainmast: "C'est exactement le phénomène observé par Vince
* à Ramagate [sic] . . . et celui observé par Scoresby dans les mers
* du Groenland." He was about 10m above the lake.


F.-A. Forel
[observations de mirages]
Bull. Soc. Vaud. 34, XII (1898).

* Another meeting abstract of mirage observations: "mirage parallèle"
* Cites Ch.Dufour (1854)


F.-A. Forel
“Détermination de la position de l'horizon apparent,”
Arch. Sci. Phys. Nat. , series 4, 8, 178–180 (1899).

* Preliminary report on VARIABLE DIP
*      "Pour mieux préciser les valeurs de ce déplacement de l'horizon
* apparent par rapport à l'horizon vrai, j'ai installé, dans une chambre
* au bord du lac, à Morges, sur un pilier en maçonnerie, une lunette
* astronomique dont j'ai établi l'axe à peu près suivant l'horizontale.
* J'ai déterminé l'angle formé par l'axe de ma lunette avec l'horizontale
* en visant le sommet d'une montagne (la Dent d'Oche), successivement la
* vision directe, puis la vision réfléchie dans un miroir d'eau; la
* moitié de l'angle ainsi obtenu me donne l'horizontale. . . .
*      "Enfin je vise l'horizon apparent et, avec le micromètre à fil
* d'araignée, je mesure la position de l'horizon du lac en secondes de
* degré."
*      [NOTE: This technique of measuring absolute altitudes by using a water
* surface as a horizontal mirror was actually invented by Mariotte, and
* published in his "Traitté du nivellement" (1672).]
*      In the 5 months from 25 Oct. 1898 to 31 March 1899, the range was from
* +476" to -272" or 12' 38" relative to the geometric horizon.
* "Le facteur le plus important est la stratification thermique, laquelle
* dépend essentiellement de la différence de température entre l'air et
* l'eau. J'apprécie celle-ci en mesurant avec le thermomètre la
* température de l'air qui entoure la lunette ta et celle de l'eau du
* lac, au rivage te ." He gives a table of group means for the middle of
* each degree difference from ta - te = -6.5 to +4.5 degrees.
* Séance du 5 avril, in the Seances de la Société Vaudoise.
*      Note that he cites p. 560 of his monograph, where earlier relative
* variations in the position of the horizon amounting to 14' were reported
* by using a method similar to Riccò's (whose work in 1889/1890 was not
* mentioned).
*      Title page says Archives des Sciences Physiques et Naturelles,
* Cent Quatrième Année, quatrième période, tome huitième, Genève
*      Available at the Biodiversity Heritage Library, at
*      NOTE: This text is identical to that published in Bull.SVNS 35,
* pages XXV-XXVI (in the procès-verbaux for the April 5 meeting),
* including the table of numerical values.
* https://www.biodiversitylibrary.org//bibliography/5919#/summary


F.-A. Forel
“Réfractions à la surface du lac Léman,”
Arch. Sci. Phys. Nat. , series 4, 8, 373–375 (1899).

* Brief account of the full series (see C.R. paper, below, for details)
* This is in the section "Société Helvétique des Sciences Naturelles"
* and appears under the heading of "Physique, Mathématiques et
* Astronomie" on p. 367, where Forel's subject is given as "L'horizon du
* lac."
* [Note that Ch.-Ed. Guillaume attended this session, giving 2 papers.]
*      Here it is "Une petite lunette astronomique établie sur un pilier
* de maçonnerie, dans un laboratoire à 2m5 au-dessus du lac . . . ."


F.-A. Forel
“Les variations de l'horizon apparent,”
C. R. 129, 272–274 (1899).

* VARIABLE DIP with Table of values seen from 2 to 3 m above the water
*      Now we have "une bonne lunette astronomique, établie sur un pilier de
* maçonnerie, . . . à 2m ou 3m au-dessus de la nappe du la, suivant la
* saison".
* "Les 607 observations valables dont je dispose, du 25 octobre 1898 au 30
* juin 1899, m'ont donné pour ha - hv les valeurs extrèmes +501" et -272",
* représentant une variation totale de 773", soit de près de 13' de
* degré."
* CALM AIR exaggerates effects:
* "L'erreur possible sur la position de l'horizon vrai, déduite de
* l'observation de l'horizon apparent, est plus grande quand l'air est calme
* que quand il est agité; . . . . L'erreur possible est plus forte quand la
* valeur ta - te est positive (quand l'air est plus chaud que l'eau) que
* quand elle est négative"
*      Mentions (without citing) "professeur E. Kayser, de Dantzig, et . . .
* lieutenant K. Koss, de la Pola ".
* O'C #36


F.-A. Forel
“La Fata-Morgana,”
C. R. 153, 1054–1056 (1911).

* FATA MORGANA paper in C.R.
* "En 1854, Charles Dufour a reconnu ce phénomène dans des apparitions
* que nous voyons chaque printemps sur notre Léman."
* ". . . la zone striée , mesure de 5 à 10 minutes de degré de
* hauteur. . . ."


F.-A. Forel
“La Fata-Morgana,”
Archives des sciences physiques et naturelles,Genève , series 4, 32, No. 12, 471–481 (15 Dec., 1911).

* Forel's full paper on FM
* This contains his most detailed exposition and description of the
* fata-morgana. He is very specific: it never appears before 1 or 2 in
* the afternoon, never after 5 or 6 pm. The eye must be a few meters
* above the surface of the lake: 2 or 4 meters is the optimum height.
*      See his 1899 papers for a little more detail about his telescope and
* the dip measurements that are mentioned here.
*      NOTE: in his references, the Roman numerals sometimes refer to the
* number instead of the volume of Bull. Soc. Vaud. Sc. Nat.; e.g., on
* p. 472, the citation of Ch. Dufour's 1854 paper is to No.32 [but should
* be No.34], but that for Forel's own note in 1896 is to Vol. 32. This
* mixup confused the translator of the present paper, Prof. C. G. Knott.


F. A. Forel
“The Fata Morgana,”
Proc. Roy. Soc. Edinburgh 32, 175–182 (1912).

* FATA MORGANA as transition between superior and inferior mirages:
* "I have seen the Fata Morgana . . . some four or five hundred times in all."
* "The best height would seem to be from two to four metres"
* (SEE ALSO Freiesleben, 1951, in DIP file)
*      NOTE: This seems to be a slightly abridged translation into English
* of the previous item. The translation is rather insipid, and contains
* some errors in the references (e.g., the wrong page is given for Charles
* Dufour's 1854 paper on the mirages; it should be p. 129 in No.34, not
* p. 271 in No.32.)


[editorial summary]
“Fata Morgana,”
Q. J. Roy. Met. Soc. 38, 219 (1912).

* a summary of Forel's Edinburgh presentation -- cf. Abbe's 1896 MWR note
* Cited by Napier Shaw (1930, 1942).


H. S. Hogg
“Out of old books,”
JRASC 59, 273–278 (1965).

* Helen Sawyer Hogg's account of Forel's book
* Available from ADS.


I. Halliday
“An observation of the `Fata Morganá in the Canadian winter,”
JRASC 61, 74–76 (1967).

* Ian Halliday's mirage observation
* He cites Hogg and Forel, so it's filed here instead of with mirages.
* The mirage was seen over a frozen lake covered with snow, on a
* "comparatively mild day". Air was clearly warmer than snow.
* Available from ADS.



*** FLOOR FILE ***

C. Floor
“Luchtspiegelingen boven de Waddenzee,”
Zenit 4, 305–306 (1977).

*
* Floor's first mirage paper
* Good photographs of inferior mirages taken with a Celestron 5 (1250mm);
* Floor comments that the altitude of the phenomenon is so small that
* pictures taken with ordinary lenses show little or nothing. Attention
* is drawn to the invisibility of the deck of the fishing boat in Fig. 2,
* and to the effects of turbulence: "In a brief exposure one sees these
* objects as if through a glass plate of inferior quality."


C. Floor
“Luchtspiegelingen boven warme oppervlakken,”
Zenit 6, 254–257 (1979).

* Floor's second mirage paper
* A good, standard presentation of inferior-mirage theory for a flat Earth
* There appear to be good photographs illustrating the effects, but they
* are useless on my photocopy.


C. Floor
“Onregelmatige luchtspiegelingen,”
Zenit 8, 25–27 (1981).

* Floor's third mirage paper
* Irregular and asymmetrical mirages.


C. Floor
“De Ω-vorm van de laagstaande zon,”
Zenit 8, 70–73 (Feb., 1981).

* (I do not yet have a good copy of the photos, which are critical here.)


C. Floor
“The Ω-shape of the low sun,”
Weather 36, 78–81 (1981).


C. Floor
“Een gerimpeld beeld van de zon,”
Zenit 8, 466–469 (1981).

* A curious paper, comparing RIPPLES on water with those on inversions
* This is essentially an exposition of Fraser's (1975) "lifted-inversion"
* mechanism. But there are no references, and no mention of Fraser.
* Perhaps Fraser's idea had percolated around and reached Floor
* indirectly? There is no quantitative estimate of things as in Fraser's
* paper; this is all qualitative. He seems aware of White's (1979)
* point about oblique waves; yet he dismisses this notion and thinks that
* foreshortening near the horizon will make it all look as if the waves
* were seen face-on.
* Furthermore, though there is an extensive discussion in the last two
* paragraphs of the green rim, and green corners on the "tied-off" parts
* at the top of the Sun, there is no mention of green flashes.


C. Floor
“The effect of waves on the image of the low sun and on a reflection in water,”
Weather 37, 148–151 (1982).

* An English translation of parts of the previous note.
* Figs. 2 and 3 here are evidently the same photographs as Fig. 1 in the
* previous paper. Now Fraser is cited; perhaps this is due to the "Advice
* of Miss S. McNab"? The peculiar word "uitstulpingen" from the former
* paper is rendered here in English as "protrusions".


C. Floor
“Kunstmatige vervormingen van de laagstaande zon,”
Zenit 9, 230–231 (1982).

* Cites Feibelman's photos around 1960; but no mention of GF
* The "artificial distortion" is mainly the effect of jet-engine exhaust,
* though some smokestack effects are also shown.
* [Probably belongs in the "distorted sunsets" file.]
* May issue


C. Floor
“The setting sun,”
Phys. Educ. 17, 174–178 (1982).

* repeats Fraser's (and his own) canard about waves


C. Floor
“Optical phenomena and optical illusions near lighthouses,”
Z. Meteor. 32, 229–233 (1982).


C. Floor
“Inferior mirages in the Netherlands,”
Z. Meteor. 33, 60–63 (1983).

* Fig. 5 nicely shows the difference between a miraged ship beyond the
* horizon, and another on the near side of the horizon.


C. Floor
“Investigating mirages with an astronomical telescope,”
Phys. Educ. 18, 80–82 (1983).

* reprints 3 figures from his 1981 Zenit paper
* He does not realize that mirages are astigmatic, but does notice the
* problem for photography: ". . . the depth of field . . . does not always
* allow one to get both the optical horizon and the object in focus."


C. Floor
“Green Flash during a partial eclipse,”
Z. Meteor. 34, 366–367 (1984).

* cf. Touchet, 1925



*** MIRAGES IN FOLKLORE FILE (see also LEHN file) ***

A. Plumptre
Narrative of a Residence in Ireland during the Summer of 1814, and that of 1815
(Henry Colburn, London, 1817), pp. 123–124.

*
* Hearsay accounts of IRISH FATA MORGANA stories (cf. Beauford, 1802)
* Near Rathlin she encounters "a clergyman of the place, by name Conolly,"
* with whom "I had a great deal of conversation on that extraordinary
* catoptric phænomenon the Fata Morgana , which is occasionally seen
* on this coast as well as the Straits of Reggio, to which it is so
* often compared. He said that he could not boast himself of ever having
* seen this beautiful delusion, but he had talked with persons of great
* credibility by whom it had been witnessed." Yeah, right. So we get
* stories about the usual Fata Morgana effects ("exactly resembling
* castles, ruins, tall spires, groves of trees, rocks . . . ") as well as
* "an enchanted island seen annually floating along the coast of Antrim,
* of which it is said a sod thrown on it from the terra-firma would fix it
* for ever. Attempts have been made at various times to throw this sod,
* but hitherto all have proved abortive. At Rathlin a belief prevails
* that a green island rises every seventh year out of the sea between their
* island and the promontory of Bengore. The inhabitants assert that many
* of them have distinctly seen it, and that it is crowded with people
* selling yarn and engaged in various other occupations common to a fair."


M. Ross
“Anchors in a three-decker world,”
Folklore 109, 64–75 (1998).

* MICEAL ROSS notices that some Irish folklore is mirage-connected.
* Lots of potentially useful references here, going back to 748 AD.



*** LEHN FILE -- Novaya Zemlya, large refraction, and polar mirage phenomena ***

Le Gentil
Voyage dans les Mers de l'Inde, Tome premier
(Imp.Royale, Paris, 1779).

* -- see also Lehn & Rees (1990), and van der Werf (2017), in mirage file.
*
* NOTE: many of Lehn's papers are available at:
* https://home.cc.umanitoba.ca/~lehn/Papers.htm
*
* NOVAYA ZEMLYA EFFECT
*
*       for the original, see the 1876 edition of de Veer's report, below
*
* See especially Bilberg (1697) in General Refraction file;
* see also MacMillan (1953), filed with MIRAGES
* see also Kramp (1799) in General Refraction file
* see also Borchgrevink in Mirage file.
*
* LE GENTIL argues from his observations in India
*
* Le Gentil was completely incredulous about the Dutch observations.
* His denunciation of them is concentrated in pp. 416-426; but there are
* little pot-shots at them starting on p. 395:
*      ". . .  elle est tout-à-fait contraire à ce qu'on sait de la
* réfraction horizontale; car quoiqu'elle varie beaucoup, on ne peut pas
* se figurer qu'elle soit si différente près du pôle de ce qu'elle est
* dans les autres climats.
*      "Plusiers célèbres Auteurs ont cherché à expliquer ce singulier
* phénomène vu par les Hollandois, entr'autres Képler &
* Jacques-Dominique Cassini; ce dernier est celui de tous qui en donne la
* raison la plus vraisemblable, en supposant que ce que les Hollandois ont
* vu étoit une espèce de parhélie: on peut voir sur cela le Volume de
* l'Accadémie, année 1700 .
*      "Pour moi je pense avec Scotto , que les Hollandois se sont
* trompés; & quoiqu'ils cherchent à prévenir l'objection qu'ils
* prévoyoient qu'on ne manqueroit pas de leur faire à leur retour, sur
* leur erreur, & qu'ils aient en conséquence écrit fort en détail leur
* observation. . . ." (p. 396)
*       This gets mentioned again on p. 398, where he asserts that his
* observations were made at about the same height above the sea as theirs,
* as if this were all that was involved. Then on p. 407 he brings up
* the seasonal effects (whereby he finds the horizon high in winter), and,
* extrapolating to higher latitudes, says:
*      ". . .  un faux horizon au-dessus de celui de la mer; d'où j'ai conclu
* que loin de voir anticiper le lever du Soleil dans la nouvelle Zemble,
* on devroit au contraire le voir retarder. Cette observation m'a rendu
* très-suspecte celle des Hollandois dans ls nouvelle Zemble."
*      On pp. 416-421 he quotes a French translation of the Dutch report;
* then: "Voici mes remarques.
*      "Il me paroît, 1.° que ce Journal a été fait d'idée, & qu'il
* n'a point été écrit jour par jour."
* He goes on at great length to refute the conjunction of Jupiter and
* the Moon, etc., etc. But the best part (pp. 424-425) is the argument
* that they were mistaken about the date because the polar bears didn't
* show up for another 2 weeks after the Sun! He concludes (p. 426):
*      "Bareints & ses compagnons d'infortune, ayant vu qu'ils s'étoient
* trompés, auront vraisemblement laissé subsister leur erreur, &
* d'après elle, ils auront bâti un roman : Bareints, dis-je, aura voulu
* donner aux Physiciens matière à exercer leur genie.
*      "Mon opinion donc, est que le prodige que les Hollandois disent
* avoir vu dans la nouvelle Zemble, doit aller à côté de celui de la
* dent d'or, & mieux encore, avec celui du lever & du coucher
* extraordinaires du Soleil observé par les anciens Egyptiens, &
* rapporté par Hérodote."


D. Thompson
in David Thompson's Narrative of His Explorations in Western America, 1784-1812. , J. B. Tyrrell, ed.
(The Champlain Society, Toronto, 1916).

* DAVID THOMPSON'S NARRATIVE
* (not a Novaya Zemlya observation, but strong refraction in polar regions)
* David Thompson wrote this between 1846 and 1851; but it was not edited
* and published until 1916. [Placed here, in order of composition.]
*      "The first and most changeable Mirage is seen in the latter part of
* February and the month of March, the weather clear, the wind calm, or
* light; the Thermometer from ten above to twelve degrees below zero,
* the time about ten in the morning. On one occasion, going to an Isle
* where I had two traps for Foxes, when about one mile distant, the ice
* between me and the Isle appeared of a concave form, which, if I entered,
* I should slide into it's hollow, sensible of the illusion, it had the
* power to perplex me. I found my snow shoes, on a level, and advanced
* slowly, as afraid to slide into it; in about ten minutes this mirage
* ceased, the ice became [distinct] and showed a level surface, and with
* confidence I walked to my traps, in one of which I found a red Fox;
* this sort of Mirage is not frequent. That most common elevates and
* depresses objects, and sometimes makes them appear to change places :
* In the latter end of February at the Reed Lake, at it's west end, a
* Mirage took place in one of it's boldest forms; About three miles from
* me was the extreme shore of the Bay; the Lake was near three miles in
* width, in which was a steep Isle of rock, and another of tall Pines;
* on the other side a bold Point of steep rock. The Mirage began slowly
* to elevate all objects, then gently to lower them, until the Isles,
* and the Point appeared like black spots on the ice, and no higher than
* it's surface; the above bold Bay Shore, was a dark black curved line
* on the ice; in the time of three minutes, they all arose to their
* former height, and became elevated to twice their height, beyond the
* Bay, the rising grounds, distant eight miles, with all their woods
* appeared, and remained somewhat steady for a few minutes; the Isles
* and Point again disappeared; the Bay Shore with the distant Forests,
* came rolling forward, with an undulating motion, as if in a dance, the
* distant Forests became so near to me I could see their branches, then
* with the same motion retired to half distance; the Bay shore could not
* be distinguished, it was blended with the distant land; thus advancing
* and retiring with different elevations for about fifteen minutes, when
* the distant Forests vanished, the Isles took their place and the Lake
* shores their form; the whole wild scenery was a powerful illusion, too
* fleeting and changeful for any pencil. This was one of the clearest and
* most distinct Mirages I had ever seen. There can be no doubt it is the
* effect of a cause which, perhaps, was waves of the atmosphere loaded with
* vapours, though not perceptible to the eye, between the beholder and the
* objects on which the mirage acts, with the Sun in a certain position,
* when the objects were seen on the ridge of the wave, it gave them their
* elevation; when in the hollow of the wave, their greatest depression;
* and viewed obliquely to the direction of the wave, the objects appeared
* to change places. There may be a better theory to account for the Mirage.
*      "While the Mirage is in full action, the scenery is so clear and vivid,
* the illusion so strong, as to perplex the Hunter and the Traveller;
* it appears more like the power of magic, than the play of nature."
* (pp.120-121)
* [Note observation of CONCAVE surface.]
*      The concave appearance is also described by Forel (1895), p. 541.
* Available at Google Books. The typesetting in this book is oddly
* justified, with few words broken at the right margin, and unsettling
* padding before semicolons in some lines.
*      Thanks to Mila Zinkova for pointing this out!


W. Coats
The Geography of Hudson's Bay
(The Hakluyt Society, London, 1852), p. 132.

* Captain Middleton's sunsets delayed by 8 minutes
* "I also find the effects of cold occasion a great error in the time of
* the sun's rising and setting, making the refraction of the atmosphere much
* greater than in Europe.
* "I have observed the apparent time of the sun's central rising and
* setting for five or six months in the winter with a good level three or
* four days a week. I had a good second watch of Mr. George Graham's for
* the time; having computed the sun's true place, thence his declination,
* at the time when such appearance happened, and found his apparent rising
* sooner than the true time by near eight minutes, and his setting
* apparently so much later, so that the apparent day is longer than the
* real or astronomical day by almost sixteen minutes, and consequently
* the apparent night is so much shorter than the true night, making the
* horizontal refraction more than a degree.
* "N.B. I used a level, by reason these observations were taken upon a
* place forty feet above the surface of the ocean, and about seven or eight
* feet above all the land in the way of the sun's rising and setting in the
* middle of winter."
* A similar extract appears in Isham's Observations and Notes 1743-1749.
* This is No. XI of the Hakluyt Society's First Series.
* Full title:
* The Geography of Hudson's Bay: being the remarks of Captain W. Coats, in
* many voyages to that locality, between the years 1727 and 1751. With an
* Appendix, containing extracts from the log of Capt. Middleton on his
* voyage for the discovery of the North-West Passage, in H.M.S. "Furnace",
* in 1741-2. Edited by John Barrow, Esq., F.R.S., F.S.A.
* We have the 1964 reprint by Burt Franklin, New York.


G. K. Bouris
“Nachrichten von der Sternwarte Athen's,”
A. N. 51, 49–56 (1859).

* ABNORMALLY LARGE REFRACTION
* ". . . ganze Reihen von regelmässig am Meridiankreise beobachteten Sterne,
* die für Athen bis  v i e r      G r a d e      u n t e r      d e m
* H o r i z o n t e culminiren, wie ξ Lupi, ε1 Arae,
* ε2 Arae, β Arae, Capella U.C. und Kanopus, welcher letzte
* aber nur der Nachhülfe der Horizontalrefraction bedarf, um bei seiner
* Culmination den Athenienser Meeres-Horizont etwa zu tangieren."


Gerrit de Veer
The Three Voyages of William Barents to the Arctic Regions (1594, 1595, and 1596)
(The Hakluyt Society, London, 1876).

* The prototypical display seen by Barents's men at Novaya Zemlya on
* 24 Jan. 1597.
* There is much discussion in Charles T. Beke's introduction to the first
* (1853) edition (printed here in the second edition on pp. cxliv - clvi),
* showing that de Veer's observations are reliable. He concludes that
* "We have therefore no alternative but to receive the facts recorded by
* de Veer as substantially true, and to believe that owing to the peculiar
* condition of the atmosphere, there existed an extraordinary refraction,
* not merely on the 25th of January, but continuously during fourteen days
* afterwards, at first amounting to nearly four degrees, but gradually
* decreasing to about one degree and a half."
* . . . "The problem is a curious, and, with our still insufficient
* knowledge of the laws of atmospheric refraction in high latitudes, a
* difficult one. Nevertheless we may confidently rely on the result being
* such as to establish the entire veracity of our Dutch historian."
* This is No.54 of the first series of works issued by the Hakluyt Society.
* First edition edited by Charles T. Beke, 1854;
* Second edition, with an introduction by Lieutenant Koolemans Beynen,
* (Royal Netherlands Navy)
* We have the 1964 reprint of the 1876 2nd Ed., by Burt Franklin, New York.


G. F. Wright and W. Upham
Greenland Icefields and Life in the North Atlantic
(D.Appleton, New York, 1896), p. 272.

* Strong refraction causes SAUCER-shaped appearance (cf. Lehn, 1975)
* "Through an optical illusion, dependent on the mirage of the ice
* horizon, it appeared to us as if we were proceeding on the bottom of a
* shallow, saucer-shaped cavity. It was thus impossible to decide whether
* we walked up or down hill, which could only be decided by the heaviness of
* the sledges in the harness . . . ."
* [Note observation of CONCAVE surface.]


F. Nansen
Farthest North
(Harper, New York, 1897).

* NANSEN
* "The mirage was at first like a flattened-out glowing red streak of fire
* on the horizon; later there were two streaks, one above the other, with a
* dark space between; and from the main-top I could see four, or even five,
* such horizontal lines directly over one another, and all of equal length;
* as if one could only imagine a square dull-red sun with horizontal dark
* streaks across it. An astronomical observation we took in the afternoon
* showed that the sun must in reality have been 2° 22' below the horizon
* at noon; we cannot expect to see its disk above the ice before Tuesday at
* the earliest; it depends on the refraction, which is very strong in this
* cold air." (pp.394-395)
* NICE DRAWING of this, p. 394.
* O'C #96


F. Nansen
In Nacht und Eis
(Brockhaus, Leipzig, 1897).

* It turns out we have the *German* edition in our library:
* Here the drawing is on p.316, and the German text reads:
* "Die Luftspiegelung war anfänglich wie ein abgeplatteter glühend
* rother Feuerstreifen am Horizont; später wurden zwei Feuerstreifen
* daraus, einer über dem andern, mit einem dunklen Raume dazwischen. Vom
* Großmaste aus sah ich vier oder gar fünf solcher Horizontallinien
* übereinander und alle von derselben Länge, ungefähr wie man sich eine
* mattrothe viereckige Sonne mit dunkeln Horizontalstreifen darauf
* vorstellen könnte."
* "Eine astronomische Beobachtung, die wir nachmittags anstellten, bewies
* uns, daß die Sonne in Wirklichkeit um Mittag 2° 22' unter dem
* Horizont gestanden haben mußte. Wir können nicht erwarten, ihre Scheibe
* vor Dienstag über dem Eise zu sehen; es hängt mit der Strahlenbrechung
* zusammen, die in dieser kalten Luft sehr stark ist." (pp.315-316)
* Here the drawing appears on p. 316, and seems better reproduced than in
* the English edition. The date of the observation was 16.Jan., 1894.


P.-L. Mercanton
“Quelques cas historiques de réfraction atmosphérique excessive,”
Arch. Sci. Phys. Nat. , series 5, 2, 513–515 (1920).

* Summaries of 4 cases, three of them near 2.3 degrees
* Note: I have only 2 of the 4 cases here in this bibliography.
*      Also note his use of the rare term "horizon géodésique".
* He seems to use it to mean the astronomical horizon, rather than the
* geometric one, with dip but not refraction taken into account.
*      cf. Mercanton's note on refraction phenomena in Dec. 1920.
* in Compte rendu des séances de la Société suisse de géophysique,
* météorologie et astronomie (G.M.A.), assemblée générale
* à Neuchâtel, le 31 août 1920
*      This appeared in the November-December issue.


W. Cornelis
“Het Nova-Zembla-verschijnsel,”
De Zee 46, 194–201 (1924).

* Cornelis names the "Novaya-Zemlya phenomenon":
* "That such reports are extremely rare I think must in the first place be
* ascribed to the modesty of the navigators. If they make an observation
* that gives strange results, they are inclined to think first of an error
* in their reckoning, and e.g. Shackleton's navigating officer became a
* laughing-stock (p.49). Likewise, Jacob van Heemskerck had to put up with
* being simply not trusted in the knowledge of navigation, because of his
* former teacher." (p.199) [cf. Koss's footnote!]
* "In case my explanation is regarded as acceptable, the obvious question
* is: `How is it possible that 300 years had to pass before an explanation
* was given?'
*      "During more than two centuries, meteorology still became hardly
* recognized as science; then, when the study became caught up in
* knowledge, dedication, etc., we got that period, which still continues,
* of excessive specialization in the study of the sciences. With the
* division into all kinds of compartments and pigeon-holes, refraction has
* become lost in the crowd. The meteorologists leave the teaching to the
* astronomers, but these have by the nature of things an abhorrence of
* everything close to the ground, and only meddle with refraction when it
* has an inappreciable value. The meteorologists also are somewhat drawn
* away from the so-called terrestrial refraction, because it is consecrated
* by the compartmentalization to the area of geodesy, while the geodesists
* have not yet extended their activities to the polar seas. That the problem
* discussed has never before been taken in hand, I think must be ascribed to
* the far too complete specialization." (pp.200-201)
*      Thanks to Denis Khotimsky for useful discussion of this paper!


W. Cornelis
“Het Nova-Zembla-verschijnsel ook buiten de Poolstreken?,”
De Zee 46, 858–861 (1924).

* Cornelis's last paper (note his obituary on the preceding page)
* He argues that large horizontal refraction may occur in lower latitudes,
* but would go unnoticed, as "With an abnormally large refraction the
* Sun would only rise a few minutes too soon or set too late, and who
* would notice such a thing? One looks at the Sun then to enjoy the
* phenomenon, to see the green flash or surely to measure the dip of the
* horizon. Only in the last case could the result raise the suspicion of
* an abnormal refraction, but one would sooner think of having made an error,
* if the measurement were in obvious conflict with later azimuths." [cf.
* Koss & Thun-Hohenstein, 1901.]
* He suggests an interesting possible mechanism: if the wind moves faster
* over the wave crests than over the valleys, there should be a pressure
* and hence a density difference between them, thus causing some refraction
* effects. (I doubt that this can be appreciable quantitatively, though.)
* He then supposes that the resulting density gradients at the wave crests
* could produce a large horizontal refraction at sea.
* kindly supplied by C. de Jager!


W. H. Hobbs
“Conditions of exceptional visibility within high latitudes, particularly as a result of superior mirage,”
Ann. Assoc. Amer. Geogr. 27, 229–240 (1937).

* more papers by William Herbert HOBBS (see also "Mirage" file)
* (These are here as they were cited by Stefansson, below)
* Another review of the geographical implications of mirages;
* cf. his 1933 paper in Geografiska Ann. It cites some of his papers
* since then. This one is cited by Stefansson (below).
* Hobbs draws a useful distinction between "high" and "low" superior
* mirages (which he thinks are due to high and low inversions,
* respectively.) He remarks that "the object can be seen only from within
* a very limited area", because "Obviously at points nearer the object the
* curvature of the rays would not be sufficient to bring them down to the
* earth." (p. 232) -- cf. Lehn & Legal, below!
*      FALSE HORIZONS and TRUNCATION of images:
* "It is characteristic of the high superior mirage, that above 1000
* meters, that there is usually a band which separates the raised image from
* the true horizon. In the case of the lower type, that near 200 meters, it
* may be the top of the object which is truncated in the image (Fig. 2)."
* At the end, he says that the examples given "do not, of course, by any
* means exhaust the many varieties of mirage which are peculiar to those
* regions. . . ."


W. H. Hobbs
“A remarkable example of polar mirage,”
Science 90, 513–514 (1939).

* Another example of long-distance vision, updating the 1937 paper
* ". . . the air was calm and the sea smooth."
* "The Snaefells Jökull (4,715 feet) and other landmarks well known to
* the captain and the mate were seen as though at a distance of twenty-five
* or thirty nautical miles, though the position of the schooner showed that
* these features were actually at a distance of 335 to 350 statute miles."
* Here again is a "snow-covered summit" (cf. Korzenewsky, 1923).
* Hobbs again supposes that inversions of a few degrees "at elevations in
* excess of a thousand meters" can cause the mirages.


V. Stefansson
Ultima Thule: Further Mysteries of the Arctic
(Macmillan, New York, 1940), pp. 50–52.

* VILHJALMUR STEFANSSON proposes island-hopping via mirages
* Cites Hobbs in AAG (1937) and Science (1939)


E. E. Rich and A. M. Johnson
Isham's Observations and Notes, 1743-1749
(The Champlain Society, Toronto, 1949), p. 73.

* Captain Middleton's EIGHT MINUTES again
* All in very antiquated spelling: ". . . making the Horizentall Refractions
* more than a Degree, and as the Refractions occation's an Error, in the
* time of the sun's Rising and Setting, so itt Likewise Vitiates the
* Amplitude; and this must be observ'd by marriners or they will never gaine
* the Declination of the magnitic Needle with any Certainty. . . ."
* This is in the Publications of the Champlain Society, Hudson's Bay
* Series, XII. Full title:
* James Isham's observations on Hudson's Bay, 1743, and notes and
* observations on a book entitled
* A Voyage to Hudson's Bay in the Dobbs Galley , 1749
* Edited with an introduction by E. E. Rich, M.A., Fellow of St, Catharine's
* College, Cambridge
* Assisted by A.M.Johnson, Archivist, Hudson's Bay Company
* with a joint letter from the chairman of the Champlain Society and the
* chairman of the Hudson's Bay Record Society


S. W. Visser
“The Novaya-Zemlya phenomenon,”
Proc. Koningl. Nederlandse Akad. Wet., Ser. B, Phys. Sci. 59, 375–385 (1956).

* NOVAYA ZEMLYA effect (he seems unaware of Cornelis's papers above)
* "The Novaya-Zemlya phenomenon is caused by repeated total reflection at
* the upper boundary of a ground inversion. . . . The conditions are most
* favorable in the arctics and the phenomenon must be confined to the polar
* regions."
* O'C #147


S. W. Visser
“Het Nova-Zembla-verschijnsel,”
Hemel en Dampkring 55, 74–77 (1957).

* A popular follow-up to Visser's technical paper, above
* Here he also reproduces Kepler's diagram, as well as explaining it
* quantitatively.
* Thanks to Albert Jansen for pointing this out!


V. Fuchs and E. Hillary
The Crossing of Antarctica: the Commonwealth Trans-Antarctic Expedition 1955-1958
(Little, Brown and Co., Boston, 1958), p. 130.

* HORIZONTAL RED RAY accompanies the refracted Sun
* "Then a fraction of the sun's disc appeared again, flickered and
* disappeared. For some time it came and went. the greatest elevation
* revealing about one tenth of the orb. Sometimes as it reappeared a
* red flash seemed to shoot out and pulsate along the horizon. This was an
* exciting moment, not only because the sun had come back to us, but because
* it had returned by refraction four days earlier than expected." (Aug.14)
* This book was simultaneously published by Cassell, London.
* Thanks to Siebren van der Werf for this reference!


E. Shackleton
South -- The Story of Shackleton's Last Expedition
(Macmillan, New York, 1962).

* Sir Ernest SHACKLETON's observations
* ". . . refraction, which amounted to 2° 37' at 1.20 p.m." (p.49)
* "Thin, wavering black lines close to the northern horizon were probably
* distant leads refracted into the sky." (p.54)
* NEGATIVE DIP:
* "Refraction generally results in too big an altitude when observing the
* sun for position, but to-day the horizon is thrown up so much that the
* altitude is about 12' too small." (p.64)
* [Note observation of CONCAVE surface.]
*      NOTE: This book has been through many editions; the one cited is what
* I have seen. Earlier Macmillan editions were copyrighted 1947 and 1920.
* There were also 1919 and 1922 editions published by Heinemann in London.
* Thanks to Siebren van der Werf for pointing out the 1920 edition!


W. H. Lehn and H. L. Sawatzky
“Image transmission under Arctic mirage conditions,”
Polarforschung 45, 120–128 (1975).

* Crude mirage calculations; many a re-invented wheel here.
* They start with the flat-Earth model and fudge in the curvature, instead
* of using the exact relations.
* ". . . the arctic mirage is fundamentally distinct from the fata morgana
* or desert mirage . . . ." (p. 120) [but the German version of the abstract
* translates "arctic mirage" as "arktische Fata Morgana"!]
* ". . . leaving the viewer with the distinct impression that the earth's
* surface is saucer-shaped." (p. 127) [cf. Wright & Upham, 1896]
* [Note observation of CONCAVE surface.]
* Stefansson's book is cited.


H. L. Sawatzky and W. H. Lehn
“The Arctic mirage and the early North Atlantic,”
Science 192, 1300–1305 (1976).

* The first hillingar and hafgerdingar paper
* hillingar      = concave surface;  hafgerdingar  = miraged surface


W. Lehn, H. L. Sawatzky, and I. Schroeder
“Lore, logic & the Arctic mirage,”
Scandinavian Review 66, no. 2, 36–41 (June, 1978).

* Popular account of the previous work, ``assembled for Scandinavian
* Review by Irmgard Schroeder, based on previous work by Lehn and
* Sawatzky.'' It contains the controversial assertion:
* "The first adequate analysis of atmospheric refraction was published in
* 1917." Via e-mail, Lehn tells me this refers to Nölke's paper in Phys.Z.


W. H. Lehn
“The Novaya Zemlya effect: an arctic mirage,”
J. O. S. A. 69, 776–781 (1979).

* Lehn discusses the hillingar and hafgerdingar again, with the
* Novaya Zemlya effect.
* hillingar      = concave surface;  hafgerdingar  = miraged surface
* He attributes the darkness of Wegener's strip to "atmospheric absorption".
* He mentions the phase shift, but does not attribute it (or the dark
* strip) to Wegener, citing only Wegener's 1918 paper. Interestingly,
* he says the strip in Wegener's example is "blank".
* Lehn models the duct as uniform, with an abrupt (discontinuous) end;
* he admits the temperature profile is not uniquely determined.


W. H. Lehn and B. A. German
“Novaya Zemlya effect: analysis of an observation,”
Appl. Opt. 20, 2043–2047 (1981).

* NOVAYA ZEMLYA EFFECT; SUNSET PICTURES


W. H. Lehn and I. Schroeder
“The Norse merman as an optical phenomenon,”
Nature 289, No. 5796, 362–366 (Jan. 29, 1981).

* Lehn & Schroeder's "merman" mirage paper in "Nature"
* Whether you believe the "merman" explanation or not, this contains a
* useful mirage photograph (their Fig. 5) taken 2 May over Lake Winnipeg
* due to a very low-lying inversion (about 2 m above the icy lake).
* "Such conditions occur almost every spring on Lake Winnipeg."


W. H. Lehn
“Inversion of superior mirage data to compute temperature profiles,”
JOSA 73, No. 12, 1622–1625 (1983).

* Lehn inverts a superior mirage of a hill 20 km away
*      The treatment is very straightforward, working up from the bottom
* of the image. But it is restricted to rays with a single vertex. All
* the ray tracing is done in closed form, with parabolic rays.
*      This properly belongs in the regular mirage file, but is kept here.


E. E. Gossard and R. G. Strauch
Radar Observations of Clear Air and Clouds
(Elsevier, Amsterdam, 1983), p. 40.

* DARK STRIP IN SUPERIOR MIRAGE OF SUBMARINE


W. H. Lehn and W. Friesen
“Simulation of mirages,”
Appl. Opt. 31, 1267–1273 (1992).

* Lehn & Friesen re-confirm the brightness theorem
* They cite, but oddly, do not refute, the Fraser & Mach paper.


W. H. Lehn and T. L. Legal
“Long-range superior mirages,”
Appl. Opt. 37, 1489–1494 (1998).

* Lehn's "long-range" mirage paper
* This properly belongs in the regular mirage file, but is kept here.


W. H. Lehn
“Skerrylike mirages and the discovery of Greenland,”
Appl. Opt. 39, 3612–3619 (2000).

* LOOMING and MIRAGES between Greenland and Iceland
* Footnote 29 gives the dictionary meaning of hillingar as "looming".


S. Y. van der Werf, G. P. Können, and W. H. Lehn
“Novaya Zemlya effect and sunsets,”
Appl. Opt. 42, 367–378 (2003).

* Modelling of the Novaya Zemlya effect and some mirages
* Unfortunately the temperature profiles used are quite non-physical,
* so their inferior mirage contains a spurious 3rd image (cf. laminar
* sublayer in mural mirages -- this could be used as an example). Also,
* they use a quasi-isothermal atmosphere (using the height-mean temperature
* to find an effective scale height) instead of a proper polytropic model
* to calculate densities. So the results are really only qualitative
* and not very accurate. However, the leakiness of the duct required to
* produce the effect is demonstrated.
* And there is a good discussion of the ray curvature. Green flashes are
* demonstrated; and a new TERMINOLOGY for these mirages is introduced.
* Nice treatment of flattened sunsets at the end; but not citing Biot.


W. H. Lehn and I. I. Schroeder
Hafgerdingar: a mystery from the King's Mirror explained,”
Polar Record 39, 211–217 (2003).

* Lehn & Schroeder's "Hafgerdingar" paper
* A nice analysis of the King's Mirror report. The only defect is
* the assumption that because the "foreground shows . . . no visible
* distortion, . . . [t]he atmosphere must therefore be relatively normal
* for the 3.7 km . . . between the observer and the point". (p. 215)
* (This is basically the same as O'Connell's error.) Also, the claim
* that "few sailors have survived to tell of them" has a logical flaw:
* we necessarily know of no sailors who went down in storms following
* such mirage displays; so there is really no valid reason to suppose
* that the mirages are a reliable precursor of violent storms. Rather,
* as the mirages are associated with high pressure, the natural
* alternation of highs and lows suffices to explain Wegener's (1926)
* Prognostische Bedeutung . Still, a nice piece of work.
*      Cites Scoresby, and points out the concave appearance of the sea,
* referring to the appearance of "overhanging cliffs". See further
* discussion by Siebren van der Werf (2017) and Young & Frappa (2017).
* [Note observation of CONCAVE surface.]


S. van der Werf, I. Spendel, H. Betlem, and G. Können
“Stagnerende Zonsondergang door Nova Zembla-effect,”
Nederlands Tijdschrift voor Natuurkunde, Vol. 85, 6–7 (January, 2019).

* A Dutch "Novaya Zemlya" display (according to the authors; I doubt it)
* Siebren van der Werf, Ingrid Spendel, Hans Betlem, and Günther Können
* Seen on 23 May, 2018 (at the peak of superior-mirage season).
* Shows a nice series of 4 highly flattened sunset images, in color,
* with Siebren's attempt to explain the sunset with his old N.Z. model.
*      (Looks to me like a typical San Diego sunset, looking up through a
* duct. At least we agree on the ducting.) Sunset delayed 5 to 7
* minutes. Some meteorological data, and times of pictures taken from
* 1.7m and 10m height (the latter not shown); Können observed from 15 m.
*      The text draws attention to the "nearly complete flattening of the
* lower limb of the Sun, not at the horizon, but appreciably above it."
*      Many thanks to Siebren for the PDF and extensive discussion!
* [This probably belongs in the "Distorted Sunsets" file; but I have put
* it here, in view of the title and the authors' opinion that it should
* be called an N.Z. display -- "the first time in the Netherlands".


M. Vollmer
“Below the horizon — the physics of extreme visual ranges,”
Appl. Opt. 59, No. 21, F11–F19 (20 July, 2020).

* Michael Vollmer's 2020 paper on LOOMING and distant HORIZONS
*      A good review of the "longest distance to the horizon" problem, with
* many good references.
* DOI: https://doi.org/10.1364/AO.390654


S. Y. van der Werf
“Novaya Zemlya effect and Fata Morgana. Raytracing in a spherically non-symmetric atmosphere,”
Comptes Rendus. Physique , No. S1, 365–389 (2022).

* Siebren's thorough analysis of the original Novaya Zemlya observation
* published online at
*
* https://comptes-rendus.academie-sciences.fr/physique/item/CRPHYS_2022__23_S1/
*
* or      https://doi.org/10.5802/crphys.102
* DOI: doi : 10.5802/crphys.102



*** REFRACTIVITY FILE ***

F. Hauksbee
Physico-Mechanical Experiments on Various Subjects
(R.Brugis, London, 1709).

*
* FRANCIS HAUKSBEE discovers "Gladstone-Dale" relation
* A second, posthumous, edition appeared in 1719, published by J. Senex
* and W. Taylor; but the material of interest here is in both editions.
* P. 175 (p. 225 of 2nd ed.):
*      "Experiments concerning the Refraction of the air"
* Hauksbee explains that John Lowthorp's 1699 demonstration of refraction
* could not be reproduced by the French Academy, so "I was order'd to make
* an Instrument for the purpose, by the direction of Dr. Halley . . . " (p.
* 176 of 1st ed.; p. 226 of the 2nd). He made a hollow brass prism fitted
* with plane glass windows at an angle of 64°, and a fitting to connect
* it to the air pump. Looking through a 10-foot telescope, he measured
* the apparent image deflection of a distant building, and found it
* proportional to the pressure.
*      "By these Experiments it plainly appear'd, That the Refraction of
* the Air was, as far as the Eye could distinguish it, exactly
* proportional to its Density ; the Refraction being the same from the
* common Air to a Vacuum , as from a double Density to the common Air,
* and the Refraction from a treble Density to the common Air exactly
* double to that from the common Air to a Vacuum ." (pp. 178-179, 1st
* ed.; p. 229, 2nd ed.) [The precision given is half an inch in 10 1/2
* inches, or about 5%; more cannot be expected, because of dispersion.]
* (mentioned by Brook Taylor, 1715, and by Ivory, 1823).
*      See Delisle (1719) for a comparable crude effort.


Biot & Arago
“Sur les affinités des corps pour la lumière, et particulièrement sur les forces réfringents des différens gaz,”
Mémoires de la Classe des Sciences Mathématiques et Physiques de l'Institut National de France 7, 301–387 (1806).

* BIOT and ARAGO did the job right (1806)
* This was written by Biot in the first person singular; but Arago
* protested (see his collected works) and had his name added. One
* should be aware that Arago was only 20 years old at this time.
*      The approach is strictly Laplacian/Newtonian; the introductory
* paragraph says of gases: ". . . les particules qui les composent étant
* séparées par le calorique, et maintenues à des distances où leur
* attraction mutuelle n'a plus d'effet sensible, . . . les recherches que
* l'on peut faire sur les propriétés des gaz sont liées à presque
* toutes les branches des sciences naturelles. Celles que nous soumettons
* ajourd'hui à la classe, ont pour objet l'action que ces substances
* exercent sur la lumière; elles intéressent à la fois la physique,
* la chimie et l'astronomie : c'est sous ce triple point de vue que nous
* allons les considérer.
*      ". . .  Newton a prouvé qu'il résulte d'une attraction que les corps
* exercent sur les molécules de la lumière, attraction seulement sensible
* à des très - petites distances, et, en cela, tout - à - fait analogue
* auz affinités chimiques."
*      On p. 303 is mentioned the work of "Hauksbée", whose experiments
* "prouvoient seulement que l'air a une force réfringente, et qu'elle
* est à peu près proportionnelle à sa densité."
*      On p. 304, the influence of Laplace is evident; Biot says, "C'est
* ce travail que la classe, sur la proposition de M. Laplace, m'a chargé
* de reprendre en l'étendant à tous les fluides aériformes, . . . mais
* comme les expériences qu'il falloit faire étoient très-délicates,
* très-pénibles, et extrêmement multipliées, j'ai engagé M. Arago,
* secrétaire du bureau des longitudes, à s'en occuper avec moi.
* Nous avons fait ensemble toutes les expériences, tous les calculs dont
* je vais entretenir la classe, et par conséquent les résultats qui
* s'en déduisent doivent être considére's comme nous étant communs à
* tous deux. Nous devons dire aussi la part qu'ont prise à ces résultats
* deux personnes dont la participation nous est trop honorable pour ne
* pas nous en prévaloir; ce sont les auteurs de la Statique chimique
* et de la Mécanique céleste . Le sujet de toutes nos recherches
* étoit indiqué dans leurs ouvrages; leur conversation et leurs conseils
* nous ont fourni les moyens de les suivre et de les terminer."
*      After a detailed consideration of experimental details, they come
* to the important conceptual contribution of the paper (p. 314): "Ce
* que l'on entend ici par pouvoir réfringent , n'est pas simplement la
* déviation produite sur le rayon lumineux; ce n'est pas non plus l'angle
* qui mesure cette déviation, mais c'est l'accroissement total du carré
* de la vîtesse ou de la force vive de la lumière après avoir éprouvé
* toute l'action du corps transparent." The table on the next page gives
* values of (n - 1) for air, and refers to the density dependence shown
* on p. 323. But their "refractive power" is clearly (n2 - 1).
*      On p. 322, this matter is discussed: ". . .  nous avons trouvé que,
* depuis le vide le plus parfait jusqu'au degré ordinaire de pression
* de l'atmosphère, la réfraction d'un même gaz quelconque est toujours
* rigoureusement proportionnelle à sa densité sans que cette règle ait
* besoin de la plus légère modification." The table on p. 322 shows
* extensive data for air; the next page gives less extensive values for
* oxygen, nitrogen, and hydrogen. So (pp. 323-324):
*      "Nous pouvons donc en conclure avec certitude, comme nous venons de
* la faire, que la force réfringente de l'air et des gaz, depuis la plus
* grande raréfaction jusqu'à la pression ordinaire de l'atmosphère,
* est, pour un même gaz, rigoureusement proportionnelle à la densité
* . . . ; nous avons même condensé l'air dans notre prisme jusqu'à 0m80
* pour obtenir des densités plus fortes, et nous avons observé à de
* hautes températures pour voir si le même rapport y subsiste; nous
* n'avons pas pu y appercevoir la différence la plus légère."
*      They were unable to find any difference between the refractivites of
* air and water vapor (pp. 324-325).
*      On p. 331, they show they can predict the refractivity of air within
* half a per cent from the refractivities of its components. So they
* try to use what we would call molar refractivities to account for the
* refractivities of compounds, as well. This works well for ammonia
* (p. 332), but not so well for water (p. 334). They go on to try this
* method with carbon and its compounds (oils and alcohol) and diamond.
* The discrepancies are arm-waved away, and Biot concludes that the
* results are "extrêmement favorables au système de l'emission de la
* lumière, et paroissant contraires à celui des ondulations." (p. 344)
*      There is an interesting remark about the dispersion of air on p. 346.
* On the next page they find excellent agreement with the refractivity of
* air deduced by Delambre from astronomical refraction.
*      On p. 347 they return to the density dependence again.  On p. 349,
* they emphasize that the determination of the density ratio of air and
* mercury gives the "height of the homogeneous atmosphere" that is needed
* in astronomical refraction theory.
*      The main text ends on p. 353; then follow some detailed Notes on the
* experimental procedures. The first examines the prism angle. The second
* (p 363) deals with data reduction and analysis. The third (p. 379) deals
* with Laplace's barometric formula.
*      This is now available from the BHL at
* https://ia600205.us.archive.org/25/items/mmoiresdelinst07inst/mmoiresdelinst07inst.pdf
* where the Histoire precedes the Mémoires (whose page numbering begins
* at 1, as usual). See also Delambre's comments on their work, on p. 9
* of the Histoire .
* Title page says "Semestre de 1806" and "Tome Septième, Première partie"


J. H. Gladstone and T. P. Dale
“Researches on the refraction, dispersion, and sensitiveness of liquids,”
Phil. Trans. Roy. Soc. Lond. 153, 317–343 (1863).

* GLADSTONE and DALE didn't even study gases!
* This paper is the origin of the "Gladstone-Dale Law" . . .
* "Every liquid has a specific refractive energy composed of the specific
* refractive energies of its component elements, modified by the manner
* of combination, and which is unaffected by change of temperature,
* and accompanies it when mixed with other liquids. The product of this
* specific refractive energy, and the density, at any given temperature,
* is, when added to unity, the refractive index." (p. 337)
* NOTE: their "refractive energy" is our "refractivity" (n-1).


W. F. Meggers and C. G. Peters
“Measurements on the index of refraction of air for wave-lengths from 2218 A to 9000 A,”
Ap. J. 50, 56–71 (1919).

* quote Newcomb and emphasize DISPERSION in astronomy
* "The practical difficulties involve . . . the necessary inattention to
* the dispersion of light. In practice the astronomer usually disregards
* all dependence of refractive index on color. This must involve errors
* in zenith-distance observations on stars whose colors are intrinsically
* different and especially in observations of stars near the horizon, where
* the short waves are largely absorbed and scattered by our atmosphere,
* causing the stars to be represented only by longer waves. Because of
* these difficulties tables of corrections for astronomical refraction
* are probably better determined from astronomical observations than from
* laboratory measures." (p. 60, following the Newcomb quote.)


D. Brunt
“The index of refraction of damp air and optical determination of the lapse-rate,”
Q. J. Roy. Met. Soc. 55, 335–339 (1929).

* OBSOLETE data on dispersion of air and water vapor effects


H. Barrell and J. E. Sears
“The refraction and dispersion of air for the visible spectrum,”
Phil. Trans. Roy. Soc. Lond., Ser. A 238, 1–64 (1939).

* Barrell & Sears have a good discussion, but obsolete values
* (available from JSTOR; filed separately because of size)


B. Edlén
“Dispersion of standard air,”
J. O. S. A. 43, 339–344 (1953).

* OLD EDLÉN formula (with 41 in second denominator)


B. Edlén
“The refractive index of air,”
Metrologia 2, 71–80 (1966).

* NEW EDLÉN FORMULA


J. C. Owens
“Optical refractive index of air: dependence on pressure, temperature and composition,”
Appl. Opt. 6, 51–59 (1967).

* Effects of compressibility are about 10-4 at 245K and increase rapidly
* at lower T. (looks like 2 x 10-4 at 200K). Edlén (1966) is off by
* 7x10-8 at -30C, and by 4x10-7 at 45C, 100% RH.


E. R. Peck and K. Reeder
“Dispersion of air,”
JOSA 62, 958–962 (1972).

* 4-parameter, 2-term Sellmeier dispersion formula


F. E. Jones
“The refractivity of air,”
J. Res. NBS 86, 27–32 (1981).

* simplified formulae for visible region, including WATER & CO2


P. E. Ciddor
“Refractive index of air: new equations for the visible and near infrared,”
Appl. Opt. 35, 1566–1573 (1996).

* DEFINITIVE REFRACTIVITY FORMULAE:


H. Matsumoto
“The refractive index of moist air in the 3-μm region,”
Metrologia 18, 49–52 (1982).

* WATER-VAPOR PROBLEMS
*


K. P. Birch and M. J. Downs
“The results of a comparison between calculated and measured values of the refractive index of air,”
J. Phys. E: Sci. Instrum. 21, 694–695 (1988).


J. Beers and T. Doiron
“Verification of revised water vapour correction to the refractive index of air,”
Metrologia 29, 315–316 (1992).

* BIRCH-DOWNS CORRECTION CONFIRMED


G. Bönsch and E. Potulski
“Measurement of the refractive index of air and comparison with modified Edlén's formulae,”
Metrologia 35, 133–139 (1998).

* New high-accuracy data in the visibile re-confirm Birch & Downs
* Thanks to Ernie Lewis for pointing out this paper!


R. J. Mathar
“Calculated refractivity of water vapor and moist air in the atmospheric window at 10 μm,”
Appl. Opt. 43, 928–932 (2004).

* INFRARED DISPERSION due to H2O
* Despite the title, this covers everything out to 25 microns.



*** REFRACTION OBSERVATIONS FILE ***

P. Horrebowio
Atrium Astronomiæ
(apud Joh.Nicolaum Lossium, Havniæ, 1732).

* (see also Jacques Cassini, 1714)
*
* PEDER HORREBOW's Atrium Astronomiæ (1732)
*      This shows how to separate the refraction, the solar parallax,
* the obliquity of the ecliptic, and the latitude from fundamental
* measurements of apparent altitudes, by determining the instrumental
* errors and correcting for them. It was written shortly after the
* great fire that destroyed Roemer's observatory and records.
*      Of particular interest here is the report that a reliable man in
* Iceland had argued that the refraction of the Sun at the winter solstice
* there amounted to a whole degree [§.17, pp. 8-9]. Horrebow's comment
* on this is more nuanced than Mathieu's French version of this story in
* Delambre's Histoire (1827): Horrebow does express uncertainty about the
* veracity of this claim; but then he adds that "nevertheless, I easily
* believe that the refractions in Iceland are much larger than they are
* in Denmark." [Mathieu suppressed this qualification.] Note that this
* report is a decade before Captain Middleton's very reliable observations
* of large winter refractions at Hudson's bay (Coats, 1852; Rich & Johnson,
* 1949)).
*      The Linda Hall library has a page on Horrebow:
*
*      https://www.lindahall.org/peder-horrebow/
*
*
* The title page says:
*
*
*                              A T R I U M
*                         ASTRONOMIÆ,
*                                    sive
*      DE INVENIENDIS REFRACTIONIBUS
*      OBLIQUITATE ECLIPTICÆ, ATQUE
*        ELEVATIONE POLI TRACTATUS,
*
*                        cui subjungitur
*                   S C H E D I A S M A
*                                    de
*      A R T E      I N T E R P O L A N D I
*        ante annum seorsum editum
*
*                         AUTHORE
*       P E T R O      H O R R E B O W I O
*
* Philosophiæ & Medicinæ Doctore, atqve in Uni-
*       versitate Regia Havniensi Astronomiæ
*                        Professore
*
*


P. C. le Monnier
“Sur la réfraction horizontale aux couchers du soleil,”
Mem. Acad. Roy. Sci. , 77–80 (1773).

* Pierre Charles le Monnier


Le Gentil
Voyage dans les Mers de l'Inde, Tome premier
(Imp.Royale, Paris, 1779).

* LE GENTIL's observations in India
*
* Contains many measurements of horizontal refraction, refraction at
* low altitudes, terrestrial refraction, etc., together with an assault on
* the integrity of the Dutch at Novaya Zemlya. See sections quoted in the
* Distorted Sunsets, Novaya Zemlya effect, and Mirage files.
*
* "Les Réfractions horizontales sont si sujette à varier, & d'une
* quantité si considérable, même d'un moment à l'autre, qu'on ne peut
* se flatter, quelqu'exactitude que l'on apporte à les bien observer,
* que d'avoir une quantité moyenne, souvent très-éloignée de la
* véritable, c'est-à-dire, des résultats très-différens les uns des
* autres. Cette inégalité est encore assez sensible à quelques degrés
* au-dessus de l'horizon, pour nuire aux observations ; & les Astronomes
* exacts ont une grande attention, dans les recherches délicates qu'ils
* font, de n'employer que des observations faites à d'assez grandes
* hauteurs pour n'avoir rien à craindre de l'inégalité des
* réfractions." (pp. 393-394)


[P. C. ] le Monnier
“Sur les Réfractions,”
Histoire de l'Académie Royale des Sciences , 40–41 (1780).

* Le MONNIER's observations of variable refraction
* The uninformative abstract
* Actually published in 1784.


[P. C. ] le Monnier
“Examen des causes générales, des principes de Physique, & de ce qui a porté les Observateurs au siècle précédent, à publier des Tables des Réfractions qui différent les unes des autres pour les mêmes hauteurs,”
Mémoires Math. Phys. Acad. Roy. Sci. , 87–93 (1780).

* Le MONNIER's full text
* His concern is to explain the divergent values of refraction reported by
* different authors. After rejecting Kepler's odd notion that refraction
* should increase with height above sea level -- which is refuted by
* Pascal's barometric observations -- he says:
*      "Mais laissant à part cette digression, peu importante aux yeux
* des Modernes trop éclairés en ce siècle-ci pour s'y arrêter, il
* sembleroit néanmoins, d'après quelques essais intéressans, publiés
* dans nos Mémoires en 1749, par M. Bouguer, que ce seroit en vain, ou
* qu'on auroit tort d'expliquer par des différentes elévations du sol
* au-dessus du niveau de la Mer, les grandes différences qu'on trouve
* dans les Tables des réfractions de Picard, Cassini & de Flamstéed . . . .
*      ". . .  ces Tables ne paroissent avoir été construites que
* conditionnellement & pour un état de température moyenne, puisqu'on
* trouve . . . des preuves suffisantes qu'ils ne doutoient nullement qu'on
* n'eût besoin de Tables différentes pour les diverses saisons du froid &
* du chaud." So he looks for the extremes of refraction in extremely hot
* and cold conditions. Furthermore, the old results are faulty, as they
* do not allow for aberration, discovered only in 1728. (And no doubt
* the height effect is best investigated from the peak on Teneriffe.)
*      ". . .  réfractions qui conviennent à l'horizon . . .  ne sont pas les
* mêmes l'hiver que l'été, j'en ai déjà publié les différences dans
* l'Histoire céleste & ailleurs, d'après mes propres observations . . . "
* (of which he cites a good number, as well as those of Picard). These
* examples show horizontal refractions of at least 40' for 2 Jan. 1675,
* and 45' for the next day, or 12 or 13' more than in summer. But on the
* same days, the refraction at 4° 30' and 5° was at most 2 minutes
* more than normal; ". . . d'où il est aisé de reconnoître que les
* différentes densités de l'air, . . .      n'influe considérablement qu'aux
* approches de l'horizon . . . ." (p. 91)
*      These conclusions from Picard's observations are confirmed by his own,
* which show more than 40' on Dec. 1 (p. 92).
*      Picard's observations, "qui ont échappé à Flamstéed" show, for
* 20 Jan. 1675, a horizontal refraction of 46' 14''1/2 and 50' 33'' for
* the solar limbs, and the Sun's vertical diameter reduced to 19' 52''.
* (Actually published in 1784.)


F. W. Bessel
“Strahlenbrechungen nahe am Horizonte,” in Astronomische Beobachtungen auf der Königlichen Universitäts-Sternwarte in Königsberg, Achte Abtheilung
(Universitäts-Buchhandlung, Königsberg, 1823), pp. IX–XVI.

* Bessel's original data (observations and reductions by Argelander)
* Here we have the individual measurements of the refractions that are
* discussed in Bessel's A.N. paper, immediately below. The tables are
* on pp. IX - XI, in order of date for each star. The solar refractions
* are on p.XII. "Diese Beobachtungen verglich Herr. Dr. Argelander
* mit den Tafeln in den Fundamentis astronomiae , wobey er aber die
* Fehler des Thermometers in Rechnung brachte und d i e Tafel für die
* Wärme-Aenderung anwandte, welche ich in der VII. Abtheilung gegeben habe;
* die Resultate dieser Vergleichung findet man in der folgenden Tafel,
* nach den Thermometer-Graden geordnet:" -- then comes the "Fehler der
* Strahlenbrechungs - Tafeln in den Fundamentis astronomiae p. a. 1755. "
* The tables of temperatures for the individual observations continue
* on the next page (XIII).
*      On p. XIV is the first appearance of the table of arithmetic means of
* the table errors, sorted in bins of Z.D., with the number of observations
* and probable errors of both single observations and bin means. The errors
* of the means are reprinted in the A.N. discussion. The table is binned in
* half-degrees, and a separate table for the solar observations follows it.
* "Die Absicht bey diesen Beobachtungen war, die Strahlenbrechung für
* jeden halben Grad der Zenith-Distanz von 86° 30' bis zum Horizonte
* unter den verschiedensten Umständen zu bestimmen;. . . ."
*      Note the mention of DISPERSION on p. XIV:
* ". . . es nothwendig war den beständigen Fehler zu bestimmen, welcher aus
* dem Unterschiede der absoluten Zeitangaben beyder Beobachter hervorgeht
* und wahrscheinlich noch verändert wird, durch die Verschiedenheit der
* Schätzung des Mittelpuncts des Farben-Spectrums, welches jeder Stern so
* nahe am Horizonte bildet."
*      On p. XV the corrections to Fund. astr. P.50 are given again, taking
* into account the instrumental errors deduced from the corrected table
* of mean refractions. Here the solar data are omitted because of their
* smaller numbers. The probable errors of the stellar observations for
* single observations seem to be the values given by Bomford (1971).
*      The famous comparisons of the eye-and-ear method with Maskelyne, and
* Maskelyne's unfortunate assistant Kinnebrook, are on pp. VII and VIII !
*      NOTE: The details of the weather and exact times of the observations
* are in the previous (7th) volume.
* Available on the Web at
*       http://reader.digitale-sammlungen.de/resolve/display/bsb10485006.html
* Thanks to Stephen McCluskey for pointing this out!


Bessel
“Auszug aus einem Schreiben des Herrn Professors und Ritters Bessel an den Herausgeber,”
A. N. 2, 381–386 (1823).

* Bessel discusses his own and Argelander's observations below 5°
* VARIATIONS near the HORIZON:
* "Bei meinen Bemühungen um diese Materie, habe ich die Refractionen
* nicht allein als Mittel, die beobachteten Zenitdistanzen zu reducieren,
* betrachtet, sondern geglaubt, dass ihre Festsetzung ein Interesse für
* sich besitzt. In dieser Ausdehnung genommen, erfordert die Auflösung
* der Aufgabe die Fortsetzung der Tafeln bis zum Horizonte; handelt es
* sich dagegen nur um die Reduction der Beobachtungen, so darf die Tafel
* nur bis zu den Höhen nöthig seyn, in welchen die Sterne noch ruhig und
* deutlich erscheinen; die nächsten 5 Grade bei dem Horizonte könnten
* dann füglich ganz unbekannt bleiben."
* He shows that his observations above 85° Z.D. agree with Bradley's
* within a few tenths of a per cent, and that the remaining discrepancy
* may be ascribed to uncertainties in Bradley's thermometric scale. "Weit
* weniger vollständig waren aber Bradleys Beobachtungen in der Nähe
* des Horizonts, und wenn sie auch keine Zweifel darüber übrig liessen,
* dass Delambrés Tafel hier zu kleine Refractionen giebt, so war eine
* weit zahlreichere Reihe von Beobachtungen doch desto wünschenswerther,
* da die zufälligen Störungen der Refraction, welche aus uns unbekannten
* Unregelmässigkeiten der unteren Luftschichten entstehen, das mittlere
* Resultat w e n i g e r Beobachtungen, sehr stark entstellen können.
* Diese Lücke füllte, auf meine bitte, Herr Dr. Argelander aus, . . . "
*      These are his remarks on cols. 382-383.  The table of probable errors
* and number of observations just after the above passage was shortened and
* copied by Bomford (1971) in his Table 4.1 on p. 301. At the end of col.
* 383 and the top of col. 384, he looks for the cause of the increasing
* errors near the horizon:
*      Then if the agreement between observed and calculated refractions is
* poor, "so müssen entweder die astronomischen Beobachtungen, [oder] die
* Ausnahme über die specifische Elasticität, welche der Rechnung zum
* Grunde gelegt worden ist, irrig seyn. Welches von beiden das sicherere
* ist, darüber kann, nach der vollständigen hiesigen Beobachtungsreihe,
* wohl kaum ein Zweifel seyn, zumahl da die in 4 verschiedenen Jahren
* wiederholten Thermometerbeobachtungen des Herrn Zumstein auf dem
* Mont-Rosa, äusserst abweichende Resultate liefern und dadurch beweisen,
* dass die Wärmeabnahme der Atmosphäre nicht weniger als gleichförmig
* ist; -- man kann noch hinzufügen, dass die directen Beobachtungen der
* Wärmeabnahme immer am Tage, die der Refractionen stets in der Nacht
* gemacht sind und dass die Erwärmung der Erdoberfläche durch den
* Sonnenschein, wahrscheinlich die Wärmeabnahme vergrössert hat. --
* Meines Erachtens müsste man die Wärmeabnahme gerade aus den
* Beobachtungen der Strahlenbrechungen folgern, wobei aber die
* Unbekanntschaft mit dem mathematischen Gesetze derselben, noch eine
* Schwierigkeit erzeugen würde; es scheint mir wahrscheinlich, dass am Tage
* beobachtete Refractionen eine grössere Wärmeabnahme geben werden, als
* Nacht-Beobachtungen.
*      "Auch dieses wird durch Herrn Argelanders  Observationen bestätigt:
* ausser den Fixsternen bei Nacht, beobachtete er auch den Untergang der
* Sonne, und dieser ergibt durchgängig kleinere Strahlenbrechungen als die
* oben angeführten, auf die Fixsterne gegrundeten . . . ." [col. 384]
* Perhaps this is the FIRST determination of atmospheric structure from
* refraction observations?
* Anyhow, Bessel's awareness of DIURNAL VARIATIONS is remarkable, as is
* his awareness that the variations near the horizon reside in the lower
* atmosphere.
* Note that the letter is dated Nov. 10, but was published by the end of
* the year!


T. Henderson
“Refractions of stars near the horizon, observed at the Cape of Good Hope,”
Mem. Roy. Astr. Soc. 10, 271–282 (1838).

* Thomas Henderson's measures at the Cape


I. Calandrelli
“Astronomia,”
Supplemento al Giornale di Roma , No. 10, (13 Jan., 1855).

* Several observations of refraction from 87°.4 to 89°.1
* Ignazio Calandrelli was director of the observatory at the Pontifical
* University at Rome.
* He is surprised to find fair agreement with the tables of Carlini.
* In one case, there is a discrepancy of 5''.27, but the rest are off by
* only 2 to 3 seconds.
* He refers to the debate between Biot and Faye in C.R.
*      This item ends on an unusual note.  After thanking Pope Pius IX and
* the University officials, he expresses gratitude to his uncle Giuseppe
* Calandrelli "who had the honor of founding the first observatory in
* the College of Rome in 1787, thus promoting with his untiring zeal the
* study of astronomy, a study that raises the human mind to that highest
* knowledge from which it is forced to conclude: THERE EXISTS A GOD."
* N.B.: the pages are not numbered.


A. Lang
“Observations of the horizontal refraction of the sun,”
M. N. 23, 58–59 (1862).

* ANDREW LANG's first paper comments on RARITY of clear horizons
* ". . . I have sometimes every morning, for six weeks running, watched,
* disappointed, to get an observation on his rising, in consequence of
* dense low clouds of cumuli at the horizon. To this day [July 11, 1862]
* I have not obtained a single observation this year. So it is not so
* easy a matter as may be imagined."
* (The 17 observations run from 1831 to 1857.)
*      He finds the dip from 440 ft. in St. Croix to be between 20' 52" and
* 21', so adopts 20' 56"; then finds a mean refraction + parallax near
* 32' 18.8" (range: 31' 48.8" to 33' 8.5") at the mean apparent horizon.
* Here he is "A. Lang, Esq." Issue dated Dec.12, 1862.


A. Lang
“Observations of the Sun at rising to determine the refraction; and of solar spots,”
M. N. 24, 26–28 (1864).

* ANDREW LANG's second paper repeats his complaint
* "I could have wished to have made many more, but long intervals will
* occur before you can obtain a sight of the Sun rising from the horizon
* of the sea, from beds of cirri prevailing at the horizon, rendering it
* impossible." The mean of the 18 new observations gives 32' 14".
* (These run from 1860 to 1863.) Again the temperatures are all near 77 F.
* Now he is "Sir Andrew Lang". But it turns out his knighthood came from
* the King of Denmark much earlier. (St. Croix was part of the Danish
* West Indies from 1733–1801, 1802–1807, and 1815–1917, and the British
* Leeward Islands in between.)
*      Andrew Lang was one of the earliest Fellows of the Royal Astronomical
* Society, having joined it only 2 years after its foundation. He provided
* time service to ships in the Caribbean from his observatory in St. Croix.
* He was born in Largs, Scotland, 28 September 1779, emigrated to St. Croix
* in 1800, and died there 17 May, 1870, aged 90.
* Thanks to John Gilchrist Lang of Melbourne, Victoria, Australia for
* providing information about his accomplished great-great-grandfather!


E. C. Pickering
“Atmospheric refraction,”
Proc. Amer. Acad. Arts & Sciences 21, 286–293 (1886).

* E.C.Pickering's measures of astronomical refraction near the horizon
* [Part I was terrestrial refraction.]
* "The fact noticed by Argelander, that the refraction derived from the
* setting sun is less than that of a star is well shown in this table.
* The difference amounts to one or two minutes of arc."
* Note his use of "elevation" for height.
* Thanks to ADS full-text search for turning this up!


O. Weidefeld
“Die Grösse der astronomischen Refraktion im Horizont,”
Mitt. Vereinigung von Freunden der Astronomie u. Kosmischen Phys. 14, 69–71 (1904).

* Weidefeld confuses the apparent and astronomical horizons, but has some
* useful SUNSET TIMING data.
* from AJB, 1904:


G. C. Comstock
“Atmospheric refraction near the horizon,”
Publications of the American Astronomical Society 4, 83–84 (1922).

* George C. COMSTOCK's sunset work -- theory
*      To check Bowditch's assertion that altitudes below 10° should be
* avoided, Comstock got "an excellent series of observations of the times
* of sunset made at Key West, Fla." from the Hydrographic Office, and used
* "mechanical quadratures to compute directly from the differential
* expression for the refraction" for a range of conditions, based on
* meteorological data. Out to 75° ZD, the computed refractions "differ
* from the tabular values by amounts that rarely exceed a few hundredths of
* a second of arc.
*      "At the horizon, however, the conditions are widely different and,
* for a given temperature and pressure, variations amounting to several
* minutes of arc may easily result from plausible changes in the
* distribution of temperature at different levels in the atmosphere."
* He used 3 models for the lowest 2 km:
*        a. an unstable surface layer
*        b. an average model
*        c. a surface-based inversion "over a snowclad earth".
*
*      "With one exception", the Key West sunsets fall within this range.
* "This result confirms that the mean refraction of the setting sun is
* "less than the tabular refraction based upon observations of stars."
* Calculated refraction for an altitude of 4° show "that the large
* variation of the horizontal refractions within the range of conditions
* a - c has almost completely disappeared at 4° altitude. The range
* of values in the refraction due to varying conditions in the lower two
* kilometers of the atmosphere is reduced from nine minutes at the horizon
* to less than one second of arc at 4° altitude."
*      This originally appeared in Pop.Astr. 27, 529-530(1919).


K. Aa. Strand
“Astronomical refraction at large zenith distances,”
A. J. 57, 166 (1952).

* Strand's AAS abstract -- cf. the Smiley-Clemence argument
* Observations made at Dearborn Observatory (Evanston, Illinois).
* The "error is somewhat larger for the first 2° of altitude."


A. Thom
“Some refraction measurements at low altitudes,”
J. Inst. Navigation (London) 7, 301–304 (1954).

* Alexander Thom's very superficial effort: 3 sunsets measured
* The data extend below the astronomical horizon. "At these very low
* altitudes the Sun's disk often appears very distorted, and the
* horizontal projections from the limb on each side give the impression
* that it is passing through layers of varying density." "The observation
* of the upper limb as it vanished into the sea horizon may well be in
* error, as the Sun was by that time very faint." (So, no GF.)
* The paper is more useful for Fletcher's comments at the end.


M. E. Tschudin
“Refraction near the horizon – An empirical approach. Part 2: variability of astronomical refraction at low positive altitude (LPAAR),”
Observatory 139, 29–68 (2019).

* MARCEL TSCHUDIN's analysis, with some NEW OBSERVATIONS
* A very substantial piece of work. He reviews all the earlier
* observations, and re-reduces the work of Argelander & Bessel, as well
* as his own and other un-analyzed data.
*      The diurnal and seasonal cycles of boundary-layer structure are taken
* into account, as well as the temperature and pressure at the observer.
* The radiosonde data used in computing ray-traced refractions are
* corrected for the time-lag in the temperature sensors. The remaining
* unexplained variations are about half a minute of arc.
*      The discussion on pp. 40-41 nicely accounts for the difference between
* the temperature dependences of refraction used by astronomers and by
* surveyors. It is mainly due to the increasing importance of boundary-
* layer structure as one approaches the horizon: astronomers avoid the
* horizon, but surveyors work close to it, where the effect of lapse rate
* (which varies strongly between day and night, as well) exceeds the
* effect of temperature at the observer.
*      The general impression is that the variations in boundary-layer
* thermal structure with time of day and year are very important near the
* horizon. The development of the nocturnal inversion increases refraction
* at the horizon by about 5 minutes of arc from sunset to sunrise.



*** TILT FILE ***

V. Fuss
“Beobachtungen und Untersuchungen über die astronomische Strahlenbrechung in der Nähe des Horizontes,” in Mémoires de l'Académie Impériale des Sciences de St.-Petersbourg, VII* Série, Tome XVIII , N°.3
(l'Académie Impériale des sciences, St.-Petersbourg, 1871).

*
*       Cf. Fletcher (1952); also Oppolzer in Valentiner (1901); Emden
*       (1923); Kolchinskii (1967); Saastamoinen (1972); and Radau (1882,1889).
*       Helmert (1884) gave a general treatment for terrestrial refraction.
*       Also, cf. the observations of Delambre (1814) and Brinkley (1815),
*       and the Argelander/Bessel measurements.
*
* FUSS (1871) seems the first to conside TILT as an explanation for large
* refraction at low altitudes.
*      "Lu le 9 février 1871"


S. P. Glazenap
Refraktsionnii Uklon'
(F.S.Sushchinskii, S.-Peterburg, 1881).

* GLAZENAP on refraction anomalies and TILT
* Glazenap's interest here is in correcting systematic errors in
* parallax determinations inferred from *absolute* positions (this was
* before photographic parallaxes). His approach was primarily to use
* meteorological observations made north and south of the Observatory to
* estimate meridional density gradients, and hence the effective tilt of
* the isopycnic surfaces. He also tried to confirm, or at least check,
* the results, by observing circumpolar stars at both upper and lower
* culminations. Because of his interest in annual periodicities, the
* data are mostly grouped into monthly means.
*      I am pleased to see that he cited Biot's work in the historical
* preface. In the conclusions, he admits the measurements are very
* difficult to make, and suggests improvements for the future. His final
* suggestion is to determine the refraction from well-observed stars near
* the horizon, and distributed evenly along the prime vertical: "It
* seems to me that this method of determining refraction gives more exact
* results than that followed by Peters in his Pulkovo observations and
* that usually employed." (His assumption of gradients only in the N-S
* direction must be the reason for choosing the prime vertical.)
*      This was his doctoral dissertation; he was interested in the effects of
* refraction in azimuth.
*      The copy ILL got from Columbia University turns out to be
* the presentation copy from Glazenap to "Otto Vasileevich Struve",
* whose publications are frequently cited in this work. ("Vasily" was
* F.G.W. Struve's Russianized name, according to the DSB.) Unfortunately,
* part of the presentation inscription and the marginal notes were trimmed
* when this paper-backed pamphlet was bound. Worse, the whole thing is
* on acid-bleached paper and is now crumbling; it will soon be lost.


C. Abbe
“A correction for gravity in the use of Refraction Tables,”
A. N. 116, No. 2761, 15–16 (1886).

* CLEVELAND ABBE mentions his work at Pulkovo
*      Although Abbe does give the correction for gravity (assuming the local
* surface pressure was measured with a mercury barometer), our interest
* here is in his closing remarks:
*      "Such differences, so far as they are due to refraction,
* must however also be caused by the observed irregularities
* in geographical distribution of pressure and temperature
* which produce effects equivalent to slight inclinations of
* the horizontal planes of equal density.
*      "These irregularities are revealed by the daily weather
* map: their importance was urged by myself when at Pul-
* kowa in 1866 and in fact led me in 1869 to establish the
* weather bulletin of the Cincinnati observatory in order to
* study them.
*      "The effect of geographical irregularity in distribution
* of pressure and temperature may amount to one or two
* seconds of arc in the refraction at small zenith distances
* and the systematic annual changes in this distribution must
* introduce an annual variation in refraction similar to that
* produced by parallax.
*      "This cause  also introduces an oft-times appreciable
* difference in the refractions on the north and south sides
* of the zenith.
*      "Thus the daily weather maps may become an im-
* portant auxilliary in refined Astronomical work."
*       Dated Washington 1886 August 16.


S. C. Chandler
“On the variation of latitude,”
Astronomical Journal 11, No. 248, 59–61 (Nov. 6, 1891).

* CHANDLER WOBBLE sub-file
*
*
* This is not a refraction phenomenon, but is mentioned here because it
* was large enough to mask the tilt effect at small ZDs.
*      Chandler announced the effect in November, 1891.  His first paper
* mentioned that Küstner's data agreed so well with his own that he became
* convinced of the reality of the effect.


S. C. Chandler
“On the variation of latitude, II,”
Astronomical Journal 11, No. 249, 65–70 (Nov. 23, 1891).

* Chandler's second paper:
*      Here he gives the details of the complementary and overlapping data
* from Berlin, and the additional confirmation by the Pulkova observations
* made by Gyldén, Nyrén, and others; and by observations made by Newcomb
* and other observaers at the Naval Observatory in Washington.
*      These two papers were followed by Chandler's many discussions of
* latitude data from many other observatories; see the ADS list of them.


M. S. Carter and W. E. Carter
“Seth Carlo Chandler Jr.: the discovery of variation of latitude,” in Polar Motion: Historical and Scientific Problems , S. Dick, D. McCarthy, and B. Luzum, eds.
(Astronomical Society of the Pacific, San Francisco, 2000), pp. 109–119.

* Review of Chandler's work
*      Here we have a modern review of Chandler's polar-motion work.
* Unfortunately, the authors and/or editors seem so ignorant of both
* astronomical and German conventions that I have little confidence in their
* account: they print the AJ issue numbers as if they were volume numbers,
* and mistakenly call the numbered columns of A.N. "Bands" --- which is
* not a word in German. ["Band" means "volume"; its plural is "Bände".]
*      It should be borne in mind that the Astronomical Journal had been
* defunct for 25 years, and had only been revived in 1886, five years
* before its publication of Chandler's diccovery. (See Comstock's
* 1922 biography of Benjamin Apthorp Gould, jr.)
*      This is Vol.208 of the ASP Conference Series; IAU Colloquium 178.


É. Mascart
Traité d'Optique, Tome 3
(Gauthier-Villars et Fils, Paris, 1893).

* An early account is in Mascart's "Traité d'Optique", pp.296 ff.
*      This is a peculiar work.  Vol. I is largely concerned with the
* dispute between the emission and the undulatory theories, and states
* that the measurements of the propagation speed in dense media show that
* the emission theory was wrong. Yet in Vol. 3, we find astronomical
* refraction presented entirely in terms of the emission theory.
*      Vol. 3 makes no mention of either Chandler's work or the measurements
* he used; but, considering that the A.J. had been suspended for 25 years
* and had only been resurrected 5 years before Chandler's announcement,
* Mascart's ignorance of it is not very surprising.
*      Stellar photometry is treated on pp. 251-270.  He begins by taking the
* airmass proportional to sec Z, and then reproduces Bouguer's results.
* Laplace's extinction result is on p. 254; Forbes and Langley are cited.
* The stellar magnitude scales of various observers are discussed on
* pp.269-270, but with no mention of Pogson, though Pickering's work
* is repeatedly cited.
*      Astronomical refraction is treated in Chapter XVII, p.272.  Dip of the
* horizon appears on p. 279. Astronomical refraction begins on p. 283,
* and the angle 1° 24' 12" is on p. 284, followed by Cassini's uniform model.
* Then the tangent-series method is introduced, but without mentioning
* its defects. Simpson is introduced on p. 286, and Bradley on 287.
* Laplace and the reduced height are on p. 288.
*      Then he shows that Laplace's fudgy temperature profile would leave a
* finite density at infinity. This can be avoided by modifying the
* function; but this makes the lapse rate too big. Also, the atmosphere
* has a finite extent that is smaller than the heights shown by noctilucent
* clouds and aurorae (p. 292). "The two hypotheses of a constant
* temperature or an adiabatic variation appear equally improbable."
*      The airmass function is briefly discussed on p. 294, where §714 ends
* with the statement that "On peut donc admettre, pour le calcul de
* absorption dans le voisinage de l’horizon, que la masse d’air
* traversée est proporuonnelle à la réfraction et en raison inverse
* du sinus de la distance zénithale, ou du cosinus de la hauteur de
* l’astre."
*      After comparing various standard refraction tables (p. 294), he
* points out their increasing divergence with Z.D. "The different Tables
* used in Astronomy are very concordant up to 60° or even 80° from the
* zenith, where simple formulae . . . are still applicable, but the
* differences are exaggerated for directions closer to the horizon. . . .
* One sees that, for the horizontal refraction, the difference of the
* extreme values is about 4' and exceeds a tenth of their mean."
*      He quotes Delambre's verdict that it's hard to believe that even
* the most complex theories suffice for the last 8 degrees. "This
* uncertainty is not surprising and the real variations should be much
* larger than the differences among the tables, as the assumed symmetry
* is no doubt not realized, because of the changes of pressure at a
* given height, and the irregular distribution of temperatures in the
* vertical.
*      "In reality, the refraction of stars near the horizon cannot be
* evaluated just by knowing the state of the atmosphere in the immediate
* vicinity of the station. Observations of this kind are often illusory
* if one tries to find them from any other means than the relative
* separations of neighboring stars."
*      He then cites the observations of Spole and Bidberg at Torneo, who saw
* the Sun completely separated while its upper limb, apart from atmospheric
* refraction, was still a considerable distance above the horizon. The
* calculated refraction was 58', almost twice the value given by the tables.
*      On p. 300 he considers deviations of the vertical.  "Here is the place
* to ask if the unequal distributions of pressures and temperatures in the
* atmosphere does not modify in an appreciable way the direction of the
* vertical, and consequently the latitude of the station."
*      He then considers that the surfaces of equal density are symmetrical
* with respect to some vertical plane, with an inclination α to the horizon.
* Considering known pressure variations, he finds that this angle could
* reach a milliradian, or about 3 minutes; then the refraction at the
* zenith would be about 0.06 arcsec.
*      He then shows that the effect increases with zenith distance, and
* derives the secant-squared correction term. (P. 302) But, given the
* observational difficulties and the inconsistant date from different
* observatories, he concludes that "a definitive opinion on this delicate
* question would be premature."
*      This discussion is followed by his treatment of mirages.  He connects
* the inferior mirage with increased dip of the horizon. He cites Monge
* and Wollaston, and then Minasi, Arago and Biot, etc.
*      The section titled "COMPLEMENT" on pp. 665- 685 contains various
* additions to and comments on the earlier volumes. It is followed by a
* Table of Contents on pp. 687-692.
*      Mascart became the first director of the Bureau Central Météorologique
* in 1878, so he had been familiar with atmospheric structure and gradients
* for more than a decade before this was written. But his interest in the
* atmosphere was mainly in atmospheric electricity, not dynamics.
*      This 714-page book is not easily available, except from Gallica.


L. Courvoisier
“Über Saalrefraktion und ihre Wirkung auf das Deklinationssystem,”
A. N. 207, Nr. 4966, 257–272 (1918).

* COURVOISIER I
*      Cites Oppolzer in Valentiner, p.580.  "Eine      e i n d e u t i g e
* Definition sollte sich nur auf die Storungen der normalen Refraktion
* infolge abweichender Form und Lagerung der brechenden Schichten, nicht
* aber auch noch auf einen Temperaturfehler erstrecken, der dadurch
* entsteht, daß -- wie bisher gewöhnlich zur Berechnung der Refraktion
* statt der »inneren« Temperatur die »äußere« gewählt wird."
*      He develops the approximate theory by assuming the refraction is
* normally (µ - 1) tan z', which is good enough out to 80° Z.D. The
* correction term is proportional to Δtg z', which he says is good out
* to 87°, even neglecting the curvature of the Earth. He compares these
* values with Oppolzer's B-R values from Nyrén's observations at Pulkovo
* (1885). Eq.(2) is the sec2 relation.
*      The whole idea here is to explain the room refraction as an effect
* of inclined constant-density surfaces.


L. Courvoisier
“Zusätze zu meinem Artikel »Über Saalrefraktion und ihre Wirkung auf das Deklinationssystem«,”
A. N. 209, Nr. 5004, 181–190 (1919).

* COURVOISIER II
*      The analysis is extended, using Grossmann's observations.  However,
* there's a lot of arm-waving. . . .
*      Kienle's note endorsing Courvoisier's remarks is in cols. 189-192.


P. Harzer
“Berechnung der Ablenkungen der Lichtstrahlen in der Atmosphäre der Erde auf rein meteorologisch-physikalischer Grundlage,”
Publikation der Sternwarte in Kiel 13, 3–89 (1922-24).

* PAUL HARZER's long paper
*      This is what Comstock (1929) was referring to.  Sugawa cites this, as
* well as an addendum in Pub. 14, p.1, which turns out to be the actual
* correction tables needed for conditions at Kiel.
*      Harzer (1857-1932) was a student of C. C. Bruhns.  He was an Adjunkt
* Astronom at Pulkovo in 1885-1887, after spending a year studying with
* Gyldén.
*      This work is the first attempt to allow for changes of vertical
* structure with geographic position. Unfortunately, so little was known
* about atmospheric structure in Harzer's day that he assumed the gases
* would separate diffuseively in the stratosphere, and that the "optical
* surfaces" (i.e., isopycnics) would be surfaces of rotation about the
* Earth's axis. So the numerical results -- which Harzer says took him
* over 6 years to compute by mechanical quadrature -- are useless today.
*      It's difficult to know how to cite this.  Citations between sections
* of the text simply say "Publikation XIII"; ADS leaves that part out
* entirely, citing it as a book, and naming the publisher (C. Schaidt).
* Google Books call it "Veröffentlichungen der Universitäts-Sternwarte,
* Kiel. Nr. 1-23" (which contains Nr. 13.) Each "Publikation" is
* separately paginated, with its title page being p. 1.      Pub. XIII
* begins on page 329 of the Google/HathiTrust PDF.
*
* The bound volume scanned by Google begins with "Publication der Sternwarte
* in Kiel. X." (so, number 10, not 1), which is dated 1899. But section
* II on p.9 suggests why Google thought this began with Publication I.
* (Section III begins near the end of p. 13.) Section VII, "Der Einfluss
* der astronomischen Strahlenbrechung", begins on p. 32. Extensive tables
* for individual stars begin on p. 57; section XIV, "Nachtrag", is pp. 68
* to 74, which is a complete revision of the foregoing material, and a few
* Errata. "Publication XI" (1901), printed by a different publisher,
* begins on the next page.
*      These early Publications (with a "c") are printed in single-column
* format. Apparently the printer did not have any large Greek Σ type,
* so summations are indicated by a big boldface S (see p. 33.)
*      On PDF page 233, we have the title page of "Publikation XII" (1910),
* which is still 1-column format. However, the sections now have Arabic
* rather than Roman numerals.
*      Paul Harzer is listed on all title pages as "Herausgeber", and as
* "Director" of the observatory in nimbers X and XI; but as "Direktor"
* from XII on.
*      Thanks to Marcel Tschudin for bringing this to my attention!


J. Schubart
“Refraktion und mittlerer täglicher Temperaturgang,”
AN 281, 255–256 (1954).

* Schubart considers the possible effect of diurnal temperature changes
* in producing an east-west TILT; the maximal tilts found are 10 arcsec
* at 100m elevation, and still less (2 or 3 sec) higher up. So he finds
* the result "praktisch ebenfalls bedeutungslos".
*      Cited by Sugawa (1960).
* Available from ADS.


P. J. Melchior
“Latitude variation,”
Physics and Chemistry of the Earth 2, 212–243 (1957).

* Melchior's 1957 review
*      This review explains Talcott's method, the importance of the
* micrometer calibration, and the Kimura term, which must be understood
* to follow Sugawa's papers (below). For a more thorough discussion,
* see Wako (1970).
*      The local Kimura term is discussed on p. 221, where the "wind effect"
* appears. Here we see mentioned the "inclination of the surfaces of
* equal pressure and temperature" and local refraction "in the building".
* Chandler's work is reviewed on p.223.


C. Sugawa
“Note on the Study of the Room Refraction,”
PASJ 6, No. 3, 122–139 (1954).

* Astronomer Chikara Sugawa's initial paper on tilt, done analytically.
*      "It has been shown by several researchers that the wind effect might
* be the principal factor in the zterm. Moreover, it may be thought almost
* equivalent to the effect of the anomalous refraction due to the tilting
* of air-strata of equal density. Then the room refraction in question
* may be nothing but a special case of the anomalous refraction due to
* the tilting of air-strata of equal density in the close neighbourhood
* of the observing room." As separating tilt from other instrumental
* temperature effects is difficult, he just finds empirical corrections by
* using 4 thermometers.
*      Note that the principal factor turned out to be a nutation error in
* the star catalogs instead. See Wako (1970) for details.
*      On p.131, he says: "As the room refraction is nothing but a special
* case of the anomalous refraction due to the tilting of air-strata of
* equal density, its effect will be expressed as follows according to our
* previous theory:" and shows the secant-squared correction term, citing
* Courvoisier.
* Available from ADS.


C. Sugawa
“On the numerical integration of astronomical refraction,”
PASJ 7, 163–175 (1955).

* Chikara Sugawa's initial paper on numerical integration of refr.
* [This paper really belongs in the "variable refraction" file, but is
* placed here because of his tilt papers (below).]
*      He stops the integration at the top of the radiosonde profile (20 km),
* but fails to add in the atmosphere above it; so the results are useless.
* However, Table 2 gives monthly mean lapse rates at midnight, and may be
* useful for further work. Unfortunately, the boundary layer is not
* resolved; only integer kilometers are given.
* Available from ADS.


C. Sugawa
“On the effect of the anomalous refraction on the latitude observations,”
PASJ 8, 27–39 (1956).

* CHIKARA SUGAWA's first paper on TILT effects
* A fairly thorough theoretical analysis, with preliminary climatic data.
* The monthly mean tilts in the lower atmosphere are typically on the
* order of 2 arcmin. Cites Radau, Harzer, Wünschmann, etc. but not the
* references cited by Oppolzer/Valentiner, or Kolchinskii.
*      This paper makes a pretty convincing, though circumstantial, case for
* the importance of the tilt effect. Cites Varnum's 1922 AJ paper.
*      Sugawa (1916-2013) was vice-President of IAU Commission 19 (Rotation
* of the Earth) from 1970 to 1973,and President of the Commission from 1973
* to '76.
* Available from ADS.


C. Sugawa
“On the relation between the wind effect and the anomalous refraction in the latitude observations,”
PASJ 10, 79–98 (1958).

* CHIKARA SUGAWA's second paper on TILT effects
*      This begins with a review of data on the wind effect.  Correlations
* with other possible causes do not support some ideas about the physical
* cause of the effect, and support the tilt effect: "The principal
* meteorological factors of the non-polar variation of latitude consist
* probably of the anomalous refraction due to the tilting of the air-strata
* of equal density in the free atmosphere and the room refraction."
* Available from ADS.


C. Sugawa
“On the relation between the anomalous refraction and the local Z term,”
PASJ 12, 42–54 (1960).

* CHIKARA SUGAWA's third paper on TILT effects
*       More extensive radiosonde data confirm the earlier results: tilts
* in the lower atmosphere are only 1 or 2 arcmin, on the average.
*      Here the case for the tilt effect is made stronger.  The Abstract says:
* ". . . the anomalous refraction due to the tilting of the air-strata of
* equal density might be a main physical cause of the wind effect on the
* latitude observations."
*      This paper sums up the tilt investigations, and repeats (with many
* typos) the earlier results. The Summary says:
*      "From a series of our study on the meteorological effect on the
* latitude observations, we have come to the conclusion that the local Z
* term may be mainly attributed to the effect of the anomalous refraction
* due to the tilting of the air-strata of equal density in the free
* atmosphere and the effects of the room refraction in the neighbourhood
* of the observing room.
*      "The effect of the anomalous refraction due to the tilting of the
* air-strata of equal density in the free atmosphere has clearly a seasonal
* character giving its maximum in winter and its minimum in summer. The
* wind effect in the lower atmosphere indicates also a similar seasonal
* variation. Therefore, the wind effect may be regarded as a convenient
* indicator of the anomalous refraction in the free atmosphere. After an
* error of the micrometer value has been carefully examined, the annual
* component of the local Z term may be mostly explained by the effect of
* the anomalous refraction or the wind effect. The six-and four-monthly
* components of the local Z term are likely to be chiefly caused by the
* effect of the room refraction."
*      Note that the tilt effect is related to just the "local" part of the
* z-term; Wako (1970) showed that the main part was due to an error in
* the star catalog, which used an incorrect nutation constant.
*      See Sugawa & Kikuchi's 1979 paper for a later view of tilts.
* Available from ADS.


K. Bretterbauer
“Über mögliche Refraktionsanomalien infolge von Schichteneigungen,”
Österreichische Zs. f. Vermessungswesen 53, 113–119 (1965).

* Kurt Bretterbauer's estimated tilts
* He considers both large-scale pressure and temperature gradients as
* possible causes, and finds maximal tilts of 5 to 10 arcmin for pressure
* gradients corresponding the Föhn conditions (p. 116). These would
* produce refraction anomalies up to 1/3 arcsec at 45° ZD.
*      For temperature differences, the problem "ist viel komplexer",
* because only local temperature differences are important, else the
* horizontal gradient would be too small to have an effect (p. 118).
* He points out that the northern slopes of mountains are much colder than
* the southern, especially when covered with snow. But these are subject
* to large diurnal changes. He assumes 2° C in 3 km over an air column
* 1500m high [probably an overestimate], which would produce tilts of
* 12.6 arc minutes, corresponding to 0.21 arcsec at the zenith, or 0.42 sec
* at 45° ZD.


K. Ramsayer
“Investigations on errors in the determination of astronomical refraction,”
Österreichische Zs. f. Vermessungswesen, Sonderheft 25, 260–269 (1967).

* Karl Ramsayer's estimates
* This seems to be a section of a larger document; the heading reads
*             B. Errors and Sources of Errors
* The English is a little awkward here; he uses the strange phrase
* "water steam" (an obvious literal translation of Wasserdampf ).
* He adds a term representing atmospheric structure to the usual 2-term
* tangent series, and concludes that for z < 60°, the influence of
* structure above the observer is "extremely small" (but not zero, even
* though his terms are still only the linear and cubed terms in tan z).
* He correctly concludes that the influence is only due to the curvature.
* Then, considering the tilt of the layers, he naturally finds the effect
* is proportional to sec2 z. On p. 264, he says "the main cause of the
* inclination of the optical layers is the horizontal gradient of
* temperature in the vertical of the observation." Here the coefficient
* at sea level is 1.7° of tilt per (° C/km) of gradient. So "in
* the neighbourhood of the ground", the tilt "may be several degrees.
* But on the other hand [it] will rapidly decrease with altitude because
* in higher altitudes the atmosphere will be better balanced."
*      He then appeals to observations by Bauschinger and by Courvoisier to
* discover the magnitude of the secant-squared term, whose coefficient turns
* out to be 0.035 arcsec for Bauschinger, and 0.032 arcsec for Courvoisier.
* As he has included a tangent term to allow for the errors in the assumed
* refraction constants, this is probably a reasonable procedure.
* Additional Potsdam data taken with the Danjon astrolabe confirm that
* "the mean influence of refraction anomalies is only +/- 0.06".
*      Likewise, the Diplomarbeit  of R. Henn showed only a very small
* increase in error with ZD: "The influence of the inclinations of the
* optical layers is very small. This is very surprising because the
* observation station is situated amidst an extended slope where large
* inclinations of the lower optical layers are to be expected."
*      Only the usual astronomical part of the sky (ZD < 82°) is considered,
* so of course he finds that Bessel's refractions are good, despite the
* unrealistic model.
*      ??? Maybe this is a preprint of Ramsayer's volume of "Handbuch der
* Vermessungskunde" (10th edition, 1970) -- which cites F. Wünschmann's
* "Über die Konstitution der Atmosphäre und die astronomische Inflexion
* in ihr". Gerlands Beiträge zur Geophysik, Band 31, S. 83-118 (1931),
* on p. 865. Wünschmann is also cited on p. 132, where the tilt effect is
* discussed. [Sugawa's 1984 article cites that as "Aerosphäre", which is
* also in the title of Friedrich Wünschmann's thesis, according to the
* Mathematics Genealogy Project.]


Y. Wako
“Interpretation of Kimura's Annual Z-Term,”
Publ. Astr. Soc. Japan 22, 525–544 (1970).

* YASUJIRO WAKO shows that the main part of the z-term was catalog error
*      Here is the detailed report.  Note that the local part, which Sugawa
* had shown was caused by the tilt effect, is barely mentioned here.
*      "The close relation between Kimura's annual z-term and the theoretical
* semi-annual solar nutation term based on the hypothesis of a liquid core of
* the Earth is suggested." [first sentence of Abstract]
*      Notice the important distinction between the annual and local parts
* of Kimura's mysterious z term. By averaging over suitable intervals,
* and particularly by using only the "chain method", Wako separates these
* two parts. The annual part is shown to be produced by the viscosity of
* the Earth's liquid outer core, which lengthens the period of the polar
* motion and increases the coefficient of the solar nutation term (see
* p.526). Taking monthly means removes the lunar nutation terms, and
* combining 12 years of observations averages out most of the 19-year
* lunar cycle as well. (p. 532) This allows him to deal with just the
* semi-annual solar terms. The monthly means of the Talcott group errors
* are strongly correlated with the declination errors in the GC.
*      Figure 4 (p. 532) "clearly shows that z , Δδ, and (GC-MD) vary in a
* very remarkably similar way. Thus it may be reasonable to consider that
* the constant parts in z should be attributed to the catalog errors of
* the latitude stars used."
*      He then discusses the chain method in detail, and shows that the
* analysis of the amplitudes and phases of the evening and morning group
* differences determine the period and phase of the annual z term. He
* then shows how to separate the variations of this term common to all
* ILS stations from the local errors.
*      On pp. 540-541, the theoretical corrections to several nutation terms
* for several Earth-core models are compared to the star-catalog errors
* inferred from the ILS data, as well as nutation corrections derived
* from observations of Earth tides. These numbers (except for one crude
* Earth-core model) agree that "the semi-annual solar nutation term for
* the actual Earth is to be corrected by 0."02 for the value calculated by
* the theory of rigid Earth." (p. 541)
*      "Consequently, Kimura's annual z-term  may be explained by erroneous
* values in the semi-annual solar nutation term and OPPOLZER's (1882)
* terms which are considered to be due to the difference between the
* perfect rigid Earth model and the actual Earth with liquid core."
*      The 9th section of the text deals briefly with the differences among
* the stations. The residual defined in eq. (40) on p. 542 "is
* customarily called . . . the local Kimura term or local z term ."
*      And in section 10, Conclusions , he says: "In this paper, we are not
* concerned with the origins of the local errors, because it is difficult
* to separate the effects of various sources from the observational
* materials." (p. 543)


C. Sugawa
“Rotation of the earth (Rotation de la terre),”
Trans. Int. Astron. Union (Reports on Astronomy) 16A, Part 1, 105–116 (1976).

* Sugawa et al. 1976 (IAU Comm. 19)
*      Section 3 of this Report, "Research in Instrumentation and Astronomical
* Refraction", begins on p.106. The "wind effect" is briefly mentioned.
*      Section 6, "Research in Problems Concerning the Rotation of the Earth"
* begins on p. 108 with Part A, "Chandler Wobble". This phrase is used
* several times on this page, and appears again on p. 109, under Part C,
* "Other Periodic Terms in Time and Latitude Observations", and p. 110,
* under Part D, "Secular Motion of the Mean Pole and Related Problems".
*      As the BIH part of the report was written by Guinot, and the ILS
* section by S.Yumi, the parts mentioned above must be due to Sugawa,
* although ADS attributes the report to C.Sugawa, B.Guinot, and S.Yumi.


N. A. Vasilenko
“Naklony sloev atmosfery po dannym zondirovaniya,”
Astrometriia i Astrofizika (Kiev) , No. 36, 81–83 (1979).

* Vasilenko gets results more like Sugawa's
* Typical slopes are around 2' in the lowest kilometer, decreasing to
* about half a minute above 4 or 5 km. He concludes that seasonal and
* daily variations are significant, based on radiosonde data.


E. Tengström & G. Teleki
Refractional Influences in Astronomy and Geodesy (IAU Symposium 89)
(D.Reidel, Dordrecht, 1979).

* An interesting but little-known IAU Symposium
*
*      The introductory front pages set the scene, in welcoming addresses by
* the heads of the relevant groups within the IAU (Teleki) and the IAG
* (Tengström). On p. xx of this volume, we see Newcomb's "wellknown"
* [I would have said "infamous"] statement about the state of astronomical
* refraction. Tatarski gets mentioned on p. xxiv, and elsewhere.
*      The next several entries are contributions to the Symposium by
* many different authors. Many of them are followed by interesting
* discussions that illuminate the thinking about refraction by astronomers,
* meteorologists, geodesists and surveyors, both observational and
* theoretical, in 1979.
*      I have commented on and quoted from these papers (and their
* discussions!) below. There are remarkably few references to them
* in the subsequent literature. However, there were several brief
* reviews of the volume. Today, it's hard to believe how ignorant the
* experts in these fields were of one anothers' work; but this was a decade
* before the first search engines appeared. Even now, we are hindered by
* the diverse nomenclature and conventions of astronomy, geodesy, and
* the atmospheric sciences.
*      Available at ADS (including the Front Matter); IAU has the Copyright.
* Cover page says:
*                                Edited by
*                          ERIK TENGSTRÖM
* Geodetic Institute, Uppsala University, Sweden
*
*                                     and
*
*                              GEORGE TELEKI
* Astronomical Observatory, Beograd, Yugoslavia
*
*                   with the cooperation of
*                               I. OHLSSON
*
* [Ingegerd Ohlsson was Tengström's secretary, who arranged the events.]


G. Teleki
“Research into astronomical refraction -- today and tomorrow,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 1–9.

* Teleki's introductory survey paper in Symp.89
*
* "Refraction, though a unique phenomenon, has hitherto been investigated
* piecemeal as astronomical, terrestrial, photogrammetric, radio or some
* other. A synthesis of these partial knowledges recommends itself as well
* as a continual cooperation of the experts in these fields. Astrometry
* would immensely benefit by such cooperation as more information would
* be acquired, in the first place that related to the surface air layers,
* which in other fields is considerable more widely investigated."
*      Here we see the consternation of astronomers at the point where space
* astrometry was about to overtake ground-based measurements of star
* positions. Almost everyone failed to see the transformation of the
* field: refraction would continue to be an enormous problem for surveyors,
* but the accurate star catalogs allowed much of the doubt about sources of
* error, as a big one was about to be removed. This solved the
* astronomers' problem, and allowed the geodesists and geophysicists to
* obtain reliable measurements of polar motion and deflection of the
* vertical.
*      The list of references is a good collection of Teleki's own papers.


W. J. Altenhoff
“Refraction in radioastronomy,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 10–11.

* Wilhelm J. Altenhoff's brief summary of radio refraction


J. A. Hughes
“Environmental systematics and astronomical refraction II,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 13–25.

* TILTs estimated for urban heat island: James A. Hughes (USNO)
* Models tilts of isopycnic surfaces near ground level as large as half a
* degree. The "heat island" is simplified but reasonable enough to show
* that "we do indeed have a problem." The calculated effects near the
* zenith are a few hundredths of an arc second, and are six times larger
* at ZDs near 60° or 70°. it is "evident that . . . the lower levels (say
* z<250m) are the major contributors to the effect,"
*      The lapse rate in the model boundary layer changes sign at heights
* of few hundred meters because there are "two 'competing' effects,
* conduction and a gravity wave. The latter is responsible for the
* negative temperature perturbation which leads to the tilt reversals.
* Very small changes in the perturbation profile lead to sensible changes
* in the tilt angles, and hence the integrated anomalous refraction."
*      "It appears to the author thst it is absolutely necessary to devise
* some means of determining these pernicious systematic effects observa-
* tionally. . . .      this effort should be expanded to determine systematic
* isopycnic tilts . . . ."
*      The abstract says "It is stressed that heat islands are not the only
* source of such systematic effects." (No reference to Sugawa's work.)
*       PDF available from ADS.


H. Yasuda and R. Fukaya
“An origin of the variations of astronomical refraction,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 27–33.

* Haruo Yasuda and Rikinosuke Fukaya review "ANOMALOUS REFRACTION"
*      These authors were at the Tokyo Observatory in Mitaka.  Their Abstract is:
* "There exists an empirical relation between the anomalous refraction
* and the atmospheric density in the surface layer. From the relations
* the variations of scale height for each night can be determined by the
* temperature and pressure in the surface layer. A correction term to
* the refraction table is derived in an analytical expression,"
*      They describe the Talcott method, without naming him.  Unfortunately
* they refer to the unreliable 4th Ed. of the Pulkovo Tables, and the FK4
* catalog, and find "the differences between the stationary atmosphere
* adopted in the Refraction Table and the dynamical atmosphere at Mitaka."
* The comparison shows an annual cycle: the measured T and p in the
* observing pavilion, implying that "the measured temperatures are too
* high in winter and too low in summer,      It coincides with an annual term
* of the grounding inversion of temperature, 1.39°C sin ( T + 295° ),
* at the Tateno Aerological Observatory."
*      Densities are in "gr/little" (sic) -- probably grams/liter ?  The
* systematic differences are correlated with the radiosonde data at 1 km
* but not at 5 km height. [No surprise there!] They try to use the
* analytical refraction theory from Newcomb (whom they give as "Newcomb, E.")
* The only other reference is to a paper by Teleki; no mention of Sugawa.
*      Not very impressive.
* Available at ADS. There is no page numbered 26 in their scans.


V. I. Sergienko
“On astronomical refraction for a three-dimensional model atmosphere,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 35–37.

* Metrologist SERGIENKO discusses ANOMALOUS REFRACTION
*      "The existing refraction theories for a one-dimensional model
* atmosphere do not account for anomalous refraction. The latter can be
* calculated using a three-dimensional model atmosphere," (Abstract)
*       A formal series expansion is presented, using the horizontal gradients
* as small parameters. These are to be determined from radiosonde data.
*      Teleki comments that the basic problem is how to get real information
* on the variations with height of inclinations of the equal density layers.


J. Dommanget
“Les effets de la refraction atmospherique sur les coordonnees tangentielles en astrometrie,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 39–65.

* J. Dommanget's paper has a long abstract in English
*      The topic is reduction of astrometric plates: the differential
* distortion due to refraction is to be corrected by using refracted
* positions of the reference stars in finding the plate constants.
* ". . . we give expressions for the refracted tangential coordinates . . . ".
* Basically, he absorbs the differential refraction in the plate constants.
* This works to astrometric accuracy as long as the center of the field is
* less than 75° from the zenith.
*      Numerical examples were run on an IBM 1620.  In the Discussion, Teleki
* asked if anomalous refraction could be corrected; Dommanget replied that
* he had used the normal refraction formulae. "Anyway, usually no observation
* at very great zenith distance." So this is basically useless.


V. I. Ivanov
“Atmospheric turbulence effects on astrometric determinations,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 67–72.

* IVANOV's paper on turbulence and image motion
*      An early application of Tatarski's work; his 1967 Russian book is cited.
* Unfortunately people were still thinking about a single turbulent layer
* at this time. "Using the differences of temperature and wind speed at
* the two levels 1 and 4 m" he finds the Richardson number and the {C n}2
* value. From measurements of image motion with apertures from 3 to 48 cm,
* "D=20 cm should be considered as the optimum objective diameter of
* astrometric instruments." The best integration time is 100 seconds."
* The random errors depend on the time spent, but their size depends on
* "astroclimatic conditions. One should search for places with minimum
* amplitude of image motion."


J. Saastamoinen
“On the calculation of refraction in model atmospheres,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 73–94.

* J.Saastamoinen's paper on refraction calculation
*      This largely continues his 3 papers of 1972, and is useful in showing
* his thinking more clearly. He continues to use the divergent tan z series,
* but fudges it to allow extension to 90° ZD. Another series is used for
* the region near the horizon. "Further applications include . . .
* photogrammetric and parallactic refractions, as well as range corrections
* in satellite geodesy."
*      He begins well, with the integral of tan z d (ln n) but quickly switches
* to the old tangent series, which he writes using a binomial series that
* converges only if (y2 - 1)*(sec2 z) < 1, where y = (nr)/(nr at the
* observer). But he never shows where this condition is met. (Later, he
* fudges the terms to make his series work.) After many pages of analytic
* gymnastics, the text ends with "to be continued" -- followed by several
* pages of Appendices. Auer and Standish were about to blow all this away.
*      A misguided mathematical exercise, ignoring the physics.  No mention of
* Biot or Bemporad, of course.


S. Mikkola
“Calculating astronomical refraction by means of continued fractions,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 95–101.

* S. Mikkola's exercise with continued fractions
*      At least here we have an admission that the series is asymptotic, and
* can be used only to some limiting ZD. Still no evidence that anyone
* at the meeting knew of Biot or Bemporad.
*      Mikkola's full paper appeared in A&A in 1981.


C. Sugawa and N. Kikuchi
“On the characteristics of astronomical refraction in the northern hemisphere,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 103–117.

* Sugawa & Kikuchi's 1979 paper
*      They begin by approximating the troposphere as an exponential,
* beneath an isothermal stratosphere. This model, with tilted layers,
* is used for numerical experiments. Monthly means of sounding data were
* used for the temperature profiles. The 2-term tangent series is used to
* calulate refraction. The tilt effect is treated in §5 (p. 113).
*      As refraction is only calculated to 45° ZD, it's hardly surprising
* that the refraction at the surface depends weakly on the atmospheric
* pressure. This gives a small zenith refraction of 3 mas, "corresponding
* to the pressure difference of 7 mb in 10° of latitude (about 1,110 km)."
*      Unsurprisingly, their simulations are well fitted by a sec2 z form.
* "It may be possible to correct an anomalous refraction with an accuracy
* of 0."1 . . . .".
* TERMINOLOGY:
*      "We have usually called astronomical refraction with the tilting of
* airstrata of equal density as an anomalous refraction. However, it
* actually appears to occur every time and everywhere. Therefore, it
* would be more exact and convenient to call it as apparent refraction."


S. Takagi and Y. Goto
“Astronomical refraction at the Mizusawa Latitude Observatory,” in . in "Refractional Influences in Astronomy and Geodesy (IAU Symp.89)" , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 119–124.

* Shigetsugu TAKAGI and Yukio GOTO see the TILT effect
*      They use radiosonde data to calculate refraction.  ". . .  the results
* show lager refraction [than] Radau's and Pulkovo Refraction Tables."
* Maybe not surprising, as they approximate the data as an exponential
* model. "Moreover, our results shows that the refraction is not symmetric
* around the zenith. For instance, the difference between the refractions for
* north star and south star with zenith distance 20° amounts to 0".13 and
* shows slight seasonal variation with about 0".01 amplitude."
*      They interpolated profiles from nearby radiosonde stations, using 3
* layers: a boundary layer (0 to 1.5 km); troposphere (1.5 to tropopause);
* and stratosphere -- each with a log-linear profile.


B. K. Bagildinsky, S. P. Puliaev, and E. G. Zhilinsky
“Chromatic refraction in the vertical circle observation,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 125–128.

* PULKOVO photographic vertical circle results
*      The instrument is a 20 cm Maksutov telescope.  FK4 stars were observed
* out to ZD 82°.5, with M.S.E of 0.".16 at the zenith and 0".30 at Z = 50°.
* Comparison with Pulkovo tables (1956) for 5753 Å showed chromatic
* effects. "Leningrad is situated to the north of the Pulkovo Observatory,
* so the northern part of the sky is more affected by the city lights
* and the atmosphere is less transparent. This circumstance seems to be
* the cause of the asymmetry of our results." Atmospheric reddening was
* included in calculating expected effects; see Fig. 2. [Results are
* preliminary.]


J. A. Hughes et al.
“Discussion about refraction corrections in star catalogue work and geodetic astronomy,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 129–130.

* Hughes et al., DISCUSSION
*      Not terribly useful.


D. G. Currie
“Two color refractometry, precision stellar catalogs, and the role of anomalous refraction,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 131–155.

* Douglas G. Currie: 2-color technique and ANOMALOUS REFRACTION
*      This is a rough analysis of the quadrant photosensor and its expected
* performance. I was surprised to see no consideration of magnetic field
* effects. At least atmospheric reddening problems are mentioned in the
* discussion.
*      This was a very preliminary state of the general idea.  In practice,
* it was not very useful. One problem not mentioned here is the effect of
* turbulence: because different colors pass through different parts of the
* atmosphere, the image motions are different in different colors of light
* -- cf. the old discussions of chromatic scintillation.
*      For a modern example of the 2-color method in a more mature form, see
*
*      Pabitro Ray, David Salido Monzú, Robert Presl, Jemil Avers Butt and
* Andreas Wieser
*      Refractivity corrected distance measurement using the intermode beats
* derived from a supercontinuum
*      Optics Express, vol. 32: no. 7, pp. 12667-12681, Optica, 2024.
* DOI: 10.1364/oe.514997
*


A. J. Anderson
“Path length variations due to changes in tropospheric refraction,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 157–162.

* Allen Joel Anderson: radio refraction
*      Microwave Doppler used to determine very small changes in path length
* to spacecraft showed rapid variations in tropospheric refraction.


W. J. Altenhoff
“Diurnal changes of radio refraction,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 163–164.

* Wilhelm J. Altenhoff: more radio refraction
*      A brief account of published work (3 references).


P. V. Angus-Leppan
“Use of meteorological measurements for computing refractional effects --- a review,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 165–178.

* Peter Vincent Angus-Leppan's EXCELLENT REVIEW paper
*      Abstract: ". . .  atmospheric models of the temperature gradient and, for
* microwaves, the humidity gradient, are needed to represent the very
* significant variations. The models should take into account variations
* due to meteorological factors, surface conditions and the height above the
* surface. Many models for the vertical gradients have been produced. That
* of Brocks (1948) is very important and has been widely used and developed
* by researchers. More recently Monin and Obukhov, basing their work on the
* physics of the lower atmosphere and dimensional analysis, have included
* equations for the vertical gradients in their turbulence theory. The
* Turbulent Transfer Model, which embodies later results in this theory,
* is currently being refined and developed for geodetic applications."
*      "The model must take into account the large number of factors
* which affect the gradients. No progress will come from trying to
* find the static, universal model, for example the best average value
* of the temperature gradient or the best value of the coefficient of
* refraction. The atmospheric model must be multi-factored to take into
* account the variations in the atmosphere, which are very large and
* real. For example, long term temperature measurements (BEST et al., 1952;
* FLOWER, 1937) show the average error due to observing temperature at 1.5
* m instead at the height of the line, say 50 m above the surface. In the
* month of April (spring) the error, in parts per million (ppm) varies from
* -3 in the day to +5 at night, at Rye, in Southern England. At Ismailia,
* Egypt, the average daily variation is -6 to +6 ppm. In mid-summer the
* errors are similar, but in winter they are quite different, with lower
* averages, but a far larger variation from day to day (ANGUS-LEPPAN, 1967).
*      "The variations in k, the coefficient of refraction, are even more
* remarkable. Table I shows values at heights of 1.5, 7.5 and 75 m for
* the same month, April."
*      There is a very clear explanation of the terminology and formulae used
* by optical surveyors and by those who use EDM (radio stadimetry).
*      He uses the acronym TTM for the Monin-Obukhov model.  It did not seem
* to have gained much traction in 1979, and still is not widely used.
* See pp. 172-173 for its discussion.
*      This is a very sensible and useful review.  It is followed by a
* very informative DISCUSSION section at p. 176. The treatment of lateral
* (i.e., azimuthal) variations in refraction near slopes and shores is
* particularly interesting. Note that Angus-Leppan says: "I do not
* recommend Brock's model any more. It was good at the time, but the
* turbulent transfer model is much better. [My own experience with it
* in studying inferior mirages agrees well with his recommendation.]


M. K. Szacherska and Z. Wiśniewski
“Statistics applied to the estimation of the influence of the environment on results of observations,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 179–189.

* Geodesists M.K. Szacherska and Z. Wiśniewski study error propagation
*      They treat systematic errors as additional parameters to solve for in
* data reduction. But they treat the different errors as Gaussian and
* independent. This model has been used in reducing real survey data in
* Poland, and included refraction and deflection of the vertical. They
* assume systematic errors were linear in temperature and "circular" in
* time [of day?].


L. Hradilek
“Evaluation of refraction by geodetic measurements,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 191–193.

* Czech geodesist Ludvík Hradilek compares two ways to treat refraction
*      He points out that the best method depends on the distribution of the
* points in the network, in both the vertical and horizontal directions.
* Cites the followeing paper as an example.


R. Blažek and L. Hradilek
“Investigation on refraction in trigonometrical leveling traverses,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 195–201.

* Radim Blažek and Ludvík Hradilek show how to do it: by adding vertical
* angles and long (4 km) separations between stations to a levelling survey.
* "To obtain more information about refraction, trigonometric leveling
* traverses were designed as double traverses, i.e. two vertical angles
* were observed both foresight and backsight at most of the stations.
* . . . .Additional observations for vertical angles made it possible to
* calculate one coefficient of refraction for each station."


K. Ramsayer
“The accuracy of the determination of terrestrial refraction from reciprocal zenith angles,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 203–212.

* Karl Ramsayer shows an experimental example.


H. Kahmen
“Numerical filtering of refraction coefficients,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 213–225.

* H. Kahmen splits refraction into daily and annual sine-waves
*      "The central moments of these two components are used to estimate
* the covariance matrix of time series of refraction coefficients.
* Different functional and stochastic models are tested in connexion with
* time averaging of refraction coefficients."
*      Not much connection with the real world; it's all based on simulations
* that use average conditions.


F. K. Brunner
“Vertical refraction angle derived from the variance of the angle-of-arrival fluctuations,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 227–238.

* Fritz K. Brunner uses MOST, citing Lawrence & Strohbehn (1970)
*      Unfortunately, he uses the old Barrell & Sears refractivity formula.
* He also uses a constant value (9.8 K/km) for the adiabatic lapse rate.
* This is purely a theoretical study; no experimental data are offered.
*      An Appendix derives the theory, and refers to Dyer's (1974) values
* for the function constants. Big N is used for the (scaled) refractivity
* of air, again referring to Barrel [sic] & Sears.


D. C. Williams
“Results from an absolute test of the NPL dispersometer over 4 km,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 239–240.

* D. C. Williams describes some test data
* ". . . in late May 1978, the effects of turbulence were particularly
* small. The refraction-corrected theodolite readings then agreed with the
* expected value to within one sexagesimal second. Other results obtained
* during the preceding two months indicate that increasing turbulence
* causes the dispersion angle to appear too large, the greatest error
* observed being about 3 seconds of refraction."
*      "The performance of the instrument has also been evaluated on a 20
* km range near Uppsala during the present Symposium, by kind invitation
* of Prof. E. Tengstrdm. The principal difference from the 4 km range was
* that the intensity scintillations of the red and blue signals were no
* longer correlated when the refraction was large."


S-G. Mårtensson
“Experiences from IDM measurements at the test base of the Geodetic Institute of Uppsala University,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 241–247.

* Swedish geodesist S-G. Mårtensson
*      "IDM measurements carried out in Uppsala sometimes show violent changes
* in refraction over short periods of time."
*      ". . .  it seems as if the refraction contains of two . . .  essential
* spectral parts."
* "The high frequency spectrum is caused by the atmospheric turbulence and
* the low frequency spectrum corresponds to the refraction obtained, for
* instance by vertical angle measurements (or atmospheric models)."
*      "This is, of course, nothing new. It is a wellknown phenomenon and has
* been mentioned in the literature by several authors, among others by
* G. Dietze (Dietze, G.: 1957) . . . ".
*      "The new and interesting thing is that parts of the high frequency
* spectrum have been detected by IDM measurements in Uppsala, and the
* contents of this paper deal with certain properties of that spectrum."
*      Refraction data are shown, measured in "cc", the abbreviation for
* "centesimal seconds". The new "high-freq." fluctuations are probably
* due to laser speckle.


J. Milewski
“Possibilities of increasing the accuracy in the determination of refractional angles with Tengström's IDM,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 249–266.

* J. Milewski discusses Tengström's instrument, and possible improvements
*      In the Discussion, there is much interesting info in Tengström's
* remarks about water vapor on pp. 264-265.


R. Pazus
“Application of refractional effects in geodetic framework of Iraq by continuous trilateration,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 267–274.

* R. Pazus describes the Polish survey in Iraq
*      "During initial observations many interesting remarks about the
* refraction effects were made. In the evening receding of the horizontal
* line was being observed and objects on the horizon had shapes unnaturally
* elongated. This phenomenon occurs during the whole night and early in
* the morning later on the profile of objects diminishes and they conceal
* under the horizon. It happened that light of desert settlements situated
* at a distance of over 100 km was being observed at night.
*      "A phenomenon of "picture division" is also interesting; the point
* is that during a very short time in the morning and in the evening,
* a picture being at a distance of several kilometers is seen double.
* At the beginning, in the evening a target picture elongates; later
* on it divides into two and, for example the target is seen distinctly
* at a higher level, and in less sharp outline, at a lower level. After
* several minutes this phenomenon disappears. However, very often during
* the day-time two horizon lines separated by a layer giving the optical
* illusion of water surface is being observed."
*      The figures show the diurnal changes in refraction quite vividly.
* The large refraction at night was used to link widely separated
* stations. [cf. the Survey of India, where the same trick was used.]


J. Kakkuri and O. Ojanen
“Computing parallactic refraction for stellar triangulation,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1979), pp. 275–279.

* Geodesists Juhani Kakkuri and Ossi Ojanen calculate PARALLACTIC REFRACTION
*      They use Oterma's (1960) tables and secant formula, which are useful
* only to 85° ZD.
*      "The analyses show that parallactic refraction can be calculated using
* Oterma's theory with an accuracy of about ± 2 sec of arc for zenith
* distances from 70° to 75°, The accuracy of this order is also obtained
* for zenith distances from 75° to 80°, but from 80° to 85° the segment
* seems to become greater and correlated to the zenith distance, which
* may be an indication of unsatisfactory modelling of the atmosphere."
*      [Most likely, the increasing errors and their sizes suggest that the
* neglected TILT EFFECT is the cause.]


T. J. Kukkamäki, J. Saastamoinen, B. Garfinkel, J. A. Hughes, and D. G. Currie
“Discussion about computing parallactic refraction in model atmospheres,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 281–283.

* Chairman T.J. Kukkamäki, et al. discuss PARALLACTIC REFRACTION
*      The discussion was introduced by Saastamoinen, who complained that
* "there is no model atmosphere that can be used for calculating it." His
* reason is that the part of the atmosphere above the balloon or light
* source is excluded, so one should know the refraction above the object.
* [I think this is not a big problem, as the missing part is usually small.]
* He also points out the neglect of tilt: "There is also the effect of
* uncompensated isopycnic tilts."
*      Garfinkel disagreed: "If the model is good for infinity, it should be
* good for a distance which is less than that."
*      Teleki supported Saastamoinen, but then said that Kakkuri's discrepancy
* "is a result of the tilting of the realistic atmosphere."
*      Garfinkel then pointed out that Saastamoinen's "compensation" only
* applies to small ZDs, not near the horizon.
* [All these people seem to miss the point that the structure near the
* observed object is basically irrelevant.]


I. Brook, D. G. Currie, A. H. Dodson, and K. Poder
“EDM panel on instruments and atmospherical corrections,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 285–292.

* I. Brook (chairman),D.G. Currie, A.H. Dodson, K. Poder
* Brook: "Very few instruments seem to advance beyond the prototype stage
* and I think it is a question of nonprogress in many ways."
*      Currie and others then discussed the economic problem: very accurate
* instruments are very expensive. Why are such high accuracies needed?
* Several people mentioned the measurement of crustal movement as an
* important problem: relative motions are about 5 mm per year. Some kind
* of 2-color instrument seemed promising (this was 1979).
*      Poder pointed out that "when you have a long range you get a
* separation between the red and the blue, which means what you are
* aiming at you do not really get, because the two waves will propagate
* in different atmospheric layers." To avoid this, he favored joining many
* short sections together to make a long line. But then Kukkamäki said:
* "How can we project these individual sections to the chord? We need
* very accurate break angles, which are hard to obtain."
*      Later, Poder returned to this point, saying "The projection effect
* is such that for a typical line you will lose a maximum of about 10% of
* the accuracy on the projection. Normally, the loss will be only a few
* percent."
*      Then the issue of absolute calibration came up.
* Brook: "How shall we calibrate these instruments? If we shall come
* down to 0.1 mm, we must have standards which are a power of ten better
* than the actual instrument."
*      Dodson, speaking of his Mekometer experience, said: ". . .  to get a
* calibration better than 0.5 ppm is certainly not easy."
*      The Discussion is summarized on p. 292.


T. J. Kukkamäki
“Levelling refraction research, its present state and future possibilities,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 293–299.

* T.J.Kukkamäki on levelling
*      He initially found that image jitter was worst in mid-summer, so he
* proposed that levelling work must be interrupted fir 6 weeks from mid-
* summer to August.
* Then he found that the rod image was bad at noon, but got better later
* in the day. "Even when the sun was below the horizon this image seemed
* to be clear and unmovable. So I proposed that we should construct fitting
* instrumentation for observations in dark period, 1.e. some devices for
* lighting the rod scale and the levelling instrument itself. Before
* starting the practical measures in that direction, we made a lot of
* research into the microclimatic and also optical conditions in the
* first three meters of atmosphere above the ground, and I think, we got
* rather clear picture of the conditions there. As these details seem to
* be unclear to many scientists, even to those who have published about the
* levelling refraction, I should like tell something about our experience
* on the matter." [This was a nice way of saying that some people don't
* know what they are talking about.]
*      He then outlines the diurnal cycle, and the fact that it's greater
* when the sky is clear. He also describes the slow motion of the sharp
* images under the nocturnal inversion. "The amplitude of the swaying . . .
* was with a temperature gradient of +0°.2/1m in average 1 mm for 75 m sight
* length."
*      "So this result showed that the levelling in night, when the vertical
* gradient always is positive, is not possible with an accuracy requested
* for precise levelling."
*      "Normal sight length in precise levelling is 40, 50 or 60 m.  I cannot
* understand that e.g. in USA even 150 m sight length was accepted still
* in the instructions of 1929. When vibration makes observing difficult
* the sight length is to be shortened. When even 30 m is not short enough
* the observation is to be interrupted. I think that this understanding
* about the vibration is accepted generally."
*      "Naturally the gradient is greater nearer to the ground. So the
* horizontal sight in levelling bends more in uphill sight where it comes
* nearer to the ground than in the downhill sight." Then he discusses the
* various (mostly wrong) formulae used for the temperature profile. To
* illustrate the general ignorance of refraction, he says:
* "Further we have noticed that in some cases rather strange apprehensions
* came in view. For instance one serious scientist said in discussion
* with me 40 years ago, that light is bending in morning upwards as the
* temperature is rising and in afternoon it is bending downwards as the
* temperature is going down. In an article of Bulletin godsique 20 years
* ago it is said that soon after the noon when the turbulent mixing reaches
* its maximum the temperature gradient is zero and no bending of light
* beam appears." So they decided to make their own temperature measurements.
* "At first we observed with thermocouple the temperature at 1/3, 1 and
* 3 meter, but we found soon that the second derivative of the temperature
* is not possible to determine from single set of temperature readings. One
* needs long recordings. Since that we have observed only one temperature
* difference between 0.5 and 2.5 meter." They adopted a weak
* negative-power (-0.1) law for the temperature, which roughly resembles
* the logarithmic term in MOST. [This was in the 1930s, long before M&O.]
*      The figure shows the mean diurnal changes in refraction.


O. Remmer
“The direct experimental detection of the systematic error of precise levelling,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 301–303.

* Danish geodesist O. Remmer solves for a single refraction parameter in the
* least-squares adjustment, citing only his 1977 paper. His 1-page note
* is followed by 2 pages of Discussion, in which the Danes and the Finns
* took different points of view:
*      Saastamoinen: "Maybe the Danish pessimism somehow depends upon the
* topography of Denmark. What is the height of the highest mountain in
* Denmark?"
*      Remmer: "I am not going to speak about high mountains in flat Denmark.
* Our experiences are based on 20 m height differences."


S. R. Holdahl
“Removal of refraction errors in geodetic leveling,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 305–319.

* NOAA geodesist Sandford R. Holdahl
*      "Refraction error is often regarded as the most serious problem with
* geodetic leveling. Its accumulation depends on the slope of the terrain
* being leveled, length of sight, and the vertical temperature gradient.
* Refraction error can be minimized by limiting and balancing sight lengths,
* and by not reading the portion of the level rod which is within 0.5 meter
* of the ground where air density changes most rapidly. The remaining
* refraction error should be removed by application of a correction to
* leveling data, otherwise heights and crustal motion may be determined so
* weakly that meaningful conclusions or interpretations cannot be inferred
* from the data by geophysicists."
*      After noting that refraction corrections to levelling originated in
* Finland, he says:
* "Most countries have been reluctant to utilize the refraction correction.
* This is probably due to several factors: (1) extra instrumentation
* and computational effort are required, (2) disbelief in the idea
* that temperature in the lowest 3 meters can be represented by a single
* temperature function, and (3) belief that refraction error is small.
* The full effect of leveling refraction is normally not seen in misclosures
* between forward and backward levelings because it is usually common to
* both in approximately the same amount. Similarly, circuit misclosures
* do not reveal the total refraction error, consequently it is sometimes
* underestimated."
*      He ran an experiment in California to check this, in December "when
* temperature gradients should be smallest. Observed vertical temperature
* differences averaged 4-10 times as large as those predicted by a table
* developed by A. C. Best (Best 1937)." (These were the data used by
* Remmer, in the previous paper.) "The high Δt values observed in
* California are alarming because they indicate, provided the existing
* refraction correction is valid, that refraction error in California and
* probably the remainder of the United States is much greater than was
* assumed previously.
*      "A further objective of the experiment was to see whether vertical
* temperature gradients were larger on south slopes (i.e. slopes facing
* down to the south) than on north slopes (i.e. slopes facing down to the
* north). Simultaneous observations on north and south slopes revealed
* that south slopes gave vertical temperature differences, between
* heights of 50 cm and 250 cm, that averaged .89° C higher than north
* slopes. This result is disconcerting because it means that refraction
* error accumulated while leveling up the south slope of a topographical
* feature will generally not be canceled adequately by refraction error
* of the opposite sign accumulated while leveling down the north side.
* In mid-latitudes, refraction error will systematically accumulate in
* the north-south direction as each topographical feature is traversed
* by leveling." He later gives formulae to correct for this; they allow
* for heat conduction into the ground. "The described method is regarded
* as tentative. . . ".


J. Larsson
“Refractional effects in photogrammetry,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 321–325.

* Swedish photogrammetrist J.Larsson
*      He first explains photogrammetry, and then summarizes the (rather
* crude) methods used to correct for reraction.
*      The Discussion is started by Saastamoinen, who seems well acquainted
* with photogrammetry. An interesting point is that if the camera in
* looking through a plane window in a pressurized airframe, the refraction
* at the window can cancel the atmospheric refraction seen from a height
* near 6 km.


J. C. de Munck
“The use of multi- or single wave methods to eliminate terrestrial refraction from geodetic measurements,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 327–330.

* Dutch geodesist J. C. de Munck briefly reviews the various methods.


E. Tengström
“Round table discussion about the use of dispersion methods for determining refractional effects in astronomy and geodesy,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 331–341.

* Chairman: E. Tengström
*      He asked if anything had been done to eliminate refraction "before
* Dr. Currie . . . . Or is this the first time the two-colour principle has
* been applied in astrometry?" Teleki said no; but Tengström mentioned
* Hertzsprung's 1912 paper. He added: ". . . it was the first time an
* astronomer tried to determine the actual atmospheric dispersion,"
* [This is absolutely not true! The green flash literature is full of
* previous qualitative (e.g., Delisle, Bouguer, Dollond, Minasi, Lee)
* and quantitative (W. Herschel, Biot & Arago, Rambaut, etc.) work.]
*      After a brief digression into whether or not the refraction is really
* proportional to the refractivity, in which Garfinkel pointed out the
* reality of "higher order terms", and Currie dismissed them as
* unimportant, the discussion shifted to the dispersion of the atmosphere.
* Here Milewski said "The region 2000 Å to 7000 Å is without great
* resonance influences with the atomic and molecular structure of the
* atmosphere." He was evidently talking about the effects of absorptions
* on the dispersion of air -- which today we know is a significant effect
* -- let alone the ozone absorptions in this region! [Milewski said "down
* to about 2000 Å which is a very deep UV." and Currie agreed with this!
*      Tengström then asserted that the 2-color method could be used to settle
* the tilt problem by observing refraction in the zenith, "or looking at
* star spectra with high resolution near the zenith," which again is
* nonsense. He then goes wrong the other way, saying that the tilt
* "would perhaps be possible to study also using greater zenith distances,
* though that is not yet proved."
*      Thankfully, Ramsayer then pointed out that the tilt effects are
* "proportional to the square of the secant of the zenith distance and
* that they get smaller the more you come to the zenith."
*      Dommanget said that "Astronomers are not really interested in the
* atmospheric refraction itself but only in the way of how to get rid
* of it." That, at least, is true.


G. H. Liljequist
“Notes on some abnormal refraction phenomena in the atmosphere,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 343–350.

* Swedish meteorologist G.H. Liljequist
*      This is a rather superficial account of refraction phenomena, mostly
* mirages and looming. "In the winter, with strong cooling of the earth's
* surface, so-called surface inversions are common . . . in fine-weather
* situations, especially when the ground is snow-covered."
*      "They are also found in late spring and early summer over the sea, i.e.
* at a time when the air is heated over the land, but the sea is still cold.
*      "In summer - or in the warm zone - the heating of the ground in daytime
* gives rise to an abnormally strong temperature decrease with height in
* the layers close to the surface."
* The superior mirage is described (but not named): "The image of a
* dark object situated at a critical distance is seen like a vertical
* dark pillar. The "points" constituting the ground - or snow surface -
* are then drawn out vertically to present an image of the surface similar
* to a gigantic wall surrounding the observer at a distance of 1/2-5 km
* or more . . . . Objects at greater distance may disappear from view."
*      Bad "seeing" is described as "scintillation".  The Novaya Zemlya
* phenomenon is described. "Over an ice-covered sea a marked inversion
* can develop in the low layer and this inversion is not affected by any
* underlying topography - the surface is more or less flat."
*      With only 3 references, this is a pretty slim effort.  I was surprised
* at the responses to it in the following session (below).


G. Teleki et al.
“Cooperation between astronomers, meteorologists and geodesists for solving refractional problems,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 351–354.

* Chairman: G. Teleki
*      Teleki: "After professor Liljequist's lecture I am more pessimistic
* than before. . . . Professor Liljequist's contribution today has
* emphasized the difficulties in treating the refractional problem without
* careful meteorological information."
*      Garfinkel asked for observational tests of his model: ". . .  the
* polytropic index . . . is not a constant, but it varies with the season
* of the year and possible also with the geographical location." He
* offered to provide his program on IBM cards, along with "corrected
* reprints of the paper, with removal of all misprints found so far."


F. K. Brunner
“On precursors of electromagnetic wave propagation,” in Refractional Influences in Astronomy and Geodesy (IAU Symp.89) , E. Tengström & G. Teleki, ed.
(D.Reidel, Dordrecht, 1989), pp. 357–369.

* F.K. Brunner
*      Brunner is plainly not a physicist.  The distinction between phase and
* group velocities is involved here.
*      Discussion of REFRACTION VARIATIONS:
*      The useful information here is that Angus-Leppan reported that his
* "TTM" model (basically MOST) cut the EDM errors in half, compared to the
* conventional method of reduction. (Of course, that has nothing to do
* with the "precursor" stuff.) ". . . we used the model for trigonometrical
* heighting over a fairly short line, but one which was grazing all the way,
* so it was a difficult case. The coefficient of refraction, which has a
* standard value of 0.13, varied by several units! But the prediction of
* that coefficient of refraction by our model was down to about 0.1 unit.
* So that it was able to model a very big variation rather accurately.
* What really impressed us, was the fact that the model was able to take
* into account some rapid changes, when shadow came over the line, and
* the agreement between the observed angles and the predicted ones was
* very good, even with the sudden changes." (P. 364)
*      There are many more pages of discussion, mainly to do with the 2-color
* method and atmospheric dispersion. Mårtensson described night-time
* measurements in which "we have never been in the neighbourhood of
* what we call normal refraction. It seems more like we are measuring in
* periods where we have two times or even three times the normal refraction.
* With normal refraction I mean a k-value of 0.13 or 0.14. We have never
* been in that region." (p. 367) ". . . most of the times we had two to
* three times the normal refraction, and even just one week ago we had a
* k-factor equal to 1.04 at 2 o'clock in the night. For practical reasons
* we only measure during night-time, and our extreme results might be
* explained by our existing inversion layers."
*      In the discussion of systematic errors, Kukkam&ki said: "When measuring
* our 900 km traverse with 25 legs, 30 km long, with geodimeter, we have
* found that there is some slight systematical difference between the
* observations before noon and after noon. And we have not been able to
* find out the reason for that. So, it means there are some systematical
* errors in these reduction formulas and reduction observations which we
* have used to reduce our observations to one and the same consistent
* system." (p. 368) [Probably the failure to use MOST was the cause.]


E. Høg and C. Fabricius
“Atmospheric and internal refraction in meridian observations,”
Astron. Astrophys. 196, 301–312 (1988).

* TILT estimated: 36" on La Palma
* (cf. Fletcher, 1952)
* ". . . the layers are on average tilted towards north, i.e. making the
* angle betweenn [sic] the layers and the terrain surface at the La Palma
* site slightly smaller than if the layers were horizontal."
* [That is, the isopycnic surfaces tend to follow the terrain.]
* ". . . and a variation from night to night also of 36" rms . . . ."


A. I. Nefed'eva and V. S. Borovskikh
“Reductions to astronomical refraction for the global tilt of air layers of equal density over the USSR,”
Sov. Astron. 32, 690–691 (1988).

* TILT measured: 1.3 arcmin
* The measurement is in an earlier paper by A.I.N. This one estimates
* tilts from meteorological data, and generally finds them less than a
* minute of arc [as we would expect from Fletcher (1952).]
* [translation of A.Zh.65,1322-1324(1988)]


Yu. A. Nefedjev and A. I. Nefedjeva
“Determination of refraction anomalies by global inclinations of airstratas of identical density,”
AN 326, No. 8, 773–776 (2005).

* Summary of work at the Engelhardt Observatory
*      Typical tilt is about 1 arcmin; refraction error can reach 0.1 arcsec
* at 70° Z.D., and more than 0.3" at 80°. Mean meteorological conditions
* are used in the models.
*      The models used include the reversal of tilts in the lower stratosphere
* (above the isopycnic level), but even so the overall effect is dominated
* by the local lapse rate at the bottom. The model calculations extended
* only to 80° Z.D., so it is no surprise that the tilt corrections are well
* represented by a sec2 Z term.
*      There is a good list of A.I.Nefedyeva's Russian papers -- mostly from
* Izvestya EAO. (No mention of Sugawa's very similar work decades earlier.)


C. Hirt
“Monitoring and analysis of anomalous refraction using a digital zenith camera system,”
Astron. Astrophys. 459, 283–290 (2006).

* HIRT sub-file: GEODESY and deflection of the VERTICAL with TILTED LAYERS.
*
* Refraction anomalies measured with digital zenith camera
* Refraction at the zenith varies from 0.05 to 0.2 arcsec at periods of
* hours; slower systematic effects reach 0.04 arcsec. "The accuracy
* of the filtered data has been found to be about 0."05 to 0."08."
* The errors are "obviously not" due to errors in the star catalog.
* Cites mainly recent literature, starting with Sugawa's papers above.
* Also cites Ramsayer's work.


C. Hirt, S. Guillaume, A. Wisbar, B. Bürki, and H. Sternberg
“Monitoring of the refraction coefficient in the lower atmosphere using a controlled setup of simultaneous reciprocal vertical angle measurements,”
JGR 115, No. D21, D21102 (2010).

* DIURNAL cycle
*Christian Hirt,Sébastien Guillaume,Annemarie Wisbar,Beat Bürki,Harald Sternberg
* These geodesists measure the refraction coefficient (in the surveyors'
* sense); but give no meteorological info (no winds, even!) So we just
* get refraction measured over grassland.
*      This seems to be just a feasibility study.
* doi:10.1029/2010JD014067


D. van Westrum, K. Ahlgren, C. Hirt, and S. Guillaume
“A geoid slope validation survey (2017) in the rugged terrain of Colorado, USA,”
J. Geodesy 95, No. 9, 1–19 (2021).

* Further work on deflection of the vertical with automated zenith cameras
* by: Derek van Westrum, Kevin Ahlgren, Christian Hirt, Sebastien Guillaume
*      Here multiple instruments were used to get an accuracy of 0.04 arcsec
* in the direction of the vertical at 222 field stations along a 360 km
* line in the mountains of Colorado.
* doi: https://doi.org/10.1007/s00190-020-01463-8



*** REFRACTION IN ANTIQUITY FILE ***

[Cleomedes]
in Cleomedis de Motu Circulari Corporum Caelestium, Libri Duo , H. Ziegler, ed.
(B.G.Teubner, Leipzig, 1891).

*
* Let's start with several mentions of refraction in antiquity.
* Besides the reference to straight objects appearing bent when put in
* water in Plato's "Republic", there's the ``CATOPTRICS'' attributed to
* Euclid. Refraction is briefly mentioned in the last of the introductory
* propositions, perhaps best translated by A. Mark Smith in Trans. Am.
* Phil. Soc. 89, no.3, p. 127 (1999):
*      "if some object is placed in a vessel at such a distance [from the
* viewpoint] that it can no longer be seen, and if water is poured in,
* then the object placed in the vessel will be seen."
*      (Whether the author was really the EUCLID of geometry has been hotly
* debated; Smith briefly reviews the fight on p. 17 of his monograph.)
*      This is the re-discussion of Smith's earlier work on Ptolemy (see
* below)
*
*      In any case, that table-top demonstration of REFRACTION certainly
* has been known since antiquity. It is repeated by CLEOMEDES --
* about whom, nothing is known; authorities have claimed dates from the 1st
* Century B.C. to the 3rd A.D. His popular work on astronomy (a) tries to
* explain the Moon Illusion with refraction (!) [as does Ptolemy in the
* Almagest], and (b) seems to have the first suggestion that atmospheric
* refraction near the horizon might affect the Sun below the horizon:
* ". . . so that the Sun, when it has set and is below the horizon,
* presents its face to us as if it had not yet set . . . .
* For many such things appear in the air, and especially around the Sea.
* For it could happen that the ray leaving our eyes is bent on entering
* wet and humid air and reaches the Sun now hidden below the horizon.
* For besides, something similar is observed to happen among us. For if
* a gold ring is put into a cup or some similar vessel, if the vessel is
* empty, from a suitable distance the object lying on the bottom is not
* seen, to which vision would go in a straight path without the obstacle
* of the edge of the vessel. However, if it is filled to the brim with
* water, the ring in the vessel is seen from that same distance, while
* vision does not pass through the edge, but on striking the water at the
* edge of the filled vessel, vision is bent so that it descends into the
* vessel and falls on the ring. Now it could be that something similar
* happens in humid and watery air, so that the ray from the eye is bent
* below the horizon and slopes to meet the Sun when it has set, so that
* it appears to be above the horizon." [My rough re-translation of
* Ziegler's Latin translation on p. 225.]
* Evidently, Cleomedes thinks water is the essential element here.
* This appears in Book II of the "Circular Theory of the Heavens",
* Chapter 6, 124-125.
*      Unfortunately, on pp. 121ff. he tries to explain the Moon Illusion the
* same way; speaking of the Sun, he says, "For it appears larger rising and
* setting, smaller in the middle of the sky. . . ." -- and then again tries
* to arm-wave his way to an explanation with "rather thick and humid air
* (for such is the air closest to the earth)," where the visual ray "is
* necessarily bent" [refracted]. And here again he says, "and besides,
* things which are under water appear differently shaped to us".
* [All from Book II, Ch. 1, 66.]
*      See also the entry for Cleomedes in the DSB.


A. M. Smith
“Ptolemy's theory of visual perception: an English translation of the Optics with introduction and commentary,”
Trans. Amer. Philos. Soc. 86, no. 2, (1996).

* A. MARK SMITH translates PTOLEMY's "Optics" (c. 170 A.D.)
*      This is an English translation of the bad Latin translation made
* by a 12th-Century Byzantine functionary in Norman Sicily from the
* Arabic translation from the original Greek; so all bets are off.
*      Still, the publication of a fudged -- or would you prefer "smoothed"?
* table showing the relation between angles of incidence and refraction
* for water/air and glass/air (in which the second differences are
* constant, so that the original data were forced to fit a simple parabola)
* seems to show Ptolemy's touch. So the attribution to Ptolemy is
* probably correct.
*      On pp. 230-231, we have the classic demonstration -- perhaps the
* first time a coin is used: ". . . a coin that is placed in a vessel . . . .
* if the eye remains fixed so that the visual ray passing over the lip of
* the vessel passes above the coin, and if water is then poured slowly
* into the vessel until the ray that passes over the edge of the vessel
* is refracted toward the interior to fall on the coin, then objects that
* were invisible before are seen . . . ." The wording is so similar to that
* in Cleomedes that one must suppose one writer was (at best) merely
* paraphrasing the other -- especially after allowing for all the
* translations involved. But which really came first?
*      Remarkably -- considering the complete ignorance of atmospheric
* refraction displayed in the Almagest -- there is a sensible discussion
* of astronomical refraction, apparently based on observation (pp. 238-239):
*      "Furthermore, it is possible for us to realize that, at the surface
* between air and ether, there is a refraction of the visual ray according
* to the difference in density between these two media.
*      "We notice that bodies that rise and set tend to incline toward the
* north when they are near the horizon and are measured by an instrument
* for measuring the stars. . . . and the more they approach the horizon,
* the more they are inclined to the north. . . . This is a result of the
* refraction of the visual flux at the surface that separates the air
* and the ether, a surface that must be spherical, its center being the
* common center of all the elements, which is the center of the earth."
* (cf. fig., p. 240)
*      As the description is couched in terms of the diurnal circles,
* it appears that the instrument Ptolemy had in mind was the armillary,
* and not (as Smith supposes), an astrolabe.
*      From the subsequent discussion, it's clear that Ptolemy supposed the
* effect to be inappreciable except close to the horizon; between the Pole
* and the zenith, "there is no difference, or only an imperceptible one,
* between apparent and true location." (p. 241)
*      Also, in true Ptolemaic style, he does not consider determining
* refraction observationally, but thinks only of computing it "if the
* distance of the interface between the two media were known." But he
* knows only that it lies below the lunar sphere; so "it is impossible to
* provide a method for determining the size of the angles of deviation . . . ."
*      Unfortunately, Smith cannot distinguish among ecliptic latitude,
* geographic latitude, altitude, and declination, calling them all
* "latitude". This garbles his "explanations" in the notes considerably.
* (See notes 15 and 16 on pp. 238-239, where he thinks an astrolabe
* measures "latitude"; and note 17, p.240; text, line 1, p.241.)
* The same errors are repeated verbatim in his rediscussion in Trans. Am.
* Phil. Soc. 89 (1999).
*      On the other hand, Smith correctly notes the lack of discussion of
* astronomical refraction in the Almagest, and Ptolemy's confusing it
* there with the Moon Illusion. We must conclude that Ptolemy did
* eventually learn of astronomical refraction from observation.


A. M. Smith
“Ptolemy and the foundations of ancient mathematical optics: a guided study,”
Trans. Amer. Philos. Soc. 89, no. 3, (1999).

* Smith's rediscussion, cited above for "Euclid".
*      Here, the "latitude" confusion is on pp. 136-137, and the notes are on
* page 146, where Smith says "apparent latitude or orbit" when what is meant
* is a diurnal circle. In note 16, he says "the actual eye-to-object
* distance has virtually no effect on refractive displacement", which is
* true for stars, but not (today) even for the Moon, and closer objects.
* And of course his phrase "actual latitudinal distance" is nonsense.
* (See p. 127)


A. Rome
Commentaires de Pappus et de Théon d'Alexandrie sur l'Almageste. Tome II. Commentaire sur les livres 1 et 2 de l'Almageste
(Biblioteca Apostolica Vaticana, Città del Vaticano, 1936).

* Rome's edition of Theon's commentaries on the Almagest (c. 400 A.D.)
* On pp. 347-351 he discusses Theon's references to Archimedes's knowledge
* of refraction. The text is in Greek; the notes are in French. See his
* discussion of the Archimedes work on Catoptrics (1932) for details.
*      More interesting here is his discussion of Ptolemy and the Almagest,
* which in fact says nothing about refraction. The odd thing is that
* the work on Optics attributed to Ptolemy says quite a lot about it;
* "Mais on ne connaît actuellement l'Optique (et même pas tout entière)
* que par la traduction latine d'une traduction arabe. L'arabe et le grec
* sont perdus. Ce passage-ci de Théon pose la question de l'authenticité
* de l'Optique, ou tout au moins la question des remaniements qu'elle a
* pu subir entre le IIe et le XIIe siècle." (p. 348)
* [cf. Smith's translation of Ptolemy's Optics, above.]
*      In discussing the supposed "explanation" of the Moon illusion by
* "refraction" -- actually, by the arm-waving about "haze" at the horizon
* -- Rome says: "En réalité, comme nous l'avons déjà dit, Ptolémée
* n'a pas l'intention de donner ici une véritable explication. Il se
* contente de rattacher vaguement le phénomène à la réfraction."



*** REGIOMONTANUS and WALTHER FILE ***

J. Schöner
Scripta Clarissimi Mathematici M. Ioannis Regiomontani
(apud Ioannem Montanum & Vlricum Neuber, Norimbergæ, 1544).

*
* SCRIPTA CLARISSIMI MATHEMATICI is the works of Regiomontanus
* (Johannes Müller), Bernard Walther, and Georgius Purbach, edited
* and published by Johannes Schöner of Carolstadt.
*
* Title page reads:
*
*                   S  C  R  I  P  T  A             C  L  A=
*                   R I S S I M I      M A T H E M A T I-
*                   CI  M.  IOANNIS  REGIOMONTANI,  DE
*      Torqueto, Astrolabio armillari, Regula magna Ptole-
*            maica, Baculoque Astronomico, & observationi-
*            bus cometarum, aucta necessariis, Ioannis
*                  Schoneri Carolostadij additionibus,
*
*                                            Item.
*                   Observationes motuum Solis, ac Stel
*                   larum tam fixarum, quam erraticarum.
*
*                                            Item.
*                        Libellus M. Georgij Purbachij de
*                               Quadrato Geometrico.
*
*
* The typography uses many obsolete glyphs that stand for common Latin
* syllables, like "pro" and "pre" and "que", made by adding crossbars
* and tildes and so on to the tails of p's and q's; see reference works
* on "paleography" to decode these.
*
* The type appears to be identical to that used in printing Copernicus's
* "De Revolutionibus" the year before. The text is full of Latin
* contractions and abbreviations, especially in the transcriptions of the
* observing records; I have the feeling it was just that way on the pages
* of the original observing logs. The folios, not the individual pages,
* are numbered (many of them incorrectly!)
*
* Walther, whose work we are interested in here, is not mentioned until
* fol. 27r, where his continuation of Regiomontanus's solar observations
* is noted in the chapter title:
*
*              I  O  A  N  N  I  S              D  E
*              M O N T E R E G I O  E T  B E R
*                  NARDI VVALTHERI EIVS DISCIPV
*                   li ad Solem obseruationes.
*
* On fol. 27v (the back of that title page) we find, after Regiomontanus's
* last observation (28 July 1475): "Obseruationes sumptæ per regulas
* Ptolemæi, de motu Solis, per Bernardum VValtherum Nurenbergæ
* discipulum M. Ioannis de Monteregio."
*      In the succeeding pages, it's interesting to see Walther's care and
* skill developing. At first there are few remarks about the quality of
* the observations; as he goes on, there are more and more frequent
* notations like "Dubia", "Certa", or "Diligens".
*      Walther's first observation of refraction is on fol. 52v/53r (the
* latter mis-numbered 57!), in the entry for the sunset of March 6, 1489.
* The cause of the discrepancy (refraction) and his investigation of it,
* are explained in the next day's entry; but there are further references
* to refraction on 12 Dec. 1490 (fol. 54r); 9 Sept., 1491 (fol. 55r,
* mis-numbered 59); and 12 Dec. 1503 (fol. 57v). There is a long list of
* ERRATA At the end of the volume.
*      Fortunately, most of this has been translated into English by
* William H. Donahue (see next bibliography item).
* Images of the pages are available at
*      https://digital.slub-dresden.de/werkansicht/dlf/14594/1
* and formerly at
*      http://num-scd-ulp.u-strasbg.fr:8080/158/
* and on Google Books.


J. Kepler
Optics: Paralipomena to Witelo & Optical Part of Astronomy; translated by William H. Donahue
(Green Lion Press, Santa Fe, New Mexico, 2000).

* DONAHUE's translation of JOHANNES KEPLER and WALTHER
* This is mostly a translation of Kepler's work on Optics; but as he has
* a whole muddle-headed chapter on refraction, in which he quotes
* extensively from Walther's observations, we get the Walther stuff
* translated along with Kepler (see pp. 162-167, in which Kepler adds a
* running commentary on Walther's rather terse account.) From Kepler's
* point of view, the reason for dragging in Walther is to demonstrate
* that refraction is measurable, and important.
*
* Original title: Ad Vitellionem paralipomena, quibus Astronomiae pars
* optica traditur (1604)



*** REFRACTION HISTORY FILE ***

R. Rashed
“A pioneer in anaclastics: Ibn Sahl on burning mirrors and lenses,”
Isis 81, 464–491 (1990).

*
* This file deals mostly with the discovery of the sine law, etc.
* I have arranged the items more nearly in historical order than their
* order of publication; so Rashed's 1990 paper on Ibn Sahl comes first,
* then the papers on Harriot; then Snel, and finally Descartes, and Newton.
*
* Roshdi Rashed's discovery of the 10th Century Arab work (Ibn Sahl)
* ". . . a treatise on burning instruments written around 984 by a
* mathematician connected with the court of Baghdad . . . ."
*      On p. 478, the law of refraction is invoked.  A certain ratio (in
* modern terms, 1/n) is asserted to have a fixed value for all incident and
* refracted rays; but this condition is simply used to advance the geometric
* development. No values are given; no experimental evidence is offered.


J. W. Shirley
“An early experimental determination of Snell's law,”
Amer. J. Phys. 19, 507–508 (1951).

*       Beginning of HARRIOT sub-file
*
* THOMAS HARRIOT discovered the sine law first
* A second-hand account of a description of Harriot's method, but
* without establishing the date.


J. Lohne
“Thomas Harriott (1560-1621), the Tycho Brahe of optics,”
Centaurus 6, no. 2, 113–121 (1959).

* The 1959 discovery that Harriot had known the sine law in 1602,
* based on his observations in 1597 and 1598.
* N.B.: there is an interesting aside here on Kircher (p. 114):
* "It is interesting to note that Kircher (Ars Magna 1646) adopted
* Kepler's formula, although Descartes had published the law of sines many
* years before. Kircher's own experimental values were poor."


J. Lohne
“The fair fame of Thomas Harriott: Rigaud versus Baron von Zach,”
Centaurus 8, 69–83 (1963).

* Johs. Lohne's 1963 paper, stating that Harriott had the law in 1601.
* (saved as Wiley's PDF only)


C. de Waard
“Le manuscrit perdu de Snellius sur la réfraction,”
Janus 39, 51–72 (1935).

*       Beginning of SNEL sub-file
*
* Cornelis de Waard's discovery of the Snellius outline
* Here we have (p. 68) prop. 47 of Liber 1: "The maximum refraction of
* the stars occurs at the horizon." Note that this occurs among
* propositions describing refraction in a sphere (props. 40-57).
* See also prop. 50, 52-55. Props. 53-55 deal with the relation between
* refraction and the height of the atmosphere.
* Note the 4 pages of the manuscript reproduced in Pl. I & II, from which
* we see that the transcription is not 100% correct. For example, Fig. 6
* shows that the manuscript has "remotior, et minor: contra in densiore",
* which de Waard transcribed as "remotior et minor, contra in densiore."


J. A. Vollgraff
“Snellius' notes on the reflection and refraction of rays,”
Osiris 1, 718–725 (1936).

* Snel's notes
* This was prompted by de Waard's paper the previous year on Snel's
* outline, which Vollgraff calls "an index". On p. 722 the place of the
* image is discussed, showing that Snel doubted the idea that it lay on
* the perpendicular (a concept much discussed later in connection with
* Descartes).
* Note the typo of "1921" for "1621" on p. 723.
*      "I venture . . .  not to affirm, but to suggest, that at . . .  December
* 1621, Snellius had already found the law of refraction." (p. 724)
* On p. 725 we have Snel's brief account of a distorted sunset, invoking
* "vapores crassos" as the cause of the flattening -- cf. Bouguer (1729).


K. Hentschel
“Das Brechungsgesetz in der Fassung von Snellius,”
Arch. Hist. Exact Sci. 55, 297–344 (2001).

* Klaus Hentschel discusses the Snellius outline
* This discusses the outline draft discovered in Amsterdam by de Waard.
* Of particular interest here are the references to astronomical and
* terrestrial refraction, both in Snel's outline and notes, and in Vossius's
* optics text. See p. 317 for Snel's discussion (in sections 47--55; Snel
* probably also was thinking of astronomical refraction in connection with
* section 56 (p. 318). It occurs again on p. 319.
*      On p. 324, the references to Snel's book by Vossius give values for
* n for glass, air, and water; density is invoked. Chapter XVIII on the
* refractions of the Sun and distant mountains are of particular interest.
* The famous example of the coin at the bottom of a vessel filled with
* water recurs on p. 329.
*      Odd that nobody caught the wrong values for the length of a degree
* of the meridian on p. 333, note 12.


R. Descartes
Discourse on Method, Optics, Geometry, and Meteorology; Translated, with an Introduction, by Paul J. Olscamp (Revised Edition)
(Hackett Publishing Co., Indianapolis, 2001).

*       Beginning of DESCARTES sub-file
*
* RENÉ DESCARTES finally publishes the law in 1637
* This is a new translation by Paul J. Olscamp
* The "Optics" section begins on p. 65. Of light, he says (p.66):
* ". . . it will suffice that I make use of two or three comparisons which
* help to conceive it in the manner which to me seems the most convenient
* to explain all those of its properties that experience acquaints us
* with, and to deduce afterwards all the others which cannot be so easily
* observed; imitating in this the Astronomers, who, although their
* assumptions are almost all false or uncertain, nevertheless, because
* these assumptions refer to different observations which they have made,
* never cease to draw many very true and well-assured conclusions from
* them."
* On pp. 80-81, the sine law is presented as an exercise in proportion,
* without once mentioning sines of angles; no doubt because (p. 66) ". . .
* inasmuch as the execution of the things of which I shall speak must
* depend on the skill of artisans, who ordinarily have not studied, I
* shall attempt to make myself intelligible to everyone, and to omit
* nothing, nor to assume anything that might have been learned in the
* other sciences." (As Lohne (see above) shows, these diagrams go back
* to Ptolemy.)
* The model used is the corpuscular one usually attributed to
* Descartes's follower, Newton: ". . . inasmuch as the action of light
* follows in this respect the same laws as the movement of the ball. . . ."
* So he requires the light to move faster in the denser medium.
* There is an interesting discussion of "burning-glasses" on pp.146-147
* in which he considers the brightness of images, concluding that two
* lenses of the same form (and hence, focal ratio) but different sizes
* must produce equally hot images. "From this you can see that those who
* are only half informed in Optics allow themselves to be persuaded of
* many things which are impossible, and that those mirrors with which, it
* is said, Archimedes burned far-off ships must have been extremely large
* -- or rather, they are fabulous."


G. Videen
“Whose law of refraction?,”
Optics Photonics News 19, No. 5, 15–17 (May, 2008).

* Gorden Videen's opinion of Ibn Sahl is like mine.


A. Malet
“Gregorie, Descartes, Kepler, and the Law of Refraction,”
Archives internationales d'histoire des sciences 40, No. 125, 278–304 (1990).

* Antoni Malet's synopsis of Gregory's belated discovery parallels Ibn Sahl's
*      This is about James Gregory's 1663 publication of the sine law, which
* he was able to discover by a process similar to that which Ibn Sahl
* apparently used. Gregory seems to have begun with Kepler's argument,
* but rejected Ptolemy's fudged "measurements" instead of believing them.
*      He had used his understanding of conic sections to design the reflecting
* telescope named after him, published in 1657.


F. Arago
“Appendice: Éloge historique d'Augustin Fresnel,” in Œuvres Complètes d'Augustin Fresnel
(Imprimerie Impériale, Paris, 1870), p. 475.

* ARAGO credits Descartes with the discovery
* After mentioning Ptolemy's work on optics, which includes a doctored
* laboratory (not astronomical) refraction table, he says:
* "Quant à la loi mathématique de ces déviations que l'Arabe Alhasen,
* que le Polonais Vitellio, que Kepler et d'autres physiciens avaient
* inutilement cherchée, c'est à Descartes qu'on la doit. Je dis
* Descartes, et Descartes seulement; car, si les réclamations tardives
* d'Huyghens en faveur de son compatriote Snellius étaient accueillies,
* il faudrait renoncer à jamais écrire l'histoire des sciences."
*      Alas for Arago's prioritistic preferences, Snel today receives the
* honor; though, in accord with Stigler's Law of Eponymy, he was preceded
* by Harriot.


J. F. Scott
The Scientific Work of René Descartes (1596--1650)
(Taylor & Francis, London, 1952).

* As fair and even-handed assessment of the priority issue as any
* Scott thinks that "Descartes did not hear of Snell's work until the end
* of 1632, and it is not impossible that by this time his own researches
* were so far advanced that he had little to learn from Snell. . . .
* [Constantyn] Huygens met Descartes in Golius's house in 1632 and
* they discussed refraction at some considerable length. If, as seems
* not unlikely, Golius on this occasion mentioned Snell's discovery,
* and if, as seems equally likely, this was the first occasion on which
* he had announced it, Descartes has every claim to be regarded as an
* independent discoverer." (p. 38)


J. G. Burke
“Descartes on the refraction and velocity of light,”
Am. J. Phys. 34, 390–400 (1966).

* A physicist's views on Descartes, refraction, and speed of light
* He seems to think Descartes's thought-experiments were real.
* Many useful references here.


W. B. Joyce and A. Joyce
“Descartes, Newton, and Snell's law,”
JOSA 66, 1–8 (1976).

* Discussion and partial translation of Descartes's work
* "Descartes' insightful derivation of Snell's law is . . . largely
* equivalent to the mechanical-particle or corpuscular derivation often
* attributed to Newton . . . ."
* [I would have said "implausible" rather than "insightful".]


S. Sakellariadis
“Descartes' experimental proof of the infinite velocity of light and Huygens' rejoinder,”
Arch. Hist. Exact Sci. 26, 1–12 (1982).

* An incredibly muddle-headed discussion: he accepts Descartes's ignorant
* assumption that the position of the Sun was known independently of the
* Earth's shadow, and that ingress could be timed to a fraction of a second!
* (Huygens, who was an experienced observer, made a more realistic error
* estimate.)
*      In addition, there's a spelling error in footnote 10.


B. S. Eastwood
“Descartes on refraction: Scientific versus rhetorical method,”
Isis 75, 481–502 (1984).

* One of the more grotesque attempts to make sense of Descartes


I. Newton
“A Letter of Mr. Isaac Newton, professor of the Mathematicks in the University of Cambridge ; containing his New Theory about Light and Colors . . . ,”
Phil. Trans. Roy. Soc. Lond. 6, No. 80, 3075–3087 (1672).

*       Beginning of NEWTON sub-file
*
* ISAAC NEWTON's first publication on prismatic dispersion
* This is the precursor to "Opticks": ". . . in the beginning of the Year
* 1666 . . . I procured me a Triangular glass-Prisme, to try therewith the
* celebrated Phænomena of Colours. " (p.3075)
*      ". . .  Light  consists of Rays differently refrangible,  . . .      When
* I understood this, . . . I saw, that the perfection of Telescopes was
* hitherto limited, not so much for want of glasses truly figured . . . , as
* because that Light it self is a Heterogeneous mixture of differently
* frangible rays. " So Newton discovers chromatic aberration, and turns
* to reflecting telescopes.



*** GENERAL REFRACTION FILE ***

T. Brahe
Astronomiae instauratae progymnasmata
(Kepler, Prague, 1602).

* see also Fletcher's masterful review, in the "Variable Refraction" file.
*
* TYCHO BRAHE's REFRACTION TABLE (first publication)
* This work is reproduced in Dreyer's TBOO, Vol. 2; see
* I.L.E.Dreyer, ``Tychonis Brahe Dani Opera Omnia'' (Hauniæ, 1913).
* The solar refraction table is on p. 64 of TBOO, but on p. 79 of the
* 1969 reproduction by Culture et Civilisation (Bruxelles).
* The refraction table for stars is on p. 280 of the latter.
* (Comparison with page citations in "Kepler's Optics" shows that the
* 1969 reprint has the original pagination.)
*      Note Tycho's comment next to the stellar refraction table saying
* that the stellar values are 4 1/2 minutes less than the solar ones.
* This is true for all the tabular values but the ones right at the horizon,
* which were apparently rounded off to the nearest minute.


J. Kepler
Optics: Paralipomena to Witelo & Optical Part of Astronomy
(Green Lion Press, Santa Fe, N.M., 2000).

* KEPLER's discussion of Tycho's refraction tables, etc. (1604)
* [See additional reference to this in the Distorted Sunsets file.]
* This is translated from Kepler's "Ad Vitellionem paralipomena" (p. 118/9)
* by William H. Donahue (p. 132 of his translation):
*      Here Kepler sees the weakness in Cassini's model half a century before
* Cassini has invented it! He discusses the homogeneous atmosphere model
* in general terms -- not knowing the law of refraction -- and sees that
* the angles of incidence at 89 and 90 degrees' apparent ZD are too similar:
*      "The increments of the refractions are in fact not large enough. . . .
*      "In sum, it should be noted that the proportional refraction from
* 89° to 90° is going to be extremely small in the difference, because,
* while the inclination on earth varies by one degree, in air it varies
* by barely 13 minutes." So he sees that, whatever is the actual
* refraction law, the model can't produce a steep enough slope at the
* horizon; but, lacking the language of calculus, he can't pin things
* down well enough to see that the model itself is in error; instead of
* a general law, he has only a mass of discrepant numbers.
*      He also points out that Tycho's numbers are rounded off at the
* horizon: "In fact, since the refractions presented by Tycho could
* not attain such precision from observation as is here required, you
* accordingly see them rounded off to exactly 34 minutes at altitude 0°
* and 26 minutes at altitude 1°." (Donahue p. 133)
*      There are also some nice early examples of variable refraction near
* the horizon, cited on pp. 147 ff. of the translation (K. pp. 135 ff.)
* [See the reference to the Landgrave of Hesse on p. 149 (K. p. 136).]


J. Kepler
Tabulae Rudolphinae
(J.Saurus, Ulm, 1627), p. 119.

* TYCHO BRAHE's refraction table, reprinted in Kepler's Rudolphine Tables
* This is the first table ever used to correct apparent positions for
* refraction. Because Tycho's observations were only good to a couple of
* minutes of arc, he could not detect refraction above 45° and thought
* there was none.
*      Note that he gives separate  tables for Sun, Moon, and stars.  As
* pointed out by Owen Gingerich, in his paper with James R. Voelkel in
* JHA 29,1-34 (1998) on "Tycho Brahe's Copernican campaign", the odd
* result for the Sun is mostly (though not entirely) due to the assumed
* solar parallax of 3' of arc. His values for stars are mostly good to
* about 2' of arc, and the errors are about equally + and -.


G. D. Cassini
Specimen Observationum Bononiensium
(Ex typographia H.H.de Ducijs, Bononiæ, 1656).

* CASSINI's pre-refraction work on the solar position
* Here he reports a selection of results from the "heliometer" (a
* gigantic pin-hole camera) in the cathedral at San Petronio.
*      Refraction is mentioned as a problem on p. 1, and gets considerable
* attention on p. 12. On p. 16 he points out that the refraction in
* Bologna is less than at Uraniburg. It is discussed in detail on p.18,
* where he accepts Tycho's table: no refraction above 45°. Finally,
* there are brief mentions on pp. 23 and 31.
*      On p.30 he points out that the two hypotheses about the motion of the
* Sun predict a difference in its apparent diameter at perigee and apogee
* of only 1 minute of arc, which is why it was so diffucult to determine
* this observationally. And "nothing is more natural than that a closer
* object appears larger." But he finds from the daily motions that the
* physical motion is faster at perigee as well --- as, of course, Kepler's
* second law requires.
*      This work shows how the refraction, the solar parallax, and the
* obliquity of the ecliptic are entangled in the observed altitudes.
* It sets the stage for Cassini's later work.
*      Note the diagram of the Ricciolian system in the Figure at the back!
* The full title is "Specimen Observationum Bononiensium, quæ novissimè
* in D. Petronii templo ad astronomiæ novæ constitutionem haberi cœpere"


G. D. Cassini
[correspondence on refraction], in Ephemerides Novissimæ Motuum Coelestium Marchionis Cornelii Malvasiæ
(ex typographia Andreæ Cassiani, Mvtinæ impensis avthoris, 1662).

* CASSINI's refraction table (first publication)
*      This is where Cassini's refraction table first appeared (p. 173).
* The nominal author is Malvasia; but the text is partly his and partly
* Cassini's. The preface (on unnumbered pages) is by Malvasia, and printed
* in italics. There are some dedicatory and introductory letters and poems
* (also unnumbered); the numbered pages begin with the Ephemeris itself;
* its frontispiece counts as page 1, and the first page with an actual
* number is p. 2, with the ephemeris for January, 1661. Each month gets
* a double-page spread; the page numbers are in the top margins at the
* outer corners.
*
*      In Malvasia's preface, the general strategy for measuring and
* separating the refraction and the solar parallax is explained on the
* second and third pages: the observations reported in the Specimen
* showed that better corrections for refraction were needed. "So that
* he [Cassini] could distinguish the refractions of the Sun at all altitudes,
* he had to study the general refraction law in bodies in which they are
* more evident, like in glass, water, and other liquids; . . . ".
*      There are also very interesting letters exchanged between Cassini
* and Count Malvasia, on the whole business of the solar ephemeris and
* parallax, and refraction, on pp. 152-156, and (after the Tables) again
* on pp. 174-186. This whole section is introduced with a large title
* sheet on p. 151, saying:
*
*
*                                            N O V I S S I M AE
*                                      MOTVVM SOLIS EPHÆMERIDES
*                                          EX RECENTIORIBVS TABVLIS
*                                                 CLARISSIMI VIRI
*                                     D. IOANNIS DOMINICI CASSINI
*                                    IN BONONIENSI ARCHIGYMNASIO
*                                          ASTRONOMIÆ PROFESSORIS
*                                                             A`
*                                      MARCHIONE CORNELIO MALVASIA
*                                                S V P P V T A T Æ
*              Cum Epistolis Authoris ad eundem Cassinum , eiusdemque
*                                                       responsis.
*
*
* The correspondence begins in October, 1661, with a letter from Malvasia
* to Cassini (p. 152). It deals with the new solar ephemeris, and says
* nothing about refraction. Cassini's second letter (Nov., 1661) also
* deals with the coordinates of Modena and Bologna, not refraction.
* Then (p. 154) comes Malvasia's brief appeal to Cassini for help with
* the tables for the new Ephemerides (June, 1662).
*      On p. 155, Cassini's letter of mid-June, 1662, first mentions the
* refraction problem.
*      On p. 186, we see a parameter used by Cassini to calculate
* refraction:
*                                                                                                        -7
* Height of the atmosphere in Earth radii:       6095 x 10
*
*      The actual ephemerides are based on Philip Lansberge's elaboration
* of the Copernican model: heliocentric, but with epicycles, rather than
* Keplerian ellipses.
*
*      This reader is surprised to see that many everyday astronomical terms
* used here are not in most Latin dictionaries: duratio, eclipticalis,
* eclipticus, libratio, parallaxis, refractio, semidiameter, . . .
*
* The title page of this folio volume is shown on the Web pages
* of the Astronomical and Geophysical Museum of Modena, at
*            http://www.museoastrogeo.unimo.it ;
* [unfortunately, that website is now closed; but it was preserved on the
* Wayback Machine at
* https://web.archive.org/web/20081207063659/http://www.museoastrogeo.unimo.it/
* where you can find most of its pages]
* see http://155.185.1.56/lbo/img%5Clink50a.jpg for the image, which
* shows:
*
*                                          E P H E M E R I D E S
*                                            N O V I S S I M Æ
*                                            MOTVVM COELESTIVM
*                                MARCHIONIS CORNELII MALVASIÆ
* . . .
*            Additis Ephemeridibus Solis , & tabulis Refractionum , ex
*                                      nouissimis hypothesibus
*
*                          DOCTORIS  IOANNIS  DOMINICI  CASSINI,
* in Archigymnasio Bononiensi Astronomia Professoris Præstantissimi.
*
* MANY THANKS to Luca Lombroso for providing a photocopy of the relevant
* pages!
* JPEG images of all the pages are available at
*       http://fermi.imss.fi.it/rd/bdv?/bdviewer/bid=000000930984
* A pretty readable copy is also available at Google Books, though their
* OCR is badly garbled (not only by the many ligatures and paleographic
* contractions, but even by rendering the long-s as "f").
*      NOTE on typography: In addition to the common uses of "q;" for "que",
* the Italic font has several unusual items. The second page of the
* preface has "poße" for "posse" (line 12), and "aiÿs" for "aliis" (line
* 15). Evidently these glyphs were already in use in Latin as well as in
* German and Dutch. A colon is occasionally used as a "wild card" for any
* omitted letter or letters (e.g., "Io:' for "Ioannum".) The glyphs "ü
* and "v" are used rather indiscriminately; and there is a variant "v"
* (as well as a variant "u") with a more elaborate left hook. A tailed
* "e" is used for "æ"; and "ẽ" for "en".
*      Also, notice the spelling in "Exemplum Quartum", p.179: "Vualterus"
* and "Mvtina" = Mutina was the Latin name of modern Modena.


I. B. Riccioli
Astronomiæ Reformatæ Tomi Duo
(Ex Typographia Hæredis Victorij Benatij, Bononiæ, 1665).

* RICCIOLI's Astronomiæ Reformatæ
* This is needed to make sense of Cassini's letter responding to
* Riccioli's mixed-up misunderstanding of refraction and parallax, given on
* pp. 41-61 of the first Book here. His specific comments on Cassini's work
* in the Ephemerides are on p. 61; note also the discussion of trying to
* determine the solar parallax by Aristarchus's "dichotomy" method on p. 41.
*      As he leans heavily on Tycho's empirical refraction table, that's
* probably what led him to call attention to the problem with Cassini's
* Table at the horizon.
*
* The Frontispiece page says:
*
*             A S T R O N O M I A
*              R E F O R M A T A
*                          A D
*
*                  Serenissimum D.
*             FERDINANDUM MARIAM
*        B A V A R I Æ      E T C.
*                    D V C E M.
*
*
* Title page:
*
*             A S T R O N O M I AE
*                  R E F O R M A T Æ
*                    T O M I  D V O,
*       QVORUM PRIOR OBSERVATIONES,
*              H Y P O T H E S E S,
*        ET FVNDAMENTA TABVLARVM,
*
* Posterior præcepta pro vsu Tabu=
*            larum Astronomicarum,
*       Et ipsas Tabulas Astronomi=
*                   cas CII. continet.
*
* Prioris tomi in decem libros divisi,
* Argumenta Pagina sequenti exponuntur.
*
*                  A U C T O R E
*
*      P. IOANNE BAPTITSTA RICCIOLO
*
*      S O C I E T A T I S      I E S V.
*
*                    FERRARIENSI.
*
*              BONONIÆ, MDCLXV.
*
* This accounts for the varying title in different lists.
* JPEG images of all the pages are available at
*       http://fermi.imss.fi.it/rd/bdv?/bdviewer/bid=000000300871


G. D. Cassini
De solis hypothesibus, & de refractionibus siderum ad dubia A.R.P.Io.Baptistæ Riccioli Soc.Iesu
(Typographia Ferroniana, Bononiæ, 1666), pp. 31–52.

* Cassini's letter responding to Riccioli.
* This is contained in Geminiano Montanari's:
*      Ephemeris Lansbergiana ad annum 1666, item de solis hypothesibus et
*      refractionibus siderum (Bononiae, 1666);
* this letter is also reprinted by Roberti in 1692 (q.v. for excerpts).
* Here, page 29 bears the heading:
*
*                   E P I S T O L Æ      D V Æ
*                                ASTRONOMICÆ
*                               Altera Auctoris,
*                   Altera D.Io.Dominici Cassini.
* De Solis Hypothesibus, & de Refractionibus siderum
*      ad dubia A.R.P.Io.Baptistæ Riccioli Soc.Iesu.
*
* and the first short letter is Montanari's, introducing Cassini's.
*      Cassini describes the procedures for disentangling the solar parallax
* from refraction in considerable detail, along with many cross-checks to
* make sure everything was consistent. He discusses the peculiar run of
* the computed parallaxes near the horizon on pp. 47 and 48.
*      Orthography: note the spelling "Vvaltherus".
* According to Pogg., this was first printed in Rome in 1665. But I find
* no trace of that version; Houzeau lists only this and the Roberti reprint.
* So does Giovanna Grassi's "Union Catalogue". I think it's likely that
* Pogg. got the "Epistolæ tres" mixed up with the 3 letters from Cassini
* to O. Falconieri, which were published in Rome in 1665, but deal with
* the Galilean satellites, not refraction. Grassi lists this letter as
* "Epistola a G. Montanarï.


J. D. Cassini
“Three letters of Jo.Dominicus Cassinus, concerning his Hypothesis of the Suns motion, and his doctrine of Refractions; printed at Bononia in 4°,”
Phil. Trans. Roy. Soc. Lond. 7, No. 84, 5001–5002 (1672).

* ENGLISH ABSTRACT of Cassini's 3 letters
* Summary of the contents of Cassini's 3 letters (above; and reprinted,
* below). This abstract is so useful that I quote it here in full:
*      "The first  Letter is in Latine,to Geminian Montanarius,
* publick professor of Mathematicks in Bononiensi Archigymnasio ;
* who was calculating Ephemerides of the Suns place, according to
* the latter  Hypothesis of Cassinus.      His former Hypothesis
* was grounded upon Observations of the Sun,from whose altitudes,when
* they were great,he made no Abatement; because,according to the common
* opinion, the Refraction is nothing,or,at least,inconsiderable.A specimen
* of it,was published about 16 years ago.But afterward he changed that
* Hypothesis, that it might agree with his observations as diligently
* made,but more artificially corrected. For,having ex meris stellæ
* Polaris altitudinibus exactissimis determined the height of the pole
* (and thereby of the Equinoctial,)at Bononia ; he observed also the Suns
* meridian height in both Solstices. And subtracting that winter height
* from that Equinoctials height ; and the said Equinoctials height from the
* Summer height, he alwaies found that former difference less,by above four
* minutes and an half, than the latter difference. Wherefore he attempted
* to order the Parallaxes and Refractions so, as that those Summer and
* Winter observations, being corrected according to that doctrine, might
* yield the Suns Southern greatest declination, equal to the Suns greatest
* declination Northward. In this Letter he sets down,What course he took
* to find the Refractions; What Experiments he made in glas and in water ;
* How he applied them to celestial Refractions ; His proceeding to determine
* the proportion of the height of the Air to the Semidiameter of the Earth;
* And at last to make Tables ad singulos gradus apparentis distantiæ
* à vertice. Those Tables make it evident, that Refractiones etiam in
* æstivis altitudinibus sunt sensibiles, &ad verticem usque conscendunt ;
* which hitherto hath alwaies been denyed.Not only his friends in Italy
* approve these Tables,but in France also. Petrus Petit in præclaro
* opere,quod DE NUPERIS COMETIS scripsit ediditque, saith, Cassini
* Tabulas (refractionum) &rationibus &Experimentis esse conformes.
*      "But Ricciolus, in a late treatise Astronomiæ reformatæ,  hath
* raised an Expectation of his new Tables of Refraction,and questions those
* Tables of Cassinus : Who,in this Letter, answereth his objections,and
* shews,how,by observations in Heliometro, we may try whose Tables
* are best.
*      "The second  Letter is in Italian,  to Carlo Rinaldini  Professor
* of Mathematicks in the University of Padua, dated August .7.1666.
*      "In it, He shews some defect in the wayes of making Experiments of
* Refraction, prescribed by Vitello, Des-Cartes,Riccioli and Manzini. And
* then he describes an Instrument of his own invention for that purpose,
* &c .
*      "The third  letter is in Italian  also,but without date:concerning
* a book of Dr.Mengoli ; wherein is a Table of Refractions for every
* degree of altitude.      But Cassinus  shews,that Table of Mengoli  to
* be false;as being easily refuted by Experience,and grounded upon a wrong
* foundation.Most writers of Dioptricks since Des Cartes do agree with
* him,in acknowledging a constant Ratio in the Sines of the Angles
* considered in Refraction.But this Doctor Mengoli, mistaking those
* Angles, hath cast away a great deal of labour in calculating so many
* Refractions, and so making a Table full of false numbers.But Cassinus
* hopeth,that Signor Mengoli will review his Principles, and put true
* ones in their room,that so beginning anew he may reform the Conclusions,
* which he intended to demonstrate."
* Mengoli's screwball work on refraction is available at IMSS:
*       http://fermi.imss.fi.it/rd/bdv?/bdviewer/bid=000000300759
*      [No author is given for the abstract; I assume it was Oldenburg.]


J. D. Cassini
“De solaribus hypothesibus et refractionibus epistolæ tres,” in Miscellanea italica physico-mathematica , G. Roberti, ed.
(Typographia Pisariana, Bononiae, 1692), pp. 281–340.

* Reprint of CASSINI's "epistolæ tres" by GAUDENZIO ROBERTI
* According to Pogg., these letters were originally printed at Rome in 1665.
* I have copied only letters 1 and 3, as the second one has to do more
* with the law of refraction itself, and measuring instruments.
*      EPISTOLA PRIMA Clarissimo Viro Geminiano Montanario
* In Bononiensi Archigymnasio Mathematicarum professori publico
* (pp. 283 - 314) is the most formal of the 3, with numbered notes
* in the margins, and the only one in Latin. In the section numbered 31
* is a brief explanation of "The method of construction of the refraction
* Tables":
*      "In the whole study, I have tried to find the ratios of the
* semidiameter of the air to the semidiameter of the Earth, and of the
* sines of the inclination of the direct and of the refracted rays, that
* exactly reconcile the observed with the solsticial refractions, in which
* there is the least need of astronomical hypotheses. From these I have
* geometrically constructed the tables at single degrees of apparent zenith
* distance . . . " -- but no explanation of how those parameters were found.
*      Note 74, p. 306, responds to Riccioli's suggestion that the peculiar
* behavior of the tables at the horizon might be a typographic error:
*      "[Riccioli] writes that my table does not show the steep increase
* of refractions near the horizon that ought to occur, as he thinks, by
* proportion, because the difference of refractions from the first to the
* second degree is larger than from zero to the first, while the opposite
* should actually be required by the laws of astronomical refraction; hence
* he suspects a typographical error has crept into them. When I read this
* note, I have calculated the refractions again trigonometrically from the
* principles in the published letters for the same degrees of altitude,
* and likewise again came out those which are arranged in the table;
* hence there is no error, either typographical or trigonometrical, but it
* really follows from the laws of astronomical refractions published by me.
* The real reason why the difference of refractions from the first to the
* second degree is bigger than from the horizon to the first, is that at the
* first, up to an altitude of a degree, the inclination of the visual ray
* to the upper surface of the air is changed only 15 minutes, and from the
* first to the second degree of altitude is changed about five and thirty
* minutes, as is deduced geometrically by me by means of the ratio of the
* height of the air to the Earth's semidiameter, but so much variation
* of the inclination to the surface of the air in the second degree of
* altitude having been made produces a bigger ratio of the differences of
* the angles to the differences of the sines at a larger zenith distance,
* which produces the bigger difference of the refractions at the horizon, of
* course, as you will understand more clearly in my theory of refractions,
* which I am working on."
* -- cf. Kepler's explanation of this problem some 62 years earlier!
*
*      The second letter, to "D Carolo Rinaldo", is in Italian.  It bears
* the dateline "Bologna li 7. Agosto 1666".
*
*      EPISTOLA TERTIA ad dominum A. P.
* In qua examinuntur fundamenta refractionum
*      & parallaxium D. Doctoris Mengoli
* pp. 323-340. In Italian; no date.
* Mengoli's screwball work on refraction is available at IMSS:
*       http://fermi.imss.fi.it/rd/bdv?/bdviewer/bid=000000300759


P. Mengoli
Refrattioni e Parallasse Solare
(per l'Herede del Benacci, Bologna, 1670).

* PIETRO MENGOLI's crank work
* One of the more bizarre items in this collection. The frontispiece
* contains the diagram whose notations are explained on p. 9. A few
* excepts will suffice to explain why Cassini was so concerned about this:
* P. 8:
*                               CONCLUSIONS
*            which are demonstrated in this work.
*
*      1  The horizontal refraction is 1' 58'' 6'''.
*      2  The summer horizontal parallax of the Sun is 38'' 49'''.
* . . .
* Well, there are 6 numbered items; maybe that's enough.
*
* P. 10:
*                                                DEFINITIONS
*      1  Incidence , I shall call the obtuse angle which the ray from the
* luminous point to the point where refraction occurs at the surface of
* the atmosphere makes with the diameter of the atmosphere: and likewise
* I shall call Incidence the acute angle which the same ray prolonged makes.
*      2  Refraction , I shall call the acute angle which the ray by which
* the observer sees the luminous point makes at the surface of the
* atmosphere with the ray leading from the luminous point to where it is
* refracted, and prolonged: and likewise I call Refraction, the obtuse
* angle.
*      3  Difference , I shall call the acute angle which the refracted ray
* makes with the diameter of the atmosphere, at the point of refraction:
* that is, Difference between the Incidence and Refraction.
* . . .
*
* P. 11:
*                                                      SUPPOSITIONS
*      1  The refractions are angles not appreciably larger than two minutes.
* . . .
*                                                      PROPOSITIONS
* P. 14:
*      20  The refractions are proportional to the sines of the zenith
* distances.
*
*      Even in Cassini's day this looked crazy.  It's interesting that this
* was published in 1670, a year after Cassini (who had taken it apart
* for Mengoli's complete misunderstanding of the matter, in his "Epistola
* tertia" that was published already in 1665 and reprinted in 1666) had
* safely gone to Paris.
*      The historians of mathematics seem to think Mengoli was an original
* and talented mathematician; but that isn't enough to make him competent
* at astronomy or physics -- as he clearly hasn't learned what the basic
* terminology of those fields means. (For that matter, consider the feeble
* efforts of Euler and Lambert in this area.) He was the last student of
* Cavalieri.
*      Mengoli's screwball work on refraction is available at IMSS:
*       http://fermi.imss.fi.it/rd/bdv?/bdviewer/bid=000000300759


Chr. Huygens
Traité de la Lumière
(Pierre vander Aa, Leide, 1690).

* CHRISTIAAN HUYGENS's ``Traité de la Lumière'' (1690)
* (placed slightly out of order so as not to break up Cassini's works)
*
* He noticed the DIURNAL VARIATIONS in terrestrial refraction very early:
*      "Mais il y a une experience qui rend cette refraction fort visible ;
* qui est qu'en fixant une lunette d'approche en quelqu'endroit , en
* sorte qu'elle regarde un objet éloigne de demi lieuë ou plus, comme
* un clocher ou une maison , si on y regarde à des heures differentes
* du jour , la laissant tousjours attachée de mesme , l'on verra que
* ce ne seront pas les mesmes endroits de l'objet qui se presenteront au
* milieu de l'ouverture de la lunette , mais que d'ordinaire le matin &
* le soir , lorsqu'il y a plus de vapeurs prés de la Terre , ces objets
* semblent monter plus haut , en sorte que la moitié ou d'avantage n'en
* sera plus visible ; & qu'ils baisseront vers le midy quand ces vapeurs
* seront dissipées." (pp. 42-43)
*      Cf. Perrault (1674); that book is dedicated to Huygens, who clearly
* picked up this description from his friend Perrault. Huygens was
* well acquainted with the Perrault brothers, Claude and Pierre.
*      See the English translation (below).
* Note that Huygens says he wrote the Treatise in 1678 and communicated
* it to the Royal Academy of Science then, intending to translate it into
* Latin ``in order to obtain greater attention to the thing. . . .      But the
* pleasure of novelty being past, I have put off from time to time the
* execution of this design . . . .'' [in Thompson's translation.]


C. Huygens
Treatise on Light
(U.of Chicago Press, Chicago, 1945).

* Huygens in English translation by Sylvanus P. Thompson
*      He says refractions in the air ``are very remarkable; for by them we
* often see objects which the rotundity of the Earth ought otherwise to
* hide; such as Islands, and the tops of mountains when one is at sea.''
* [p. 44]. Then come the standard remarks about astronomical refraction.
* But the best part is on p. 45: ``But there is one experiment which
* renders this refraction very evident; which is that of fixing a telescope
* on some spot so that it views an object, such as a steeple or a house,
* at a distance of half a league or more. If you then look through it
* at different hours of the day, leaving it always fixed in the same way,
* you will see that the same spots of the object will not always appear at
* the middle of the aperture of the telescope, but that generally in the
* morning and in the evening, when there are more vapours near the Earth,
* these objects seem to rise higher, so that the half or more of them will
* no longer be visible; and so that they seem lower toward mid-day when
* these vapours are dissipated.'' Huygens picked up this DIURNAL
* VARIATION in terrestrial refraction from Perrault (q.v.).
*      To this he adds that the astronomical refractions ``are not altogether
* constant in all weathers, particularly at small elevations of 2 or 3
* degrees'' [p. 49]; so we may even say he noticed that the variations
* are confined to these small altitudes.
*      This is a reprinted edition; the original publication was by Macmillan,
* London (1912).


J. J. Hartman
De usu refractionum astronomico, praese M. Jo. Jacobus Hartman, respondente Frider. Christophorô, in auditorio minori, d. 3. Januar. 1694 publicè disputabit, horis matutinis
(C. Schrödteri, Wittembergae, 1694).

* Jo. Jacobus HARTMAN's review article on refraction
* I'd count this as the first real review article on refraction, though
* Kepler's chapter in his Optics book might also be considered a review.
* This has copious references to the literature (more detailed than one
* usually finds), from Pliny's lunar-eclipse suggestion to an interesting
* discussion of the latest stuff: Cassini's reprinted letter, Huygens's
* treatise on light, etc. Interestingly, the reviewer thinks the air is
* so much more uniform than the discontinuity between air and æther that
* Huygens's suggested effect of refraction from one layer of air to the
* next is probably unimportant.
*      Section XIII discusses the flattening of the Sun at the horizon.
* The pages are not numbered; this is hardly more than a pamphlet: the
* text of a public lecture.


J. Bilberg
“Refractio Solis inoccidui,”
Miscellanea Curiosa sive Ephemeridum Med.-Phys. Dec. III 4, App.1–48 (1697).

* JOHANNES BILBERG and solar refraction
*
* Bilberg's paper begins with a dedication: "Serenissimo potentissimoque
* Principi ac Domino, D O M I N O      C A R O L O      X I .      Suecorum,
* Gothorum, Vandalorumque Regi, Magno Principi Finlandiæ, Duci Scaniæ,
* Esthoniæ, Livoniæ, Careliæ, Bremæ, Verdæ, Stetini,
* Pomeraniæ, Cassubiæ, et Vandaliæ, Principi Rugiæ, Domino Ingriæ
* et Wismaræ, nec nos Comiti Palatino Rheni, Bavariæ, Juliaci,
* Cliviæ et Montium Duci, &c. &c." [This is Charles XI of Sweden, the
* illiterate father of Charles XII who conquered Poland a few years later.]
*      Then, on pp. 6 and 7, there is a little poem about the work and its
* author (cf. Galileo's book on sunspots), introduced with the interesting
* phrase "in Tornea Urbe spectatum". [This is not Torun, but Tornio,
* Finland, at the northern end of the Gulf of Bothnia]. "Tornea" ia
* also the Swedish name.
*      P. 8 is the table of contents; the most interesting items for us here
* are "Cap. III. Observationes solis diurnæ & nocturnæ" and "Cap. IV.
* Doctrina refractionum."
*
* The narrative describes his expedition to high latitudes to see the
* "never-setting Sun"; after being partly frustrated by clouds at Tornio,
* they went up-river nearly a degree, finally seeing the Sun 3 diameters
* above the horizon near midnight.
*       The chapter on refraction begins with the coin-in-a-basin experiment,
* and says that an oar in the water appears broken for the same reason.
* "Just as a lead ball shot obliquely into water draws away from its
* original direction at the surface, losing some force in traversing the
* different media . . . ." [p. 33]
* Referring to the diagram facing p. 23, he says, "The ray SB is bent in
* passing from the æther into a denser medium, the atmosphere ABC, and
* the line BO represents the other part of the line; while otherwise the
* line would be extended to R, if it were the same medium, and not really
* to the eye O." [p. 34]
*
* Comments on NOVAYA ZEMLYA observations:
*      Then he says the refraction is greater in regions near the Pole, "as
* can be confirmed by the experience of the Batavians" (i.e., the Dutch)
* "in nova Zembla". "For they saw the body of the Sun when it should have
* been 4 degrees below the horizon, which is surely a paradox; for by this
* reason the horizontal refraction grows excessively beyond the numbers
* in the refraction tables commonly computed.
*      "Not unjustly, therefore, have many held these Batavian observations
* to be suspect." So he cites the supporting details: the clock, the
* conjunction of Jupiter and the Moon, etc. And he cannot agree with the
* doubters; "for in our observations something very similar occurred. For
* if the elevation of the pole of Torno is found to be 65° 43',
* subtracting this from a quadrant of 90° gives the complement of the
* elevation of the pole, 24° 17'. Now as the observed fact is around
* the solstice, the Sun is in the beginning of Cancer; if the declination
* of the Ecliptic, which is commonly taken to be 23° 30', is taken
* away, there remains 47' for the position of the Sun below the horizon."
* [This is demonstrated with the upper diagram facing p. 34.]
*      Note that de la Hire (1700) re-reduced the observations, concluding
* that the refraction at Tornio was 58', and even more at Kangis.
*
* (cited still later by Le Gentil (1779), p. 394.)
*
* BIBLIOGRAPHIC COMPLICATIONS: This volume has several title pages,
* each with a slightly different title! The first says:
*
*                                    Decuriæ
*                              Annorum Quartæ
*                              MISCELLANEORUM
*                          Medico-Physicorum
*                                      Sive
*                               EPHEMERIDUM
*                              GERMANICARUM
*                              Annus Quartus
*
*
* The engraved frontispiece shows the motto:
*
*       Cæsaro-Leopoldinæ Naturæ Curiosorum Academiæ
*
* below the imperial eagle, and below this the title:
*
*                    Ephemeridum Physico-Medicarum
*                                     Decadis III
*                                      Annus IV
*
*
* Then comes the title page proper:
*
*                                    Miscellanea Curiosa
*                                                sive
*                                      EPHEMERIDUM
*                                Medico-Physicarum
*                                      Germanicarum
*                                          ACADEMIÆ
*                          CÆSAREO-LEOPOLDINÆ
*                              Naturæ Curiosorum
*                                    Decuriæ III .
*                                    ANNUS QUARTUS
*                                     Anni M DC XCVI
*                                          Continens
*                          Celeberrimorum Virorum
*      Tum Medicorum tum aliorum Eruditorum in Germania
*                                          &extra eam
*                                      OBSERVATIONES
*      Medico-Physico-Anatomico-Botanico-Mathematicas
*                                                Cum
*                                          APPENDICE
*                                                 &
*              Privilegio Sac. Cæs. Majestatis.
*      ----------------------------------------------
*                  Edita sumtibus Academiæ 1697.
*                          Francofurti & Lipsiæ,
*      apud Johannem Michaelem Rüdiger, & Engelbertum Streck.
*                  Literis Christiani Sigismundi Frobergii.
*
* An English translation appeared the next year, with the title
* "A Voyage of the late King of Sweden. . . " (Edward Castle, London, 1698)
* -- see below.


J. Bilberg
A Voyage of the Late King of Sweden, and another of Mathematicians, sent by Him: In which are discover'd The Refraction of the Sun, which sets not in the Northern parts, at the time of the Summer Solstice, Variation of the Needle, Latitudes of Places, Seasons, &c. of those Countries
(Edward Castle, London, 1698).

* The English translation of the previous item.
* The translator has translated the given names of the various Swedes;
* so here Bilberg is "John Bilberg". The translated dedication reads:
*
* To the Most Serene, and Most Mighty Prince and Lord Charles XI.
* King of Sweden , Goths , and Vandals ; Great Prince of Finland ;
* Duke of Schonen, Estland, Lifland, Carelen, Bremen, Verden, Stetin,
* Pomerania, Cassuben, and Vandalia ; Prince of Rugen ; Lord of
* Ingria, and Wismar ; Palsgrave of the Rhine ; Duke of
* Bavaria, Juliers, Cleves, and Mons, &c. &c.
*
* Many of these place names are no longer used. Scania (Schonen) is the
* southernmost tip of Sweden; Estland (like "Schonen", a German place-name)
* is Estonia; Livonia (Lifland) is partly Latvia today; Karelia (Carelen)
* is now on the border between southern Finland and Russia; Verden is
* in Lower Saxony; Stetin is now Szczecin, Poland; Cassubia (Cassuben)
* spans the border between the German "Land" of Mecklenburg-Vorpommern
* and western Poland; the Vandals originally migrated from Scandinavia
* into Pomerania, but were long gone by the 17th Century, so it isn't
* clear what was meant by Vandalia here; Rugen is now Rügen, Germany's
* largest island, in the Baltic near Pomerania; Ingria (Ingermanland)
* is a region near St. Petersburg, Russia, and adjacent to Karelia;
* Wismar is a Hanseatic League town in Mecklenburg-Vorpommern, where
* Friedrich Wilhelm Murnau set his 1922 classic Nosferatu ; Juliacum
* or Juliers is now Jülich (it and Cleves were duchies, just west of
* Düsseldorf); Mons is in Belgium, a little west of them.


J. Lowthorp
“An experiment of the refraction of the air made at the command of the Royal Society, Mar. 28. 1699,”
Phil. Trans. Roy. Soc. Lond. 21, 339–342 (1699).

* The Royal Society's experiment to measure refractivity of air
* As can be seen from the failure of the French attempt to repeat the
* experiment (see below), maintaining the necessary hermetic seals was
* the tricky part. So he wisely says, "It is not (I think) an unnecessary
* trouble, that in this account of the Apparatus I have mention'd so many
* minute Circumstances, for we found it difficult enough to exclude the Air,
* and almost Impossible to discover the very little holes through which
* so subtil a fluid would freely enter and possess the spaces deserted by
* the subsiding Mercury."
*      Both the raw and reduced measurements are given; the ratio of the
* sines of the angles was found to be 1.00036. The refractivity, which he
* calls the "refractive power", is "not always proportional to the Density
* (at least not to the Gravity) of the Refracting Medium . . . . And there
* are some fluids which tho lighter than Water yet have a Greater Power
* of Refraction . . . . But the Refractive Powers of Air and Water seem to
* observe the simple Proportion of their Gravities . . . .
*      "And if this should be confirm'd by succeeding Experiments . . .  it
* would be more than probable that the Refractive Powers of the Atmosphere
* are every where, at all heights above the Earth, proportional to it's
* Densities and Expansions. And here it would be no difficult matter
* to trace the Light through it, thereby to terminate the shadow of the
* Earth; and . . . to Examin at what distances the Moon must be for the
* Earth to suffer Eclipses of the Observ'd Duration. This Limitation is
* considerable enough in Astronomy, abundantly to recompense the trouble
* of Prosecuting such a New Experiment."
* [For Hauksbee's confirmation of this, see his 1709 paper in the
* Refractivity file.]



*** CASSINI - LAVAL sub- FILE ***

Anon.
“Sur les refractions,”
Hist. Acad. Roy. Sci. , 112–116 (1700).

*
* General discussion of refraction, and Homberg's faulty experiment
*      "Les refractions qui changent le lieu apparent de tous les Astres,
* ont trompé jusqu'à ces derniers tems tous les Astronomes . . . .
* Quand on commenc,a à s'en défier & à les connoître, on crut qu'elles
* n'agissoient que jusqu'au 45 degré d'élévation, au-delà duquel on
* croyoit en être de;livré. Mais M. Cassini fit voir qu'elles alloient
* jusqu'au Zénit, quoiqu'en diminuant extrêmement, & mit par-là une
* nouvelle précision dans les Calculs Astronomiques."
*      Then there is discussion of the supposed large variation with
* latitude, mentioning Bilberg's "Livre nouveau" (1695), asserting that
* the King of Sweden had actually seen the Sun did not set on the summer
* solstice. "Ces grandes Réfractions du Septentrion sont fort utiles à
* des Peuples prive's du Soleil pendant plusieurs mois . . . ."
*      Some speculation about possible differences in density and thickness
* of the air at high latitudes follows, with de la Hire's remark "que le
* Barométre de Stokolm est comme celui de Paris."
*      Finally, the laboratory experiment made by the Royal Society comes up,
* and Homberg's attempt to reproduce it (with negative results). This
* worries them: "It paroît presque incompréhensible . . . . Mais . . .
* peut-être n'est-il pas impossible que les réfractions célestes
* se fassent, non pas dans le passage de la Matiére Ethérée à
* notre Atmosphére, mais dans le passage d'une couche supérieure de
* l'Atmosphére à une inférieure plus épaisse."
* [NOTE: Hauksbee's 1709 experiment was made in response to this failure.]
*      Bibliographic note: the proceedings of the pre-revolutionary Royal
* Academy of Sciences in Paris appear in two parts, usually bound together
* but separately paginated. The year usually given is that when the
* meetings took place; the actual date of publication is some years later.
* The first part is the meeting notes and abstracts of papers, entitled
* (typically) "Histoire de l'Académie Royale des Sciences, Année 17xx".
* This is usually abbreviated "Hist. Acad. Roy. Sci."
* The second part is the full text of the papers read, entitled
* something like "Mémoires de Mathématique et de Physique, tirés des
* registres de l'Académie Royale des Sciences" and again with the year
* of the meetings appended.
* This is usually abbreviated "Mem. Acad. Roy. Sci."
*      The official title, according to the "Gallica" website from which
* this copy came, is "Histoire de l'Académie royale des sciences avec
* les mémoires de mathématique et de physique tirés des registres de
* cette Académie".
*      Their scan is from the "Seconde Edition, revûë, corrigée &
* augmentée," printed in 1761.


de la Hire
“Remarques sur les observations des refractions, tirées du Livre intitulé, Refractio Solis inoccidui in Septentrionalibus oris, jussu Caroli XI.Regis Suevorum, &c. à Joanne Bilberg Holmiæ. 1695.,”
Mem. Acad. Roy. Sci. , 37–38 (1700).

* de la Hire's commentary on Bilberg's observations
* Here the story is a little different: "Le Roi de Suéde fit un voyage
* à Torneo, ville située dans la partie Septentrionale de la Suéde,
* vers le Solstice d'Eté de l'année 1694, mais comme il n'arriva dans ce
* lieu que quelques jours après le Solstice, il donna ordre à l'Auteur
* de ce Livre . . . ."
*      He cites the facts of the case, and concludes that the refraction was
* 58' at Torneo, and still more at Kangis. Then comes his remark about
* the barometer, quoted in the meeting summary.


[J. D. ] Cassini
“Reflexions sur les observations faites en Botnie,”
Mem. Acad. Roy. Sci. , 39–47 (1700).

* J. D. CASSINI's commentary on Bilberg's observations
* "Je calculai des ces Observations, les Refractions du Soleil à ma
* maniére, & je les trouvai un peu plus grandes qu'elles n'avoient été
* calculées par les Observateurs."
*      He re-reduces the Swedes' observations, using his refraction model
* and a solar parallax of 10''.
*      I have a poor copy, as well as a much more readable one from
* "Gallica", which uses the second edition (1761). Both copies appear
* to be typographically identical.


de la Hire
“Examen de la ligne courbe, formeé par un rayon de lumiére qui traverse l'Atmosphére,”
Mem. Acad. Roy. Sci., Année MDCCII , 52–60 (1743).

* Philippe de la Hire's botched attempt
* He deserves credit for having made the first attempt to study the path
* of the refracted ray, taking account of the compression of the lower
* layers of the air by the weight of the upper ones --- the basic idea
* of hydrostatic equilibrium. But, not having the gas law, he supposes
* the thicknesses of successive layers of equal mass to be in arithmetic
* progression. Worse, he then mis-formulates the problem so as to obtain a
* cycloid for the shape of the ray path (in the flat-Earth approximation),
* or an epicycloid (allowing for sphericity). Why did no one notice that
* this would make the Sun and stars invisible, as every ray returns to the
* Earth's surface?
* This was read on 25 Feb. 1702, but not published until 1743.


de la Hire
“Suite de l'examen de la ligne courbe, que décrivent les rayons de lumiére en traversant l'Atmosphére,”
Mem. Acad. Roy. Sci., Année MDCCII , 182–187 (1743).

* Continuation of de la Hire's epicycloidal theory
* This was read on 5 Aug. 1702, but not published until 1743.


(J. D.) Cassini
“Reflexions sur les observations envoyées à Monsieur le Comte de Pontchartrain par les Pere Laval Professeur Royal d'Hydrographie,”
Mem. Acad. Roy. Sci. , 78–82 (1706).

* very early DIP VARIATIONS
* Pere Laval, reported by Cassini
* Dip varied from 13.5 minutes to 15
* ``. . . la diversité de la hauteur apparente de l'horizon se devroit
* attributer plutôt aux divers temperamens de l'air qui causent les
* refractions.''
* Cassini reports double images of the Sun at sunrise several times;
* Laval has seen the Sun set ``en forme de bonet detaché de tout l'horizon
* apparent''
* SEEING: ``Dans le plus grands instrumens on appercoit dans le Soleil &
* dans les autres astres un petit tremblement qu'on peut attributer aux
* divers degrés de la temperature de l'air par où ses rayons passent. . . ''
* ``Les observations proches de l'horizon sont sujettes à des variations
* par les diverses temperatures de l'air comme il paroît par l'usage des
* Lunetes, qui dans les grandes chaleurs sont voir une apparence de
* boüillonnement dans les objets éloignez.'' [first use of BOILING?]
*
* Bibliographic note: the proceedings of the pre-revolutionary Royal
* Academy of Sciences in Paris appear in two parts, usually bound together
* but separately paginated. The year usually given is that when the
* meetings took place; the actual date of publication is a few years later.
* The first part is the meeting notes and abstracts of papers, entitled
* (typically) "Histoire de l'Académie Royale des Sciences, Année 17xx".
* This is usually abbreviated "Hist. Acad. Roy. Sci."
* The second part is the full text of the papers read, entitled
* something like "Mémoires de Mathématique et de Physique, tirés des
* registres de l'Académie Royale des Sciences" and again with the year
* of the meetings appended.
* This is usually abbreviated "Mem. Acad. Roy. Sci." or sometimes
* "Anc. Mem. Acad. Sci." or ". . . depuis son établissement," to
* distinguish it from the later volumes (for years after 1699).
*      According to the title page, this volume was printed in 1731!
* There was a still later edition, reprinted in Amsterdam, with different
* pagination. Reuss (Repertorium Commentationum ) gives its page as 98.


A. F. Laval
“Sur les refractions,”
Hist. Acad. Roy. Sci. , 111–114 (1707).

* very early DIP VARIATIONS
* Pere Antoin François Laval, reported by Cassini
* DIP varied from 11'46" to 14'30" from 144 feet height
*      I have 2 copies of this.  The one from the Gallica website has
* this item on pp. 89-91 (though p. 89 is mis-numbered 79). The Gallica
* copy has the long-tailed Q, and sets the names in Roman face; the other
* has a more modern Q, and sets the names in italics. Probably Gallica
* has the original, and I have the reprint, edition.


[J. D.] Cassini
“Des irregularitez de l'abbaissement apparent de l'horizon de la mer,”
Mem. Acad. Roy. Sci. , 195–197 (1707).

* Cassini's discussion of Laval's observations
* He calculates that the height of 144 (Paris) feet would produce a dip
* of 13' 14"; but the observed dip is only 11' 46"; "la difference entre
* cette hauteur & celle du rayon direct seroit d'une minute 28 secondes,
* que l'on pourroit attribuer à la plus grande refraction du rayon visuel
* qui rasoit la surface de la mer.
*      "Mais le plus grand abbaissement apparent de l'horizon de la mer a
* été observé de 14' 30", qui est plus grand que celui du rayon direct
* d'une minute & 16 secondes; ce qui est contre les regles de la refraction
* qui devoit diminuer cette inclinaison . . . .
*      "Nous avons déja remarqué par diverses autres observations, qu'une
* partie de la surface de la mer contiguë à l'horizon sensible, se confond
* à la vûë avec le Ciel, & que pour lors la circonference apparente de
* l'horizon sensible tombe dans la mer exposée à notre vûë." This
* must refer to some earlier observation of an inferior mirage at sea?
*      "Comme nous avions communiqué cette reflexion au P. Laval sans
* qu'il ait eu aucune occasion de distinguer par quelque signe sensible
* cette difference, l'on voit combien il est difficile de la distinguer,
* & à quelle erreur est exposée la methode de chercher la grandeur du
* diametre de la Terre par l'observation de la tangente de la mer sans
* cette circonspection." (p. 196)
*      ". . .  la variation des hauteurs apparentes de la mer n'a aucun
* rapport regulier avec la variation qui s'observe en même temps dans le
* Thermometre & dans le Barometre; ce qui semble confirmer ce que nous avons
* remarqué plusiers fois, qu la partie de l'air qui cause la refraction
* est d'une nature differente de la partie à laquelle on attribuë la
* pesanteur qui équilibre la hauteur des liqueurs dans le vuide." (p. 197)
* [copy downloaded from Gallica.bnf.fr]


A. F. Laval
“Sur les refractions,”
Hist. Acad. Roy. Sci. , 129–131 (1708).

* Pere Laval, reported by Cassini
* According to Reuss, the copy I have is from the reprint edition; the
* original first page was 105.


A. F. Laval
“Remarques sur les reflexions de Mr. Cassini, sur les Observations des Basses apparentes de l'horizon de la mer, faites à Marseille par le P. Laval, Jesuite Professeur d'Hydrographie,”
Mémoires pour servir à l'Histoire des Sciences et des beaux Arts (Mém. de Trévoux) , 1079–1088 (1708).

* Pere Antoin François Laval


J. Cassini
“Sur les refractions astronomiques,”
Hist. Acad. Roy. Sci. 1714, 79–87 (1719).

* JACQUES CASSINI's refraction theory and observations
* This is the abstract of Jacques Cassini's talk to the Academy on Feb.28,
* 1714. He reviews his father's theory, and explains how it was worked out.
* He explicitly says, "Afin que la difference de la hauteur veritable & de
* l'apparente soit plus sensible, & par consequent la quantité de la
* refraction plus exacte, il est bon d'observer le Soleil à une petite
* hauteur." [p. 80]
*      On p. 83 occurs a typo that has been widely propagated: he first says
* the "seconde refraction" (i.e., in addition to that at the horizon) is
* 5' 28'' at 19 degrees above the horizon; but everywhere else, this is
* given as 10°. Then the method of approximation appears:
* ". . . il cherche en tâtonnant, ou estime à peu-près quelle doit être
* la hauteur de la matiere refractive qui les donne, & comme il trouve
* que cette hauteur étant supposée de 2000 Toises , les deux refractions
* viennent juste, il en conclut que la hauteur de la matiere refractive est
* de 2000 Toises , après quoi on peut calculer les angles d'incidence &
* de refraction pour tous les degrés , & par consequent les refractions
* qui leur conviennent.
*      "Cette hauteur de 2000 Toises , qui n'est pas d'une Lieuë , est
* beaucoup plus petite que celle de 6 lieuës ; que donnent à l'Atmosphere
* ceux qui lui donnent le moins, comme Mrs. Cassini & Maraldi , car
* il y en a d'autres qui vont jusqu'à 18 ou 20. L'Atmosphere ne seroit
* donc refractive que dan une petite partie de son étenduë , & dans son
* couches les plus basses, ou, si l'on veut, la matiere refractive seroit
* differente de l'Atmosphere.
*      "Mais l'hypothese d'où l'on tire cette hauteur de 2000 Toises est
* que le rayon rompu vienne à l'œil en ligne droite, & l'hypothese peut
* fort bien n'être pas vraye." [p. 84]
*      ". . .      M. Cassini  fait l'hypothese la plus simple qu'il soit
* possible, c'est que la densité croisse toûjours également à chaque
* couche infiniment peu épaisse de la matiere , c'est-à-dire , comme
* les nombres naturels 1, 2, 3, &c. De-là il suit que le rayon rompu se
* détourne toûjours également, & comme à chaque pas infiniment petit
* qu'il fait il est le côté de la Courbe qui se décrit , cette Courbe
* est toute composée de côtés qui se détournent également, ou qui sont
* des angles de contingence égaux, & par consequent elle est Circulaire,
* puisque le Cercle seul a cette uniformité de Courbure." [p. 85]
* [Manifestly this is not true, as the local zenith distance varies.]
*       On p. 86 is the first mention of greater refraction in winter; it
* is attributed to "vapeurs grossieres". But (p. 87)
*      "Il faudroit donc differentes Tables de refraction pour les
* differentes saisons, & même pour les differentes temperatures de l'air,
* comme nous avons dit ailleurs qu'il en faudroit pour les differens
* climats." So SEASONAL EFFECTS are asserted.
*      This is (of course) available at Gallica, and at the BHL.
* Its original title page shows a publication date of 1717, and cover
* pp. 61-67. But I have a photocopy of the Amsterdam reprint, whose
* title page shows it was actually published in 1719; its pages are 79-87.
* The page numbers above refer to the reprint, not the original.


J. Cassini
“Des refractions astronomiques,”
Mem. Acad. Roy. Sci. 1714, 42–67 (1719).

* JACQUES CASSINI's full paper
* Here the details of the theory are worked out. More important, a
* considerable number of OBSERVATIONS of large refraction at the horizon
* in winter are given in detail.
*      Some interesting quotes:
* "Ces refractions . . . diminuënt à mesure que les Astres s'elevent,
* & ne cessent entierement qu'au Zenith, comme mon Pere l'a démontré,
* quoique tous les Astronomes avant lui ayent été persuade's qu'elles
* étoient insensibles à la hauteur de 45 degrés." [p. 43]
*      "Par la regle des refractions reçuë de tous les Philosophes, les
* sinus d'incidence sont toûjours proportionels au sinus des refractions,
* . . . ." [p. 45]
*      In describing his father's method, he says:
*      "Si cette refraction avoit été trouvée plus grande ou plus petite
* que celle qui avoit été déterminée par observation, il auroit fallu
* diminuer ou augmenter la hauteur AP de la surface refractive, jusqu'à
* ce qu'on l'eut trouvée de la quantité requise." [p. 46]
*      His circular-arc ray moves the top of the atmosphere up about 3 1/2
* times higher than the uniform or "rectilinear" model. But: "Cette
* hauteur . . . est encore beaucoup plus petite que celle qu'on attribue
* à l'Atmosphere, ce qui sembleroit confirmer le sentiment de ceux qui
* croyent que les refractions sont causées par une matiere particuliere
* dont l'étenduë n'est pas si grande à beaucoup près que celle dont
* l'Atmosphere est composée." [p. 49]
*      And of course he finds ". . .  que les differences entre les refractions
* calculées pour la même hauteur par les deux methodes diminuent ensuite à
* mesure qu'on s'eloigne de l'horizon jusqu'à la hauteur de 15 degrés où
* les deux hypotheses donnent la même refraction . . . ." [p. 57]
*      The OBSERVATIONS begin on p. 58.  On 11 Jan. 1711, he found the Sun's
* upper limb refracted by 49' 48" at an altitude of 3' 5". The refraction
* near the horizon remained 7 or 8 minutes high (compared to the Table)
* on 30 and 31 Jan. and 7 Feb., "ce que j'attribuai aux vapeurs épaisses
* dont l'horizon est chargé en Hiver." On 1 Dec. 1712, the refraction
* was 41' 7" at 16' 50" altitude. The biggest was 51' 4" at 2' 40"
* altitude on Dec. 1, 1712. He has "toûjours trouvé la refraction
* horizontale en Hiver plus grande de quelques minutes qu'on ne la suppose
* ordinairement". [p. 60] Other large values were 46' 0" at 4' 50" on
* 7 Feb. 1713 and 43' 54" at 5' 0" on 24 Feb. 1713. [p. 61]
*      Of course the refractions at altitudes of a few degrees fit his new
* model better than his father's. The daily variations die out at 3°
* or so. He concludes that ". . . vers l'horizon les refractions sont plus
* grandes en Hiver qu'en Eté, & qu'il faut employer des Tables differentes
* pour avoir la hauteur des Etoiles dans ces differentes Saisons."
*      The figures are on a gatefold (p. 66) that can be laid out to the
* right of the bound volume while one reads the text. The Table (p. 67)
* is also a foldout.       [These page numbers are for the Amsterdam edition,
* actually published in 1719. The 1717 original is available at the BHL
* and Gallica, where the pages are 33-52, the foldout figures are on p. 53,
* and the Table on p. 54.]


J. Flamsteed
Historiæ Coelestis Britannicæ, Vol. I
(Typis H. Meere, Londini, 1725), p. 396.

* JOHN FLAMSTEED's observed refraction table
* Filed slightly out of order here; it really belongs just after the
* Flamsteed-Newton file, but was published posthumously in 1725. But
* the refraction table was deduced in 1698 from observations made in the
* 1680s. And, as an empirical table, it logically goes with Kepler's
* Rudolphine tables -- whose arrangement it resembles, with the table of
* refractions at the very end of the volume. Used by Euler.
*      The actual refraction table appears at the end of both Vol. I and Vol.
* II of this 3-volume work. The table at the end of Vol. I is headed:
* "Refractionum TABULA â præcedentibus Observationibus deducta &
* composita ab J. F. 1698", which means it was done after the exchanges
* with Newton about refraction theory. The table at the end of Vol. II
* simply says "Refractionum TABULA, per J. F. " The values in both are
* the same; but the seconds column in Vol. I always has 2 digits, with a
* leading 0 if the value is less than 10.
*
* The title page of Vol. I reads:
*
*            HISTORIÆ COELESTIS
*            B R I T A N N I C Æ
*             VOLUMEN Primum.
*
*                   Complectens
*        STELLARUM      FIXARUM
*                        Nec non
*        PLANETARUM  OMNIUM
*       O B S E R V A T I O N E S
* Sextante, Micrometro, &c.peractas .
*
*            Quibus subjuncta sunt
*  P L A N E T A R U M      L O C A
* ab iisdem Observationibus deducta
*
* Observante JOANNE FLAMSTEEDIO, A.R.
*            In Observatorio Regio
*        G R E N O V I C E N S I
*              CONTINUA SERIE
* Ab Anno 1675, ad Annum 1689.
*
*
* This faces a fine engraving of "JOHANNES FLAMSTEEDIUS Derbiensis
* Astronomiæ Professor Regius, Anno Ætatis 74 "
*


B. Taylor
Methodus Incrementorum directa & inversa
(Prostant apud Gul. Innys, Londini, 1715).

* BROOK TAYLOR
* Yes, this is the Taylor of "Taylor's Series". The final section of the
* book deals with refraction. He derives the exponential atmosphere, and
* the differential equation for the refraction, but then says (p. 110)
* it's necessary to resort to series expansions. No actual refraction
* is computed. The most interesting result is that the curvature of the
* ray is 1/5 that of the Earth (see p. 118 -- the last page of the book.)
* The notation is excessively awkward, using both dots and primes, both
* above and below the letters.
* Typographical note: Taylor often uses "q;" for "que". (Cf. Walther.)


L. Feigenbaum
Brook Taylor's Methodus Incrementorum: a translation with mathematical and historical commentary
(Yale University Ph.D. thesis, New Haven, 1981).

* LENORE FEIGENBAUM's English translation of Taylor's "Methodus Incrementorum"
* See also Thomas Young's 1825 translation.
* Thanks to Lenore Feigenbaum for providing a copy of the refraction part!


[J. ] Cassini
“Sur la distance des etoiles fixes à la Terre, & sur leur grandeur,”
Hist. Acad. Roy. Sci. [1717] , 62–67 (1719).

* JACQUES CASSINI thinks he has found annual parallax of Sirius
* But he worries about annual variations in refraction: ". . . les
* refractions sont inégales en differentes saisons de l'année, plus
* grandes ordinairement en Hiver qu'en Eté." [p. 65]


[J. ] Cassini
“De la grandeur des etoiles fixes, et de leur distance a la Terre,”
Mem. Acad. Roy. Sci. [1717] , 256–268 (1719).

* Details of Jacques Cassini's "parallax" and seasonal refraction work
*      An interesting sidelight is the remark on p. 260 about "l'hypothese
* de Copernic, laquelle est la plus generalement rec,ûe" des Philosophes à
* cause de sa merveilleuse simplicité."
*      Note also the paragraph at the top of p. 263 on daytime observations
* of Sirius transits, even when it passes the meridian at the same time
* as the Sun.
*      But our interest here is in the SEASONAL VARIATION of refraction.
* On p. 264, he explicitly mentions the coldest day of the winter; on
* p. 266: "Il reste presentement à considerer si ces variations que nous
* venons de trouver . . . ne peuvent point être attribuées à l'effet des
* refractions, & l'on remarquera pour cela que s'il y a quelque inégalité
* dans les refractions d'une saison de l'année à l'autre, elles doivent
* être plus grandes en Hiver où l'air est plus condensé qu'en Eté où
* ce même air est plus dilaté.
*      "Nous en avons même un exemple dans l'Observation de Sirius
* du 18 Janvier 1715, où le froid étant le plus frand de l'année,
* la hauteur Meridienne de cette Etoile fut observée plus grande qu'à
* la fin de Decembre de l'année précedente, ce qui ne peut attribué
* qu'à l'effet d'une refraction extraordinaire."
*      See Halley (1720) for a strangely off-base comment.


E. Halley
“Some remarks on a late essay of Mr. Cassini, wherein he proposes to find, by observation, the parallax and magnitude of Sirius,”
Phil. Trans. Roy. Soc. London 31, 1–4 (1720).

* EDMUND [sic] HALLEY criticizes Jacques Cassini's "parallax" of Sirius
* (on the grounds that the variations are due to refraction changes)
* NOTE: filed slightly out of order here, because of the publication delay
* of the French Academie; but it logically follows Cassini (above).
* Citing Hauksbee's lab demo, Halley argues that the refraction changes in
* proportion to the pressure; as the barometer changes by over two inches
* out of 30, the refraction will likewise change by 1/15 of the 1' 55'',
* i.e., 7 or 8'' at the 25° meridian altitude of Sirius at Paris.
*      Remarkably, the issue of seasonally varying refraction was already
* raised in the Histoire account of Cassini's paper! And in the Memoir he
* discusses this on p. 266, correctly attributing the seasonal variations
* in refraction to the expansion of the air (i.e., temperature) rather
* than Halley's implausible pressure variation.
*      Referred to, but not cited, by Bruhns -- who mistakenly thinks the
* observations are Halley's rather than Cassini's.


Anon.
“Sur la refraction du vuide dans l'air,”
Hist. Acad. Roy. Sci. , 71–74 (1719).

* The second attempt by the French to measure refraction (air vs. vacuum)
* The work was done by Delisle; "l'experience qu'on avoit faite ici est
* fausse, & celle de Londres est vraie." (This must have been painful.)
* Delisle found that the French apparatus had leaked, so that the "vacuum"
* was actually air -- hence, the null result. He found a deflection of
* 45" at the window inclined 45°; but recognized that not all the air
* had been pumped out. "Si le Vuide du Tuyau de M. Delisle . . . a été le
* plus parfait, . . . il s'ensuite que le rayon . . . a dû en passant dans
* nôtre air souffrir une refraction sensiblement égale à la refraction
* astronomique . . . ."
* [published in 1721; the Academy is starting to catch up.]


de Mairan
“Memoire sur a Cause generale du Froid en Hiver, & de la Chaleur en Eté,”
Mem. Acad. Roy. Sci. , 104–135 (1719).

* de Mairan shows how literally the "surface" of the air was understood
* The argument of interest here begins on p. 108: "Aux deux causes
* précedentes de la diminution de la chaleur en Hiver, . . . il en faut
* necessairement ajoûter une troisieme, qui est celle de leur obliquité
* par rapport à l'Atmosphere.
*      "Il y a eu de grandes Physiciens qui . . .  ont eu recours à
* l'obliquité des rayons sur l'Atmosphere, comme à la principale &
* presque unique cause du froid de l'Hiver." He then quote from Rohault's
* physics text: "L'air . . . s'élevant au dessus de la Terre jusqu'à
* la hauteur d'environ deux ou trois lieuës, ou les vents ni les nuages
* n'arrivent jamais, sa surface doit être fort unie, de même que celle
* de toutes les liqueurs qui ne sont pas agitées ; & comme c'est une
* proprieté des rayons de lumiere qui se presentent pour passer d'un
* milieu dans un autre, de n'y pas entrer tous, mais de se reflechir
* d'autant plus que leur chûte est plus oblique . . . ." Enough said.
*      On p. 110 he talks about total internal reflection, and gives the
* critical angle for water: ". . . si la lumiere . . . passoit de l'eau dans
* l'air, du Milieu le plus dense dans le moins dense, elle ne se romproit
* plus du tout, de's que l'angle d'incidence seroit parvenu à n'être
* que de 41° 25' ; & que depuis cette obliquité jusqu'au parallelisme,
* tous ses rayons seroient absolument reflechis à la rencontre du nouveau
* Milieu."
*      P. 111: "Chaque rayon prêt à entrer dans l'Atmosphere, peut être
* consideré comme une balle de Mousquet tirée contre la surface de l'eau
* d'un Bassin, laquelle aura d'autant plus de chemin à faire dans l'eau,
* avant que d'en toucher le fond, qu'elle y sera tirée plus obliquement.
*      "Il semble donc, en supposant la surface particuliere de l'Atmosphere
* d'un Pays parallele au terrain, & de la même obliquité que l'Horison
* par rapport aux rayons du Soleil . . . ." (p. 112) -- but, as he has also
* vaguely alluded to scattering, maybe that's what he has in mind?
*      On p. 113, he considers "l'Atmosphere chargée de vapeurs &
* d'exhalaisons, telle qu'elle est ordinairement dans toute sa partie
* inferieure, lorsque le Soleil est proche de l'Horison," and then says,
* "je ne pense pas que la surface de cette seconde Atmosphere, non plus
* que celle de la premiere, puisse être aussi unie que la surface d'une
* eau tranquille," which allows him to fudge, or at least arm-wave, about
* the calculation of the resulting attenuation.
*      On p. 129 is an interesting reference to "les Hollandois, qui
* passerent l'Hiver dans la Nouvelle Zemble en 1597," and observed a
* refraction of 4 degrees: "sept à huit fois aussi grande qu'à Paris.
* De sorte que pour peu qu'elle augmentât encore à proportion en
* approchant du Pole, elle pourroit devenir suffisante, ou même plus que
* suffisant, pour y procurer un jour ou un crepuscule perpetuel."


Delisle
“Detail de l'experience de la refraction de l'air dans le vuide,”
Mem. Acad. Roy. Sci. , 330–335 (1719).

* DELISLE's details of the air-refraction experiment
* "Par M. Delisle le Cadet". He modified the apparatus used by Homberg
* to ensure evacuation. The later English experiments agree closely
* with Flamsteed's measures of astronomical refraction; and the measures
* made with compressed air (evidently referring to Hauksbee's work)
* confirm that the refraction is proportional to the density of the air.
* "J'ai trouvé la même chose par mes Experiences," he says. But he
* can't reproduce the right absolute value; so (p. 334) "il paroît que
* la regle du rapport direct des Refractions avec les hauteurs de Mercure
* n'est pas toûjours vraye . . . ." On the last page, he offers several
* suggestions for improving the experiment, one of which indicates part of
* the source of his trouble: the glass covers of the tube ends need not be
* inclined so much; "il est vrai qu'en les inclinant moins, on diminué la
* quantité de la Refraction, ce qui la rend plus difficile à mesurer, mais
* aussi on voit moins distinctement au travers des Verres fort inclinés;"
* so it appears the problem is with the bad optical quality of these plates.
*      So it was a very marginal technical accomplishment, which the English
* managed to do better than the French.


Dr. Edm. Halley
“Some remarks on the allowances to be made in astronomical observations for the refraction of the air,”
Phil. Trans. Roy. Soc. Lond. 31, 169–172 (1721).

* NEWTON's refraction table, published by Halley
* [actually filed in the NEWTON file.]
* As Kramp (1799) and Biot (1836) showed much later, this is calculated
* from an exponential (i.e., isothermal -- because the gas laws weren't
* known to Newton) model atmosphere.


J. Cassini
Élémens d'Astronomie
(Imp.Royale, Paris, 1740).

* JACQUES CASSINI's textbook
* Jacques ("Cassini II" or "Cassini fils") was the son of the original
* Giovanni Domenico Cassini, who became Jean Dominique Cassini when he
* moved to Paris. He claims this was the first textbook of astronomy in
* French: "Comme on n'avoit point encore d'Elémens d'Astronomie écrite
* en françois, & que le public sembloit le désirer . . . ." [p. xj]
* On the same page, he explains his approach: "La méthode que j'ai
* suivie, a été de ne supposer, autant qu'il a été possible, que ce
* qui étoit parfaitement connu, & de passer des notions les plus simples,
* à celles qui paroissent les plus composées."
*      Of interest here is the explanation of his father's refraction model,
* which is on pp. 12 - 17. It is all done geometrically, in words; there
* are no equations. [See his Fig. 6 for the diagram.]
*      "On peut déterminer les réfractions en deux manieres différents,
* ou par des observations immédiates des Astres, faites à tous les degrés
* de hauteur, ou bien par deux seules observations faites à deux degrés
* différens de hauteur, par le moyen desquelles on trouve la hauteur
* de la matiere qui rompt les rayons, & la réfraction qui convient à
* tous les autres degrés jusqu'au Zénit.
*      "La premiere méthode paroît la plus naturelle, & on s'en sert
* ordinairement pour déterminer les réfractions des Astres lorsqu'ils
* sont peu éleve's sur l'horison: mais on est obligé d'avoir recours à
* la seconde dans les plus grandes hauteurs, lorsque la différence d'un
* degré à l'autre n'est pas assez sensible pour être apperc,ûe par des
* observations immédiates." [pp. 12-13]
*      After explaining the direct method first, he arrives at the
* theoretical one, on p. 15:
*      "Soit S  (Fig. 6. ) le Soleil ou une Etoile, dont le rayon SH ,
* rencontrant la surface réfractive EGH en H , se rompt & vient à
* notre œil en A ; en sorte que HA soit perpendiculaire au
* demi-diametre AC de la Terre.
*      "Cette Etoile sera vûe suivant le ligne AHI , & l'angle IHS
* mesurera la réfraction horisontale que l'on a trouvée par observation,
* de 32' 20'', de même qu'elle est marquée dans la Connoissance des Temps.
*      "L'Etoile étant parvenue de S  en F , soit un autre rayon FG ,
* qui rencontre en G la surface réfractive EGH , et vienne en A ;
* en sorte que l'angle HAG ou IAT , qui mesure la hauteur apparente de
* cette Etoile sur l'horison, soit de 10 degrés. L'angle TGF mesurera
* la réfraction qui convient à la hauteur de 10 degrés, que l'on a
* trouvée par observations, de 5' 28''.
*      "Suivant la regle des réfractions . . .  il s'agit de déterminer quelle
* doit être la hauteur AE de la surface réfractive EHL au-dessus de la
* surface de la Terre ABD , pour que le sinus de l'angle d'incidence PGF
* du rayon FG , soit au sinus de l'angle PGT ou AGC de réfraction
* de ce même rayon, comme le sinus de l'angle d'incidence OHS du rayon
* SH , est au sinus de l'angle de réfraction OHI ou AHC de ce rayon;
* et que l'angle TGF , qui mesure la réfraction à la hauteur de TGF ,
* qui mesure la réfraction à la hauteur de 10 degrés ,soit à l'angle
* IHS , qui mesure la réfraction horisontale, comme 5' 28'' à 32' 20''.
*      "Soit supposée AE , hauteur de la surface réfractive, de 2000
* toises; le semi-diametre AC de la Terre étant, suivant la mesure de
* la Terre, de 3271600 toises, on aura CE , CG & CH de 3273600 toises;
* & dans le triangle rectangle CAH , dont les côtés CA , CH sont
* connus, on trouvera l'angle CHA ou OHI de 87d 59' 50'', auquel si
* l'on ajoûte l'angle IHS de 32' 20'', on aura l'angle OHS de
* 88d 32' 10''.
*      "Maintenant dans le triangle CAG , dont les côtés CA , CG
* sont connus, de même que l'angle CAG de 100 degrés, qui est égal
* à l'angle droit CAH , plus l'angle HAG de 10 degrés, hauteur
* apparente de l'Astre sur l'horison; on trouvera l'angle AGC ou PGT
* de 79d 48' 12'', & l'on fera, comme le sinus de l'angle CHA de
* réfraction, lorsque l'Astre paroît à l'horison, que l'on a trouvé
* de 87d 59' 50'' est au sinus de l'angle OHS d'incidence, qui est de
* 88d 32' 10''; ainsi le sinus de l'angle AGC de réfraction, lorsque
* est élevé de 10 degrés sur l'horison, qui est de 79d 48' 12'', est
* au sinus de l'angle PGF d'incidence qui lui répond, que l'on trouvera
* de 79d 53' 40'', dont retranchant l'angle PGF de 79d 48' 12'',
* reste l'angle TGF de 5' 28'', qui mesure la réfraction qui convient
* à la hauteur de 10 degrés." [pp. 15-16.] Now comes the revealing part:
*      "Si cette réfraction avoit été trouvée plus grande ou plus petite
* que celle qui avoit été déterminée par observation, il auroit été
* nécessaire de diminuer ou augmenter la hauteur AE de la surface
* réfractive, jusqu'à ce qu'on l'eût trouvée de la quantité requise.
*      "La hauteur de la surface réfractive étant une fois établie,
* on peut trouver de la même maniere, la réfraction qui convient à
* tous les degrés de hauteur apparente d'un Astre sur l'horison,
* comme lorsqu'il est en K ; car dans le triangle AKC , les côtés CA
* & CK étant connus, aussi-bien que l'angle CAK , qui est égal à
* la hauteur donnée plus 90 degrés, on trouve l'angle CKA ou RKN ,
* que ce rayon fait avec la perpendiculaire, & l'on fera, comme le sinus
* de l'angle CHA de 87d 59' 50'' est au sinus de l'angle OHS de
* 88d 32' 10''; ainsi le sinus de l'angle CKA ou RKN est au sinus
* l'angle RKM , dont retranchant l'angle RKN , reste l'angle MKN ,
* qui mesure la réfraction qui convient à la hauteur apparente de
* l'Astre sur l'horison.
*      "Suivant cette hypothese, qui représente assez exactement
* les réfractions que l'on a déterminées par observation, pour les
* diverses hauteurs des Astres sur l'horison, la substance qui cause les
* réfractions s'étend au-dessus de nous à une distance beaucoup plus
* petite que celle qui compose l'Atmosphere, puisque l'on trouve qu'elle
* ne monte qu'a 2000 toises, au lieu que l'Atmosphere doit surpasser de
* beaucoup la hauteur des montagnes de la Terre les plus élevées, dont
* il y en a plusiers qui excedent cette étendue.
*      "Il est vrai que l'on a supposé dans cette recherche, que les rayons,
* après avoir rencontré la surface réfractive qui les détourne de leur
* premier direction, viennent droit à notre œil sans souffrir d'autre
* réfraction, au lieu qu'il y a beaucoup d'apparence, qu'en traversant
* l'Atmosphere, ils passent continuellement d'un milieu plus rare dans
* un milieu plus dense, & forment une ligne courbe suivant la tangente de
* laquelle nous appercevons les Astres. Mais comme il seroit nécessaire,
* pour déterminer cette courbe, de connoître les diverses dilatations
* de la matiere réfractive, à différents hauteurs au-dessus de la
* surface de la Terre, ce que l'on ignore jusqu'à présent; nous nous
* sommes contentés de rapporter cette méthode simple, par le moyen de
* laquelle on trouve avec facilité les réfractions, à peu-près de la
* même quantité que par les observations immédiates." [p. 17]
*      We have this only on P-10 microprint cards!


Cassini de Thury
“Sur la réfraction,”
Mém. Acad. Roy Sci. , 203–215 (1742).

* CASSINI III examines seasonal (temperature) effects
* He still has doubts that the refraction is due to air itself:
* ". . . de supposer que puisque la matière réfractive est plus dense
* en hiver qu'en été, & que cette densité a un certain rapport à
* la constitution de l'air . . . ."
*      But he is mainly concerned with seasonal effects due to temperature
* variations: "Le grand froid qu'il a fait cette année qui a plus
* approché de celui de 1709 . . . , nous a fourni une occasion de
* déterminer le maximum de l'effet de ces variations en hiver."
* He is careful to check for instrumental effects; ". . . l'instrument
* que l'on a employé pour ces observations, avoit six pieds de rayon,
* & . . . on ne peut guère se tromper de plus de 5 secondes dans l'estime
* des divisions." [The observations were all made at altitudes from 18
* to 20 degrees, so they show only refractivity effects, not gradients.]
*      On p. 211, he explains that "Avant que l'on connût les règles de
* l'Aberration, on ne sçavoit à quoi attribuer les différences que l'on
* remarquoit dans les hauteurs de certaines Étoiles, ou plûtôt on les
* rejetoit sur les erreurs de l'observation, & c'est une des principales
* raisons pourquoi on a ignoré si long-temps la cause d'un phénomène
* qui paroissoit si singulier, mais qui s'explique parfaitement dans
* l'hypothèse de M. Bradley."
*      There follows a short section on observations of terrestrial
* refraction, which "On a toûjours négligé d'y avoir égard, soit
* parce qu'on les croyoit trop petites ou trop irrégulières, soit qu'on
* n'eût pas assez approfondi les règles de cette variation, ou formé
* des hypothèses suffisantes pour y avoir égard . . . ." On p. 214 there
* is further discussion of the variations in dip of the sea horizon.
* He thinks these variations are partly due to the humidity of the sea
* air, and partly due to the sea breeze, "qui repousse les eaux vers
* les côtes" [!]
* Actually printed in 1745.



*** BOUGUER FILE ***

Anon.
“Sur les réfractions astronomiques,”
Hist. Acad. Roy. Sci. 1739, 45–48 (1741).

*
* Report of Bouguer's observations in Peru
* The news here is that Bouguer has found the refraction less at higher
* elevations of the eye, contrary to Cassini's model: ". . . il a découvert
* un autre fait formellement contraire à ce qui paroissoit bien établi."
* At Pichincha, 527 toises above Quito, "On y respiroit à peine à
* cause de la grande subtilité de l'Air à cette hauteur, & le froid y
* étoit extrême . . . ." Tables are announced, citing the Mémoire.


Bouguer
“Sur les réfractions astronomiques dans la Zone Torride,”
Mém. Acad. Roy. Sci. 1739, 407–423 (1741).

* Details of Bouguer's observations in Peru
* This is a letter, datelined Quito, sent by Bouguer 24 Juillet 1737.
* He reserves for a later time the individual observations, and the
* method of constructing tables. Even so, a number of individual
* observations are given. The tables are constructed "en suivant en
* partie la méthode que j'ai expliquée dans la Piéce que je publiai en
* l'année 1729, sur la maniére d'observer en Mer la hauteur des Astres."
* [i.e, his prize essay.]
*      From the smallness of the refractions observed at Quito, he concludes
* that Cassini's model merely assigns the refraction to a mean height
* (pp. 412-413). Interestingly, he recognizes that, at great heights,
* ". . . le froid, . . . en condensant l'air, peut faire une espece de
* compensation, & rendre l'inégalité moins considérable." (p. 414)
* He concentrated his attention around 15° altitude, because
* "Au-dessous, les Réfractions sont trop variables, & au-dessus trop
* petites, pour pouvoir être saisies avec précision."
*      He thinks the refractivity falls with the 7th power of the distance
* from the center of the Earth (p. 420).


Anon.
“Sur les réfractions,”
Hist. Acad. Roy. Sci. 1749, 152–157 (1753).

* BOUGUER'S SECOND MEMOIRE, 10 years later
* Here is promised "tout le géométrique & toute la théorie qui l'ont
* guidé dans cette occasion." From Chimborazo, he saw the Sun more
* than a degree below the astronomical horizon; but he claims a sudden
* jump in refraction at the astronomical horizon. Bouguer calls the
* part of the refraction on the ascending branch of the ray "de son
* véritable nom de Réfraction astronomique ; & la seconde, eu égard au
* trajet qu'il fait depuis l'œil . . . c'est ce que M. Bouguer nomme
* Réfraction terrestre . . . ." (p. 153)
* The limit of the refractive atmosphere (p. 154) he puts at 5158 toises.
*      There is an interesting philosophical remark on p. 155 about the use
* of approximations to simplify the calculation: "Il y a peut-être un peu
* à perdre sur la précision géométrique, mais la véritable élégance
* d'une solution est d'être simple ; l'Astronomie offre assez de
* difficultés réelles, sans en aller chercher d'imaginaires, & qui
* n'auroient pour but qu'une exactitude inutile." Bouguer finds that
* the refraction is proportional to the angle at the center of the Earth
* between the observer and the point where the line of sight reaches the
* top of the atmosphere. (p. 156)
*      He looked for diurnal variations, and found the refraction at night
* 1/6 or 1/7 greater than in the daytime, though this is only appreciable
* below 7 or 8 degrees. (p. 156) "Les variations diurnes des réfractions
* ne sont probablement dûes qu'à la dilatation des couches le plus basses
* de l'atmosphère . . . ."
*      There is a curious remark about the effect of the supposed elongation
* of the Earth at the poles, and its effect on refraction, on p. 157.
*      Finally, regarding his revisions of the earlier tables:  "Combien de
* choses inconnues sur une matière aussi importante, & qui avoit été
* déjà traitée tant de fois!"


Bouguer
“Second mémoire sur les réfractions astronomiques, observées dans la Zone Torride ; avec diverses remarques sur la manière d'en construire les Tables,”
Mém. Acad. Roy. Sci. 1749, 75–112 (1753).

* BOUGUER's second memoir (1749) -- an amazing piece of work!
* He starts out: "On étoit persuadé en Europe, lorsque nous partîmes
* pour le Pérou, que les Réfractions astronomiques devenoient plus grandes
* à mesure que l'Observateur s'élevoit au dessus du niveau de la mer :
* ce ne seroit pas assez de dire que ce sentiment étoit presque général,
* car il n'y avoit sur ce sujet qu'un seul avis, & personne ne pensoit à
* en douter. C'est ce qui m'invita à ne pas abandonner si tôt l'examen
* des réfractions, après que j'eus reconnu qu'elles changeoient dans un
* sens contraire à celui qu'on avoit cru . . . ." -- and continues:
* ". . . je proposerai des expédiens aussi exacts que commodes pour
* construire les Tables anaclastiques . . . & de développer davantage tous
* les moyens de calcul que m'a fourni la solution analytique que j'avois
* déjà donnée de ce problème dans une pièce publiée en 1729" --
* i.e., the prize essay on measuring altitudes at sea.
*      There is a nice description of the path of a ray from a star seen
* below the astronomical horizon, with the double path through the
* atmosphere below the observer (p. 80 and Fig. 1). He even has (p. 81)
* an early description of parallactic refraction: "il faudroit donc, dans
* la rigueur, augmenter la parallaxe de cette planète vers l'horizon,
* puisque c'est à peu près la même chose que si le semi-diamètre de la
* terre étoit un peu plus grand." [Note also his distinction between
* "l'atmosphère" and "la matière réfractive."] He explicitly points
* out the symmetry of the ray about its lowest point. Here (p. 82) he
* denotes the terrestrial refraction as the whole part below eye level.
*      In discussing the theory (p. 84), he refers to "la matière qui cause
* la réfraction & qui est répandue dans l'air" -- clearly distinguishing
* between "air" and "the refractive medium". He then refers to his 1729
* theorem involving a power of the distance from the center of the Earth,
* and offers a more direct and elegant proof of it. (pp. 85-90 & Fig. 2)
* There is a nice line on p. 85: "Toutes les fois qu'on parvient par
* de longs circuits à des propositions très-simples, il doit y avoir
* d'autres chemins qui y conduisent : il n'est pas possible qu'une vérité
* qui se réduit à des rapports peu complique's, ne soit pas susceptible
* d'une démonstration très-courte."
*      Note that his "dilatations" are the reciprocals of the refractive
* index as a function of radial distance from the center of the Earth; so
* if we would say n is inversely proportional to Rm, this gives his
* exponent m .
*      On p. 86, he discusses explicitly the question of the "refractive
* material": "Il se pourroit fort bien qu'il n'y eût point de matière
* réfractive, & que les réfractions répondissent, non pas aux dilatations
* de l'air grossier, mais à une certaine fonction de ces dilatations . . . .
* Ce seroit toûjours la même chose pour nous : nous serions même tentés
* d'admettre cette seconde hypothèse, mais nous continuerons néanmoins
* à designer sous le nom de matière réfractive cette fonction . . . le
* rapport de sinus d'incidence & du sinus de réfraction . . . ."
*      He then uses the geometric impact parameters at two neighboring points
* along the curved ray to relate them to the ratio of sines (i.e., the index
* of refraction). The ordinates of his curve BGI plot the reciprocal of
* our index of refraction. The argument proceeds in very geometric terms;
* the analytic relations are expressed in terms of ratios and proportions.
* On pp. 89-90 he effectively derives the refractive invariant.
*      On p. 93, he points out that if the refractive index were inversely
* proportional to radial distance, the ray would keep a constant inclination
* to the local vertical, and be exactly a logarithmic spiral. Thus a
* horizontal ray would circle the Earth: "elle s'étendroit circulairement
* tout autour de la Terre, & elle ne seroit bornée que par l'Observateur
* même, qui se verroit de dos." [Thus beating Kummer by over a century!]
* He also sees that a stronger rate of decrease of refractive density will
* cut off the sky near the horizon -- thus pre-empting Bravais (1853) and
* Hasse's Kimmfläche (1960).
*      On p. 95, he says that the radius of curvature of the ray must be 7
* or 8 times that of the Earth. Then, as the ray is so nearly straight,
* its length can nearly be replaced by that of its tangent or its chord.
* This leads to the conclusion that, if the refraction is proportional to
* the projection of the curved part onto the Earth's surface, it is also
* proportional to the projection of the line of sight from the observer to
* the upper surface of the atmosphere -- which he found from his Peruvian
* observations to be at a height of 5158 toises (about 10 km). He adds
* (p. 96) that for more accuracy, the apparent ZD should be decreased by
* about half the refraction, in doing this calculation. [The similarity
* to Bradley's rule is obvious.] "Ainsi il suffira de connoître m , ou
* de connoître une des réfractions, pour avoir toutes les autres, & cela
* par un calcul extrêmement simple ; il faudra seulement être attentif
* à ne pas conclurre les grandes réfractions par les petites, mais à
* inférer au contraire les petites de l'observation des grandes." (p. 97)
* He concludes that m is about 7 5/8.
*      [Notice that all this scaling of refractions in proportion to the
* horizontal lengths, or the length from the observer to the "top of the
* refractive material," is a result of assuming a linear decrease in
* refractivity from the ground to the top of the atmosphere.]
*      Then he considers the refraction at the edge of the Earth's shadow
* in lunar eclipses. He also (pp. 98-99) invokes terrestrial refraction
* observations made from both ends of a long line of sight to estimate m
* independently, which gives him 7 22/25 from his observations in Peru.
* A further check comes from the observed "terrestrial" refraction
* observed at a depression of 1 degree from Chimborazo; this gives 7 and
* 431/967 for (m - 1). On pp. 100-101, he tries another check, this time
* searching for the m that fits 2 refractions at different altitudes by
* successive approximations; this gives m = 9 1/8.
*      Section III (p. 102) considers DIURNAL VARIATIONS.  He finds (p. 105)
* that the nocturnal refraction is greater than the diurnal by 1 part in 6
* or 7. [Of course, some of this must be due to temperature, which he did
* not record.] This applies at apparent altitudes below 7 or 8 degrees.
* "Sans doute qu'elles ne sont jamais portées plus loin que quelque temps
* avant le lever du Soleil : c'est alors que le froid est le plus grand;
* l'atmosphère plus condensée doit avoir perdu le plus de sa hauteur,
* au moins par sa partie inférieure, & il n'est guère vrai-semble que
* la matière réfractive ne participe aussi un peu à cette altération."
*      He then shows (p. 106) that the horizontal refraction should change
* inversely as the square root of m , if m changes [of course, assuming
* the same refractivity at the surface!] -- cf. Ivory's later comment
* on Mayer's formula. He notes that "Hauksbée . . . en Angleterre" had
* found a much smaller change in the volume of air with seasonal change
* in temperature than needed to account for the observed diurnal changes
* in refraction. So (p. 108) he invokes de Mairan's 1721 remarks about
* "vapeurs". But he makes a good argument that the diurnal effects must
* reside in the lowest layers of the atmosphere: "l'air est trop diaphane
* pour contracter beaucoup de chaleur par l'action immédiate des rayons du
* soleil qui le traversent; il s'échauffe par le voisinage de la terre &
* par celui des corps qu'il touche : la chaleur qu'il a acquise doit ensuite
* se transmettre peu à peu aux couches supérieures; mais elle doit le
* faire toûjours assez lentement . . . : les plus grandes changemens se
* font donc toûjours en bas . . . ."
*      On p. 109, he mentions the effect of the shape of the Earth: the
* radius of curvature depends on azimuth. He has the sense of the effect
* correct: "La courbure de la circonférence de la Terre se trouvant plus
* grande dans le sens du méridien que dans celui du premier vertical,"
* so the refraction should be larger in the latter. But the effect is
* negligible for ordinary purposes.
*      The paper concludes with a revised table of refractions for Quito,
* superseding that of 1739.



*** SIMPSON - BRADLEY - MAYER FILE ***

T. Simpson
Mathematical Dissertations on a Variety of Physical and Analytical Subjects
(T.Woodward, London, 1743), pp. 46–61.

*
* THOMAS SIMPSON's work -- a lead-in to Bradley and Oriani
* This is the origin of "Bradley's formula" -- Bradley found better
* values for the constants.
*      P. 54: ". . .  let the Law of Density of the Atmosphere be what it
* will, the Refractions of the Sun , Moon and Stars, at all Altitudes
* except very small ones, will be nearly as the Tangents of their apparent
* Zenith Distances drawn into the respective Density of the Atmosphere, at
* the Places and Times, for which such Refractions are to be determined ;
* and therefore if the Density be the same, are simply as the Tangents
* of their Zenith Distances." On p. 55, he investigates the accuracy of
* this rule, by dividing the atmosphere into two parts at the level where
* the density is half that at the surface. "Now the Height of this Surface
* . . . cannot be more than about 5 Miles, or 1/800 of the Earth's Radius."
* So, on p. 56, he finds that the refractions above 20° altitude can be
* inferred from that at this limit, regardless of the "Law of Density".
*      P. 57: "If the Density of the Atmosphere, in going from the Earth,
* be supposed to decrease uniformly (which Law will be found to answer
* better to Experiment than the commonly received one, founded on the
* Elasticity of Air) . . . " [Of course, Mayer re-did this model better
* in 1755, but failed to publish his work.]
*      Simpson adopts the uniform decrease of density with height, but worries
* about its conflict with the exponential decrease of pressure with height.
* On the other hand, the exponential model predicts too large a horizontal
* refraction.
*      P. 61: ". . .  the refraction in high altitudes, it has been proved,
* will be but little affected by different Laws of Density, and therefore
* come out very near the same, compute them according to what Hypothesis
* you will; even so near, that if the Refraction at any Altitude not less
* than about 7 Degrees be truly given from Experiment, the Refractions,
* computed from thence, for any higher Altitude, will never differ from
* one another by more than about 2 Seconds." [cf. Oriani]
*      Available from Google Books.


E. G. Forbes
The Euler-Mayer Correspondence (1751--1755)
(American Elsevier, New York, 1971).

* TOBIAS MAYER's unpublished (until recently!) letters, translated by
* Eric Forbes, who gives the chronology on p. 8; see p. 25 for its notes.
* Mayer's formula first appears on p. 50; the derivation is discussed rather
* sketchily on p. 46. Both cover his letter to Euler dated 6 Jan. 1752,
* which is why I place this reference here instead of 219 years later.
* Forbes notes that Mayer's formula is too small near the horizon, but
* apparently does not understand why.
* Here is Forbes's translation of Mayer's explanation [the notes to these
* pages are on pp. 102-103.]:
*      ". . .  the most worthwhile result that I got out of it was when I took
* the curve of density to be a straight line . . . . Then, in this case,
* the formula for the refraction may be integrated by simple logarithms,
* or even algebraically by means of a suitable approximation. . . .      Now,
* although this hypothesis is an open contradiction of the truth, the
* resulting formula for the refraction nevertheless agrees very closely
* with observations, and this makes me think that it would not really help
* much if one were to choose straightaway another and better expression
* for the density of the air. I have already seen Mr. Bouguer's treatise
* ten years ago . . . ." [Note: Mayer uses ρ for the refraction, and
* α for the zenith distance. And, according to Delambre's Histoire ,
* the Bouguer works cited by Euler on p.44 and Mayer on p. 46 must be his
* crowned essay "Méthode d'observer exactement sur mer la hauteur des
* astres"; Forbes's references to B.'s papers in Mem. Acad. Roy. Sci.
* make no sense, as those contain only observations, not theory.]
*      It appears from Mayer's remarks on p. 47 that he found it useful to
* fudge the height of the atmosphere to agree well with the refraction data:
* ". . . where 36,000 is the number" of Paris feet in the model atmosphere's
* height. "According to Mr. Bernoulli one must assume for it 22,000 which,
* however, is contrary to experience; and if the densities decrease in
* exactly the same ratio as the elasticities" [i.e., if the atmosphere
* were isothermal], "the same divisor would be 27,000."


[L. ] Euler
“De la réfraction de la lumiere en passant par l'atmosphére selon les divers degrés tant de la chaleur que de l'elasticité de l'air,”
Histoire de l'Académie Royale des Sciences et Belles-Lettres de Berlin, Année MDCCLIV [1754], vol. 10, 131–172 (1756).

* LEONHARD EULER's paper
* See Kramp (1799) for trenchant criticism of Euler's work -- although
* Plana (1828) showed that Kramp himself made many serious errors.
*      Of interest here is his matter-of-fact acceptance of atmospheric
* dispersion (p. 131): ". . . comme les rayons, qui sont de diverses couleurs,
* souffrent des réfractions differentes, je considère ici seulement
* les rayons d'une telle nature moyenne, qui est également eloignée de
* ceux, qui subissent ou la plus grande, ou la plus petite réfraction :
* car c'est par rapport à ces rayons moyens, que les Astronomes sont
* accoutume's de dresser leurs tables de réfraction."
*      Euler calls the refractive index 1/α .  However, he then says
* that the refraction is the same in passing from air of density c to
* density 2c as in passing into the first from a vacuum, thus making
* α, or the refractive index, a power-law function of the density.
* [This is of minor practical consequence, however.] (p. 132)
*      This might be the first paper where ζ is the local zenith distance
* at the observer; ω is the local ZD along the ray (p. 133).
* His constant C (p. 134) is the refractive invariant. The equations here
* show an interesting transition from the pure proportions used earlier
* toward the purely algebraic notation of later writers.
*      Euler works largely geometrically; so he thinks the way to discover
* the refraction is to have the path of the ray first (p. 135). But
* one good consequence is that he sees immediately that the perpendicular
* to the ray's tangent at infinity is the impact parameter of the ray's
* asymptote in air (p. 136); he calls this perpendicular length p .
*      He then (p. 137) considers the hydrostatic equation, and realizes that
* the density is proportional to the pressure only at constant temperature
* (p. 138). And he imagines a thermometer graduated on an absolute scale,
* so that at constant pressure this temperature is inversely proportional
* to the density. (p.139)
*      The cumbersome rational exponents on p. 139 show the typographical
* disadvantage of using a fixed size of type, instead of a smaller font for
* superscripts and exponents. Although the printer finally resorted to a
* smaller exponent face on p. 141, the equations there too are hard to read,
* due to (a) extra-long equality and minus signs, (b) a refusal to break
* equations across lines, and (c) placing the LHS on the line above the RHS.
* The lack of space before and after equations also impairs legibility.
*      On p. 142, Euler assumes the ray has the form of a negative power-law
* with exponent m . This is far from the truth, so the rest of his
* development is not very useful. The familiar number 206265 appears on
* p. 148. Then complete speculation is introduced about the height at
* which the (absolute) temperature would be half that at the surface; he
* guesses it would "surpasse de beaucoup une mile d'Allemagne." So he
* tries 2 German miles [about 15 km]. (Later he tries 3 miles.)
*      Another typographical note: he uses an S turned sideways for an
* infinity sign (pp. 150-152).
*      On p. 158, he comes up with the first 2 terms in the tan Z expansion,
* when 10 μ tan2 ζ is small; another expansion when it is large;
* and yet a third expression for the intermediate values. There is an
* interesting Freudian slip on p. 159, where he says "parallaxe horizontale"
* for horizontal refraction. He proposes a horizontal refraction that
* varies with the barometer and thermometer. Perhaps these considerations
* influenced Mayer.
*      On pp. 161-164, he compares his theories with the observational  table
* of Flamsteed, and the theoretical one of Cassini. Finding Cassini's
* values more consistent with his model with a temperature gradient, and
* Flamsteed's closer to the isothermal one, he concludes: "D'où il semble
* qu'en Angleterre le degré de chaleur de l'atmosphère en montant diminuë
* moins qu'à Paris." Only a theoretician could do such a thing!
*      On p. 168, he decides that the tangent approximation is good enough
* out to 70° ZD; and that "qu'à moins que l'astre ne soit trop proche
* de l'horizon, la réfraction est assés exactement proportionnelle
* à la hauteur du barometre; & réciproquement proportionnelle à
* la hauteur du thermometre, ou plutôt au degré de chaleur. Mais,
* pour les hauteurs de l'astre fort petites, le changement causé par le
* barometre & le thermometre devient plus grand que selon lesdites raisons,
* & cela surtout à l'égard des changemens de la chaleur."
*      He then summarizes his results, dividing them into 3 cases as before
* (near zenith, near horizon, and intermediate). Interestingly, he
* notes that when the zenith distance exceeds 90°, which can occur
* when the observer is quite high, the refraction becomes greater than
* the horizontal; but of course this was already seen by Bouguer in Peru.
*      The Supplement on p. 171 refines his earlier derivations somewhat,
* and again recognizes that the tan Z approximation is good near the
* zenith, and does not depend on atmospheric structure.
*      Note: the Plate with Figs. 1 and 2 follows p. 346.
* This paper is in the section called: Mémoires de l'Académie
* Royale des Sciences et Belles-Lettres, Classe de Mathématique
* and is available at
*
* http://bibliothek.bbaw.de/bibliothek-digital/digitalequellen/schriften/#A2


J. H. Lambert
Les proprietés remarquables de la route de la lumière
(N.van Daalen, La Haye, 1759).

* JOHANN HEINRICH LAMBERT's refraction monograph (1758 and 1759 editions)
* Note the extended references to Bouguer's work on photometry in
* the Avant-Propos (pp. 5-7): "La Photométrie n'est pas un païs
* entierement inculte. Des savans fort célebres y ont travaillé. Mr.
* Bouguer en a donné un tres bel Essai sur la Graduation de la lumiere.
* Il la fait pasier par plusieurs vitres, par l'eau, par l'athmosphere. Il
* en cherche l'affoiblissement. Il s'en sert pour la célebre expérience
* sur la comparaison de la Clarté du Soleil & de la Pleine-Lune." And
* this passage is *quoted* in the introduction to Lambert's Photometria
* -- so how can people say he did everything independently from Bouguer?
*      Lambert's orientation as a theoretiker shows in the presentation:
* he begins with many geometric theorems, and only later gets to the
* matter of refraction. According to Houzeau, Lambert introduced
* the notorious series-expansion approach; and here it is, on p. 45:
* "\section. 76. Exprimer les refractions par une suite." He expands
* the square root in the denominator using the binomial theorem, first
* obtaining a slowly-convergent series in sin z (which he calls γ),
* ". . . dont les termes croissant suivant les puissances impair . . . "; then,
* transforming the terms into a faster-converging series in the tangents.
* So on p. 47, section 78: "On poura donc exprimer les refractions par la
* suite . . . ", which is the usual one with alternating signs.
*      On p. 70, section 103, is an application to terrestrial refraction.
* "Mr. Cassini a observé au pied du clocher a Massanne la dépression
* apparente de la surface de la mer, & la trouva de 50',20''. & la hauteur
* de la Tour au-dessus du niveau de la mer de 408 1/2 toises. . . . Ces
* valeurs etant substituées dans la formule . . . [p. 71] on trouve
*
*              x = 7,06 = R.
*
* De sorte que la raïon horisontal etoit sept-fois plus grand que celui
* de la terre." [A second example gave 7.02; he adopts 7.]
*      pp. 75-76: He shows that the terrestrial refraction is half the
* reciprocal of this number, times the angle at the center of the Earth,
* so that 1/14 of that angle is the terrestrial refraction.
*      A curious feature (and one typical of Lambert) is his "proof", on
* p. 77, that refraction cannot alter the apparent size of an object:
* having established (given certain assumptions and approximations!) that
* the terrestrial refraction depends only on this central angle, he derives
* as a corollary that it can only displace objects vertically, not alter
* their apparent size. [So mirages would be impossible!] -- another
* example of Arthur Searle's comment [Obs.22, 310-311 (1899)] that
* "In particular, Lambert's theory, developed in his `Photometria,'
* had been regarded as almost demonstrably true, while, in fact, it
* consisted of an ingenious mathematical superstructure on a very
* insecure foundation."
*       Full title is:
* "Les proprietés remarquables de la route de la lumière, par les
* airs et en general par plusieurs milieux refringens spheriques et
* concentriques, avec la solution des problèmes, qui y ont du rapport,
* comme sont les refractions astronomiques et terrestres, et ce qui en
* depend"
*      N.B.: This seems to be a reprint on the Readex cards.  The NUC lists
* the 1758 edition, published by "Chez H. Scheurleer, F.Z. & Compagnie",
* also at La Haye -- a photocopy of which is now available at
*
*       http://www.kuttaka.org/~JHL/L1758a.pdf
*
* The body type of the two editions is identical, even including the same
* list of "Fautes á corriger" at the end of p. 116. Only the title
* page appears to have been reset for the 1759 edition. The Dutch
* typesetters seem to have had some difficulty with the French: the
* left-hand running head varies from "Les Propriétés Remarquables" (pp.
* 10 - 16) to "Les Propriétes Remarquables" (p. 18) to "La Propriétes
* Remarquables" (p. 20) to "Propriétes Remarquables" (pp. 22 - 26) and
* back again.
* [cited by Kramp]


N. Maskelyne
British Mariner's Guide
(J.Nourse, London, 1763).

* NEVIL MASKELYNE publishes BRADLEY's rule (1763)
*      Bradley's rule is described on pp. 120-121: ". . .  a rule formerly
* communicated to me by the late Dr. Bradley, and deduced by him from his
* observations, according to the principles contained in a paper of the
* late Dr. Simpson's, in his Mathematical Dissertations." And the whole
* procedure then follows, including the corrections for temperature and
* pressure.
*      On pp. 86 ff. are directions for observing lunar eclipses.  I was
* surprised to read: "if any telescope is used, it must be one that has a
* great deal of light . . . . Those called night glasses may be very
* conveniently used . . . ." I was not aware that term was in use this early.
*      This is the first edition of many; it seems to be a sort of precursor
* to the old Nautical Almanacs, with tables of the Sun and Moon, star
* positions, etc. The years covered are 1760 to 1780. These tables are
* given capital Roman numerals, and are at the back of the book. The
* refraction table is on p. I.
*      The title page says "Printed for the author; and sold by. . . " (listing
* several London booksellers). I list only the first.
*      Available at the Gale website


N. Maskelyne
“Concise rules for computing the effects of refraction and parallax in varying the apparent distance of the Moon from the Sun or a star,”
Phil. Trans. Roy. Soc. (Lond.) 54, 263–276 (1764).

* MASKELYNE publishes BRADLEY's rule
* [For proof that it comes from Simpson, see Rigaud's Supplement, 1833.]
* On the first page, he says, "The two rules for the correction of
* refraction and parallax I have also . . . communicated to the public in
* my British Mariner's Guide" [published in 1763].
* P. 265: "This rule is founded upon an hypothesis that the refraction
* in altitude is as the tangent of the zenith distance . . . . This rule
* is exact enough for the purpose of the calculation of the longitude
* from observations of the distance of the Moon from stars at sea as
* low down as the altitude of 10°, for there the error is only 10''
* from the truth. But, if the altitude of the Moon or star be less than
* 10°, the rule may be still made to answer sufficiently, by only first
* correcting the observed zenith distances by subtracting from them three
* times the refraction corresponding to them taken out of any common table
* of refraction, and making the computation with the zenith distances
* thus corrected. This correction depends upon Dr. Bradley's rule for
* refraction, which he found to answer, in a manner exactly, from the
* zenith quite down to the horison, namely that the refraction is = 57''
* × tangent of the apparent zenith distance lessened by three times
* the corresponding refraction taken out of any common table."
* [See Maskelyne's further comments in 1787. Bradley died in 1762.]


T. Mayer
Tabulæ motuum Solis et Lunæ novæ et correctæ
(Typis Gulielmi et Johannis Richardson, Londini, 1770).

* TOBIAS MAYER's refraction formula, published posthumously by Maskelyne
* An amazingly important work in the history of astronomy, for it contains
* the "lunar distance" method of finding longitude that won Mayer's widow
* a share of the Board of Longitude prize, as well as testimonials from
* navigators about the practicality of the method. However, our interest
* here is merely in the formula for refraction.
*      The text is given in both Latin and English.  The refraction formula
* appears on pp.64 (Latin) and 117 (English). On the next page, we read
* that the formula is "deduced from theory", without further explanation.
* (The origin of Mayer's theory was debated for years -- cf. Delambre,
* Plana, etc. -- until the Euler-Mayer correspondence was discovered, and
* published by Eric Forbes in 1971.)


Lambert
“Sur la densité de l'air,”
Nouveaux Mémoires de l'Académie Royale des Sciences et Belles-Lettres (Berlin), Année MDCCLXXII [1772] , 103–140 (1774).

* Lambert's crazy paper about the atmosphere
* Having essentially repeated Newton's calculation for the speed of sound,
* assuming the isothermal compressibility of air (Mem. 1768, p. 70-79),
* which gives a result about 15% too small, Lambert thought he could
* fudge up the right answer by increasing (!) the density by some 30%,
* attributing this to foreign matter suspended in the air.
*      Here he extends this idea to refraction.  He distinguishes between
* a supposed "air pur" and "air naturel" that contains the suspended
* matter, starting from the discrepancy in calculated refraction at the
* horizon found by Simpson, who "trouve qu'en supposant l'air naturel,
* la réfraction horizontale iroit à plus de 50', tandis qu'elle n'est
* que de 32 ou 33 minutes. Cela le porte à supposer une matiere
* réfractive, qui décroisse uniformément en montant. Cette hypothese
* emporteroit la conséquence, que la matiere réfractive ne s'étend
* qu'à une certaine hauteur, puisqu'au-dessus de cette hauteur elle
* devendroit négative. Mr. Bouguer paroit admettre une supposition
* assez semblable, puisqu'il prétend qu'a une hauteur qui va au-dessus de
* 5118 toises sur la mer, le réfractions sont nulles." " (p. 104) This
* somewhat misrepresents Bouguer's actual point of view; but it provides
* an interesting hint as to why the French supposed the "refractive matter"
* did not coincide with the air itself.
*      On the next page, he argues that the "particules étrangeres" affect
* only the weight of the air, not its refractivity. On p. 106, he notes
* that "On sait qu'en pompant l'air il paroit d'abord un brouillard" -- an
* early observation of the cloud-chamber effect! -- "& qu'à mesure qu'on
* continue d'exténuer l'air ces particules commencent à tomber peu à
* peu dans le fond du verre, l'air exténué n'ayant plus assez de force
* pour les soutenir toutes dans ses interstices." So far, so good.
* But then: "Mais comme avec tout cela le brouillard qu'on voit dans le
* cloche après les premiers coups de piston, tombe peu à peu au fond de
* la cloche, il semble que la densité des particules étrangeres diminue
* plus fortement & plus vite que la densité de l'air."
*      The real sloppiness begins on p. 107, where he has AEC for AEB
* (second line of section 9). On p. 108, the second equation in section
* 10 is missing an R on the RHS. Then in section 11, he supposes the
* density proportional to the log of the refractive index, instead of
* the refractivity. Naturally, this leads to a contradiction (p. 109) --
* but he attributes the discrepancy to a deviation of the refractivity
* from being proportional to the density of air (despite having cited
* "Hawksbee" on p. 106); and then attributes this difference to the effect
* of the foreign matter.
*      On p. 110, the ever-popular "vapeurs" take a share of the blame.
* He contrives to fudge the compensating effects of the vapors and
* the suspended particles so as to maintain Mariotte's law. But then
* (p. 112) he acknowledges that he has to take account of the decrease in
* temperature with height; and now it gets really arm-wavy. In section 24
* (p. 114) we have: ". . . le feu est spécifiquement plus léger que l'air.
* En conséquence les particules de feu doivent monter avec une vitesse
* accélérée, la vitesse initiale étant celle avec laquelle elles
* s'élancent par leur propre élasticité. La force accélératrice est
* cette même légéreté spécifique." We are off into far left field;
* this is practically a crank work from here on -- especially as he then
* has many pages of mathematics purporting to describe the equations of
* motion of the "particles of fire". This is indeed "an ingenious
* mathematical superstructure on a very insecure foundation," to quote
* Searle again.
*      On p. 118, he decides that "la densité des vapeurs décroit comme le
* quarré du poids de l'atmosphere," and affirms that "Cette conséquence
* paroit être assez vraie par elle-même." But on p. 120, there is
* some weasel-wording: "il faut observer que l'air peut être extremement
* chargé de particules aqueuses, sans qu'il paroisse être humide" --
* whatever that is supposed to mean. By p. 128 he has worked out his
* elaborate theory for the air, giving a table of the adopted components
* as functions of height. On p. 131 is more weasel-wording to explain
* away situations in which his model doesn't work.
*      Then he returns to the speed of sound, taking into account his
* elaborate model -- again (p. 132) cautioning that it doesn't work
* "pour les anomalies journalieres ou acidentalles." In other words,
* when his theory agrees with observations, it proves the theory is right;
* when it doesn't, the atmosphere is "abnormal" so it doesn't matter.
* Classic crank reasoning. Discrepancies with observation are also
* blamed on the wind (section 52).
*      He returns to refraction on p. 138; on the next page, he gives the
* differential equation for refraction in his theory, but does not solve it
* (section 58). In the final section, he refers briefly to his earlier
* result about terrestrial refraction.
*      In sum: Lambert at his worst.  Note that Bruhns missed this one.
* (Available at the Berlin Academy website, bibliothek.bbaw.de/bbaw/ )


[J.-L. ] la Grange
“Sur les réfractions astronomiques,”
Nouveaux Mémoires de l'Académie Royale des Sciences et Belles-Lettres (Berlin), Année MDCCLXXII [1772] , 259–282 (1774).

* JOSEPH-LOUIS LAGRANGE's paper on refraction
* Lagrange cites de Luc's (1772) experiments on the density of air, and
* assumes a linear lapse rate. He denotes the natural log function by "l",
* and common ("tabulaire") logs by "L"; so his conversion modulus m
* is 1/l10 = 0.4342945. The first part is devoted to the barometric
* law, and determining the heights of mountains. Only on p. 270 does he
* start to deal with refraction at last, citing "Hawksbee"'s experiments.
* He calls the refractive index (i.e., the ratio of sines) "raison de
* réfraction"; then his n is what we would call the refractivity [our
* (n-1)], The refraction he calls ρ.
*      His temperatures are all Réaumur degrees above or below de Luc's
* reference temperature of 16°¾; so his absolute zero for thermal
* expansion is 215°R below that point. This makes his correction
* factor (1 + t /215). [Oriani adopts this value also.]
*      On pp. 278-279, he shows that "la réfraction est généralement
* proportionelle à la hauteur du baromêtre, & à la tangente de la
* distance apparente de l'astre au zénith, lorsque cette distance est
* assez différente de 90° pour que 2α/cos Z soit une quantité
* très petite vis à vis de 1." [His α is essentially H/R.]
*      Then he shows that the refraction can be integrated if one assumes
* the radial distance is a power of the refractive index. But (p. 281)
* Simpson's values of the constants disagree with de Luc's measurements
* [in our terms, Simpson's linear model requires the wrong lapse rate.]
* He then examines Bradley's formula, and shows how it corresponds to his
* power-law relation. "Ainsi la regle de Mr. Bradley est nécessairement
* sujette aux mêmes difficultés que celle de Mr. Simpson, à laquelle
* elle revient dans le fond."
*      He concludes by saying that Mayer's formula disagrees with the tangent
* rule below 70° Z.D. (p. 282)
* The Berlin Academy was modelled after the Paris one, including the use
* of French as its official language. These pages are available as *.jpg
* images at http://www.bbaw.de/bibliothek/digital/ now. Note that
* they appeared 2 years after the year of the meetings; so this is
* usually cited as "1772". Plate V follows p. 140 (Lambert's paper).
*      Cited by Delambre/Mathieu, and mentioned without citation by Bruin;
* reprinted in Serret's Oeuvres de Lagrange, v. III (Paris, 1869),
* pp. 519-545. Oriani's 1787 work is based on this paper.


Le Gentil
Voyage dans les mers de l'Inde,Vol.1
(Impr.royale, Paris, 1779), pp. 426–447.

* LE GENTIL's refraction observations below 14° altitude, and table
* Here he criticizes Bouguer's measures in Peru as being too small.
* Le Gentil's observations were all made in 1769 (not 1796 as printed
* on p. 431).
*      In the discussion, he prefers Cassini's model of a uniform
* atmosphere. To fit his own data at 10° and 14°, he requires the
* height to be 1750 toises, not 2000 as Cassini had it for Paris.
* [NOTE: He correctly describes Cassini's procedure (p.441), namely
* that he assumed a height, calculated a table from the horizontal
* refraction, and adopted the result that agreed best with observations.
* The calculations on pp. 442-443 show in detail how Cassini's model
* is worked out.]
*      The adjoined Table (pp. 446-447), calculated by Duvaucel, of course
* shows the parabolic behavior near the horizon, being tabulated at 15'
* intervals there, the (tabulated!) differences being very nearly in the
* ratios of 1 : 3 : 5: 9 for the first degree.
*
* Ch. I, Art. IV. Observations sur les réfractions, à différentes
* hauteurs au-dessus du niveau de la Mer, toujours à 46 pieds environ
* au-dessus de son niveau.
* The footnote says:
* "Ces Observations ont été lûes à l'Académie royale des Sciences,
* dans son assemblée du 27 Novembre 1774."
* Note that p. 439 is incorrectly marked 349.


N. Maskelyne
“Concerning the latitude and longitude of the Royal Observatory at Greenwich; with remarks on a memorial of the late M.Cassini de Thury,”
Phil. Trans. Roy. Soc. Lond. 77, 151–187 (1787).

* MASKELYNE's further reminiscences of Bradley's work
* Maskelyne's aim is to correct Cassini III's notion that the separation
* between Paris and Greenwich was uncertain by 15 seconds or so. To do
* so, he exposes the details of the determination of Greenwich's place by
* Bradley, and this brings up his refraction rule.
*      "Had Dr. Bradley lived longer, for the benefit of astronomy, to
* publish his valuable observations . . . .
*      "However, having formerly been apprised by Dr. Bradley himself of
* several particulars . . . particularly of the method which he used for
* settling his latitude and refractions, . . . and being assisted with some
* of his manuscript calculations, I flatter myself I can throw the light
* wanted on the question . . . ." (p. 153)
*      "He afterwards, from the consideration that the refractions at the
* pole and equator [i.e., the celestial ones, as seen from Greenwich]
* may be taken without sensible error as the tangents of the zenith
* distances, according to Mr. Thomas Simpson's theory of refractions in his
* Mathematical Dissertations . . . found . . . the mean refraction at 45° 3'
* to be 57'', the barometer standing at 29,6 inches, and the thermometer
* of Fahrenheit's scale at 50°." (p. 155)
*      ". . .  and thus at length he inferred his elegant rule for determining
* the refraction in all circumstances, that it is to 57'', in the direct
* compound ratio of the tangent of the apparent zenith distance lessened
* by 3 times the refraction to the radius . . . .
*      "But it may be proper to confirm this rule for refractions also from
* the same manuscript of Dr. Bradley . . . ." (p. 156)
*      "This valuable rule was first communicated by myself to the public
* in vol. LIV. of the Philosophical Transactions, p. 265. and in p. 49. and
* 129. of the first edition of Tables requisite to be used with the Nautical
* Almanac, together with a Table of the mean Refractions deduced from it,
* with the first Nautical Almanac, that of 1767, published by order of
* the Commissioners of Longitude in 1766; and again, at page the 5th of
* the Explanation and Use of the Astronomical Tables . . . . The words in
* page the 5th of the said Preface are as follows. `The astronomical
* refractions . . . were settled with the greatest accuracy by Dr. Bradley
* . . . . The following elegant rule was the result of his observations,
* that the refraction at any altitude is 57 seconds, in the direct compound
* ratio of the tangent of the apparent zenith distance lessened by 3 times
* the refraction to the radius . . . .' " (pp. 157-158)
*      Note: Bradley's pressure and temperature corrections have been elided.
* He adopted 29.6 inches of mercury as the standard pressure, and "the
* degree of height of Fahrenheit's thermometer increased by 350 to 400"
* as the temperature correction, relative to 50° F.
*      Maskelyne goes on to point out that Bradley's refractions were
* slightly too large, owing to the adoption of a solar parallax also
* too large. His corrected reduction of Bradley's work then gives
* "the refraction at the apparent zenith distance of 45° 3' = 55'',8,
* which is 1'',2 less than Dr. Bradley's determination, and 1'',2 greater
* than deduced from Mr. Hawksbee's experiment of the refraction of air
* hereafter cited." (p. 168; see p. 173 for Hawksbee.)
*      "Mayer's refractions agree almost exactly with Dr. Bradley's, and
* are entitled to much weight, having been determined by a 6-feet mural
* arc constructed by Mr. Bird." (p. 172)
*      There is then a long section in which he shows that La Caille's
* refractions were too large, owing to a systematic error in his circle;
* but that the errors compensate if La Caille's refractions are applied
* to just his own measurements. (This systematic error is the source of
* Cassini de Thury's impression of an uncertainty of 15 seconds or so.)
*      There are many contemporary references to Bird, Short, Dollond,
* and other great instrument makers, as well as an appeal to measurements
* made by Messier in Paris to confirm the longitude there. On p. 186,
* "M. Mechain, the learned editor of the Connoissance des Temps ,
* informs me . . . ." A fascinating work, in many ways.


B. Oriani
“De refractionibus astronomicis,” in Ephemerides astronomicae Anni Intercalaris 1788.
(Apud Joseph Galeatium, Mediolani [Milan], 1787), pp. 164–227.

* BARNABA ORIANI's work: ``Oriani's Theorem.''
* For summary, see the next entry.
*      The typography is hard to read: the Greek font is much smaller than
* the Latin body type, and oddly shaped. The Italic font used for
* variables has some peculiarities: an obliquely tailed z ; and the
* Italic lower-case h is nearly indistinguishable from b . Oriani
* uses L to denote the common logarithm: "L A/b " means "log(A/b)"
* in modern notation. Likewise, he uses a period (.) rather than a
* centered dot to denote multiplication, and a comma as a decimal point.
* So his "1649.0,9739" means 1649×0.9739 in our notation. But he writes
* common logs as "L " and natural logs as "l. " before their arguments.
* So his "l.10" is the familiar modulus 2.302585. . .      Blessedly, he writes
* the base of natural logs as e ; but all the exponentials are written
* out as e raised to some (often complicated) power. Breaking equations
* in the text across lines does not help, either. There is a long list
* of Errata on the page after the title page.
*      A much more readable account of Oriani's work is the summary given
* by Bruhns (1861), p. 69, which boils it down in modern typography, showing
* how closely Oriani followed Lagrange's 1774 notation and development.
*      The 2-term result appears at the bottom of p. 217.  Remember that the
* temperatures are on the Réaumur scale.
*      This is now available from Google Books.  As usual, they have made
* the figures impossible to read.


B. Oriani
“De refractionibus astronomicis,” in Opuscula Astronomica ex Ephemeridibus Mediolanensibus ad annos 1788 & 1789 excerpta
(Joseph Galeatium, Mediolani [Milan], 1787), pp. 44–107.

* BARNABA ORIANI's work: ``Oriani's Theorem.'' [reprinted]
*      NOTE: The page numbers here are exactly 120 less than in the original
* Ephemerides. The reprint also corrects 3 Errata on pp. 60, 80, and 94
* of the reprint (= 180, 200, and 214 of the original). The typeface
* and framing are exactly those of the original, so the original type must
* have been used, changing only the page numbers.
*      Oriani's work begins with a discussion of the barometric law and the
* expansion of gases, complicated by the different thermometric scales of
* Réaumur, Fahrenheit, and Hauksbee. On p. 70, he has adopted a law of
* density vs. height in the atmosphere, and begins with the refraction
* problem. The refractive invariant appears (in rather obscure notation)
* in the middle of p. 78. After a lengthy discussion of the refractivity
* of air under standard conditions, he expands the differential of the
* refraction as a power series in x/r [x = height, r = radius of Earth]
* on p. 86. Expressing the tangent in terms of the sine, he then can
* write out the series in terms of integrals of powers of x times the
* differential of the density [rho]. He can't integrate exp(-x2) and
* so has recourse to numerical quadrature of his density table (Tab. II)
* to evaluate the coefficients (pp. 89, 90). The isothermal atmosphere
* (p. 93) presents no difficulties.
*      He concludes that for Z.D. not exceeding 50 degrees, the refraction
* can be taken proportional to tan Z, with 57 seconds as the constant at
* 28 inches on the barometer and 0 deg. Reaumur (p. 97). For greater
* values of Z up to 65 or 70 degrees, the first 2 terms of the series
* suffice (p. 98): "This expression depends on no hypothesis about
* either the law of heat in the atmosphere or about the density of the
* air at various distances from the surface of the Earth." Up to
* Z = 80 or 85 degrees, the third- and fourth-power terms must be
* included; but his expansion diverges at 86 deg.
*      Comments on usage and notation: Oriani uses "L." for common, and
* "l." for natural logarithms. He sometimes writes "x x" for x2.
* His "French fathoms" (hexapedia gallicia) are toises. He uses the
* abbreviation "D." for "Dominus" as an honorific title; it may be simply
* translated as "Mr." We also have "Cl." = Clarissimus.
*      MANY THANKS to Brenda Corbin for supplying a photocopy!!  (with many
* helpful marginal comments in Latin handwriting.)


Chr. Kramp
Analyse des Réfractions Astronomiques et Terrestres
(E.B.Schwikkert, Leipsic, 1799).

* CHRISTIAN KRAMP's monograph
* This is heavily concerned with the gamma function, which was invented
* by Euler in 1729; the Γ notation was introduced in 1809 by Legendre; see
* https://www.csie.ntu.edu.tw/~b89089/link/gammaFunction.pdf for a readable
* history and account of its properties.      Kramp introduces it here as the
* integral over an exponential atmosphere of various powers of the height.
* [He later introduced the modern ! notation for factorials; but in this
* work, he is still using a very awkward notation. To confuse things more,
* he has a "Gamma" function; but it is more like the modern log-gamma
* than the usual factorial version. Here he calls them "facultés"
* instead of "factorielles".]
*      The old terminology makes this difficult reading: the scale height
* is called a "soutangente" (i.e., the intercept of the tangent at the
* origin.)      Angles are sometimes given in centesimal seconds [as
* when he cites the result of ``citoyen Laplace'' that the refractivity
* of air corresponds to an angle of "183 sec " (p. 120)]. He also uses
* "horison" for both "sea level" and "astronomical horizon". Furthermore,
* he seems to use "temperature" to mean "weather conditions," as in ". . . à
* la température de 28 pouces de hauteur barométrique, et à 0 dégrés
* du thermometre." (Those are Réaumur degrees, of course.)
*      The first chapter is mostly arm-waving about possible atmospheric
* models. He claims that the "specific elasticity" of the air might be
* a negative exponential function of height (to allow for the known
* temperature gradient in the atmosphere, and possible composition
* gradients). This gives him what he wants: an exponential density law.
*      Though Lavoisier (who had been guillotined just 5 years before) had
* discovered oxygen a few years earlier, its abundance was still not well
* known; in discussing the properties and composition of air, Kramp cites
* Kirwan's Essay on phlogiston , and refers to "l'air commun, composé,
* comme on sait, de 27 parties de gas oxygène, et de 73 de gas azote."
*      In comparing various published refractions with his own (anticipating
* the results of later chapters), he says (p.19):
*      "Prenons pour dernier exemple, la table de réfractions que nous a
* laissé le plus grand de tous les géomètres, et le plus habile de
* tous les observateurs qui aient jamais existé; l'homme sans lequel notre
* astronomie mériteroit à peine le nom de science, parce que c'est à
* lui seul que nous devons la connoissance des éternelles loix de la
* nature, et l'application de l'analyse à ces mêmes loix, en un mot,
* l'immortel NEWTON." [Poor Flamsteed must be spinning in his grave!]
* But Kramp also notices (well before Biot) that Newton's table must
* have been calculated for an exponential atmosphere with a scale height
* of 4377 toises:
*      "La table de Newton . . .  indique une température de 18 dégrés
* et deux tiers au-dessus de la glace. Et réciproquement, l'air se
* trouvant à la température de 18 dégrés et deux tiers, la réfraction
* horizontale de Newton est exactement ce qu'elle doit être dans la
* supposition d'une élasticité spécifique constante. Est-ce
* l'observation ou l'analyse qui a fourni cette table au géomètre anglois?
* Dans le premier cas, l'exemple d'un pareil accord seroit unique peut-etre
* dans toute l'histoire de la physique . . . ." [p.19]
* So, although he can't understand how Newton could have calculated it,
* he decides the table must be a theoretical one: "Comme il paroît
* cependant que la table de Newton est beaucoup plutôt le résultat de
* l'analyse que celui de l'observation, nous la mettrons de côté, quelque
* favorable qu'elle soit d'ailleurs à la supposition d'une élasticité
* spécifique constante . . . ." [p. 20]
*      The second chapter introduces refraction; by p. 35, he has the
* refractive invariant. He calls the refractivity little omega.
* There is also the usual "deduction" of the sine law of refraction
* from the supposed "attraction of the luminous particles" by the air.
* His series expansion is like Oriani's, and breaks down at 84° Z.D.
*      Chapter 3 is a lengthy discussion of the mathematical properties of
* factorials (i.e., the Gamma fcn.). On p. 64, the integral form is
* introduced. This allows him to show (p.65) that the integral of
* exp(-t2) dt is (1/2)sqrt(pi) -- or, as he is fond of saying,
* "L'intégrale . . . revient à la quadrature du cercle." The chapter
* ends on p. 112 with the remark: "Tels sont les principes analytiques,
* dont nous aurons besoin dans le chapitre qui suit, ayant pour objet
* les réfractions approchantes de l'horison." (all in italics!)
*      Chapter 4 picks up where Chapter 2 left off.  The divergent series
* encountered near the horizon can now be transformed into convergent
* ones, using the results of Ch. 3. By p. 119 he has put it all
* together, and on p. 120 offers as an example the case already
* mentioned by "Le citoyen Laplace" (but without proof of the method
* used) in l'Exposition du système du monde ; Kramp shows that his
* method agrees numerically with Laplace's result for the horizontal
* refraction, within 1 part in 1000. [It's interesting that he
* anticipates that Laplace's derivation will be given in detail in the
* forthcoming Méchanique Céleste , which is mentioned here explicitly
* -- though it was not to be published yet for several years!]
* On p. 122 there is mentioned a fourth table at the end of the volume,
* which does not exist in the copy I have seen (which ends on p. 210).
* Was there such a table, or did it fail to get published?
* On pp. 127-132, there is a discussion of observations of very large
* refraction, mainly based on observations by le Monnier, but also
* mentioning the Dutch observations at Novaya Zemlya. He shows that
* if the scale height shrinks to 1880 toises (p. 130), the curvature of
* the ray equals that of the Earth, and the refraction becomes infinite
* at the horizon. He adds that "souvent nous en aurions dans nos
* climats, si les vapeurs dont l'air est chargé, ne nous empêchoient
* pas alors de discerner les objects éloignés." (i.e., LOOMING)
*      On p. 133, he shows that the refraction problem requires the error
* function, which he then tabulates (explaining how the tables were
* constructed). Then, p. 138, he has the complete solution of the
* refraction problem near the horizon in terms of the error function.
*      On p. 141, he derives the refraction gradient at the horizon (or,
* effectively, the magnification). Comparison with the available
* observations shows a systematic discrepancy. [In fact, it is due to
* the temperature gradient in the troposphere; but Kramp doesn't know
* that.] Of course, Newton's table nearly fits; but this discrepancy
* was the reason why Flamsteed was unhappy with Newton's results.
* Kramp tries to explain away Bouguer's discrepant values as due to
* "une interpolation défecteuse." He also criticizes Bradley's rule,
* which does not fit his theory (p. 144).
*      On p. 150, he gives his calculated refraction table, compared to the
* results of Bradley's rule, which is off by more than a minute of arc
* between 1 and 2 degrees' altitude. (He also gives a table in the
* units of the "new division".)
*      The 5th Chapter, p. 159, compares his theory with earlier ones, and
* Bradley's rule in particular. His criticisms of Euler and Bradley are
* generally just; but some of his points assume that his own model is
* faultless. Euler's error was to assume a power-law form for the ray
* (a sort of hyperbola), which caused his results to be quite poor even
* near the zenith; "Il paroît au reste que le jugement que nous venons
* de porter, n'appartient pas à nous seuls; car d'un côté, l'on ne voit
* pas que les formules d'Euler aient été suivies par aucune astronome;
* de l'autre, nous ne voyons pas non plus qu'Euler y soit jamais revenu
* dans aucun de ses ouvrages postérieurs."
*      Bradley's rule is based on the supposition that the refraction
* is proportional to the angle subtended at the center of the Earth,
* which Kramp readily shows leads to all sorts of contradictions and
* inconsistencies. From this false assumption, Bradley deduced the rule
* that the refraction is the tangent of the apparent Z.D. diminished by
* a certain multiple of the refraction.
*      Mayer's method is to apply some fudging to equations arising in the
* theories of Euler and Bradley, allowing some extra adjustable parameters
* in an attempt to get a better representation of the data; but his results
* differ negligibly from Bradley's, and so accomplish nothing.
*      Lambert assumes a certain locus arising in the theory is an arc of a
* circle; it is not, so his theory is inconsistent -- though, remarkably,
* not all that far from the truth.
*      The 6th Chapter (pp. 175 - 192), on terrestrial refraction, finally
* deals with the actual ray curvature ("rayon osculateur"). Where the
* ray is horizontal, this "est nommé rayon horizontal par quelques
* auteurs, et nommément par Lambert . Ce rayon est donc égal à
* s/ω ou a/n; il est donc au rayon de la terre comme c : ω ou
* comme 1 : n." As he assumes a constant temperature, he finds this
* cannot exceed 6.652 even for 30° Réaumur, and is less for lower
* temperatures (e.g., 5.54 at 10°). "Il ne pourra donc jamais être
* égal à sept fois le rayon de la terre, valeur que Lambert lui avoit
* assigné d'après quelques observations de Cassini . . . ." [Here he
* is of course too sure of himself.] He goes on to consider dip of the
* horizon, distance to the horizon, and related questions. Here, he
* shows that Bradley's rule works, provided the heights are small
* [pp. 182-184]. Finally (pp. 188 ff.) he considers the effects of
* refraction in lunar eclipses.
*
*      Even a cursory reading reveals several typos and lapses:
* The missing Table IV, cited on p. 122, has already been mentioned.
* Ch. IV, section 14 (p.117) is missing a minus sign in the denominator.
* Ch. IV has 2 sections numbered 57, none numbered 58 (to which he refers
*       in sections 91 and 92, p. 146).
*      More serious errors in Kramp's analysis were found by Plana (1828),
* who showed that Euler's analysis was actually pretty good.
*      These lapses seem incongruous, considering Kramp's frequent claims of
* superiority to everything that has gone before.
*
*      NOTE: Some of this is translated by Thomas Young (1825).
* There is a brief commentary on Kramp's paper by A. Mason Du Pré, Jr.,
* Isis 29, 43-48 (1938); but as it is written from the point of view
* of a mathematician who explicitly excludes the refraction theory from
* consideration, it is of little interest to us here.
*
* The title page says "Par le citoyen KRAMP"; the Strasbourg publisher
* is Philippe Jacques Dannbach; the date, "l'an de la République VII "


P. S. Laplace
Traité de Mécanique Celeste 4, book 10, Chapter 3
(Chez J.B.M.Duprat, Paris, 1805).

* LAPLACE's REFRACTION & AIRMASS theorem
* [duplicate entry, repeated here for the sake of logic.]


P. S. Laplace
Celestial Mechanics. Translated, with a commentary, by Nathaniel Bowditch
(Chelsea Pub., Bronx, New York, 1966).

* BOWDITCH's annotated translation of Laplace
* This is a modern reprint edition. Bowditch's translation and commentary
* originally appeared under the title:
* "Méchanique Céleste. By the Marquis de La Place . . . "
* (Hillard, Gray, Little, and Wilkins; Boston; 1829-39)


J. B. J. Delambre
Astronomie Théorique et Pratique, Tome Premier
(Courcier, Paris, 1814), pp. 319–320.

* DELAMBRE again (cf. his entry in the "Distorted Sunsets" file)
* Delambre's textbook might be listed with the later ones; but I have
* him here for two reasons: first, his discussion of Cassini's model,
* and second, his observations of VARIABLE REFRACTION.
*      NOTE: It is essential  to consult the long list of "Additions et
* Corrections" that follows the Preface. The pages correcting the
* material mentioned here are xxxij and xxxiij.
*      Of Cassini, he says (p. 294):
* "Dominique Cassini est le premier qui ait proposé une hypothèse
* propre à calculer les réfractions pour toutes les hauteurs; et la
* table qu'il en dressa était déjà d'une exactitude très-remarquable."
*      Delambre is fond of the tangent-series approach, and develops it for
* the plane-parallel case. (pp. 295-296)
*      Of Tycho's table, he says (p. 297): "Cette table, qui lui avait
* coûté beaucoup de travail, est extrêmement défectueuse, et il était
* difficile qu'elle fût meilleure, puisque le plus souvent l'erreur de
* l'observation surpassait la réfraction cherchée." Then he continues:
*      "Cassini supposa l'atmosphère sphérique ainsi que la terre, et
* voici à peu près comme il raisonna : nous donnerons seulement une
* forme plus analytique à ses calculs." But this is nonsense; Cassini
* lacked the analytic ideas Delambre uses. So Delambre introduces
* cosines and tangents where Cassini had only sines. However, he does
* at least start out where Cassini did; and he says (p. 298) that
* "Cassini détermine par des essais successifs la valeur de h . . . ".
* He plugs in modern values for (n - 1), and adopts the example used by
* Jacques Cassini, using 5' 28'' for the refraction at 10° altitude.
* From an exact solution, he finds n = 1.0002924339; "mais si nous
* donnons au rayon de la terre sa valeur 3271200T, nous aurons
* h = 2000T,4;. . . ." [But Jacques Cassini's value is 3271600 toises!]
*      "Rien de plus simple que le calcul des formules" involving the
* difference of the inverse sines; "mais quand y approche de 90°,
* les tables donnent peu de précision, et l'on pourrait se tromper de 2
* ou 3''."
*
*      This part could as well go under the "Variable Refraction" file;
* it's here only because of Biot's reference to it. The discussion begins
* with CHAPITRE XIII (p.291): "Petites irrégularités dans les hauteurs
* des Étoiles."
*      ". . . passé 82° les réfractions varient d'un jour à l'autre et
* dans des circonstances en apparence toutes pareilles de quantités qui
* passent ces différences." (p. 305)
*      Sections 50 and 51 are devoted to the variable refraction at low
* altitudes: "J'ai déjà parlé de l'incertitude des observations de
* réfraction dans le voisinage de l'horizon. J'ai remarqué que d'un
* jour à l'autre, et dans des circonstances qui étaient les mêmes en
* apparence, la réfraction variait de 15 à 20" sans qu'on pût en
* soupçonner la cause; mais les variations sont encore bien plus
* sensibles à l'horizon, on en jugera par le tableau suivant:"
* which, for example, shows two days with the same T and p but horizontal
* refraction differing some 4'. (Sunrise observations 4 days apart in
* June.)
* In section 51, he gives the range of observed variations: 6 or 7" at 75
* degrees' Z.D.; 10 or 11 at 77; 15" at 79; over 30 from 82 to 86 degrees;
* 35" at 88°; 45" at 89. "Les tables de Bradley et Mayer donnaient
* des erreurs plus fortes encore, ensorte qu'il me paraît impossible de
* faire aucune bonne table pour ces derniers degrés. Mais du zénit à
* 82°, on peut avoir nombre de tables à peu près également bonnes."
*      He then adds that Piazzi's refractions have differences "au moins égales
* à celles qui se trouvent dans mes observations."
*      In § 52, he says he has seen Z.D.s of terrestrial objects at sunset
* increase from 2 to 2½ minutes, "ensorte que des objets cachés pendant
* tout le jour devenaient visibles le soir." [LOOMING]
*      N.B.: Biot (Addititons to the CdT.,1836) says that the values at 75°
* are impossible.
* (But Brinkley (1815) observed similar "irregularities" at low altitudes.)
*      Text available at Google; but as usual they lost the figures.


S. Groombridge
“XVII. Some further observations on atmospherical refraction,”
Phil. Trans. Roy. Soc. (London) 104, 337–347 (1814).

* GROOMBRIDGE, and DELAMBRE's comments (1814)
*      Stephen Groombridge's refraction measurements
* Groombridge's text is about as opaquely written as possible; it's amazing
* that Ivory was able to make use of these data. His previous measurements
* were restricted to Z.D.s less than 78°10'. Here he reports observations
* made in 1811 and 1812, "as near to the horizon, as the trees in Greenwich
* Park would permit", which turns out to have been about 87°.
*      "With a view to assist me in ascertaining whether the refractions were
* affected by local vapours, D r. B r i n k l e y has kindly communicated
* to me some observations of low stars;" which got him to 88°. So he was
* still above the low zone where the refraction becomes wildly variable
* due to (at least) variations in lapse rate.
*      There is much discussion of which thermometer to use (i.e., that
* "within" or "without" the telecope room). Of more interest is the
* commentary by Delambre, who translated this into French for the CdT.
*      Thanks to Luc Dettwiller for calling my attention to this!
*      The Royal Society's website would have you believe this was published
* Jan. 1; but the date on the paper says "Read March 31, 1814".


M. Delambre
“Remarques sur le Mémoire précédent,”
Additions pour la Connaissance des Tems de l'année 1818 , 229–243 (1815).

* DELAMBRE translates and comments on Groombridge (and others)
*      The translation begins on p. 219.
*      Delambre's comments actually begin on p. 224; and the footnotes inserted
* in the translated text and denoted by (a) through (h) begin on p. 220.
*      There is much information of historical interest here, in addition to
* the technical details of refraction measurements. In the long historical
* note (a), Delambre says of his own observations: "les variations extrêmes
* que j'y remarquai, malgré l'état stationnaire du baromètre et du
* thermomètre , me faisaient désespérer qu'on pût jamais avoir une Table
* conforme aux observations de 89 à 90° principalement ; mais même à 78
* et 80°, je trouvais, d'un jour à l'autre, des variations de plusieurs
* secondes, qu'il me paraissait difficile de rejeter en entier sur les
* observations. Je remarquais des différences aussi irrégulières dans celles
* qu'a publiées M. Piazzi, qui avait pris le parti de regarder comme la
* réfraction moyenne qui convient à un certain degré de distance au zénit, le
* milieu entre toutes celles qu'il avait observées à ce degré. M. Groombridge
* a suivi cet exemple, mais il ne nous a pas mis à même de juger de la
* précision avec laquelle s'accordaient les observations entre lesquelles il
* a pris un milieu. On pourrait juger, par les distances solsticiales d'été,
* qu'il a pu trouver des anomalies semblables à celles qui se rencontrent
* dans les étoiles de M. Piazzi; il est vraisemblable aussi que ces irrégu-
* larités augmentent avec les distances, ce qui pourrait nous faire douter
* qu'on puisse jamais représenter des variations qui ne paraissent dépendre
* ni de l'état du baromètre, ni de celui du thermomètre." (p. 230)
*      "La formule de Bradley est sans doute fort simple, ou du moins
* fort aisée à retenir;" well put. And on the next page, he discusses the
* deficiencies of any one-parameter "law" for refraction, because the
* parameter has to change with the atmospheric state. But once the
* horizontal refraction is given, everything in between can be found.
*      Delambre then (p. 236) shows how a few slightly different formulae of
* Bradley's type can represent the "mean" refraction in a satisfactory way
* from the zenith to 87°; "mais au-delà, les réfractions calculées seraient
* toutes plus faibles que les réfractions observées." [Of course, we now
* understand that this is just the region where the local lapse rate comes
* to dominate the refraction.] ". . . il est donc bien évident que la
* formule de Simpson est insuffisante" (p. 237). (He shows several
* numerical examples.) [Of course the Simpson-Bradley model fails in this
* region, because it is based on a model with an impossible lapse rate!]
*      On p. 240, Delambre goes back to consider Groombridge's previous
* refraction measurements (Phil. Trans., 1810), and compares the various
* sets of Tables (i.e., interpolation formulae used in making them.)
* He concludes that the errors can be attributed to the observations out to
* 88°, but that at 89 and 90 degrees, the disagreements are due to errors
* in the formulae used to construct Tables.
*      Note: For more details of Groombridge's work, with comments by
* Delambre, see the 1819 item below.
*
*      His discussion of Groombridge is followed by a summary and discussion
* of the 3 volumes of Mudge and Dalby work, which had remained unknown in
* Paris due to "the difficulty of communications" between 1799 and 1811
* -- i.e., the chaos that followed the French Revolution. On pp. 255-256,
* he discusses their observations of variable terrestrial refraction, and
* adds an account of his own experiences, one of which he saw in "fog".
*      Thanks to Luc Dettwiller for providing a PDF of this!


J. Brinkley
“Analytical investigations respecting astronomical refractions and the application thereof to the formation of convenient tables together with the results of observations of circumpolar stars, tending to illustrate the theory of refractions,”
Trans. Roy. Irish Acad. 12, 77–118 (1815).

* John Brinkley (Andrews Prof. of astronomy at U. of Dublin) pays
* particular attention to the "irregular refraction" beyond 80°.
* "It is shewn that at 80° 45' the error of the formula deduced cannot
* amount to half a second, whatever be the variation of density in the
* atmosphere." (p.79) Did Biot read this? His method is similar.
* "But the quantity of refraction varies so much from some unexplained
* cause, the heights of the barometer and thermometer remaining the same,
* that observations below 80° can be of little use. This irregularity
* is very manifest at 80° 45' in the observed refractions of Capella
* below the pole." (p. 81) [These observations are reported in detail
* on p. 110.]
* "It has been shewn . . . that above 80° the refraction will not be
* sensibly changed by any law of variation of density . . . ." (p. 105)
* "It is well known to those conversant in observations made with good
* instruments that near the horizon an irregularity in refraction hitherto
* unexplained shews itself. This commencing even at less zenith distances
* than 80°, is at first very small, but increases to a very considerable
* irregularity as we approach the horizon." (p. 108) [cf. Delambre, above.]
*      [Note that p. 109 is numbered 104.]  On that mis-numbered page, he has
* a footnote pointing out that "The hypothesis upon which refractions are
* computed is that the different strata of air are concentrical with the
* earth's surface, circumstances may be easily imagined to affect this
* hypothesis, with respect to low stars."
*      His observations of Vega below the Pole, at Z.D. 87° 42', are given
* to the nearest tenth of a second of arc, but show variations from +26 to
* -17 seconds; so he concludes that "It is not likely the irregularities
* will ever be submitted to any law, and investigations respecting formulae
* for refractions for zenith distances greater than about 80° may be
* considered more curious than useful." (p. 117) [The individual Vega
* observations are on pp. 115 and 116.]
*      Available from JSTOR at  https://www.jstor.org/stable/30078777
* Unfortunately, that copy is full of typos and garbled glyphs, so that a
* 3 often looks like an S, and the base of natural logs is written 2.7128
* instead of 2.7182. . . .
*      I lack the figure, as does the JSTOR copy.  However, the BHL gives
* access to a copy at the Natural History Museum, London, which shows the
* figure following p. 32, and facing p. 33, which is Brinkley's paper
* "Read May 9, 1814" describing how the observations were made, and
* tentatively suggesting he had detected parallaxes on the order of a
* second of arc in a few bright stars.
* Its URL is:
*                              https://www.biodiversitylibrary.org/page/2428795
*
* Unfortunately there is an error in the page numbering: Brinkley's paper
* follows Vince's (on a waterspout) that ends at a page numbered 40.
* So the numbers from 33 to 40 inclusive appear twice in this volume,
* first in signature F and then again in signature G.


J. Brinkley
“A method of computing astronomical refractions for objects near the horizon,”
Trans. Roy. Irish Acad. 13, 165–173 (1818).

* Brinkley's semi-empirical corrections to the "French Tables" (Delambre)
* He distinguishes between "regular" and "irregular" refraction.
* Referring to his 1815 paper, he says, "It is admitted, that the true
* refraction is always less than that computed on the hypothesis of an
* uniform temperature, and greater than that obtained by supposing the
* density to decrease uniformly; that, as far as 80° from the zenith,
* these limits approach each other very closely; and that, till very near
* the horizon, they do not widely recede from each other." (p. 166)
* SCALED REFRACTION IS INCORRECT: "When however it is required to
* compute the refraction for other states of the Barometer and
* Thermometer, the results by my tables and the French differ for low
* altitudes. This is occasioned from it being supposed in the French
* Tables that the refraction is proportional to the density, which is by
* no means sufficiently exact in very low altitudes." (p. 170)
* Note that the paper itself cites Young's work in 1819, and was "read,
* January 17, 1820" -- so the date on the title page is not right.


M. Groombridge [and Delambre]
“Réfractions près de l'horizon et observations solsticiales,”
Additions pour la Connaissance des Tems de l'année 1821 , 348–352 (1819).

* Discussion of VARIABLE REFRACTION near the horizon, between GROOMBRIDGE
* and DELAMBRE (addendum to the 1815/1818 item)
*      This contains additional details of Groombridge's measurements.  Delambre
* writes it in the first person, and refers to Groombridge in the third,
* but credits Groombridge as author, so I list them both here.
*      Referring to the earlier item, Delambre says that he had expressed
* regret at finding only the mean values in Groombridge's Memoir. "It
* appeared to us impossible that he had not noticed the frequent anomalies,
* as we had.  . . .      M. Groombridge has responded to our remarks, and made us
* aware of the extreme deviations that he had found in each of the stars
* that pass between 81°40' and 88°42' from the zenith."
*      Delambre explains that the format of this volume (i.e., narrow pages)
* prevent him from reproducing Groombridge's data in the form provided,
* "so we are limited to giving the names of the stars, their zenith
* distances, the height of the barometer, that of the thermometer (interior
* and exterior). the excess of the calculated refraction over that
* observed, in using the interior and exterior thermometer successively."
*      In fact, the two tables here (on pp. 350 and 351) contain the same
* stars, in the same order, as Tables I and II, respectively, on p. 345
* of Groombridge's 1814 paper in Phil. Trans., and should be read in
* conjunction with it. There, only the mean values are given; here,
* only the extremes.
*      [Notice that the tabulated residuals are C-O, not the usual O-C.  So
* the excess of negative resids. means that the observed refractions were
* on average larger than the calculated ones -- hardly surprising, as the
* model was the old Simpson-Bradley one.]
*      Delambre points out several outstanding examples of large refraction
* changes with no, or very small, change in T and p. "Fortunately these
* variations only occur at altitudes where one never observes the Sun or
* the planets. We see this in Groombridge's solstitial observations,
* which agree as well as one could wish. The deviations of several
* seconds, which one notices mainly in summer, should be attributed to
* the difficulty of putting the edge of the Sun in contact with the wire
* of the telescope."
*
* The ADDITIONS begin on p. 217 of this volume; this is near the end of the
* volume.
*      Available at Gallica.
*      Thanks to Luc Dettwiller for bringing this item to my attention!


T. Young
“Remarks on the probabilities of error in physical observations, and on the density of the Earth, considered, especially with regard to the reduction of experiments on the pendulum: Postscript to Dr. Young's letter on the reduction of experiments. 5. Corrections for refraction,”
Phil. Trans. Roy. Soc. Lond. 109, 70–95+1–4 (1819).

* THOMAS YOUNG's first Postscript
* The main paper is about error analysis, as the title shows; the
* refraction part is an addendum, paginated separately from 1-4.
* He starts out by quoting Brinkley out of context.
*      Interesting for an early guess at the existence of a STRATOSPHERE:
* "The variation of t can only be determined from conjecture; but
* supposing the alteration of temperature to cease at the height of about
* 4 miles . . . ." [which would place the tropopause near 6.4 km]
* The variation of lapse rate "in the lower regions of the atmosphere
* . . . appears to be amply sufficient to explain the irregularities of
* terrestrial refraction, as well as the uncommon increase of horizontal
* refraction in very cold countries . . . ." -- that is, he assumes a
* constant temperature for the upper air, and infers the tropospheric
* lapse rate from this, and the variations at the surface.
*      Young published a slightly corrected version of the Postscript in
* Quart. J. (1821), q.v.


J. B. J. Delambre
Histoire de l'astronomie moderne, T.2
(Courcier, Paris, 1821).

* DELAMBRE's "Histoire moderne" comments on Cassini's model
* Here Delambre translates snatches of Cassini's remarks in Malvasia's
* Ephemerides into French, and adds some comments.
* P. 724: "En supposant les réfractions du Soleil les mêmes pour toute
* l'année, et telles qu'il les a données pour l'été, la parallaxe du
* Soleil sera nulle ou tout au plus de 15'' . . . . Au reste, la parallaxe
* de Képler, qui est de 59'' 36''', comparée à l'excentricité qu'il
* vient de trouver, lui donne une symmétrie for élégante entre les
* orbes ; car il en résulte 3460 diamètres de la Terre pour la
* moyenne distance du Soleil, dont la fraction 0,017 vaut 58,822 pour
* l'excentricité du Soleil, ce qui est précisément la distance moyenne
* de la Terre à la Lune. Ainsi le centre de la route annuelle du Soleil
* est un point de la circonférence de l'orbe lunaire, et ce point est celui
* qu'occupe la Lune quand elle est à l'apogée du Soleil, c'est-à-dire au
* 7e degré du Cancer. D'où il suit que la plus grande équation simple
* du Soleil, la parallaxe horizontale de la Lune, qui est le demi-diamètre
* de la Terre, vu de la Lune, et le demi-diamètre de l'orbite lunaire,
* vu du Soleil, sont également exprimées par le nombre 58' 26'' 20'''.
* [NOTE: the sine of this angle is 0.016998. . . , or 0.017 very nearly.]
* Cassini développe encore avec plus de détails ces conséquences, qui
* sont un peu [!] dan le goût du Mystère cosmographique de Képler,
* et malgré le doute que nous avons énoncé ci-dessus, il nous est
* clairement démontré qu'il avait bien lu et bien médité Képler,
* auquel il a fait plus d'un emprunt." . . .
*      "Il conclut de ses observations, qu'un rayon quelconque tombant
* obliquement sur la surface extérieure de l'atmosphère, est accoursi de
* 0,0002841, et que la hauteur de l'atmosphère est de 0,0006095 du rayon
* terrestre pris pour unité; c'est-à-dire apparemment que le sinus de
* l'angle est diminué de 0,0002841, ou qu'il faut multiplier le sinus de
* l'angle d'incidence par la constante 0,9997159, c'est-à-dire ajouter
* au log. sin. de l'angle le log. constant 9,9998666. En effet, ayant
* calculée la table d'été, j'ai retrouvé les quantités ci-jointes, qui
* prouvent que la formule est exacte, au moins jusqu'à 74°. Cassini ne
* donne pas d'autre explication. Nous trouverons sa théorie dans les
* Élémens publiés par son fils en 1740, et nous l'avons mise en formules
* (Astronomie , t.I, p. 297); mais nous n'avons pu deviner comment il a
* trouvé les deux réfractions fondamentales. Il a l'air de les prendre
* dans la Connaissance des Tems, pour donner un exemple de calcul."
* [This discussion, which ends on p. 725, does not quite do Cassini fils
* justice; his discussion is clearly a ``textbook example'' in which the
* numbers are chosen arbitrarily for convenience, so as to obtain the
* desired result. Delambre seems to have missed the "Epistolae Tres" that
* reveal a bit more about how Cassini proceeded.]
*      [We have this only on P-10 microprint cards!]


T. Young
“Computation of the effect of terrestrial refraction, in the actual condition of the atmosphere,”
Quart. J. Sci. Lit. & Arts 11, 174–176 (1821).

* Young's RADIUS OF CURVATURE paper
* He derives the radius of curvature via the lapse rate required to
* counteract the density change due to pressure: ". . . at 50°, with the
* barometer at 30 [inches] . . . the height of the homogeneous atmosphere . . .
* is 27,000 feet; and the temperature descends about 1° for every 300
* feet that we ascend."      So, as the refractivity is about 1 part in 3540,
* it "varies 1/3540 * 1/27000 in every foot, as far as the diminution of
* pressure is concerned, amd 1/3540 * 1/300 * 1/494 is to be deducted for
* every foot, on account of the diminution of temperature, or as much more
* or less as this diminution of temperature is more or less rapid; so that
* if the change were 1° in 27000/494 = 55 feet, the refraction would
* be annihilated, and, if still more sudden, there would be a depression
* or looming, instead of an elevation. But in ordinary circumstances,
* supposing Professor Leslie's estimate of 1° in 300 to be correct,
* we have 1/3540 (1/27000 - 1/148200) = 1/116873000 for the variation in
* a foot, and consequently, 116873000 feet for the radius of curvature
* of the ray; which is to the Earth's radius, or 20900000 feet, as 5.6
* to 1; consequently, the elevation of a distant object must be 1/11.2
* of the angle subtended at the earth's centre, since the angle contained
* between an arc and its chord is always equal to half the angular extent
* of the arc."
*      Note: 1° F in 300 ft = 6.1 K/km; 1° F in 55 ft = 33° C/km.


J. Ivory
“On the atmospherical refraction,”
Phil. Mag. 57, 321–325 (1821).

* JAMES IVORY's first paper on refraction
* Is he the FIRST to notice that "The simple hypothesis of Cassini seems
* hardly to have met from astronomers with the attention it deserves;
* for, if we use accurate elementary quantities in the computation, it will
* determine the refractions to the extent of 74° from the zenith with
* the same degree of exactness as any of the other methods, without even
* excepting the formula of Laplace." (p. 322) He also notes that in
* Cassini's model, "the depression of 1° of the centigrade thermometer
* will correspond to an elevation of nearly 4343/250, or about 17½
* fathoms." [He effectively assumes absolute zero is -250° C.]
*      He then goes on to consider what we would call POLYTROPIC models:
* "Between the two extreme cases just described" [i.e., Cassini's model
* and the isothermal one] "we may consider that an infinite number of
* intermediate ones are interposed, while the total height of the atmosphere
* increases from its least limit of 4343 fathoms to be infinitely great;
* the heat in each particular atmosphere decreasing uniformly as the
* elevation increases, which is the law most conformable to experience.
* We have thus an infinite number of different hypotheses, in all of which
* the refractions will be the same to the extent of 74° from the zenith;
* coinciding in every case with the formula of Laplace, the exactness of
* which is indisputably established by observation. But beyond the limit
* mentioned, the refractions will diverge from one another, and each
* particular case will have a horizontal refraction peculiar to itself.
*      ". . .  The hypothesis advanced by Thomas Simson [sic], of a density
* decreasing uniformly with the elevation, is also contained in the series
* of atmospheres above mentioned . . . ." [p. 323]
*      On p. 324, he decides that the observed horizontal refraction
* corresponds to an atmosphere 4 times the height of Cassini's, with a
* lapse rate of one degree C in 70 fathoms [128 m], or about 7.8°/km.
* He notes that this differs from the observed rate of 1° in 90 fathoms
* [165 m] -- about 6°/km -- which corresponds to an atmosphere 5 times
* the height of Cassini's, and a horizontal refraction of 2164'' which is
* too much. [Apparently the problem here is the error in the "elasticity
* of air" (i.e., the zero of the absolute temperature scale).] But he
* attributes the discrepancy to a non-uniform decrease of temperature:
* ". . . hence we may infer that the supposition of a uniform decrease of
* heat in the atmosphere, cannot be reconciled with the astronomical
* refractions. But, although this be strictly true, yet the refractions
* are so nearly represented by the law mentioned, that the actual deviation
* from it must be very inconsiderable."
* So his best estimate is a polytrope of index 3, or perhaps 4.
* (May issue)


J. Ivory
“On the atmospherical refraction,”
Phil. Mag. 57, 404–406 (1821).

* JAMES IVORY's first paper, continued
* Here he discusses the horizontal refraction more, finding that "there
* are good grounds for thinking that the horizontal refraction in the
* French Tables is rather too small." He cites "the observations of
* Mr. Brinkly" [sic] and the table based on Groombridge's observations,
* and [p. 406] notices that "the refractions at the horizon depend not
* only upon the initial rate of the decrease of heat, but also, although
* in a very small degree, upon the acceleration." So he comes close to
* seeing Biot's result, but misses.
* (June issue)


T. Young
“A Postscript on atmospherical refraction . . . with a parenthetical correction,”
Quart. J. Sci. Lit. & Arts 11, 353–364 (1821).

* Young's Postscript reprinted, corrected, and augmented
* The "parenthetical correction" restores some of Brinkley's wording,
* as well as considerable correction and simplification of the math.
* We now find: "It is not possible, in the present state of our knowledge
* of the subject, to determine, from observation, either the refraction
* with sufficient accuracy to enable us to compute from it the law of the
* variation of temperature, or the variation of temperature with sufficient
* accuracy for computing the refraction." [Section 8.]


J. Ivory
“On the new method proposed by Dr. Young for calculating the atmospherical refraction,”
Phil. Mag. 58, 161–168 (1821).

* Ivory's comments on Young's "Postscript"
* Here begins the feud between the two. "The principal point we have to
* inquire into will therefore relate to the convergency of the new
* series for low altitudes, and more particularly in the extreme case of
* the horizontal refraction." (p. 161) But there are also plenty of
* snide remarks about "the pretensions held out" and "the numerical
* computations . . . are so inaccurate that no conclusion can be drawn from
* them in which confidence can be placed." (p. 162)
*      Here is where he calls Young's Table on the 1822 Nautical Almanac
* "empirical". (p. 167) What he means is that the Table is just a
* fudge-fit to the French Tables, not based on a separate physical theory.
*      (Sept. issue; dated Sept. 4)
* This volume of Phil.Mag. is available at JSTOR.


J. Ivory
“On Mayer's formula for the astronomical refraction,”
Phil. Mag. 58, 341–347 (1821).

* Ivory, on Mayer's formula
*      Ivory explains that if the density is proportional to p/T, the
* refraction near the zenith is proportional to the density; but at the
* horizon, to T to the -3/2 power. He applies this to Cassini's model
* (of which he says, "As is apt to be the case in some more complicated
* suppositions, the attention is not here so absorbed by intricate
* combinations of the quantities concerned, as to overlook the manner in
* which the phænomenon is produced by its real causes, which are the
* alterations in the refracting power of the medium and in the extent of
* the homogeneous atmosphere." (p. 345) "We must, therefore, conclude
* that the rule of Mayer is true, not only in the hypothesis of Cassini,
* or in that of Mayer whatever it was, but absolutely in every supposition
* that can possibly be formed with regard to the constitution of the
* atmosphere." And he notes that near the zenith, "the variation in
* refraction is very nearly proportional to β, that is to the density
* of the air, according to the usual practice of astronomers. But when
* the zenith distance is great . . . another mode of calculation must be
* pursued . . . which necessarily leads to the rule of Mayer."
*      So (p. 347) "At the horizon . . .  the correction for heat, according
* to Mayer, is quite different from the common rule." [i.e., the
* assumption that the refraction is proportional to the refractivity.]
* [This behavior at the horizon might be regarded as prefiguring Biot's
* theorem.]
*      The frequent references to the September issue, p. 167, refer to
* Ivory's previous paper; this one is in the Nov. issue.


J. Ivory
“Postscript,”
Phil. Mag. 58, 420–421 (1821).

* Ivory's Postscript on Cassini's model
*      This is an addendum to Ivory's paper "On the Rolling Pendulum" on
* pages 417-420. The Postscript refers to the previous paper, on Mayer's
* formula, in which he made an application to Cassini's model.
*      Here, he derives an approximation for Cassini's refraction, and points
* out that it differs from Laplace's result by only 0."074 at 70° ZD, and
* 0."154 at 80°. "We are therefore warranted in saying that, when the
* same elementary quantities are used, there is, practically speaking, no
* difference in point of accuracy between the formula derived from the first
* and most simple hypothesis relating to the constitution of the atmosphere,
* and that obtained by the last effort of scientific skill ; and this is
* a coincidence which it is surely both curious and instructive to mark."


J. Ivory
“Calculation of the horizontal refraction in an atmosphere of uniform temperature,”
Phil. Mag. 59, 90–93 (1822).

* Ivory's note on horizontal refraction
* He refers again to his "Sept." paper. Here the method is to expand
* the exponentials in series; note the use of c rather than e as the
* base of natural logs. "Both these series were found in Kramp and
* Laplace; but these geometers proceeded in an inverse order to that
* followed here. . . . But the analysis given here seems to have the advantage
* of greater simplicity." (pp. 92-93)
*      "Although the case of the horizontal refraction has alone been
* considered, yet the same analysis will apply to the general state of
* the problem; but, as this is attended with no difficulty, and further
* explanation will be unnecessary." (p.93)
* Dated Feb. 4, 1822.


T. Young
“Apology for the Postscript on Refraction, in answer to Mr. Ivory's remarks,”
Quart. J. Sci. Lit. & Arts 12, 390–396 (1822).

* Young replies to Ivory's comments . . .
* Sarcastic sniping at Ivory for having called the Nautical Almanac
* formula "empirical". He proposes to extend the series expansion by
* extrapolating the terms, using their logs as the basis of the
* extrapolation, and assuming the series to be convergent. This
* dubious procedure, not surprisingly, leads him to extrapolate a
* horizontal refraction at variance with Laplace's result; "so that there
* must probably be some numerical error in one of the computations; at
* any rate the difference does not arise from the want of convergence of
* the series."
* [N.B.: Not signed; but the authorship is hardly in question.]


T. Young
“The variation of the Temperature of the atmosphere deduced from the mean Refraction.,”
Quart. J. Sci. Lit. & Arts 12, 396–398 (1822).

* More of the same. Here Young claims that the atmospheric structure
* can be inferred from the refraction data. The argument leads him to
* an expression for a barometric formula, which gives the height of Quito
* (from the pressure there) of "8740 feet, instead of 9377; or if we augment
* the 8740 in the proportion of the expansion of air from 50° to 80°,
* it will become 9264; but it is well known that in computations of this
* kind it is necessary to introduce a variety of subsidiary corrections."
* [In other words, he gets the wrong answer, and arm-waves it away.]
* "But it is at present impossible to expect any thing like perfect
* accuracy in a determination so liable to uncertainties of various kinds."
* [N.B.: Not signed; but the authorship is hardly in question.]


Anon.
“An extension of the inverse series for the computation of refraction, together with a direct solution of the problem,”
Quart. J. Sci. Lit. & Arts 16, 139–148 (1823).

* Thomas Young's anonymous "Inverse Series" paper
* Much detailed mathematical churning, which Ivory (1824) shows is
* equivalent to his own (Phil. Trans., 1823) results.
* There is much arm-waving here, as well as posturing; all potential
* difficulties are waved aside.
*      There are a few interesting historical remarks; on p. 144:
* ". . . Taylor, who first applied to the problem of atmospherical
* refraction his very useful theorem for `integration by parts,' as the
* process is sometimes now called, . . . ."
* [issue no. 31, dated October, 1823.]


J. Ivory
“On the astronomical refractions,”
Phil. Trans. Roy. Soc. 113, 409–495 (1823).

* JAMES IVORY's important paper [N.B.: FILED separately, due to length]
* This paper begins with a clear historical review; develops the theory
* for a temperature profile that fits the atmospheric data near the
* ground and the astronomical data near the horizon, and concludes with
* informative comparisons of earlier tables, explaining that the "French
* Table" of 1806 is (deliberately) slightly in error, and that Bessel's
* table is soundly based on observation only to 86° Z.D. and quickly
* fails beyond that.
*      The whole derivation is strictly Newtonian; but there are numerous
* trenchant remarks here:
*       "Perhaps it is owing to its great simplicity, that the method of
* Cassini seems not to have met from astronomers with the attention it
* deserves." (p. 410)
*      "If we reflect that all these atmospheres will agree in giving the
* refractions actually observed by astronomers as far as 70° or
* 80° from the zenith, it is natural to think that the one which
* likewise coincides with nature at the horizon, will deviate but little
* from the truth in the intermediate 10°." (p. 411)
*      [From Gay-Lussac's balloon ascent] "the elevation for depressing the
* thermometer one degree will come out equal to 95 fathoms: and if we
* suppose that the same rate prevails in all parts of the atmosphere, the
* whole height will be . . . nearly 29 miles. The observations of twilight
* show that this is less than the true altitude; and hence we must infer,
* that the thermometer falls at a slower rate in the higher, than in the
* lower, parts of the atmosphere." Ivory took this decrease to be
* gradual; but today we know it is due to the stratosphere -- which this
* comment might be seen as predicting! (p. 416)
*      "Hauksbee first determined by experiment, that air refracts light in
* proportion to its density . . . ." (p. 417) -- What about Gladstone &
* Dale? Stigler's Law of Eponymy again!
*      ". . .  it much be observed that the French table was originally
* constructed for 32° of Fahrenheit, and was reduced to the mean
* temperature of 50°, on the supposition that the refractions vary in
* the same proportion with the density of the air . . . ." (p. 448)
* -- but Ivory is aware this SCALING is an error. (Cf. p. 479 also)
*      On p. 449, Ivory introduces his parameter f  that determines how
* rapidly the lapse rate changes with height. This allows him to have
* a mixed model that has one polytropic index near the surface, and a
* gradually increasing one higher up. "f = 0, when m = 4 . . . ; and
* f = 1/4, when m is infinitely great." This allows him to make the
* height of the atmosphere big enough to agree with twilight, while having
* the observed lapse rate at the surface, and the observed horizontal
* refraction. (p. 450)
*      "It appears that, although the refractions near the zenith are
* affected in a degree hardly perceptible by the peculiar constitution of
* the atmosphere, yet, near the horizon, they depend entirely on the same
* arrangement of the strata of air indicated by terrestrial experiments."
* That is, the horizontal refraction depends on the lapse rate near the
* ground, and the observed average lapse rate agrees with the horizontal
* refraction. (p. 456)
*      "With regard to altitudes less than 2°, it is not clear that the
* astronomical refractions do not participate of the extreme irregularity
* that attends the terrestrial refractions . . . ." (p. 472)
*      Laplace, Delambre, and Brinkley are heavily referred to.  Note that
* the "base of hyperbolic logarithms" is called c here; his e is a
* different quantity.
*      On p. 467, Ivory points out that the usual (i.e., Lambert's) series
* expansion is only semi-convergent. This remark seems to have been
* generally overlooked; evidently the term was fairly new, and unfamiliar
* to the English astronomers. It seems to have been invented by Legendre;
* according to Morris Kline's "Mathematical Thought from Ancient to Modern
* Times" (Oxford, 1972), pp. 1097-1098, it first appeared in Legendre's
* "Essai de la théorie des nombres", p. 13 (1798); but I don't see it
* there. However, Giovanni Ferraro points out that Legendre's "Exercices
* de Calcul Intégral, sur divers ordres de Transcendantes et sur les
* quadratures" (Paris : Courcier, 1811-1817) p. 294, discusses series
* "which he termed semiconvergent (demi-convergent) because they first
* decrease (converge, in his language) and then increase (diverge))."
* This wording is so similar to that used by Ivory that I think it likely
* this is where he learned the term. [However, this book is not among
* Ivory's surviving library, preserved at Dundee, at:
*
*              http://www.leisureandculturedundee.com/localhistory/ivory
*
* where it's necessary to click on "The Collection"; Ivory's books are then
* listed alphabetically by author. Thanks to librarian Erin Farley for the
* URL!]
*      On the other hand, Legendre's "Essai de la théorie des nombres" is
* in Ivory's library. Can someone find the passage in it where the term
* "semi-convergent" or "demi-convergent" (or something of the sort) occurs?
*      Thanks to Craig Fraser, via Jed Buchwald and Richard F. Lyon, for
* helping uncover these references! In addition, I find that Josef Lense
* discusses this issue in his "Reihenentwicklungen in der mathematischen
* Physik" (Walter de Gruyter & Co., Berlin, 1953). On p. 16 he says:
* "Solche Reihen nannte Legendre semikonvergent oder halbkonvergent,
* weil sie sich für zahlenmäßige Berechnungen fast wie konvergente
* Reihen verhalten. Jetzt pflegt man sie nach H. Poincaré asymptotisch
* zu nennen . . . ".
*      Lense cites v.1, p. 267 of Legendre's "Exercices"; and, indeed, on
* that page one finds: ". . . la suite . . . deviendra nécessairement divergent
* après un certain nombre de termes. Mais ce qui est fort remarquable,
* c'est que cette formule n'en est pas moins propre à donner la valeur
* . . . avec tout le degré d'approximation qu'on peut desirer.
*      ". . .  on aura . . .  une suite d'abord très-convergent, mais dont la
* convergence diminuera de plus en plus, jusqu'à un certain terme où
* elle deviendra divergente, et cette divergence augmenterait de plus en
* plus à l'infini.
*      "Nous donnerons cì-après un exemple du calcul de ces sortes de
* suites qu'on peut appeler suites demi-convergentes ."
*      The passage on p. 294 cited by Giovanni Ferraro gives the promised
* example of
*      ". . .  suites demi convergentes , c'est-à-dire des suites qui sont
* convergentes dans les premiers termes, et qui deviennent ensuite
* divergentes."
*
*      Ivory suffered from persistent delusions of persecution throughout
* his life, but never seems to have accused anyone of actually conspiring
* against him -- see de Morgan's "Budget of Paradoxes" on this.
* N.B.: from 1792 to 1852 the volumes were not numbered; this would be 113.


Plana
“Recherches analytiques sur la densité des couches de l'atmosphere, et la théorie des réfractions astronomiques,”
Memorie dell'Accademia delle Scienze di Torino 27, 143–322 (1823).

* G. PLANA's first paper on refraction
* There is much review of the works of Gay-Lussac, Leslie, etc. in the
* early pages. In discussing the barometric law, he points out (p. 176)
* that Oriani discovered the independence of the refraction at ZDs less
* than 74° before Laplace.
*      Unfortunately, Plana plunges into the details of the math before
* trying to understand things; so there is a lot of useless thrashing.
* (See, e.g., the futility of the numerical trials on pp. 242-243.)
* However, there is some merit in his view (p. 256) that one can regard
* the true atmosphere as a perturbation from a simple exponential.
*      Starting on p. 300 is an interesting quibble about the history of
* the differential of refraction. He thinks Laplace's derivation is
* the only valid one, picking holes in Young's work.


H. Atkinson
“On astronomical and other Refractions; with a connected Inquiry into the Law of Temperature in different Latitudes and at different Altitudes,”
Mem. R. Astron. Soc. 2, 137–260 (1826).

* Henry ATKINSON's long paper
*      He begins with a long study of observed refractions, looking for "the"
* law that determines the (supposedly fixed) structure of the atmosphere;
* but of course finds there is none. ". . . for the fluctuations of
* the atmosphere are so frequent and so great, that on a superficial
* view, they would seem to set at defiance any attempt to subject them
* to calculation. This difficulty, however, I hope to show is not
* insurmountable. In the prosecution of this subject, it is intended,
* first, to show how to calculate, to any required degree of accuracy,
* the quantity by which a ray of light is deflected from its rectilinear
* course in its passage through any given horizontal stratum of air ;
* on the supposition that the density of the air, not only at the top and
* bottom of the stratum, but at any intermediate point, can be accurately
* caleulated :---secondly, to ascertain as far as possible, from a great
* number of the best observations that can be got, not only the mean state
* of the atmosphere at the surface, but the law by which its temperature
* varies as we ascend:---how this change of temperature modifies its density
* :---whether the same laws obtain in cold as in warm climates :---what
* fluctuations these laws are liable to, and to what height they extend
* :---and lastly, to apply the knowledge thus obtained to the calculation
* of tables of refraction, both celestial and terrestrial." (p. 140)
* There is an elegant derivation of Bradley's rule on p. 145; cf. Delambre.
*      On p. 150, he cites General Roy's measurements of temperature and
* pressure, published in 1777, as a reliable source of atmospheric data.
* On p. 157, the finds the mean lapse rate to be 6.4°F in 1666 feet, or
* 3.56°C in 508 m, which is 7°C/km -- not bad for 1826. He goes on to
* investigate geographic variations in temperature, and investigates data
* for various mountains in Europe, which provide seasonal mean values.
* These data lead him to conclude that the general rule is that the lapse
* rate is approximately constant with height, rather than the linear
* density decrease assumed by Simpson et al.
*      On p. 171, he uses Humboldt's observations to estimate lapse rates for
* the tropics. Combining those data with mean temperatures from places
* at greater latirudes, he then fits a formula involvoing both height and
* latitude by "Legendre's method of minimum squares " (p. 174) After
* some further analysis of widespread temperature measurements, he finds
* that "the law of the gradation of heat, as we ascend in the atmosphere,
* is the very same for the temperate and torrid zones". (p. 191)
*      He seems not to have heard of Charles's law, but fits General Roy's lab
* results to an empirical formula, and so calculates densities for the
* refraction calculations (pp.197 ff.) As he approached the horizon, he
* found it necessary to divide the lower atmosphere into more and more
* parts. A single layer sufficed from the zenith to 44°Z.D.; then two
* layers, from 45° to 60°; then 4 layers to 75°, 8 to 81°; 16 to 86°;
* 32 to 88°; and 64, to 89° 40'. In these later calculations, only the
* lower atmosphere had to be so finely subdivided. "In computing the
* refractions for 89° 40' and 90° of zenith distance, it was found
* necessary to make the strata in the lower part of the atmosphere
* very thin." The table on p. 203 gives the details. The resulting
* refraction table is on p. 205, and is compared with Brinkley's and
* Groombridge's observed refractions..
*      He then discusses the corrections for pressure and temperature.  This
* brings him to the seasonal variations, which he finds do not vary with
* height below about 21,000 feet. And he notices that changes in thermal
* structure above that height have very little effect on even the horizontal
* refraction.
*      On p.220, he appeals to General Roy's observations of temperatures at
* the tops and bottoms of hills to show that "there are occasionally very
* great deviations from the mean state of the atmosphere, but that such
* fluctuations occur at all seasons of the year. . . . But it does not always
* turn colder as we ascend." On p. 221, he tries to find how far upward
* these anomalies extend.      Even at heights of 2400-3600 feet, they are
* "not greater than at the height of 600 or 700 feet." So the limited data
* available "seem to indicate that those fluctuations do not extend to any
* great height." Still, "The irregularity, or deviation from the mean
* state, amounts to something considerable at low altitudes, and therefore
* ought not to be neglected Where accuracy is required." (p. 222)
*      Pages 223-227 contain a discussion of extinction, and the visibility
* of faint stars near the horizon: ". . . at 85° of zenith distance very
* little more than one-tenth of the light of the star arrives at the eye;
* and at 89°, only .003. It is therefore quite plain that no star can
* be seen at 89° of zenith distance, unless the air possess a degree of
* transparency far, very far, beyond what it possesses in its mean state.
* Indeed, I believe, experience shows that at 85° or 86° of zenith
* distance small stars frequently cannot be observed . . . ." So there is
* a selection effect in measured "mean" refractions: the numerous faint
* circumpolar stars can't be seen at low altitudes on murky nights with
* humid air, so the means are biased toward high-pressure systems when
* the air is clear: ". . . whenever . . . the degree of cold must either
* increase more slowly than it commonly does, or else that it must diminish,
* and the air become warmer . . . either of these states of the atmosphere
* gives a refraction greater than the mean. A correction must therefore
* be applied on this account, when we compare a Table of mean refractions
* with observations very near the horizon." (pp.224-225). He constructs
* a table of this correction, based on the statement that "at about
* 85° of zenith distance, stars of the second, and perhaps of the third,
* magnitude may generally be seen with a good telescope, whenever the air
* at greater altitudes is fit for observations." (p. 227) The table of
* corrections for this bias below 5° altitude is on p.229.
*      Then he worries about the air in the observing room being a couple of
* degrees warmer than the outside air.
*      On p.233, he turns to terrestrial refraction, and soon cites the paper
* by Williams, Mudge, and Dalby (1795). Of course he quickly finds that
* the radii of curvature of the rays depend on the lapse rates (which he
* calls "the gradation of heat".) He checks his refraction formula with
* General Roy's observations. (p. 241) Of course, that confirms that
* the terrestrial refraction depends mainly on the lapse rate. "We
* know that the change of temperature . . . is much more rapid near the
* ground than it is a little above it".
*      Text available from ADS; but their PDF copy of Plate III is nearly as
* useless as the ones Google Books usually produces.
*      NOTE: This paper was used as the basis for refraction corrections in
* the Great Trigonometrical Survey of India; see
*
*              An Account of the Measurement of two sections of
*                    the Meridional Arc of India, bounded by the
*             parallels of 18° 3' 15"; 24° 7' 11"; & 29° 30' 48".
* conducted under the orders of the Honourable East-India Company
*                               by Lieut.-Colonel Everest, F.R.S
*                                late Surveyor-General of India
*                                                (London, 1847)


T. Young
“A finite and exact expression for the Refraction of an Atmosphere nearly resembling that of the Earth,”
Phil. Trans. Roy. Soc. Lond. 114, 159–161 (1824).

* Thomas Young tries to out-do Ivory
* This is supposed to be a closed-form solution for what we would
* now call the polytrope of index 2 -- and hence, an atmosphere with a
* super-adiabatic lapse rate. He loses the minus sign before the final
* result.
* But when I try to evaluate his expression -- correcting for the missing
* minus sign -- I get numbers that agree with his at the horizon, and at
* 5° 44', but are off by more than a minute of arc higher up!


J. Ivory
“Remarks on an article published in No.23 of the Journal of Science, and treating of the new tables of refraction,”
Phil. Mag. 63, 261–266 (1824).

* Ivory's reply to Young's comments
* The dispute here is about the temperature to be used in correcting the
* Table entries. Ivory also points out that Young's model is a
* special case of his own more general one, and so feels his work has
* been appropriated. More sniping at the table in the N.A., which "may
* be withdrawn, and another of a less mysterious construction substituted
* in its place, as it appears that a new method for the refractions was
* read before the Royal Society at their meeting on the 5th February last."
* [That would be Young's note in Phil. Trans., above.]
* April issue.


J. Ivory
“Letter on the astronomical refractions,”
Phil. Mag. 63, 418–427 (1824).

* Ivory continues his dispute with Young
* "The Table in the N.A. is one of no authority. No astronomer in Europe,
* except the author, can tell how it was constructed. Its character rests
* upon a dictum . We know that there is no correct theory." (p. 419)
* "I have also ascertained, by sound principles as I shall show below,
* that no confidence can be placed in my Table, nor in any other at present
* in existence, passing 88½° of zenith distance. Nearer the horizon
* the errors of every Table increase at a prodigious rate." (p. 419)
*      Interestingly, he returns to POLYTROPES again (pp. 420-421); Ivory's
* m is the polytropic index. He now finds m = 4 to be best.
*      "But the foregoing hypothesis, although it agrees sufficiently
* with the observed refractions, is opposed to Nature in another respect.
* It limits the extent of the atmosphere above the earth's surface to 25
* miles, which is probably less than half the real height." (p. 422)
*      And the really interesting feature is the mention of Dalton's study of
* what we would call ADIABATIC atmospheres, on pp. 423-424: he cites lab
* measurements that give the exponent as 1.3492 or 1.3748 rather than 4/3
* -- but then concludes that the discrepancy indicates that this is just
* a first approximation, and that unknown higher-oder terms will account
* for the difference: "It thus appears that the other terms of the
* development beside the first have a sensible influence on the refractions
* at very low altitudes." However, he correctly notes that the speed of
* sound is connected with the adiabatic exponent (p. 426).
* cites his April paper (above).
* June issue; letter is dated June 14.


T. Young
“Historical sketch of the various solutions of the problem of atmospherical refraction, from the time of Dr. Brook Taylor, to that of the latest computations,”
Quart. J. Sci. 18, 347–378 (1825).

* Young's "Historical sketch"
* Notable for English translations of Taylor's work, and some of Kramp's.
*      Unfortunately, he continues to make snide remarks about Ivory --
* whose "ridiculous accusations" he attributes to "an unfortunate
* enthusiast, whose imprudence seems almost to have impaired his reason"
* [pp. 369-370] -- though he has to eat crow a bit on p. 373, where
* he admits that Ivory had observed "with some truth that Dr. Young's
* inverse series was not in all cases so convergent as could be desired,
* or even as the author appeared to believe it . . . ."
*      Here is yet another attempt to divine how Newton came to construct
* his refraction table: naturally, Young assumes Newton did it his way
* (which, in this case, is by using Taylor's work.)
*      Young's "history" is very lopsided and uneven, being largely taken
* from second-hand sources. So he slights Lambert, without giving him
* credit for establishing the binomial-series expansion method.
*      And there is no mention of Oriani at all!  So we get:
* "For the mathematical theory of refraction it may be said that nothing
* of immediate importance was done from the time of Newton and Taylor, to
* that of Laplace and Kramp." (p. 363)
* [published anonymously, but clearly by Young.]


J. Ivory
“A letter in reply to the historical sketch of the problem of atmospherical refraction in the last number of the Journal of Science,”
Phil. Mag. 65, 32–37 (1825).

* Ivory's swift response to Young's "Historical Sketch"
* More sniping at Young; and (effectively) an accusation of plagiarism:
* "What Dr. Young calls his latest solution of the problem, published
* in the Philosophical Transactions 1824, and another particular solution
* mentioned at the end of the XIVth Number of the Astronomical Collections
* in the Journal of Science, are both taken from my paper." (p. 34)
*      "I made no observation on the infinite series, except that it does not
* converge; and I proved the want of convergency in a particular instance.
* This brought upon me a torrent of vehement writing not confined within
* the limits of bienseance ." (p. 36)
*      "The table of refractions in the Nautical Almanack is a singular
* instance of a set of practical calculations seemingly deduced from a deep
* theory; and yet, when we fully reach into the truth, having a slight,
* or even no, connexion with the theory. For it is not the formula which
* produces the table; it is the table, after the choice is made to make it
* consist of number from the tables of M. Bessel and the French astronomers,
* which determines the formula." (p. 37)
*      So much for a "torrent of vehement writing"!
* Jan. issue; dated Jan. 14.


J. Ivory
“Comparison of Mr. Ivory's table of refractions, Philosophical Transactions 1824, with Dr. Bradley's observations published in M. Bessel's Fundamenta Astronomiae, pp. 53, 54,”
Phil. Mag. 65, 107–108 (1825).

* Ivory's comparison with Bradley's observations
* Ivory agrees with Bessel to about 87° ZD, within a second or two.
* Beginning at 87° 23' Ivory is increasingly below, and Bessel
* increasingly above Bradley; their errors are nearly 40" at 89° 27'.
* Around 88°, Ivory is closer than Bessel to the observations.
* Dated Feb. 8, 1825.


J. Ivory
“On the constitution of the atmosphere,”
Phil. Mag. 66, 81–93, 241–250 (1825).

* Ivory's essays on adiabatic atmospheres
* There are some mentions of refraction here, but mostly in passing.
* On p. 84, he notices that the actual lapse rate is smaller than the
* adiabat inferred in the laboratory "by one part in four". The
* "dilatation for one degree of the centigrade thermometer" is now 3/800,
* making absolute zero -267° C -- certainly an improvement over his
* earlier value of 250. (p. 85)
*      Again, on p. 88, he notes that the actual lapse rate is slower than
* adiabatic; on the next page, he finds the sound speed in agreement with
* the lab data on adiabatic expansion. On pp. 89-90, he notes that the
* adiabatic atmosphere would correspond to m = 3 [polytropic index 3]
* "and the horizontal refraction will be found equal to 33' 7" at the
* mean temperature of 50° of Fahrenheit, and the barometric pressure
* of 30 inches." For the isothermal one, he gets 37' 34" at the horizon.
* ". . . they are the limits between which the real atmosphere is contained."
*      P. 243: ". . .  the arbitrary number m  . . .  may vary from zero to
* infinity." But in Dalton's adiabatic model m =3; so "m cannot be
* less than 3." And "So long as m has a finite value, the total height
* of the atmosphere is limited, and equal to l × (m + 1) . . . ."
* From his adopted lapse rate of 1° C in 90 fathoms, he gets m = 13/3
* or "in round numbers", 4.
*      P. 247: Here he worries about the inadequate total height of the
* polytropic models: "If instead of taking m = 4, we make it 5, which
* is a supposition not inconsistent with observations, the objection will
* still remain . . . ." So he introduces his variety of fudge-factor to
* extend the upper atmosphere.
*      P. 249: "Even the horizontal refractions are not much different in
* the several cases, and approach nearly to the quantity found by
* observation, -- if indeed we can affirm any thing of an element hitherto
* ascertained with so little precision."
*      P. 250: "Now if we . . .  make make the initial graduation of heat the
* same in the two atmospheres, the refractions in both will very nearly
* coincide, the difference amounting to only a few seconds at the horizon."
* So again he nearly sees Biot's result, but misses it. He concludes that
* the horizontal refraction is between 34' and 35' at 50° F, making the
* lapse rate between one degree in 84 fathoms [corresponding to 6.5 C/km]
* and 120 fathoms [4.6 C/km]. "The true atmosphere is undoubtedly
* contained between these limits."
* The first installment is in the Aug. issue; the second, in Oct.


J. Ivory
“Atmospheric refraction at very low temperatures and altitudes,”
Phil. Mag. 68, 177–180 (Sept., 1826).

* Ivory compares observations with Brinkley's table, and his own
* The emphasis here is on the unreliability of *any* table at low
* altitudes; and on the claim that Brinkley's table is superior.
* "We may therefore conclude that no table of refractions hitherto
* published can safely be trusted to at altitudes less than 2°. And this
* conclusion is corroborated by the parallel instance of the terrestrial
* refractions, which are found to vary from a certain limit through all
* degrees of magnitude, and even to change from positive to negative.
* . . . The boundary which separates the refractions irreducible to any
* degree of regularity, from those that can be theoretically computed, at
* least with tolerable regularity, . . . seems to be placed at an altitude
* of 2° or 1° ½ above the horizon."
* NOTE: "the New Table" evidently is Ivory's from 1823, though he says
* 1824 in this paper.
*      This volume is the last in the first series of Phil.Mag.


J. B. J. Delambre
Histoire de l'astronomie au dix-huitième siècle
(Bachelier, Paris, 1827).

* DELAMBRE's posthumous work, edited by Claude Louis MATHIEU
* I include this here because of its coverage of refraction, and
* especially because of Claude-Louis Mathieu's footnote on p. 696.
* Of Le Gentil's miraged sunrises, he says: "Ces apparences singulières
* ne sont pas rares dans nos climats; car, pendent l'hiver de 1808,
* je me trouvais à Dunkerque avec M. Biot, et nous avons eu occasion de
* voir des effets très varie's de réfraction extraordinaire." He then
* mentions Biot's book on mirages, and says of Biot, "il a rassemblé,
* dans des planches, tous les dessins que je faisais sur les lieux."
* So it is his drawings that appear in Biot's book, and have been
* reprinted so many times!
*      N.B. This is *not* the Mathieu of the Mathieu functions; that is
* Émile Léonard Mathieu.
* Alas, we have this only on Readex Microprint cards; but Gallica has it.


S. P. Rigaud
Supplement to Dr. Bradley's Miscellaneous Works: with an account of Harriot's astronomical papers
(Oxford Univ. Press, Oxford, 1833).

* RIGAUD's Supplement: Bradley; Harriot and Greaves
*      The first 16 pages puzzle out Bradley's reasoning from his notes.
* His "rule" turns out to have come from Simpson's paper. Notable
* for the demonstration that Bradley discovered empirically that the tan2
* term is negligible, so that refraction should involve tan z and tan3 z.
* The observations were made in 1750 and 1751, so I suppose Bradley's
* analysis followed shortly thereafter.
*      There is also much interesting stuff on Harriot, including the
* information (p. 33) that Lalande is responsible for the legend that
* the blindness of Galileo and Cassini was due to their solar observing.


J. Ivory
“Note on the astronomical refractions,”
A. N. 12, 109–114 (1835).

* Ivory compares his table with Bessel's tables
* He finds a systematic error in the Fundamenta Astronomiae beyond
* 85° Z.D. For the Tabulae Regiomontanae the agreement is better,
* but those (observed) values are still larger than Ivory's theory
* beyond 88°. But Plana's mean observed value at 88° 24' is only
* about a second of arc greater than Ivory's table -- though with a range
* of some 31''. "The discrepancies of the individual values . . . have
* not been explained . . . ." Note that he assumes the two tables can be
* harmonized by a constant factor at all Z.D.
*      There are tantalizing hints here that Ivory has some insight into
* refraction at last: "The quantity f used in the construction of the
* Table in the Phil. Trans. seems to be determined with considerable
* exactness: for a small variation of its value would materially alter
* the refractions at low altitudes." (col. 112)
*      "If attention be paid to the construction of the Table in the Phil.
* Trans. it will appear that it determines the refractions only so far as
* they depend upon two principles, namely, the refraction power of the air,
* and the rate, expressed by (1 - f ), at which the density decreases in
* ascending at the surface of the earth." (col. 114)
*      The table at the bottom of col. 112 starts with 84°, but this is
* obviously a typo for 88° (as is correctly given at the end).
*      He refers to his 1824 Phil. Trans. comparison with the Fund. Astr.;
* this is a typo for 1823.
*      Note that the discrepancies at 89 and 89.5° with Bessel's [i.e.,
* Argelander's] observed values could be used to estimate a typical
* nocturnal inversion at Königsberg. [Marcel Tschudin (2019) has finally
* done so!]
* This letter was communicated 15. Decbr. 1834, says the editor.
* Note: Ivory had been knighted in 1831.


F. Baily
An Account of the Revd. John Flamsteed
(Lords Commissioners of the Admiralty, London, 1835), pp. 134–153.

* The NEWTON-FLAMSTEED correspondence       [FILED separately]
* An appalling tale of growing mistrust and enmity, in which there is
* more than enough blame on all sides (including, apparently, Halley).
* Fortunately, we need only concern ourselves with the refraction
* discussion, before the atmosphere became completely poisoned. It
* begins with Flamsteed's letter No. 17 to Newton, dated Oct. 11, 1694,
* in which he mentions finding the horizontal refraction to be 33',
* decreasing to 23' a degree above the horizon; whereas the existing
* theories (based on a uniform atmosphere) would make this difference
* only about 5' instead of 10. "It seems only the medium, in which the
* refractions are made, is not equable as supposed by those who build
* their tables upon theories. This subject deserves your consideration:
* I desire your thoughts of it at your leisure." Newton's reply (No. 18,
* October 24, 1694) says, "The reason of the different refractions, near
* the horizon, in the same altitude, I take to be the different heat of
* the air in the lower region. For, when the air is rarefied by heat, it
* refracts less: when condensed by cold, it refracts more. And this
* difference must be most sensible when the rays run along in the lower
* region of the air for a great many miles together; because 'tis this
* region only which is rarefied and condensed by heat and cold: the middle
* and upper region of the air being always cold. I am of opinion also
* that the refraction in all greater altitudes is varied a little by the
* different weight of the air discovered by the baroscope. For, when the
* air is heavier, and by consequence denser, it must refract something
* more than when 'tis lighter and rarer."
*      On Nov. 17, 1694, Newton sent Flamsteed a preliminary table of
* refractions, based on a linear decrease of refractivity with height (see
* p.141). Below 30° altitude, it has separate entries for the seasons,
* based on Newton's estimate of "the rarefaction of the air in winter and
* summer; which I found some time ago, by certain experiments, to be as 8
* to 9, or thereabouts." On Dec. 4, Newton wrote again: "The table of
* refractions I sent you I do not design to publish. 'Tis not so accurate
* as it may be made . . . . There being a certain circumstance omitted in
* computing it, I intend to examine it with allowance for that
* circumstance, and when I have set it right I will send you a new copy of
* it."
*      On Dec. 20, Newton sends the diagram and explanation (see p.145): "Let
* A K L represent the globe of the earth, and suppose this globe is covered
* with an atmosphere of air whose density decreases uniformly from the
* earth upwards to the top . . . ."
*      No. 24, Jan. 15, 1694-5; Newton to Flamsteed: "The theorem of
* refractions I sent you has this fault, that it makes the refracting power
* [i.e., the refractivity gradient] of the atmosphere as great at the top as
* at the bottom. This has put me upon thinking on a new theorem . . . . But
* the calculation is intricate.
*      "I thank you for your observations about the morning and evening
* refractions. The reason why the former are greater in summer than the
* latter, I take to be nothing but the different heat and coldness of the
* air. For the air cools all night, and is coldest at sunrise: and heats
* all day, and is hottest about 12 hours after sunrise. The cold condenses
* the air, and makes its refraction greatest at sunrise; and the heat
* rarefies it, and thereby diminishes its refractive power in the evening."
*      Flamsteed's notes on this summarize his reply: "I grant the heat and
* cold of the air is the chief cause of the change of its refractive power,
* but not all: for other days were as hot as that, yet had less refractions.
*      "The sun rose then over the Thames and adjacent marshes.  Set over a
* dry hill on the west end of London. It was a misty morning, and a great
* fog over the meadows."
* Newton to Flamsteed, Jan.26, 1694-5 (No.25): "I agree with you that the
* dense vapors, which always stagnate upon the surface of the sea and often
* upon fenny places, cause a strong refraction. And it's probable that
* those, which rise to a greater height, may increase the refraction of the
* horizontal sun. But can you tell whether the refraction of the sea-vapors
* or fen-vapors be greater in hot weather or in cold? at morning or at
* night?
*      "To make a new table of refractions has taken up almost all my time
* ever since the holidays: and I have hitherto lost my pains in fruitless
* calculations, by reason of the difficulty of the work. For considering
* that such a table is the foundation of astronomy, and very necessary for
* your great work, and that you have taken so great pains in providing
* materials for it, I was desirous to complete it . . . ."
* No. 26, Newton to F., Feb. 16, 1694-5: "I have been, ever since I wrote
* to you last, upon making a new table of refractions and have not yet
* finished it: 'tis a very intricate and laborious piece of work; yet
* something I have done towards it. For, supposing the atmosphere to be of
* such a constitution as is described in the 22nd proposition of my second
* book (which certainly is the truth) I have found that, if the horizontal
* refraction be 34', the refraction in the apparent altitude of 3gr. will be
* 13' 3": and if the refraction in the apparent altitude of 3gr. be 14', the
* horizontal refraction will be something more than 37'." [But 14' and 33'
* are Flamsteed's observed values, which he asserted were "incontestable".]
* "So that, instead of increasing the horizontal refraction by vapors, we
* must find some other cause to decrease it. And I cannot think of any
* other cause besides the rarefaction of the lower region of the atmosphere
* by heat."
*      Newton then goes on to speculate about the effects of "sea-vapors and
* fen-vapors" as being in fact due to "condensation of the air by cold. For
* in travelling we find it always colder upon the water than upon the land
* . . . and therefore the water doth cool the air to the height of some fathoms
* above it, and by cooling condenses it and increases its refractive power.
* . . . And, were the air upon the sea overloaded with vapors, it would scarce
* be so transparent as to let Calais with its buildings and church steeples
* be seen through it cross the Channel."
*      On p. 152, the footnote gives Flamsteed's comment: "He adds a great
* many words to persuade me that to have the theory of the moon published
* with my observations, would be a great proof of their accuracy : whereas,
* theories do not commend observations ; but are to be tried by them :
* and theories are then only probable, when they agree with exact and
* indubitable observations ."
*      Finally, No. 27, March 15, 1694-5, Newton to Flamsteed: "I have now
* finished the table of refractions, and send you enclosed a copy of it."
* To which is footnoted: "This table is not found. F.B." The only value
* mentioned is 13' 20" at 3° altitude; which agrees with Newton's table
* published by Halley (1721).
*      Available at Google Books.


J. B. Biot
“Sur les réfractions astronomiques,”
C. R. Acad. Sci. 3, 237–244 (1836).

* BIOT finds refraction gradient at horizon while reading NEWTON's letters
* to FLAMSTEED, published by Baily the previous year. He finds that
* Newton assumed a simple exponential (i.e., const.-T) atmosphere.
* Of more interest to us here is his discovery of a theorem about the
* horizontal refraction. He first mentions the well-known result that the
* refraction depends only on local conditions, out to about 74° Z.D.
* "Mais, ce qu'on n'avait pas remarqué, il existe près de l'horizon, ou
* plutôt à l'horizon même, un théorème analogue, qui a, de plus, la
* singularité de s'y réaliser toujours, dans toutes les constitutions
* possibles d'atmosphères, non pas approximativement, comme celui que nous
* venons de rappeler, mais d'une manière absolue et rigoureuse." (p. 241)
* He calls the derivative of the refraction with respect to the apparent
* zenith distance the " coefficient varié de la refraction."
* "Mais, tandis que, près du zénith, le coefficient varié dépend
* seulement du pouvoir réfringent observable dans la couche où
* l'observateur se trouve, sa valeur à l'horizon dépend à la fois de
* ce pouvoir et de son décroissement immédiat, à mesure qu'on s'élève
* au-dessus de l'observateur; de sorte que l'action des couches lointaines
* n'y influe absolument pour rien." (p. 242)
* "Outre la singularité inattendue de trouver un élément de la
* réfraction horizontale, indépendant de l'état des couches lointaines,
* et s'obtenant, dans tous les cas possibles, sans intégration; outre la
* liaison qui en résulte entre l'accroissement de la réfraction près de
* l'horizon et les variations également observables du pouvoir réfringent
* à partir de la couche inférieure, le théorème que je viens d'énoncer
* aura encore d'autres applications utiles." (p. 243)
* Of course the latter connection immediately lets one obtain the
* magnification at the horizon from the local lapse rate, though Biot does
* not say so explicitly. Thus, we may fairly attribute the MAGNIFICATION
* theorem to him -- especially in view of his calculation of the
* flattening of the Moon at the horizon in his 1810 Physical Astronomy
* textbook, which shows a long-standing interest in the subject.
*
* The details are given in his Connaissance des Tems addendum (see
* below)


J. B. Biot
“Note additionnelle à un mémoire sur les réfractions atmosphériques,”
C. R. Acad. Sci. 3, 504 (1836).

* Biot thinks DUCTS improbable on Earth
* Concerning his theorem about horizontal refraction, he says:
* "En revoyant depuis ma démonstration j'ai reconnu que ce théorème
* n'aurait pas lieu dans des atmosphères qui donneraient des trajectoires
* horizontales rentrantes sur elles-mêmes. Quoique ce cas d'exception
* soit purement idéal, je crois devoir le signaler, pour que les
* géomètres qui chercheraient à démontrer le théorème dont il s'agit,
* ne se trouvent pas embarrassés par cette difficulté inutile."


J. B. Biot
“Sur les réfractions astronomiques,”
Additions a la Connaissance des Tems 1839 , 3–114 (1836).

* This is the detailed analysis corresponding to the C.R. summaries
* A very nice piece of work! Biot mentions the possibility of ducting
* (p.42), but does not think it can occur in our atmosphere. Here
* (pp.95-108) he explains how he figured out what Newton did. The
* writing is all very clear and easy to read throughout. There are
* frequent references to Ivory and Delambre, as well as Kramp (and, of
* course, to ``the author of the Mécanique Céleste .'')
*
* Much of the following also appears in the two C.R. notes above:
*
* Of most interest to us here is his discovery of a theorem about the
* horizontal refraction. He first mentions the well-known result that the
* refraction depends only on local conditions, out to about 74° Z.D.
* "Mais, ce qu'on n'avait pas remarqué, il existe près de l'horizon, ou
* plutôt à l'horizon même, un théorème analogue, qui a, de plus, la
* singularité de s'y réaliser toujours, dans toutes les constitutions
* possibles d'atmosphères, non pas approximativement, comme celui que nous
* venons de rappeler, mais d'une manière absolue et rigoureuse." (p. 6)
* He calls the derivative of the refraction with respect to the apparent
* zenith distance the " coefficient varié de la refraction."
* "Mais, tandis que, près du zénith, le coefficient varié dépend
* seulement du pouvoir réfringent observable dans la couche où
* l'observateur se trouve, sa valeur à l'horizon dépend à la fois de
* ce pouvoir et de son décroissement immédiat, à mesure qu'on s'élève
* au-dessus de l'observateur; de sorte que l'action des couches lointaines
* n'y influe absolument pour rien." (p. 7)
* "Outre la singularité inattendue de trouver un élément de la
* réfraction horizontale, indépendant de l'état des couches lointaines,
* et s'obtenant, dans tous les cas possibles, sans intégration; outre la
* liaison qui en résulte entre l'accroissement de la réfraction près de
* l'horizon et les variations également observables du pouvoir réfringent
* à partir de la couche inférieure, le théorème que je viens d'énoncer
* aura encore d'autres applications utiles." (p. 8)
* Of course the latter connection immediately lets one obtain the
* magnification at the horizon from the local lapse rate, though Biot does
* not say so explicitly. Thus, we may fairly attribute the MAGNIFICATION
* theorem to him.
*
* Considers (but rejects) the possibility of a DUCT (p. 42):
* "On peut concevoir, et constituer théoriquement des atmosphères où
* la condition dont il s'agit serait satisfaite en plus d'un point pour
* certaines valeurs données du second membre. Alors les trajectoires
* jouissant de cette propriété seraient rentrantes sur elles-mêmes, et
* comprises dans l'intérieur de l'atmosphère réfringent; de sorte que la
* vision des objects extérieurs ne serait pas généralement possible par
* une trajectoire horizontale." [This predicts Wegener's BLANK STRIP !]
* But "Dans l'atmosphère terrestre, les trajectoires étant toujours
* très peu courbes, leur horizontalité n'a lieu qu'en un point."
*
* In considering the effects of water vapor, he remarks that they are
* insufficient to account for the variations of refraction near the
* horizon, citing DELAMBRE, p. 321: "Néanmoins, . . . on se convaincra
* aisément qu'elles ne peuvent pas produire des variations accidentelles
* de 5" et 6" à 75° de distance zénithale, comme Delambre assure en
* avoir observées." (p. 71) (So he is aware of VARIATIONS.)
*
* As the rays are no longer nearly horizontal in the upper atmosphere, the
* simple tangent formula applies there. Thus he can "expliquer un
* résultat de calcul obtenu par M. Ivory, et dont il a signalé la
* singularité. Il consiste en ce que les valeurs calculées des
* réfractions se trouvent presque exactement les mêmes dans des
* atmosphères de hauteur très inégale, différant, par exemple, depuis
* 1/62 du rayon terrestre, pourvu seulement qu'elles s'accordent avec
* l'atmosphère réelle dans les températures et les pressions de la couche
* inférieure, ainsi que pour les premiers décroissements qu'elles leur
* assignent; les décroissements ultérieurs pouvant d'ailleurs se trouver
* très divers l'une à l'autre, et devant même l'être, pour leur donner
* de si inégales extensions." (p. 73) (So the upper air is unimportant.)
*
*      On p. 76 begins the 3rd section: "Calcul des réfractions, par
* quadratures numériques à toute distance du zénith, et dans une
* constitution quelconque d'atmosphère." Here is where he changes
* the variable of integration to "l'angle continuellement formé par la
* tangente de la trajectoire, avec son rayon vecteur mené du centre
* des couches." (This is exactly the local zenith distance of the ray;
* so his integrand V is, apart from notation, identical to that of Auer and
* Standish.) He uses a 13-point quadrature, done with a piecewise-parabolic
* fit through these 13 points (i.e., basically the same kind of iterated
* Simpson's rule used by Auer & Standish.) On p. 81 he gives the numerical
* values at the 13 nodes, and shows that this method reproduces Ivory's
* result at the horizon to 1.247 arcsec. [He uses the 2-term tangent
* approximation for the top 1% of the atmosphere.]      He makes the following
* interesting comment on this small difference:
*      "Il se peut que cette petite différence vienne de ce que
* l'interpolation n'aurait pas été tout-à-fait assez serrée dans ses
* premiers termes; mais je n'oserais pas non plus répondre qu'elle ne soit
* pas due à quelques petites erreurs dans l'appréciation des dernières
* décimales des nombres que ces calculs nécessitent." (p. 81)
*      He then applies his method to the isothermal model, and to the
* polytrope of index 1, and discusses Bradley's formula. He also shows
* that his method works for zenith distances exceeding 90° (i.e.,
* below the astronomical horizon.)
*
*      In the 4th section (p. 95), he shows in detail that Newton's table
* is for an isothermal atmosphere.
*      In the 5th (p. 108), he compares Ivory's model atmosphere with that
* used by Laplace.
*      The lack of sensitivity to atmospheric structure, particularly at
* great heights, is discussed on pp. 74 and 112.
*
* NOTE: the development is all in terms of the emission theory.
*
* Full title is "Connaissance des Tems ou des Mouvemens Célestes,
* a l'Usage des Astronomes et des Navigateurs, pour l'An 1839" and this
* is the part called "Additions a la Connaissance des Tems".
* -- note the use of the spelling "tems" throughout.
* "(Lu à l'Académie des Sciences, le 5 septembre 1836.)"
*      Note the Erratum at the end of Biot's paper.  As usual, Google's scan
* lacks the essential figures. As the Additions are paginated separately
* from the ephemerides, Biot's paper begins at Google's image 427.
* Thanks a million to Brenda Corbin at USNO for a copy of the figures !!!


L. Dettwiller
“Le théorème de Biot et le changement de variable de Biot–Auer–Standish: commentaire historique,”
Comptes Rendus. Physique 23, No. S1, 483–501 (2022).

* LUC DETTWILLER's review of Biot's refraction work, centered on the
* magnification theorem, and so put here out of chronological order.
*      This is a nice review of Biot's works on refraction, boiled down to
* the main points, with extensive quotations from the original papers.
* (His comments on Biot's verbosity remind me of Glaisher's comments on
* Flammarion's loquacity.) The introduction briefly reviews Biot's
* wide-ranging accomplishments; the rest of the paper illuminates Biot's
* path to the magnification theorem with detailed derivations.
*      Part of the special issue: Astronomy, Atmospheres and Refraction
*      Available at https://doi.org/10.5802/crphys.117
* DOI: doi:10.5802/crphys.117


J. Challis
“Supplementary report on the mathematical theory of fluids,” in Report of the Sixth Meeting of the British Association for the Advancement of Science,held at Bristol in August 1836
(John Murray, London, 1837).

* CHALLIS comments on Biot
* Cites Brinkley (1815) and Ivory (1823): "The fact is, astronomical
* refractions are very little influenced by the higher parts of the
* atmosphere, so that supposititious [sic] atmospheres agreeing with the
* existing atmosphere in the lower strata, and widely differing in the
* upper, may yet produce the same amount of refraction." (p. 233) Here
* he cites Biot: "The memoir of M. Biot on astronomical refractions, read
* before the Paris Academy, Sept. 5, 1836, and printed in the additions
* to the Connaissance des Tems for 1839, treats the problem with all
* the generality and precision that may be hoped for on a subject of
* this nature."
*       Google's scan, of the U. of Michigan library copy, is missing
* pp. 228 and 229.


J. B. Biot
“Sur la constitution des régions supérieures de l'atmosphère terrestre,”
C. R. Acad. Sci. 3, 597–604 (1836).

* A further fine paper by Biot on refraction and atmospheric models
* The "hook" here is that, as Laplace's work on the oblateness of the
* Earth has allowed it to be inferred from observations of the Moon more
* readily than from direct measurements, one might also suppose that his
* work on refraction would equally well allow the structure of the upper
* atmosphere to be inferred indirectly from refraction observations.
* ". . . les intégrales analytiques que l'on en déduisait embrassant toute
* l'étendue de l'atmosphère supposée, ne laissaient pas discerner la part
* que les couches supérieures seules prenaient dans la réfraction totale
* obtenue, ni surtout celles qu'il fallait leur attribuer nécessairement."
* He again asserts that "la petitesse absolue des réfractions à toute
* distance du zénith exclut la possibilité des trajectoires lumineuses
* rentrantes sur elles-mêmes," despite his work on mirages. [p. 598]
* "Puis, dans les hauteurs qui nous sont accessibles, on trouve
* expérimentalement que le pouvoir réfringent décroit à mesure qu'on
* s'elève, et que la dépression de l'horizon apparent augmente; d'où
* l'on conclut qu'en s'éloignant de la surface terrestre, les éléments
* de chaque trajectoire forment des angles graduellement moindres avec
* leur rayon vecteur central." -- a nice argument based on DIP!
*      P. 599: an interesting remark about the thinness of the atmosphere,
* argued from twilight. But Arago objects, in a note saying that this
* argument is based on single scattering, while polarimetric observations
* have shown that skylight involves multiple scattering. Biot then says
* this shows the atmosphere is even thinner than the single-scattering
* argument suggests, which makes his own argument stronger!
*      P. 600: He again points out that any reasonable atmospheric model
* must give nearly the same refraction out to large Z.D., the uncertainty
* being less than 0".001 at 45°, 0".277 at 74°, and 2".243 at 80°.
* This restriction becomes tighter at greater heights, so that the
* sea-level horizon ray receives a contribution uncertain by less than 0".15
* above 5/1000 of the Earth's radius. "Les couches supérieures, d'où
* cette portion résulte, pourraient donc être constituées de toutes les
* manières imaginables, quant à leurs densités, leurs températures,
* et jusqu'à un certain point leur nature physique même, sans que nous
* apercevions jamais aucun effet appréciable de ces différences dans les
* réfractions totales que nous observons; et ainsi, par réciprocité,
* les réfractions observées ne peuvent nous fournir aucune notion sur
* ces régions élevées de l'atmosphère." [p. 601] Here are his two
* limiting models for calculating refraction: ". . . si on les [réfractions]
* calcule en supposant les pressions proportionnelles à la première
* puissance des densités. on les trouve plus fortes que la réalité;
* et avec la seconde puissance de ces mêmes densités on les trouve trop
* faibles. La vraie loi est donc intermédiaire entre des deux-là; . . . "
* -- that is, between these two POLYTROPES: the isothermal one and the
* polytrope of index n = 1, corresponding to a lapse rate of 17°/km
* (nearly twice the adiabatic lapse rate).
*      P. 603: "Si les considérations précédentes détruisent la
* possibilité d'inductions qui eussent été précieuses pour la physique
* du globe, elles nous montrent comment on pourra rendre les tables de
* réfractions plus parfaites, et surtout plus générales qu'elles ne
* le sont aujourd'hui. . . . Car, par exemple, le décroissement de la
* température près de la surface terrestre paraît très variable dans
* un même lieu, aux différentes saisons; et il est peu probable que sa
* quantité absolue soit la même dans toutes les localités. Or, cet
* élément influe sur une des constantes les plus importantes des tables;
* et, d'après un théorème que j'ai démontré, c'est de lui surtout
* que dépendent les différences des réfractions entre elles près de
* l'horizon. Il faut donc déterminer expérimentalement ses variations,
* . . . et l'en affecter dans le calcul des tables, au lieu de l'y supposer
* constant et partout le même, comme on l'a fait jusqu'ici." And:
* ". . . on pourrait . . . observer régulièrement les constantes de ces
* régions de trouble, au moyen de petits ballons captifs qui porteraient
* des instruments à indicateurs, dont les résultats s'appliqueraient
* comme correctifs à des tables permanentes, construites pour la région
* non troublée." [p. 604] ". . . et alors l'analyse aurait fait pour
* la théorie des réfractions astronomiques tout ce qu'il est permis
* d'espérer."


Biot
“An account of the Rev. John Flamsteed, etc.,”
Journal des Savants , pp. 156–166, 205–223, 641–658 (1836).

* BIOT's series in J.Savants, reviewing the Newton-Flamsteed correspondence
* Of the 3 parts, the last deals with the refraction question.
*      This volume is now available at Gallica, under the old "Sçavans"
* name, at
*              https://gallica.bnf.fr/ark:/12148/bpt6k110181v#
*
* Biot's installments are in the March, April, and November issues.


Biot
“Analyse des Tables de réfraction construites par Newton, avec l'indication des procédés numériques par lesquels il a pu les calculer,”
Journal des Savants , 735–754 (1836).

* Biot's more detailed analysis of Newton's refraction table
* This evidently was extracted from the CdT article (above) and expanded.
* It must be read after the previous item, as several things otherwise
* unexplained would not make sense.
* Décembre issue


A. N. Krylov
Nyutonova Teoriya Astronomicheskoi Refraktsii
(Izdatel'stvo Akademii Nauk SSSR, Moskva, 1935).

* KRYLOV's attempt to read Newton's mind retroactively . . . .
* Another stab at unravelling Newton's refraction table.
* Already on p. 15 he is expanding the refraction in powers of sec z or
* tan z; on p. 18 he finds that Newton's table agrees [as it must!] with
* the one-term approximation out to about 55° ZD. . . . So [p. 20] he
* even supposes it possible that Newton used the first 2 terms in the
* series expansion! Worse, he assumes [p. 25] that beyond 87° ZD,
* Newton's table is based on Flamsteed's observations rather than on
* calculation.


D. T. Whiteside
The Mathematical Papers of Isaac Newton, Vol. VI: 1684-1691
(Cambridge University Press, Cambridge, 1974), pp. 431–436.

* Whiteside's transcription of Newton's working papers
* As Biot conjectured, these turned up in the Portsmouth collection of
* Newtoniana. The refraction discussion is mainly in the enormous
* footnotes on these pages.
* On p. 432, he calls Biot's analysis "brilliant", and adds, "We are
* heavily indebted to his pioneering lead."
* N.B.: filed here out of order, for its clarification of Newton's table.


D. T. Whiteside
“Kepler, Newton and Flamsteed on refraction through a `Regular Airé: the mathematical and the practical,”
Centaurus 24, 288–315 (1980).

* Whiteside's refraction paper
* I find the rather arch tone of this paper a bit unpleasant; but the
* worst part is his bizarre final paragraph (p.308), where he wrongly
* claims that "working astronomers still find computational advantage
* in maintaining the fiction of a Newtonian emission theory" -- which
* is sheer nonsense! Apparently he has no understanding of what
* geometrical optics is all about: as it depends only on Snel's law,
* which long predates Newton's emission theory, the latter is irrelevant.
* Furthermore, he doesn't understand the statement (which he attributes
* to Woolard & Clemence, but which was extensively discussed by Biot in
* his CdT paper) that the refraction within 80° of the zenith is nearly
* independent of the atmospheric model used. Had he understood
* Biot's 1836 CdT paper (which he even cites!), he would have understood
* this fact. Unfortunately, this wrong-headed final paragraph seriously
* undermines the good parts of the paper, and reveals that Whiteside was
* as much an "armchair astronomer" as Newton.
* Again filed out of order for relevance here.


P. A. Hansen
“Ueber die Verfinsterungen auf der Erde überhaupt,”
A. N. 15, No. 339-342, 33–104 (1837).

* PETER ANDREAS HANSEN's papers on PARALLACTIC REFRACTION
*      This is a long, detailed analysis of the geometrical circumstances of
* solar and lunar eclipses, as seen from an arbitrary point on the Earth.
* The term "parallax" appears several times; but there is no explicit
* treatment of parallactic refraction.
*      A "Zusatz" begins in the middle of col. 100.  "Refraction" appears
* briefly in cols. 101 and 102. The bulk of the paper assumes a spherical
* Earth; in Col. 102, the flattening is introduced, and the astronomical
* latitude is distinguished from the geocentric latitude of the observer.
*      The issue is dated 7 December 1837.


P. A. Hansen
“Ueber den Einfluß der Strahlenbrechung auf Sonnenfinsternisse und Sternbedeckungen,”
A. N. 15, No. 347, 185–192 (1838).

* This is an addition to the paper above. Here, refraction is included:
* "In der Theorie der Verfinsterungen hat man nie die Einwirkung der
* Strahlenhrechung entwickelt. Man hat entweder gradezu gesagt, dass
* diese keine Wirkung auf die Verfinsterungen äussere, oder man hat
* dieses wenigstens stillschweigend angenommen. Dieses ist aber nicht
* richtig, denn die Strahlenbrechung ist nicht ohne Einfluss auf die Zeit,
* Dauer und die Oerter des Anfanges oder Endes einer Verfinsterung oder
* Sternbedeckung, wenn gleich in den méhrsten Fällen diese Wirkung
* unbeträchtlich ist." (first paragraph.)
*      Now for the PARALLACTIC REFR.:
*      ". . .  in der That die Strahlenhrechung nicht nur von der scheinbaren
* Zenithdistanz, sondern auch von der Entfernung des Himmelskörpers
* abhängt." (col. 184) He then distinguishes between the total ray
* bending (the ordinary astronomical refraction) and the angle between the
* ray at the observer and the direction to an object at a finite distance
* (the Moon): "in allen Fällen, wo die Entfernung des Himmelskörpers
* endlich ist, ist die wahre Zenithdistanz kleiner, als die durch unsere
* Strahlenhrechung verbesserte scheinbare Zenithdistanz."
*      His derivation follows the Cél. Mech. notation (i.e., the emission
* theory) and (like Biot) he follows Laplace's awkward notation. From this
* he derives the size of the correction needed when the nearby object is
* near the horizon.
*      As the effect is just as if the observer were raised to some height
* and the atmosphere were removed, he then derives the height required
* to move the observer up to the extension of the ray's path outside
* the atmosphere.
*      Note the corrections in col. 192 of printer's errors in Nr.339-342.


Fr. W. Barfuß
“Beitrag zur Theorie der astronomischen Strahlenbrechung,”
A. N. 15, 137–152 (1838).

* Friedrich Wilhelm Barfuss's paper
*      An interesting piece of work.  Barfuss starts out expounding basic
* refraction theory like a student's term paper; but he carries it on to
* remarkable lengths. In col. 139, he suggests that, despite the continual
* decrease of temperature in the region explored by balloons, "Daß indeß
* diese Progression durch die ganze Atmosphäre gelten sollte, ist nicht
* wahrscheinlich, vielmehr ist es glaublich, daß in einer gewissen Höhe
* die Temperaturdifferenzen wieder abnehmen, oder wohl gar die Temperatur
* constant bleibt." -- a guess at the stratosphere matched only by Young's.
*      At the foot of col. 141, he derives the 2-term series expansion
* in nearly as good a form as Green's version; at the end of the section
* (col.143) he comes up with Stone's criterion: "Wenn nun bei der Berechnung
* der Refraction ein Fehler von 0"05 für nichts geachtet wird, so setze
* man obigen Ausdruck = 0"05, . . . woraus tg z = 3,04 gefunden wird, wozu
* eine Zenithdistanz > 70° gehört. Also lassen sich durch obige Formel
* für r die Refractionen aller Zenithdistanzen bis 70° genauer als
* bis 0"05 berechnen.
*      ". . .  Aber für größere Zenithdistanzen wird die Sache weit
* schwieriger, weil nun das Gesetz der Abnahme der Brechungen immer stärker
* zu wirken anfängt, und seinen Einfluß nicht bloß in einzelnen Secunden,
* sondern sogar in Minuten äußert. . . . In den untersten Luftschichten
* walten diejenigen Ursachen von welchen . . . die Dichtigkeit der Luft
* abhängt . . . so gut wie ohne Regel, und diese Regellosigkeit in der
* Luft, muß auch eine Regellosigkeit in der Strahlenbrechung bewirken,
* welche um so stärker wird, je größer die Zenithdistanzen werden.
* Diese Betrachtungen leiten uns zu dem Entschlusse, die Refractionen
* größerer Zenithdistanzen, als etwa 86° aus den Tafeln, welche für
* die practische Astronomie bestimmt sind, gänzlich auszuschließen, und
* noch fehlenden Refractionen der Zenithdistanzen von 70° bis 86 Grad
* weniger durch ein hypothetisches Gesetz der Abnahme der Brechungen,
* sondern mehr auf einem empirischen, durch die Theorie gehörig
* unterstützten Wege zu bestimmen." [col. 144] He suggests that the
* slowly-converging series in sin z can be used to find an approximation
* in this region with only one free parameter to be found from observation,
* if the theoretical expressions for the others are used. (col. 145)
*      Note that the paper is introduced by a brief endorsement by Bessel!
* Published as "BEILAGE zu No. 344. der Astronomischen Nachrichten"
* dated 25 Jan. 1838.
*      Typographical note: the ß is printed here as a long-s/short-s
* kerned pair or logotype, not joined as a ligature.


J. Ivory
“On the theory of the astronomical refractions,”
Phil. Trans. Roy. Soc. Lond. 128, 169–229 (1838).

* IVORY's Bakerian lecture on refraction
* Chiefly useful today for its historical introduction. From the start,
* he appears uncertain about the relative importance of upper and lower
* atmosphere, mentioning "The limit of the atmosphere . . . " on p. 170, but
* ". . . a great share of that part of the astronomical refraction which
* depends upon the constitution of the atmosphere, must be ascribed to
* the initial rate at which the density decreases." (p. 171).
*      Newton's table (published by Halley) is treated on pp. 178-183.
* Ivory emphasizes (pp.181-182) that the refractions at altitudes above
* 16° depend only on the refractivity of air and not on the vertical
* structure (or, as he says, the "constitution") of the atmosphere.
* So a table of mean refractions above this altitude "gives no intimation
* with respect to the particular constitution of the atmosphere".
*      On p. 185, he again emphasizes that "as far as 74° from the zenith
* . . . all tables of refraction may be computed by CASSINI's method."
* On the next page, he describes Laplace's method of mixing "the two
* atmospheres with densities decreasing in arithmetical and geometrical
* progression," namely, a weighted product of their density profiles.
* He compares the result with Bessel's measured refractions, but warns
* that "With respect to the two degrees of altitude next the horizon, no
* accurate judgement can be formed, for want of observed refractions
* that can be depended on." (p.186)
* He seems to go out of his way to pick a fight with Biot (pp. 189-190);
* and his procedure is just as arbitrary as that of Biot, or Laplace
* (whom he criticizes). [No mention of Oriani.]
* He comes closest to the truth on p. 190: ". . . we are now acquainted
* with three things . . . that have an influence on the mean refractions.
* These are, the refractive power of the air, the spherical figure
* of the atmosphere, and the mean rate at which the density of the air
* decreases . . . ."
*      Ivory then tries "to complete the solution of the problem by
* estimating the effect of all the quantities on which the density at any
* height depends." (p. 191)
*      On p. 196, he says that the lapse rate is so difficult to measure that
* some mean value must be adopted. On the next page, he discusses the
* available data, and adopts a value that increases the horizontal
* refraction by only 19" from his 1823 result for dry air. He then works
* out the effect of water vapor, and concludes that the refraction is the
* same as for dry air at the same T and p. (p. 209)
*      In searching for the next-order term in his series expansion, he says
* "In the present state of our knowledge of the phenomena of the atmosphere,
* it seems impossible to determnine f' by experiments. " (p. 215)
* On the next page, he notes that the unknown terms are "of no account
* whatever, except the apparent altitude be equal to 2° or less", and on
* p. 219 finds that the contribution from the part that depends on the
* height of the atmosphere "will be a minute fraction of a second" even at
* the horizon. He ends by concluding that finding the unknown small
* corrections to the mean refraction would require "many good observed
* refractions at altitudes less than 5°. If such values were found, our
* knowledge of the decrease of heat in ascending in the atmosphere would
* be improved. . . ."
*      Ivory, like Biot, speaks of "the molecule of light" and uses the
* emission theory to "derive" Snel's law. (pp. 174-175)
*      His frequent references to the "Principia", as well as his religious
* training, suggest that he knew Latin; but he never seems to have read
* Oriani's work,


J. B. Biot
“Remarques sur quelques points d'une discussion élevée dans la 7e réunion de l'Association Britannique pour l'avancement des sciences, partie Mathématique,”
C. R. Acad. Sci. 6, No. 4, 71–78 (1838).

* BIOT's argument with POISSON begins
* Biot takes as his point of departure the discussion at the 7th meeting
* of the British Association, Mathematical division, where apparently
* Poisson's idea that the upper limit of the atmosphere might be liquid
* was discussed, with its supposed consequences for refraction
* calculations. Referring to his Connaissance des Tems memoir, he
* points out that the uppermost layers must have negligible effects. He
* also comments on Atkinson's paper in Mem. RAS, vol. 2, pointing out that
* his own method is greatly superior for actual calculations, and that
* Atkinson falls back on Bradley's rule for the top layer. ``En cela
* donc, le calcul de M. Atkinson, analysé avec exactitude dans ses
* éléments physiques, prêterait à la même illusion que les autres
* lois continues de décroissement employées par tous les géomètres qui
* l'ont précédé; illusion qui consiste à supposer qu'en pliant ces
* lois aux mesures de température faite dan les couches inférieurs, et
* tirant de leur emploi analytique des réfractions conformes à celles
* qui s'observent, on peut inférer de cette coïncidence, que les
* mêmes lois s'étendent, même approximativement, aux couches
* supérieures par lesquelles l'atmosphère est terminée. Car lorsque
* l'on maintenant ainsi, jusque dans ces couches, l'état et les
* propriétés habituelles des gaz, la portion de la réfraction totale
* qu'elles produisent, a toujours une valeur sensiblement égale dans
* tous les modes de superposition qu'on peut leur attribuer. Donc,
* inversement, on ne doit pas alors chercher des indices de leur
* température dans les valeurs des réfractions observables.''
*      Poisson's objection is attributed to a report printed in the Atheneum
* No. 519, p. 743, from which Biot gives a short translated excerpt.


J. B. Biot
“Sur la vraie constitution de l'atmosphère terrestre déduite de l'expérience, avec ses applications à la mesure des hauteurs par les observations barométriques, et au calcul des réfractions,”
C. R. Acad. Sci. 6, 390–401 (1838).

* Biot on atmospheric structure
* He points out that both the refraction and the barometric formulae in
* use are based on an empirical mixture of isothermal and what we would
* now call polytropic models, and looks for a more exact solution.
* The pressure, temperature, and density at each height are connected by
* the gas law and the requirement for hydrostatic equilibrium; so only
* one more relation is needed to solve the problem. Poisson has given
* a fictitious example; but one can also use empirical data, obtained by
* balloon ascents. He tries this with Gay-Lussac's balloon data, finding
* that the pressures and densities are almost linearly related, and show
* only a slight curvature in the lower atmosphere. A linear extrapolation
* of the uppermost data would make the density finite when the pressure
* vanishes; but this would make the atmosphere end at 23 km, which he
* knows is too low. But drawing a line from the last point to the origin
* gives an error of the opposite kind; so the truth must lie between them.
* So he finds that the temperatures must continue to decrease in the
* upper half of the atmosphere. He thinks it is impossible for the
* pressure and density to go to zero together at the top of the
* atmosphere, and so adopts a parabolic extrapolation that gives a finite
* density, and a reasonable height for the top of the atmosphere. With
* better balloon data, one could apply his methods from the CdT for 1839
* and thus obtain realistic refraction to the horizon; "et l'on
* appliquerait aux couches inférieurs les corrections variables que
* leur état nécessite; corrections qui seules peuvent faire
* connaître la vraie valeur de la réfraction qui s'y produit."


J. B. Biot
“Addition au mémoire sur la constitution physique de l'atmosphère terrestre,”
C. R. Acad. Sci. 6, 479–481 (1838).

* More of the same


Biot
“Mémoire sur la vraie constitution de l'atmosphère terrestre déduite de l'expérience, avec ses applications à la mesure des hauteurs par les observations barométriques, et au calcul des réfractions,”
Additions a la Connaissance des Temps . . . pour l'An 1841 , 3–112 (1838).

* BIOT's monograph on atmospheric structure and refraction
* The sub-title says "Lu à l'Académie des Sciences les 2, 16 et 30 avril
* 1838" -- so the preceding items are the abstracts.
*      There is an interesting historical note on pp. 3 -- 5, in which he
* extols the work of Laplace, but then remarkably says that Ivory's work
* is still better. Also on p. 4, he says (of inferring atmospheric
* structure from refraction observations):
*      "Et enfin j'ai montré que cette induction cesse même totalement
* d'exister pour les régions supérieures de l'atmosphère, parce que
* les réfractions observables ici-bas sont sensiblement indépendantes
* du mode de superposition qu'on peut leur attribuer."
* Astronomical refraction is briefly considered on pp. 89-90.
* Note that the fling with spelling reform has passed!


Th. Dieu
“Sur les réfractions atmosphériques,”
J. Math. Pures et Appl. 14, 372–400 (1849).

* A minor follow-up to Biot
* Dieu spends most of his effort reviewing the subject, with emphasis
* on Biot's work. At the end, he tries a pressure proportional to a
* quadratic function of the densities (i.e., a linear plus a quadratic
* term).
* This is a "Thèse d'Astronomie" and Dieu is listed as "Professeur de
* Mathématiques supérieures au Lycée de Dijon".


H. Faye
“Note sur les réfractions astronomiques,”
C. R. Acad. Sci. 39, 381–389 (1854).

* BIOT's 1854-55 series of papers
*
* These were initiated by a paper by Hervé Faye, suggesting that
* astronomical refraction could be improved by using measurements of
* terrestrial refraction. Faye seems to have had a black thumb: Miss
* Clerke reports that he believed the solar prominences were appendages
* of the Moon; that he maintained the "cyclone" theory of sunspots; had
* a strange theory for the formation of the planets, etc.
*
* Here is Faye's initial paper:
* He starts out well enough, in pointing out that the tables of mean
* refraction are based on some particular model atmosphere; "Mais s'il en
* était ainsi, je veux dire, si la loi de succession des indices de
* réfraction était fixe, les réfractions terrestres ou géodesiques
* seraient fixes aussi. On sait au contraire qu'elles sont éminemment
* variables . . . . Par conséquent, . . . l'hypothèse des astronomes est en
* désaccord avec ces faits:" -- so far, so good -- "en d'autres termes,
* les réfractions moyennes ne peuvent pas être constantes, sauf dans la
* partie où l'effet de la rondeur de la Terre est négligeable." Whoops!
* Worse, he assumes the approximation used in geodesy, that the refraction
* is proportional to the angle at the center of the Earth, is exact.
* This leads him to Bradley's formula, which he seems to regard as
* reliable. Then, citing the large daytime variations in terrestrial
* refraction, he derives a predicted variation (for fixed p and T at the
* observer) of 0."07 at 45° and 2."97 at 75° Z.D.
* Finally he says that all the unresolved disagreements, between
* catalogues, between Sun and stars, obliquities in summer and winter,
* latitudes measured at different times, etc., etc., "toutes ces
* discordances proviennent d'une seule et même cause, et cette cause
* serait la partie de la réfraction dont les astronomes n'ont pas tenu
* compte." --- all depending on "le coefficient de la réfraction
* géodésique." Talk about overplaying your hand!
*      Among all his other misunderstandings, he refers to Hossard's measures
* of diurnal changes in terrestrial refraction; but fails to understand
* that these changes are due to near-surface lapse rate changes.
*      NOTE: This is the 28 Aug. meeting.


Biot
“Note lue par M. Biot, à l'occasion du Compte rendu de la dernière séance,”
C. R. Acad. Sci. 39, 445–448 (1854).

* Biot basically says Faye is all wet
* He refers to Faye's Note, "dans laquelle notre confrère nous apprend,
* que la théorie de ces phénomènes, telle que a été établie par
* Newton, Laplace, Ivori [sic] et la généralité des géomètres,
* présente une contradiction qui l'a toujours frappé . Il spécifie en
* quoi elle consiste; et il indique les moyens qu'il a imaginés, pour la
* faire disparaître.
*      "Mon nom étant rappelé deux fois dans cette Note, à propos de
* recherches relatives à ce grand problème physique, dont je me suis en
* effet longtemps occupé, je me trouve dans la nécessité de déclarer
* ici mon complet dissentiment avec M. Faye, tant sur l'essence de la
* faute qu'il signale dans les théories adoptées, que sur la valeur du
* procédé qu'il propose pour y porter remède."
*      He points out that all the theories give "presque identiquement les
* mêmes indications" up to 60 or 70° from the zenith, and that the
* large variations of terrestrial refraction are more likely to introduce
* noise than a useful correction, as they are "si capricieusement
* variables". (Did Willard Fisher ever read this?)
*      Finally, "Je n'aurais ni le temps, ni la volonté, de prolonger sur
* ce sujet une polémique qui me semblait superflue . . . ."
*      NOTE: This is the 4 Sept. meeting.


Faye
“Réponse à la Note de M. Biot,”
C. R. Acad. Sci. 39, 481–486 (1854).

* But Faye won't take NO for an answer:
* ". . . j'y ai cherché quelque argument décisif, mais, je dois le dire,
* je n'ai trouvé qu'une fin de non-recevoir."
* Regarding the first point (that refraction is independent of model up
* to 70°), he re-asserts his numbers for 45 and (now) 65°. He makes
* the valid point that at Greenwich the Sun barely reaches 75° on the
* meridian in winter, and that Airy's observations for the theory of the
* Moon extend even to 85° Z.D.
*      Regarding Biot's assertion that only the part of the trajectory
* where the local Z.D. exceeds 70° is affected by structure, he says
* that the whole path meets this criterion at an observed Z.D. of 72° 10'.
*      Regarding Biot's objection that the large variations would produce
* wildly varying corrections, he asserts that his corrections are small.
*
* The note is followed by comments by Mathieu (pp. 486-487) and Regnault
* (pp.487-488). Mathieu says Biot is right, and astronomers will
* never adopt Faye's proposal. Regnault points out the need to measure
* temperature profiles directly, and the difficulty of measuring air
* temperatures at any height, but especially in a balloon, because of
* environmental radiation: "Tout le monde sait combien il est difficile avec
* certitude, à terre, la température de l'air, même à l'ombre, parce
* que le thermomètre est influencé simultanément par le rayonnement des
* corps ambiants. La difficulté est bien autrement grande dans un ballon
* . . . ."
*      NOTE: This is the 11 Sept. meeting.


Biot
“Note sur les articles relatifs aux réfractions atmosphériques, inserés au dernier numéro du Compte rendu,”
C. R. Acad. Sci. 39, 517–519 (1854).

* Biot tries to spread oil on troubled water . . .
* "Lorsqu'une discussion scientifique s'elève dans une Académie telle
* que la notre, et acquiert un développement qui amène plusiers de ses
* Membres à y prendre part, en attirant l'intérêt de tous, ce peut
* être une excellente occasion de faire concourir au perfectionnement des
* théories controversées, les connaissances spéciales que chaque
* individu possède,et qui s'adapteraient à leurs détails avec moins
* d'entente, par le manque d'une direction commune, si elles y étaient
* appliquées isolément. Cela peut offrir aussi l'avantage de répandre
* dans un plus grand nombre d'esprits éminents, des doctrines que leurs
* études propres ne leur ont pas donné lieu d'approfondir, quoiqu'ils
* pussent y apporter des améliorations importantes, si on les décidait
* à y pénétrer. Supposant donc de telles discussions, suives et
* soutenues, dans la seule intention de fortifier, d'accroître, la somme
* des vérités déjà acquises, sans y mêler de misérables sentiments
* d'aigreur ou d'animosités personnelles, la science ne saurait que
* gagner à ce qu'elles se produisent . . . .
*      ". . .  il faut que chacun soit rec,u à dire complétement sa pensée
* sans qu'on s'en offense; à exposer librement ce qu'il croit vrai, ce
* qu'il croit faux, en accordant à ses contradicteurs la même patience,
* la même indulgence, dont il aura presque infailliblement besoin, à son
* tour, pour peu que la controverse se prolonge, et s'étende aux régions
* de l'inconnu."
* But then comes the punch line:
* ". . . ceci exige que j'établisse préalablement la proposition suivante:
*       "Remonter de la réfraction opérée entre deux signaux terrestres,
* à la réfraction astronomique, par des résultats transportés de la
* première à la seconde, c'est un mode de déduction, qui, bien que
* théoriquement admissible, au point de vue mathématique, conduirait à
* des conséquences vicieuses dans l'application."
*      "Cette proposition sera l'objet d'une Note . . .  dans la séance
* prochaine."
*      NOTE: This is the 18 Sept. meeting.


Faye
“Remarques de M. Faye à l'occasion de la Note précédente,”
C. R. Acad. Sci. 39, 519–521 (1854).

* . . . but Faye is hardly mollified:
* "Puisque M. Biot annonce qu'il va reprendre ses recherches sur les
* réfractions atmosphériques, je crois devoir signaler de nouveau à
* son attention, malgré la dernière phrase de la Note dont nous venons
* d'entendre la lecture, le fait fondamental que j'ai pris moi-même pour
* point de départ. Ce fait consiste en ce que les variations
* périodiques des réfractions ne sont pas toutes accusées par le
* thermomètre et encore moins par le baromètre place's dans la couche
* où se trouve l'observateur."
* ". . . j'ai rencontré une opposition décidée, parce que, dans
* l'esprit de mes contradicteurs, la réfraction terrestre s'est aussitôt
* présentée avec in cortége de mirages et d'anomalies énormes."
*      "Il est facile de montrer, en effet, que les réfractions terrestres
* convenablement étudiées, ne sont pas des phénomènes capricieux,
* désordonne's, mais des phénomènes réguliers, en général . . . ."
* ". . . je me crois en droit d'affirmer que M. Biot se trouvera conduit,
* par ses nouvelles recherches, à des conclusions équivalentes aux
* miennes . . . ."
*      NOTE: This is also the 18 Sept. meeting.


Laugier
“Note sur la formule proposée par M. Faye pour calculer les réfractions astronomiques,”
C. R. Acad. Sci. 39, 521–524 (1854).

* Laugier shows that Faye's result makes no sense
* He enumerates 5 problems: I. Bradley's formula does not represent the
* mean refraction well unless the correction term depends on Z.
* II. While the daytime terrestrial refraction gives the term a value
* in fair agreement with nocturnal refraction, the terrestrial refraction
* is much larger at night; so there is an inconsistency.
* III. Bradley's form causes the correction term to be flat when the
* terrestrial refraction is large, and steep when it is small:
* "Ainsi, plus la réfraction terrestre sera faible, plus ses effets
* seront à craindre . . . ; au contraire, lorsque la réfraction terrestre
* sera très-forte, son influence totale sera sans doute très-grande,
* mais elle pourra varier beaucoup, les réfractions astronomiques ne
* changeront presque pas."
* IV. Faye takes as rigorous the geodesists' formula, which is known to
* be an approximation: "or cette formule, suffisamment approchée pour le
* calcul des petites corrections qu'on applique aux distances zénithales
* des objets terrestres, n'est pas mathématiquement rigoureuse" and its
* consequence "ne me paraît pas acceptable."
* V. Faye thinks he has obtained Bradley's formula "sans avoir consulté
* le ciel," but it is a necessary consequence of his having used the
* ordinary differential equation of astronomical refraction and proves
* nothing.
* "En résumé, la formule proposée par M. Faye . . . ne saurait, dans
* aucune cas, expliquer les incertitudes des réfractions qui ont lieu à
* des petites hauteurs."
*      NOTE: This is still the 18 Sept. meeting.


Mathieu
C. R. Acad. Sci. 39, 524–525 (1854).

* Mathieu's verbal comments on all this so far:
* "M. Faye vient de parler longuement de la réfraction terrestre et
* de ses capricieuses variations, mais il n'a rien dit pour justifier
* l'emploi qu'il en fait dans sa formule de la réfraction et pour
* répondre aux graves objections présentées par M. Laugier."
* He then points out that the reverse transfer (from astronomical to
* terrestrial refraction) was done "par l'auteur de la Mécanique
* Celeste . Comme la réfraction terrestre n'est que la partie de la
* réfraction astronomique comprise entre l'observateur et le point où la
* trajectoire lumineuse rencontre l'objet terrestre," he was able to apply
* simplifications leading to the relation for terrestrial refraction that
* Faye has used as his starting point. "Laplace ne considère donc pas
* son coefficient n comme l'expression complète, rigoureuse, du rapport
* entre la réfraction terrestre et l'angle au centre . . . . Eh bien, M.
* Faye déduit de la formule approchée . . . une loi . . . entachée de
* l'erreur qui existe . . . et il arrive à la formule . . . . M. Faye porte
* dans la formule des réfractions une loi défectueuse de constitution
* atmosphérique; il n'est donc pas étonnant qu'il en tire une formule
* qui conduit aux étranges résultats que M. Laugier a signale's tout à
* l'heure.
*      "Il est permis de conclure de cette discussion que la formule de
* Bradley ne peut pas être employée dans le calcul des réfractions
* astronomiques avec le coefficient (1 - 2n)/4n , variable seulement comme
* l'entend M. Faye."
*      NOTE: This is STILL the 18 Sept. meeting!


Biot
“Sur les réfractions atmosphériques,”
C. R. Acad. Sci. 39, 567–580 (1854).

* Biot's first installment, followed by several heated comments
*      NOTE: This is the 25 Sept. meeting that went on for 5¾ hours !!
* (See p.938 of the 7 Oct. issue of "l'Athenaeum Française" for a summary!)
* Here, Biot starts to lay out the theory of atmospheric refraction for
* the Academy. He begins with the Proposition that ended his previous
* note. Then, pointing out that the terrestrial refraction depends only
* on the lowest layers, and that their properties cannot be extrapolated
* to the higher ones that affect the astronomical refraction, he comments
* that "Cette impossibilité, dont on verra ci-après la preuve, rend mon
* dissentiment avec M. Faye encore plus complet que je ne l'avais
* témoigné d'abord.
*      "Ces dénominations, de réfraction terrestre et de réfraction
* astronomique, sone impropres. La première n'est que la petite partie
* de la seconde, qui s'opère dans les couches d'air les plus basses et
* les plus rapprochées de l'observateur . . . ."
* Then, getting in a dig at Faye, he says that the mathematical details
* of refraction "sont énoncées et fixées, dans le livre X de la
* Mécanique céleste , avec un détail et une rigueur de démonstration
* qui ne laissent rien à désirer. Je les ai tirées de là, en
* conservant scrupuleusement les mêmes notations symboliques avec
* les-quelles l'illustre auteur les a exprimées, et qui doivent être
* familières à tous ceux qui ont voulu étudier, après lui, ce
* problème, où il faut faire concourir des considérations de
* mécanique, de physique, d'astronomie, si délicates et si multiplées."
* -- adding that he hopes to summarize the experimental side as well,
* "sans y chercher le futile intérêt d'une polémique individuelle qui
* ne conviendrait ni à mon âge ni à mes goûts, mais en conservant
* toutefois l'entière liberté de discussion que l'indépendance
* académique autorise, et qui est indispensable pour séparer l'erreur de
* la vérité."
*      After presenting the outline of the general theory, he mentions his
* work with Arago and the sighting of 4 images of the signal at Campvey as
* seen from Desierto de las Palmas in Spain. "Le lendemain le temps
* était encore calme, mais la mer était couverte au loin de masses de
* brouillard, arrondies, détachées les unes des autres, représentant
* des montagnes. Nous pensâmes que des courants d'air locaux avaient
* pu refroidir certaines parties de la surface de la mer, entre l'île
* d'Yviça, où était le signal, et la côte de Valence, où nous étions."
* (He takes this as evidence that the terrestrial refraction is not to be
* trusted.) (p. 571)
* Then there is a numerical example, to show that the same model
* atmosphere (based on Gay-Lussac's sounding) gives different
* terrestrial coefficients of refraction for targets at different
* distances. Furthermore, the observations give only the sum but not
* the difference of the refractions at the two ends of the sight line; the
* latter is also required to obtain the true difference in level of the
* stations. "On y supplée en les supposant égales, ce que nos tableaux
* . . . montrent devoir être peu en erreur, aux distances restreintes où
* la convexité de la Terre oblige de placer les signaux géodésiques.
* Cela revient à considérer comme circulaire la portion de la
* trajectoire lumineuse . . . . Mais cette hypothèse, suffisante pour la
* pratique de l'ingénieur, n'est pas théoriquement acceptable comme
* réalité." (p. 575)
* Then he discusses the coefficient of terrestrial refraction, which he
* characterizes as an average over the layers involved. If the density
* is a power of the radius -- an hypothesis introduced by Laplace to make
* the integration possible -- we get the same form as Bradley's law.
* But there are no degrees of freedom to allow the model to conform to
* physical reality; in fact, the model at STP gives a value of the
* refraction coefficient quite different from what is observed, and too
* low a refraction at the horizon (30' 24."12), corresponding to a lapse
* of 1 degree C in 63.8 m or about 3 times what is observed.
*      He gets in another dig at Faye by referring to "la nouvelle notation
* que M. Faye a substituée à celle de Laplace." (p. 579)


Laugier
[verbal comments following Biot's paper]
C. R. Acad. Sci. 39, 580–585 (1854).

* Laugier attacks Faye . . .
* This is a rather vicious attack on Faye, turning his own words against
* him, and even accusing him of plagiarism:
* "L'idée d'emprunter au coefficient de la réfraction terrestre un
* élément de correction pour les réfractions astronomiques, est sans
* doute venue à l'esprit de plusiers personnes. Je l'ai rencontrée dans
* un ouvrage publiée récemment, et l'on sera bien étonné d'apprendre
* que cet ouvrage est précisément le tome IX du Mémorial du Dépôt
* de la Guerre , si souvent cité par M. Faye dans cette discussion."
* He quotes extensively from it, adding: "Cette idée est exactement
* celle que M. Faye expose et développe dans les différentes Notes qu'il
* a présentées à l'Académie, et après la lecture de ce passage si net
* et si précis, on ne comprend pas comment il a cru pouvoir se dispenser
* de citer M. Hossard au commencement du Mémoire qu'il a lu dans la
* séance du 28 août . . . ."


Faye
“Réplique de M. Faye,”
C. R. Acad. Sci. 39, 585–586 (1854).

* and Faye counters Laugier: "je demande la permission de repousser une
* accusation que M. Laugier vient de produire avec un certain éclat.
* . . . il me serait bien facile d'établir, s'il était sérieusement
* contesté, car je me suis publiquement occupé de ces sujets dans le
* sens que j'y attache encore aujourd'hui, longtemps avant que le tome IX
* du Mémorial ait paru, et j'en montrerais au besoin la preuve dans des
* feuilles lithographiées, authentiques, qui datent de 1852 ou même de
* 1851."


Faye
“Réponse de M. Faye aux critiques de MM. Laugier et Mathieu,”
C. R. Acad. Sci. 39, 586–593 (1854).

* Faye's formal reply to the earlier criticisms
* He compares his formula to Laplace's table, with differences of 0."1
* or more from 40° Z.D. onward; 0."7 at 75°, 7" at 86°, -35" at
* 89°, and -2' 26" at the horizon. He cites, from the Greenwich
* observations, discordances from day to day of nearly 4" at 75° and
* 10" at 85° 39'. He objects that the derivative used in Laugier's
* item III is not a fair comparison, as "les variations absolues de n
* sont d'autant moindres que n est lui-même plus petit . . . ."
* He also objects that it is unfair to attack his assumption as not
* rigorous: "Ce raisonnement serait parfaitement juste si la loi de
* Laplace était elle-même rigoureuse. Or on sait bien que cette loi
* n'est nullement rigoureuse; on sait que Laplace l'a adoptée après en
* avoir essayé deux autres, dont l'une donnait une réfraction
* horizontale trop grande, l'autre une réfraction horizontale trop
* petite, du moins il croyait ainsi. Il en a conclu naturellement que
* la vraie loi devait se trouver entre les deux; mais, dans l'ignorance
* où il était et où nous sommes encore de cette vraie loi, il s'est
* borné à combiner analytiquement les deux premières, de manière à
* obtenir pour l'équation différentielle de la réfraction la
* possibilité d'une intégration élégante."
* But he criticises Biot, claiming that daytime convection can vitiate
* "les lois d'équilibre, telles que M.Biot les formule d'après les
* pages si connues de la Mécanique céleste ".
* ". . . les objections . . . ont laissé intact le fond même de la question
* principale: Doit-on tenir compte, oui ou non, des variations
* atmosphériques que ni le baromètre ni le thermomètre ne font
* connaître, quand on se borne à les consulter dans une seule couche,
* mais que la réfraction terrestre indique parfaitement?"


J.-N. Legrand
“Remarques sur la loi des réfractions,”
C. R. Acad. Sci. 39, 633–635 (1854).

* Legrand shows that Faye's "correction" is due to wrong pressure
* ". . . si la formule de M. Faye ne concorde pas numériquement avec
* celle de Laplace, ce n'est pas à cause de l'ordre de densité qu'elle
* suppose, mais à cause qu'elle ne satisfait pas à la pression
* barométrique que suppose celle de Laplace. L'ordre de densité des
* couches est indifférent, mais le poids de l'atmosphère ne l'est pas.
* Que M. Faye détermine la constante de sa formule de façon à
* reproduire la pression atmosphérique, et il verra disparaître le
* désaccord qu'il dénonce. Qu'il suppose même à l'atmosphère une
* densité constante, pourvu qu'elle exerce la même pression, et à 79
* degrés du zénith (ancienne division) elle lui donnera à 1 seconde
* près la même réfraction que la formule sur laquelle les Tables sont
* construites; Laplace donne (art. 4) la formule qu'il faut employer à ce
* calcul, et je l'ai fait."


Biot
“Sur la théorie des réfractions atmosphériques,”
C. R. Acad. Sci. 39, 708–721 (1854).

* In this paper, Biot discusses the agreement of all theories up to 80°
* from the zenith.
* "On donne à ce système un arrangement intérieur, qui . . . s'assimile
* aussi approximativement qu'il est possible à l'état moyen de
* l'atmosphère réelle, sans être compliqué par ses perturbations, dont
* l'analyse mathématique de notre temps ne saurait pas calculer les
* effets accidentels." (p. 708)
* "La parité presque exacte de résultats numériques conclus
* d'hypothèses si diverses, présente déjà un mystère mathématique,
* qu'il faut nécessairement éclaircir, avant de chercher à découvrir
* pourquoi ces résultats se trouvent si approximativement conformes aux
* réalités." (p. 711)
* "Si donc, les hypothèses . . . conduisent, par le calcul, à des
* réfractions peu différentes entre elles, et qui ne s'écartent pas
* excessivement de la réalité, cela tient à ce que, au delà d'un
* certain degré de raréfaction de l'air, tout le reste de l'atmosphère
* fictive ne contribue à la réfraction totale que pour une part
* insensible ou à peine appréciable, qui, en outre, devient
* indépendante du mode de stratification que l'hypothèse employée lui
* attribue." (p. 717)
* Then (p. 720) he quotes the table from his CdT paper showing that the
* maximum limit of error of any atmosphere in hydrostatic equilibrium
* cannot exceed 0.277 arcsec at 74° and 2.24 sec at 80° Z.D.


Biot
“Sur la théorie des réfractions atmosphériques,”
C. R. Acad. Sci. 39, 817–828 (1854).

* This installment considers the irregularities of refraction.
* Biot cites his own experiences with the effects of the Bora near Fiume:
* the oscillations of Polaris were regular, with amplitudes of a few
* seconds of arc (8 or 9 max.). He shows that the horizontal ray enters
* the atmosphere (supposed 51 km high) some 7.5° from the observer's
* location; but the ray at 80° from the zenith enters only a little
* over 2° from the observer, and is quite close by in the lower
* atmosphere. So the rays closer to the zenith experience essentially the
* local conditions.


Biot
“Sur la théorie des réfractions atmosphériques,”
C. R. Acad. Sci. 39, 933–949 (1854).

* Biot attempts to explain why the assumptions of hydrostatic equilibrium
* and concentric spherical layering are justified in the real atmosphere.
* To my mind, this is a weak paper, based on only semi-quantitative
* arguments. He makes a plausible but not rigorous case that these
* assumptions are very nearly correct up to 80° Z.D.


Biot
“Sur le degré de confiance que l'on doit accorder aux Tables de réfractions actuelles. Détermination des circonstances hors desquelles leur application cesse d'être légitime,”
C. R. Acad. Sci. 40, 83–96 (1855).

* Biot prepares to discuss the Tables
* This is largely a review of the introductory parts of his CdT paper.
* Here he takes Delambre to task for having fitted Laplace's small-Z
* approximation with data extending to 90° 20' Z.D.
* He points out that the only differences among the tables of Bessel,
* Ivory, etc. are their assumptions about the atmospheric model.
* (He discusses each model in a separate paper later.)
* He is careful to define the refractivity in terms of T, P, latitude,
* etc. He also notes the radius-of-curvature condition: ". . . il
* représente le rayon de la sphère qui serait osculatrice à la couche
* d'air de la station, suivant le plan vertical où la réfraction
* s'opère." But, as he points out, this makes the equatorial or polar
* refraction differ from that at 45° by only 0."377 at 80° Z.D.


Biot
“Note de M.Biot sur l'ensemble des articles relatifs aux réfractions atmosphériques insérés par lui dans les Comptes rendus précédents,”
C. R. Acad. Sci. 40, 597–604 (1855).

* Biot's summary of the series: a brief historical reprise
* Biot is rather hard on Flamsteed, Bessel and Ivory. He says, of the
* refractions near the horizon: ". . . échappent inévitablement à
* toute théorie . . . dans l'impossibilité où l'on est de prévoir leurs
* caprices . . . ", thus anticipating Fisher's characterization. He also
* points out that empirical tables furnish information about the lowest
* layers of the atmosphere.
*
* This ENDs the Biot-Faye debate.



*** REFRACTION AFTER 1860 FILE ***

P. de Saint-Robert
“On the measurement of heights by the barometer, and on atmospheric refraction, having regard to the constitution of the atmosphere, resulting from Mr. James Glaisher's observations,”
The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science , series 4, 27, No. 184, 401–425 (1864).

*
* Count Paul de Saint-Robert cites Ivory and Biot
* The Count's name was Paolo Ballada; he spent 45 years in the Army, having
* entered the Military Academy of Turin as a boy. He quickly became a
* Professor of Ballistics at the School of Artillery and Engineers,
* eventually retiring to devote himself to mountaineering and entomology.
* He was well known for his work on the thermodynamics of gunpowder. His
* interest in mountaineering evidently led to his interest in Glaisher's
* studies of the atmosphere ar great heights, and this paper.
*      He begins by showing that Glaisher's balloon observations support a
* uniform decrease in density with height. Then "the trajectory described
* by a ray of light passing through an atmosphere so constituted is an
* arc of hyperbola." Already on p. 408 he notes that "refraction . . . is
* for the most part dependent on the first envelope of air not extending
* very far from the earth's surface."
*      However, his main interest is in using pressures to determine heights.
* So he develops hypsometry, starting with Simpson's model atmosphere.
* He immediately grants that this would have the atmosphere only 10 or
* 11 miles high, "which height is no doubt too small, it having been
* estimated by means of the duration of the twilight to be between forty
* and fifty miles." (p. 409) He also admits that his model makes the
* density go to zero before the pressure, "which is physically impossible."
* But for hypsometry and refraction, "it is quite sufficient that the law
* adopted represents the constitution of the atmosphere in the first
* envelope of air near the earth's surface, and that it is useless to
* consider the higher strata, which do not materially affect the inquiries
* we are about." He finds that "the height necessary to ascend to
* have a fall of one degree in the temperature . . .      increases while the
* elevation increases".
*      The treatment of refraction begins on p. 412.  He points out that the
* height is so small compared to the radius of curvature that the plane-
* parallel model is good enough so that "astronomical refraction, down to
* about 74° zenith-distance, is hardly affected in a perceptible degree
* by the peculiar constitution of the atmosphere.
*      "Near the horizon the same ray of light encounters the several
* concentric strata of air in parts which are far from being parallel;
* hence we cannot determine the deflections caused by them without knowing
* the arrangement of their density. But happily refraction depends almost
* entirely upon the lower portion of the atmosphere (which is accessible
* to exploration), and is not sensibly affected by the higher regions."
*      He then brings up Ivory's 1823 paper, quoting the line "the
* refractions undergo hardly any change in all the atmospheres comprehended
* in the formula" from Ivory. He then says, "The physical cause of this
* fact was afterwards shown by Blot," citing the CdT for 1839, and
* explaining that "As we recede from the earth's surface, the angle
* between the curve and the radius-vector, directed to the centre of the
* earth, will progressively decrease. It is obvious that in continuing to
* ascend we must come to an altitude where this angle will not be greater
* than 74°, or whatever other zenith-distance beyond which refraction is
* no longer influenced by the superincumbent atmosphere, and depends only
* upon the density at such altitude." (p. 413)
*      He immediately grants that "to reach the angle of 74°, it is
* necessary to ascend to a very great elevation." What he failed to grasp
* is that we need not reach 74° Z.D.; we merely need to reach a height
* above which the additional ray bending is negligible. He nearly gets
* this when he says "the extreme tenuity of air renders the amount of
* refraction so small that it may be well supposed to depend only on the
* density of the air at that place, though the angle of incidence should
* not yet be reduced to the limit of 74°." And he illustrates this with
* the Z.D. of the horizontal ray (at sea level) at the greatest height
* reached by Glaisher, 30,000 feet: 87° 8' 25". (p. 414)
*      "When the law of equable decrease of density upwards from the
* sea-level is admitted, the path followed by a ray of light is an arc of
* an hyperbola whose interior focus occupies the centre of the strata,"
* as he shows on the next pages. On p. 418, he finds a horizontal
* refraction of 33' 37", which he calls "a very satisfactory value."
* "It is often repeated that the refraction computed on the hypothesis
* of uniformly decreasing density is less than the truth. But I may observe
* that this happens only when the rate of the decrease of density is taken
* too small." He goes on to point out that what counts is the density
* gradient at the bottom: "What we want is the rate of decrease of the
* density in the inferior portion of the atmosphere". He reproduces a
* result from Biot's work, and says: "Biot's three memoirs . . . are the
* most complete writings that have hitherto appeared on the subject."
*      He then turns to the terrestrial refraction, and discusses the
* surveyors' "refraction coefficient" (i.e., the ratio of curvatures.)
* On p. 422, he argues that the terrestrial refraction coefficient is
* quite variable, and should be inferred from "direct meteorological
* observations." There is an interesting footnote on this page that
* says: "A series of observations for determining the hourly variations
* was carried out by M. Hossard, at Angoulême, during the months of May
* and June 1844. The observations were made half-hourly, from daybreak
* till twilight ; and the object observed was at a distance of about
* thirteen miles. The conclusions to which they led are the following:---
* The refraction is greatest about daybreak; from 5 or 6 A.M. until 8 A.M.
* it diminishes very rapidly; from 8 A.M. until 10 A.M. the diminution is
* slow; from 10 A.M. to 4 P.M. the refraction is nearly constant; from 4
* P,M. the refraction commences to increase."
*      DOI: 10.1080/14786446408643693


C. M. Bauernfeind
“Die atmosphärische Strahlenbrechung,”
Astron. Nachrichten 62, 209–252 (1864).

* CARL MAX BAUERNFEIND does the POLYTROPE of index 5 . . .
* An extreme example of the 19th-Century habit of representing everything
* analytically. Bauernfeind's series expansions go to the 28th power of
* sec z (see col.222)! However, he finds not all are appreciable; so his
* final expansion for z < 83° only goes to the 19th power. . . .(col.226)
* Note that his parameter m is 6 times the usual (h/R) parameter, as his
* height is the *total* height of the atmosphere, not the uniform height.
* He derives a lapse rate of 5.77° C/km [Emden gives 5.69 for n = 5].
* His model atmosphere ends at 47.25 km, corresponding to a uniform
* height of 7875 m.
*      However, he does show reasonable agreement with "Bessel" (i.e.,
* Argelander) between 85 and 90° ZD. Another interesting bit is the
* attempt to calculate refraction below the astronomical horizon; he tries
* to compare with Bouguer's observations at Chimborazo.
*      Full title of these 2 works is "Die atmosphärische Strahlenbrechung
* auf Grund einer neuen Aufstellung über die physikalische Constitution
* der Atmosphäre." This is AN Nr. 1478-1480.


C. M. Bauernfeind
“Ueber terrestrische Strahlenbrechung,”
Sitzungsberichte der königl. bayer. Akademie der Wissenschaften zu München, Jhg. 1866, Band I , 313–323 (1866).

* Bauernfeind's treatment of terrestrial refraction, summarized.
* (This is his meeting abstract.)
* On p.314 he says density but means density gradient. He also claims
* to have discovered the minimal ratio of 5 for the radii of curvature,
* ignoring T. Young (and many others). On p. 321, he notices that the
* terrestrial refraction -- i.e., the ray curvature -- "nahezu dem
* Quadrat der Luftdichtigkeit proportional ist." So he seems unaware
* of Ivory's paper on Mayer's result.


C. M. Bauernfeind
“Die atmosphärische Strahlenbrechung,”
Astron. Nachrichten 67, 33–88 (1866).

* Bauernfeind's detailed treatment of terrestrial refraction.
* In view of his excessively mathematical treatment, and my lesser
* interest in terrestrial refraction, I have only copied the first page.
* One good line: "Hiernach unterliegt es keinem Zweifel, dass beide
* Refractionen aus einer und derselben Differentialgleichung . . . hervorgehen
* und ihr Unterschied nur aus den Integrationsgrenzen entspringt . . . . so
* ist offenbar die Bestimmung der terrestrischen Refraction r aus der
* Differentialgleichung der atmosphärischen Strahlenbrechung der allgemeine
* und die der astronomischen Refraction der besondere Fall . . . ." (col.34)
* AN Nr. 1587-1590.


Th. v. Oppolzer
“Vorläufige Mittheilung über eine neue Refractionsformel,”
A. N. 89, Nr. 2135, 365–366 (1877).

* THEODOR von OPPOLZER's preliminary note
* The error-function formula briefly announced, with a comparison to
* Bessel's table.
* Note: there were two Oppolzers. This is the father; Egon was his son.


Th. v. Oppolzer
“Eine Bemerkung über die Berechnung der Refraction,”
A. N. 92, 29–30 (1878).

* Oppolzer, on neglecting small terms
* "Es ist übrigens klar, dass . . . bei der Darstellung der Beobachtungen
* keinen wesentlichen Fehler aus dieser Uebergehung entstehen; es erscheint
* nur die Konstante um Etwas fehlerhaft bestimmt."
* [cf. Bauernfeind's (1864) discussion in his section 9, cols. 231 ff.]


C. M. von Bauernfeind
“Ergebnisse aus Beobachtungen der terrestrischen Refraktion. Erste Mittheilung enthaltend die Feststellung von Thatsachen.,”
Abhandlungen der II. [math.-phys.]Classe d. k. bayer. Akad. Wiss. München, (3. Abth.) 13, 179–310 (1880).

* Bauernfeind's first big report of results
* See his 1888 and 1892 papers for corrections of some serious errors.
*      The big fold-out color lithograph, "Steindrucktafel II", shows the
* DIURNAL VARIATIONS in the terrestrial refraction very plainly. The
* actual numerical data are given as well, in the very extensive tables
* beginning on p. 267. (Cf. Hossard, 1853)
*      Also notable for the extensive discussion of attempts to detect
* LATERAL REFRACTION, without success (pp. 226-243): the random noise
* in Tafel Nr. 8 (pp. 230-234) is typically 2 or 3 arcsec, and the
* systematic effects cannot exceed a few tenths of a second. However,
* the sight-lines lay an average of 200 m above the ground, so no effects
* were to be expected (pp. 264-265).
*      Full title is "Abhandlungen der mathematisch-physikalischen Classe
* der königlich bayerischen Akademie der Wissenschaften. Dreizehnten
* Bandes. In der Reihe der Denkschriften der XLVIII Band." So this
* may also be cited as Münchener Denkschr. vol. 48. Also, each number
* in the volume is separately paginated, starting at p. 1; this is the
* III. Abtheilung.
*      Note that B. has another big paper in the same issue: the 5th in his
* reports on "Das Bayerische Präcisions-Nivellement." (pp. 49-136)


J. C. Houzeau
Vade-mecum de l'astronome
(F.Hayez, Bruxelles, 1882).

* JEAN-CHARLES HOUZEAU's VADE-MECUM
* This is an annotated bibliography of all of astronomy. The refraction
* sections are in Chapitre VI (pp. 299-310, 318-320).
* The selections are limited to the most important papers. See Houzeau's
* Bibliographie Générale for a more complete listing.
*      Luc Dettwiller tells me this is available at
* https://archive.org/details/in.ernet.dli.2015.377029


J. C. Houzeau and A. Lancaster
Bibliographie Générale de l'Astronomie, Tome Second
(Havermans, Bruxelles, 1882).

* HOUZEAU and LANCASTER's BIBLIOGRAPHIE GÉNÉRALE
*      This is a chronological listing, by subject categories, of references.
* By resorting to cryptic abbreviations (like those used later in ADS), the
* authors managed to compress the bare listing of citations to only about
* 1300 pages; the internal references are by column numberss. Our main
* interests are in Section III (Astronomie Sphérique):
*      § 18.  Refraction theory                                      cols. 370 -- 1597
*      § 19.  Refraction measures and tables             cols. 377 -- 1597
*      § 20.  Refraction near the horizon                   cols. 385 -- 1598
* Dispersion is put under "Astronomie physique" (Section VI):
*      § 34.  Diffraction & "effets optiques"            cols. 787 -- 1643
*
* Notice that the Russian literature is largely excluded; its titles were
* translated into French, in some cases. "Nous avons fait usage du
* français, notre langue maternelle , qui est généralement compris par
* le plus grand nombre des hommes de science." (p.XLIX)
*      The rules for encoding the names of publications are given on pp. L ff.
* More complicated rules were needed for the names of authors, where German
* umlauts were dropped, Hungarian accents and Russian letters were made
* French in some way, and honorific titles were removed.
*      The Key to the abbreviations begins on p. 1 (PDF image 95).  But the
* main part of the volume is the numbered columns , which begin at image
* 182 of the Google PDF. So column C is on image (2*C + 181) of the PDF.
*
* Available at Google Books.


R. Radau
“Recherches sur la théorie des réfractions astronomiques,”
Annales de l'Observatoire de Paris 16, B.1–B.114 (1882).

* RADAU's review paper compares previous theories
* Biot's form of the integral is given on p.6, without further use.
* Has closed formulae for Cassini and Mayer on p. 7. On p. 10, he
* chooses the nice phrase "reduced height" for the uniform atmosphere.
* The series-expansion coefficients are discussed on pp. 13 - 14.
* On pp. 30 - 31, he shows (in effect) that Bauernfeind's k is the
* polytropic index (note the discussion of the ratio of specific heats).
* Polytropic models are discussed in detail on pp. 46 - 55; k is the
* polytropic index. Detailed numerical results are given for k = 4, 5,
* and 6. The table on p. 55 shows that Bessel's [i.e., Argelander's]
* observed refractions exceed those calculated, even for k = 6, below
* 2° altitude.
*      On p.53, having cited large variations at low altitudes in the
* observations of Fuss (1871) and Kowalski on p.52, he says: "Il n’est
* pas probable que ces différences extraordinaires viennent toujours des
* irrégularités du décroissement; elles peuvent être dues, dans beaucoup
* de cas, au dénivellement des couches réfringentes." He then refers to
* the theory he had developed in his earlier Mḿoire (p.104 et seq.) and
* gives his table of the small effects produced by a 1-arcmin tilt. On
* the next page, he describes a different derivation, which produces the
* 1/cos2 correction that would later be derived by mny other people.
* The correction term is then proportional to sec2 z in eq. (59). So
* a tilt of a degree would change the refraction by 0.1 arcsec near the
* zenith, and 0.2 sec at 45° Z.D. Even assuming the tilt extended to
* the whole atmosphere, he gets only 13 or 14 seconds at the horizon.
*      Diurnal and seasonal effects appear on p. 57.  Ducts, p. 58 - 60.
* He seems to think the infinite refraction in ducts is merely a
* mathematical problem!
*      Bruhns is cited on p. 62; perhaps he misled Radau as well as Newcomb.
*      The major models are compared on p. 64.  Radau notices that the
* model with the smallest initial lapse rate (Bessel's Fundamenta )
* gives the largest refraction near the horizon (p. 63), and that the
* one with the largest initial lapse rate (Kowalski) gives the smallest
* refractions. P. 65 tabulates refractions for initial lapse rates of 4,
* 5, 6, and 7° per km.
*      Finally, non-spherical models are considered in §XVIII, pp. 99 ff.,
* though the main emphasis is on TILTed layers. He thinks (p. 112) that the
* variations in refraction are due to such tilts, although his calculation
* in p.111 gave only 10" of arc change in refraction at the horizon for
* a tilt of 1'.
*      To calculate the tilt effect, he starts with a plane-parallel model
* (p.101). The invariant gives him the limiting angle (88°36'). He
* concludes that the plane-parallel model is OK to ZD < 60° or 70°.
* Then adopting λ as the tilt angle, he tilts all the layers through this
* angle. (This notation was also used by Sugawa and Courvoisier.)
* On p. B.103, he finds that the maximum refraction error is inversely
* proportional to cos2 z (which of course is sec2 z). "In sum, the
* irregular deviation is always in the sense of the tilt of the layers,
* which is to say, probably, in the direction of the wind." (p. 104)
* "A south wind should raise, and a north wind, lower, stars that pass
* south of the zenith, etc." Then he cautions that the effect would be
* smaller if the tilt is not the same throughout the whole atmosphere.
* For example, he supposes that the layers become horizontal above 1100 m.
* Then the correction is not more than 1/10 as big. (This is why he finds
* such small effects in his final results on p. 112.)
*      He also shows that tilting all the plane layers by λ produces the same
* effect as displacing the centers of spherical layers by this angle,
* instead of having their centers at the center of the Earth. On p.106,
* he reproduces the formula of Gyldén cited by Fuss.
*
* This is evidently the basis for Newcomb's treatment.
* Note that Contre-Amiral Mouchez was the Directeur de l'Observatoire.
* The (previously defective) ADS copy is now complete.


C. M. von Bauernfeind
“Ergebnisse aus Beobachtungen der terrestrischen Refraktion. Zweite Mittheilung enthaltend weitere Thatsachen und ihre Erklärung.,”
Abhandlungen der II. [math.-phys.]Classe d. k. bayer. Akad. Wiss. München 15, 1–102 (1886).

* Bauernfeind's second big report
* See his 1888 and 1892 papers for corrections of some serious errors.
*      The big fold-out color lithograph, "Steindrucktafel I", shows the
* DIURNAL VARIATIONS in the terrestrial refraction very plainly.
*      Full title is "Abhandlungen der mathematisch-physikalischen Classe
* der königlich bayerischen Akademie der Wissenschaften. Fünfzehnter
* Band. In der Reihe der Denkschriften der LIII Band." So this
* may also be cited as Münchener Denkschr. vol. 53. Now, the numbers
* are continuously paginated, so the Abtheilung Nr. is no longer required.


Th. v. Oppolzer
“Über die astronomische Refraction,”
Denkschriften kaiserl. Akademie der Wiss., Wien, Math.-Naturwiss. Cl. 53, 1–52 (1887).

* Hofrath Prof. Theodor Ritter v. OPPOLZER's big paper
* He neglects water vapor. On pp. 2-3, he points out the need to use
* temperatures measured inside the observing room, not outside.
*      At the bottom of p. 9, he cautions against the use of Taylor series,
* "besonders wenn durch die Natur des Problems die assymptotische
* Annäherung an einen Grenzwerth erwartet werden darf," and then goes on
* to consider a parabolic temperature formula (p. 10). Its difficulties
* lead him to assume a temperature gradient proportional to the density
* gradient. This (effectively) exponential form then leads to Gamma
* functions for the refraction integral (pp. 15-18); he recognizes that
* his series expansion is semi-convergent (p. 18); cf. p. 27.
*      At the bottom of p. 28, he discusses briefly the Oriani theorem (which
* he attributes to Laplace). He thinks the peculiarities of refraction
* near the horizon are due to "local disturbances" (by which he evidently
* means the temperature difference between the observing room and outdoors).
*      Finally he determines the correction terms to be added to his "main
* term" and presents tables for everything. See Bemporad's encyclopedia
* article for further comments. [Not a very useful paper.]


C. M. von Bauernfeind
“Ergebnisse aus Beobachtungen der terrestrischen Refraktion,”
Abhandlungen der II. [math.-phys.]Classe d. k. bayer. Akad. Wiss. München 16, 517–567 (1888).

* BAUERNFEIND's big summary paper
* Here he corrects the errors of the 1866 and later papers: "Dieser Fehler
* fiel mir erst im Sommer des Jahres 1883 auf . . . ."
*      This contains a useful review of his past papers; but it's so
* defensive, and so full of priority disputes, as to be offensive.
* However, he does review the history of his efforts (see mostly the
* introductory section A, pp. 519-524; and section E, pp. 547ff.)
*      The corrected plots on Tafel V at the end of the paper clearly show
* the DIURNAL VARIATIONS in refraction.
*      The references to "mein leider so früh gestorbener Freund und Kollege,
* Prof. Theodor v. Oppolzer," (p. 550) are particularly interesting.
* He objects to Oppolzer's (1886) criticisms; yet he ends the text
* (p. 561) with a complementary quotation from Oppolzer's paper.
*      On p. 559 there is a serious slip, in which he says that a constant
* temperature means the ray path is a straight line!
*      He also has the curious habit of referring to "meine Beobachtungen"
* when it's clear that they were all made by underlings -- whom he at one
* point accuses of reading the wrong thermometers! [p. 558]
*      See his 1892 paper for further corrections.
*
* Marcel Tschudin tells me this is available on the Web, starting at
*      https://archive.org/stream/abhandlungenderk16kn#page/518/mode/2up


R. Radau
“Essai sur les réfractions astronomiques,”
Annales de l'Observatoire de Paris 19, G.1–G.80 (1889).

* RADAU's big paper with refraction tables and comparison with observations
*      He calls the lapse rate Δ (defined on p. G.5.)
* Notes that temperature inversions increase the horizontal refr. (G.7)
* TILTS of a few minutes are to be expected from typical pressure and
* temperature gradients horizontally. (G.8) ". . . il est évident que la
* température est la cause principale des dénivellements des surfaces
* réfringentes. Comme ces dénivellements troublent l'équilibre, ils sont
* accompagnés de courants atmosphériques, et l’on peut admettre que ces
* courants suivent en général les pentes des couches de niveau."
*       He then takes up the lapse rate.  His symbol k  is the polytropic
* index; he gives the values for k = 4, 5, 6, and 7, and notes that
* Newton used an isothermal model. The heights of several models are
* on p.10. On p.11 he says that ". . . la température des couches très
* élevées n’a aucune importance . . . ", and notes that the infinite height
* of an isothermal model is "une fiction mathémalique qui à pour excuse
* le fait que la densité théorique devient insensible à partir d'une
* hauteur modérée (60{km} ou 70{km})."
*      He then considers more complicated analytical models, which are quite
* unrealistic, and goes on to include humidity, citing the works of Fizeau
* and Jamin. (p. 15) On p.17, he considers tilted layers by assuming
* the ray path is a brachystochrone. But then he says that it's usually
* enough to consider concentric spheres, and so treats the refractive
* invariant (p. 20).
*      Dispersion is briefly treated on p. 24; symmetry, on p. 27.
* The problem of convergence of the series expansion appears on p.36,
* but semi-convergence is never explicitly mentioned. A table there
* gives numerical values of the series-expansion coeffs.
*      The refraction near the horizon is vaguely related to the lapse
* rate in the lower atmosphere (pp. 47 ff.); but the connection is never
* made clearly. He notes that an inversion can greatly increase refraction
* near the horizon, and that such excesses are often observed (p. 52);
* here he cites the observations of Fuss (1871) and Kowalski (????).
* But he is more inclined to attribute them to TILT than to lapse rate
* (pp. 53-59), as in his 1882 paper --- much of which he repeats here.
*      An anonymous 1-page summary in English appears in MN 50, 237 (1890).


H. Bruns
“Zur Theorie der astronomischen Strahlenbrechung,”
Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig, Math.-Phys. Classe 43, 164–227 (1891).

* HEINRICH BRUNS
* A unique piece of work! Bruns says he used this approach for his
* lecture series at the Geodetic Institute in Berlin in 1879/80; one
* wonders what his students must have thought of it, as the mathematical
* development becomes quite complicated. (However, his 1891 student
* Felix Hausdorff went on to become a famous topologist. Bruns himself
* was a student of Kummer's, having obtained his own doctorate in 1871.
* Bruns was the second director of the Leipzig observatory, succeding Carl
* Christian Bruhns, q.v.)
*      According to Helmert (Geodäsie, vol. 2, p.552 (1884)), Bruns hoped to
* obtain a better determination of the geoid from measured zenith distances
* by means of this improvement in refraction theory; Helmert cites Bruns's
* Figur der Erde (1878), pp. 45-49.
*      Biog.: http://www-history.mcs.st-andrews.ac.uk/Printonly/Bruns.html
*
*      Note the footnote on p. 169, about the proportionality between
* density and (μ - 1): "Die gewöhnlich benutzte Formel, die statt μ
* das Quadrat von μ enthält, entspricht den Beobachtungen nicht besser
* als die obige, bringt dagegen in die Entwickelungen eine überflüssige
* Complication hinein."
*      p. 171: "Ferner lehrt ein Blick auf die Formeln . . .  dass dann die
* zweckmässigste Variable für die Integration nicht, wie es bisher
* geschah, der Kugelradius r , sondern die Grösse ν = μ r ist,
* denn in diesem Falle tritt das . . . noch unbekannter Element . . . nur als
* einfacher Factor unter dem Integralzeichen."
*      Now comes an important point: "Die vorstehenden Bemerkungen enthalten
* bereits die Lösung der Aufgabe, Refractionstafeln auf Grund einer
* gegebenen Reihe von Refractionsbeobachtungen zu construieren, ohne dass
* man über die Constitution der Atmosphäre mehr weiss, als von vornherein
* allgemein feststeht." So he proposes to find differential corrections
* to the model parameters by using the observed errors of a provisional
* table to adjust the parameters used to construct the table; "d. h. es
* ist möglich, unter Umkehrung des bisher immer befolgten Weges,
* von den Refractionsbeobachtungen ausgehend das Gesetz der verticalen
* Temperaturänderung in freier Luft numerisch so weit fest zu legen,
* als dies die Natur der Sache eben zulässt." [Of course, this last
* phrase is the tricky part, as Biot showed; but Bruns seems not to have
* read Biot.] Still (p. 174): ". . . [die] höheren Schichten . . . welche
* zu dem Werthe von R überhaupt nur einen kleinen Beitrag liefern."
*      He points out that the series expansion in odd powers of tan z is only
* semiconvergent (p. 180). But, applying it to Oppolzer's formula, he
* shows that reasonable results can be obtained -- but only if the height
* of the atmosphere is about 31 km. "Wenn . . . zwei Refractionsformeln,
* die den Beobachtungen gegenüber als gleichberechtigt anzusehen
* sind, erheblich verschiedene Höhen der Atmosphäre voraussetzen, so
* ist zu erwarten, dass die daraus abgeleiteten Temperaturen . . . zwar in
* geringen Erhebungen übereinstimmen, in grösseren Höhen dagegen rasch
* auseinandergehen werden." [Here is an indication of the unimportance
* of the upper atmosphere, though he does not say so explicitly.] (p. 183)
*      Now comes the really  interesting part (p. 184): expanding the
* refraction R as a sum of rational functions of ξ = cot z (which is
* equivalent to rational terms in tan z). So R is expressed as a sum
* of partial fractions. The development is limited to one or two terms.
*      (Note the remark on p. 190: "Rechnet man . . .  mit den Constanten . . .
* welche von einem meiner Schüler, Herrn Hausdorff abgeleitet sind . . . .)
*      A one-term fit is moderately satisfactory: comparison with Gyldén's
* table shows "dass man mit einer mässigen Aenderung von H bereits durch
* die eingliedrige Formel einen besseren Anschluss erzielen kann, als ihn
* viele der bisher aufgestellten Refractionstheorien besitzen." (p. 196)
* [Here H is the value of R at the horizon.] It is interesting that
* the auxiliary angle φ is near 5° -- i.e., about where the zenith
* behavior goes over into the near-horizon behavior of the refraction.
*      He has trouble fitting Bessel's mixture of theory and observation.
* Imposing a least-squares fit (p. 199), he find poor agreement between
* 85° and 86° ZD. He thinks (p. 201) this is due to remaining
* observational errors that have not been smoothed out.
*      All these fits lead to model atmospheres that end around 30 or 40 km.
* Nevertheless, he concludes "dass die Partialbruchformel bereits mit
* zwei Gliedern eine Biegsamkeit besitzt, welche allen Anforderungen
* genügt". (p. 202) From the discussion on p. 208, it's clear that
* his model atmosphere has p = 0 and T = 0 at the upper boundary; and
* ". . . man aus Refractionsbeobachtungen keinen Schluss auf die
* Constitution desjenigen Theiles der Atmosphäre ziehen kann, der zu
* der Refraction nur einen unmerklichen Beitrag liefert . . . ." The table
* on p. 209 gives the temperature decreases for his models at heights up
* to 10 km.
*      Furthermore, the strategy of forcing the approximation to fit near the
* zenith and then at a few well-chosen large ZDs is a good one.
*      See Bemporad's encyclopedia article (1913) for further discussion.
* According to Julius Bauschinger's obituary notice in AN 252, No.6026,
* pp.29-32 (1934), Bauschinger succeeded Bruns in Leipzig about 1920.


F. Hausdorff
“Zur Theorie der astronomischen Strahlenbrechung.,”
Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig, Math.-phys. Classe 43, 491–566 (1891).

* FELIX HAUSDORFF's thesis on refraction theory (part I)
* (not yet in my files)


R. Wolf
Handbuch der Astronomie, ihrer Geschichte und Literatur, Dritter Halbband
(F.Schulthess, Zürich, 1892).

* RUDOLF WOLF's fine review of refraction -- lots of historical references
*      (Yes, this is  the Wolf of the sunspot numbers.)
* The refraction section is on pp. 259 - 278, sections 453 - 459. He is
* influenced by Carl Christian Bruhns's history, and so misses Biot's 1836
* accomplishment; but he understands the importance of Oriani's theorem.
* Very helpful and illuminating comments throughout. This is a much
* fuller account than the brief one in his 1877 Bd. 16 of "Geschichte
* der Wissenschaften in Deutschland" that was reprinted in 1965.
*      Note that the P-10 version calls this "Volume 2, half-volume 3".
* The first volume appeared in 1890; the last, in 1893.
* Thanks to Sharron Huling, for providing photocopies of these pages!


C. M. von Bauernfeind
“Nachtrag zu den Mitteilungen II und III über die Ergebnisse aus Beobachtungen der terrestrischen Refraktion,”
Abhandlungen der II. [math.-phys.] Classe d. k. bayer. Akad. Wiss. München 17, 445–456 (1892).

* Bauernfeind again
* Here he finds fault with his assistants again for making errors:
* "Einige solche Fehler kamen leider bei dem im Jahre 1881 von zwei
* tüchtigen Assistenten ausgeführten Präzisionsnivellement zwischen
* Höhensteig und Kampenwand (H-K) vor . . . . Nach dem Berichte des
* Assistenten Oertel war von Höhensteig bis zum Fixpunkte Nr. 1629 bei
* Hohenaschau Alles in Ordnung; von da ab . . . stellten sich alsbald einige
* erhebliche Abweichungen ein." So the results have to be corrected
* again.


F. Hausdorff
“Zur Theorie der astronomischen Strahlenbrechung. II.,”
Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig, Math.-phys. Classe 45, 120–162 (1893).

* FELIX HAUSDORFF's continuation of his refraction theory (part II)
*      This is a continuation of his thesis, done under Heinrich Bruns
* -- who presented it to the academy here. It begins (after an
* introductory pargraph) with section 10.
*      He develops beautiful mathematical properties of the refraction
* integral here (see pp. 135-136), mostly by means of clever changes of
* variable.
*      NOTE: This volume is available at Google Books.


F. Hausdorff
“Zur Theorie der astronomischen Strahlenbrechung. III.,”
Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig, Math.-phys. Classe 45, 758–804 (1893).

* FELIX HAUSDORFF's continuation of his refraction theory (part III)
* Here he considers the effects of ellipticity of the geoid, which of
* course turn out to be quite small.
*      When one looks at other titles in the same volume (Sophus Lie and
* Elie Cartan on group theory, for example), it's clear why Hausdorff
* quickly gave up on his dead-end work in refraction and moved into math.
*      NOTE: This volume is available at Google Books.


E. von Oppolzer
“Eine Bemerkung zur astronomischen Strahlenbrechung,”
A. N. 135, No. 3225, 159–162 (1894).

* EGON von OPPOLZER (Theodor's son) goes in the wrong direction
* Remarkably, he accepts Hann's (1875) idea that nitrogen and oxygen
* are diffusively separated in the *troposphere*! So the upper atmosphere
* is supposed to be mostly nitrogen. In any case, his supposed "correction"
* amounts to 0".1 at 75 or 80°, and only a second at the horizon --
* another example of the UNimportance of the upper atmosphere.


G. C. Comstock
“Investigation of the aberration and atmospheric refraction,” in Publications of the Washburn Observatory of the University of Wisconsin, vol. 9, part 1
(Democrat Printing Co., Madison, Wis., 1895), pp. 1–203.

* GEORGE COMSTOCK's first paper introducing an effective wavelength
* A very meticulous investigation. He arranged mirrors in front of the
* telescope objective, so that pairs of stars nearly 120° apart could
* be seen together in the micrometer eyepiece. Closure was achieved
* by using sets of 3 stars near the equator. (see pp. 50, 55-56)
*      P.188: ". . .  if we assume the D line as corresponding to the wave
* length of the light of an average yellow star . . . ", he finds the
* wavelength for an average red star is 621.5 nm and for an average
* white star, 558.0. "As a control . . . , I have submitted to four
* different persons the Stern-Spectraltafel of H. C. Vogel with a request
* to identify upon it the colors: yellow, ruddy yellow, yellowish red and
* the superior limit of red. I have also had similar determinations made
* directly from the prismatic solar spectrum by two persons. The mean
* wave lengths corresponding to the color symbols as thus determined are"
* (and he gives a short table).
*      Comstock here assumes that the effective wavelength for refraction
* corresponds to what a color scientist would now call the "dominant
* wavelength" corresponding to the visual color of each star. But:
* "It is obviously impossible to determine in this manner the wave lengths
* to associate with any of the symbols involving the letter W, white."
*      On p. 189 he adopts the mean wavelength for the stars observed as
* 562.0 nm; but this depends heavily on his assumed D-line for yellow
* stars.
*      On p. 192 he correctly takes account of the radius of curvature
* and its dependence on azimuth. He also takes account of the influence
* of water vapor on the refractivity; and concludes (p. 194) that the
* visual refractivity of dry air for the conditions of the Pulkovo Tables
* (0° C, 760 mm Hg, standard gravity at 45° latitude, and the D line)
* is 0.00029209 for stars 69° from the zenith, which agrees with lab
* data. Corrections to Bessel's mean refractions are discussed on
* pp. 193-195.
*      On pp. 195-196 he discusses possible TILT of the layers, noting
* that a tilt of 1' at 75° Z.D. would change the refraction by 0.24".
* "The practical conclusion is that the computed refractions in zenith
* distance may be made considerably more precise by taking into account
* the inclination of the strata, i. e. the barometric and thermometric
* gradients. This will be most conveniently done by using as the argument
* of the tables the zenith distance of the star reckoned from the normal
* to the strata instead of from the vertical." (p. 196)


J. Bauschinger
“Untersuchungen über die astronomische Refraction,”
München Sternw. Neue Ann. 3, 41–229 (1896).

* JULIUS BAUSCHINGER's observations near the horizon
*      Julius Bauschinger (1860-1934) was the son of the Munich engineer
* Johann Bauschinger. He got his Ph.D. in Munich in 1883, having studied
* under Hugo von Seeliger, and been a member of the Venus-transit expedition
* to Hartford, Conn., in 1882. He became an assistant, then Observator
* in Munich. Shortly after this was published, he went to Berlin as
* Professor at the University, and became the Director of the Astronomisches
* Rechen-Institut, and publisher of the Berliner Astronomisches Jahrbuch.
* He was co-author of Peters' 8-stellige Tafeln, and published many works
* on orbit determinations, eventually directing the Leipzig Observatory,
* where he succeeded Bruns in 1920.
*      An interesting piece of work.  He observed to just past 88° ZD.
* His discussion of the expansion coefficient of air is spoiled by his
* assumption that the refraction is proportional to the density at all
* zenith distances; but at least all the data are published here.
*      He considers (pp. 212 ff.) the lapse rate, and even a nocturnal
* inversion of 2° C at 200 m height. Using a procedure much like
* Wegener's [did Weg. read this?], he numerically integrates the lower
* region, divided into layers 10 m thick, and then adds the refraction
* of the atmosphere above from tables. The effect of the inversion is
* inappreciable to 80° ZD, but reaches 16" near 88° . [p. 218]
*      From his failure to distinguish between Ivory's and Gyldén's
* theories, he concludes that ". . . der Einfluss der obersten Schichten bis
* zu Zenitdistanzen von 88° ein nahezu verschwindender ist; für sie
* sind lediglich die unteren Schichten massgebend und in diesen genügt
* die Ivory'sche Formel." [p. 217]
*      He uses Kayser & Runge's dispersion curve for air to find the
* effective wavelength of observation from the refraction constant (p. 222)
* and finds about 600 nm, "etwa auf die Mitte zwischen den Linien C und D,
* die an der Grenze von gelb und roth liegt. Ob die Ursache hievon in der
* selectiven Extinction des Lichtes in der Atmosphäre zu suchen ist, wonach
* besonders bei starkem Wasserdampfgehalt der Luft die blauen Theile des
* Spectrums stärker absorbirt werden als die rothen, muss bei dem Mangel
* an exacten Messungen hierüber dahin gestellt bleiben. Die hiesigen
* Wahrnehmungen würden dafür sprechen, denn das Spectrum der Sterne
* zeigte stets nur gelb und roth, und nur ein einziges Mal . . . auch blau."
*
* Full title:
*
*        Beobachtungsergebnisse des Repsold'schen Meridiankreises der
*                                                 K. Sternwarte zu München
*                                                              I. Theil
*
*
*                                                        Untersuchungen
*                                                              über die
*
*                                                 astronomische Refraction
*
* mit einer Bestimmung der Polhöhe von München und ihrer Schwankungen
* vom November 1891 bis October 1893 und einem Katalog der absoluten
*                              Declinationen von 116 Fundamental-Sternen
*
* The manuscript is dated "April 1895"; Roy. Soc. Cat. gives "[1896]".


G. C. Comstock
“On the application of interference methods to the determination of the effective wave-length of starlight,”
Ap. J. 5, 26–35 (1897).

* Comstock's second paper
*      NOTE: This is the earliest mention of the term "effective wavelength"
* in the ADS lists.
*      Here, after citing the first paper, he grants that "since the colors
* . . . will usually be quite different from the pure spectral colors, the
* average wave-length of the light of a given star must not be assumed to
* be even approximately determined by matching its color . . . with that
* of a definite part of the solar spectrum, and the same holds true,
* a fortiori for the effective wave-length, if we understand by that
* term the wave-length of that part of the stellar spectrum which the
* observer adopts as determining the position of the star and upon which
* his attention is concentrated in the observing." (This definition is
* quoted by Cherubim.) Comstock now says his previous conclusion that
* the color effect corresponded to dominant wavelengths was erroneous.
*      Note BRIGHTEST PART criterion: "The term effective wave—length as
* above defined is nearly equivalent to the wave-length of the (visually)
* brightest part of the star’s spectrum, it being assumed that in
* ordinary visual observations the observer’s attention is concentrated
* upon this part of the spectrum into which the atmosphere transforms the
* stellar image." (p. 27)
*      Citing Schwarzschild's paper, he applies the interference method,
* but with two slits instead of a grating, and choosing their widths to
* suppress the even-numbered orders. (pp. 28-29)
*      On p. 29, he again emphasizes that ". . .  for those parts of the pattern
* in which the fringes are indistinguishable in appearance from faint stars,
* e. g. , of the tenth magnitude, . . . the total amount of light here present
* is so small that only the brightest part of the spectrum is visible,"
* so that ". . . the value of \lambda corresponding to the point of maximum
* brightness in the spectrum, i. e. , the effective wave-length" can
* be determined.


L. de Ball
“Über den Einfluß der Refraktion auf die Distanz zweier Sterne,”
A. N. 164, No. 3934, 373–186 (1904).

* LEO DE BALL sub-file
*
* L. de Ball wrote a series of papers on refraction in 1902-1906.
*
* The 1904 paper is a simplification of the earlier one with the same
* title in A.N. 158,Nr.3774 (1902). This is just a study of differential
* refraction due to the differennt ZDs of the two stars.
*      Our only interest here is the use of the derivative of the tangent
* of the zenith distance; he derives the sec4 relation. Mentions, but
* does not cite, Hansen's refraction formula.


L. de Ball
“Über den Einfluß des Dampdrucks auf die Refraktion,”
A. N. 169, No. 4044, 179–186 (1905).

* His 1905 papers are identical, except for language; the first (dated
* Mai 25.) is in A.N.; its English translation is dated June 15. This
* is all about the seasonal systematic errors caused by ignoring the
* small but significant effect of ignoring the effect of water vapor
* on both the mean molecular weight (and hence the scale height) and
* the refractivity of air. The theory is based on Radau's 1889 paper.
*      An interesting sidelight is that the "3/8" that often appears in the
* water-vapor term is 1 minus the ratio of mol.wts. of H 2O and dry air
* (here taken to be 0.622), or 0.378 .


L. de Ball
“On the influence of vapour pressure on refraction,”
MNRAS 65, 750–755 (1905).

* This is the exact English translation of the previous entry.


L. de Ball
“The value of the constant of refraction,”
MNRAS 66, 76–79 (1906).

* de Ball's refraction-constant discussion
*      Here the "constant" is the factor before the whole series of tangent
* terms, rather than just the coefficient of the first term in the
* r = A tan z - B tan3 z two-term version.
* de Ball's aim is to reconcile various "constants" used at different
* observatories -- some of which included water vapor effects, and some did
* not. The comparisons are reduced to the form given in his 1905 MN paper
* (above) which is obliquely mentioned but not explicitly cite, complete to
* the "3/8" fraction.
*      This seems to be the work that Nefed'eva (1975) criticized.  It
* cites Courvoisier's paper in Heidelberg Pubs., vol. 3. (1904); Nefed'eva
* phonetically Russianizes his name, which became "Kurvuav'e" in
* transliterating back to Latin letters.


H. H. Turner
“An empirical law of astronomical refraction,”
M. N. R. A. S. 68, 496–510 (1908).

* H.H.Turner's paper. GOOD Cassini derivation.
* Models the refraction with 2 or 3 homogeneous layers. Largely an
* exercise in numerology. He derives the Cassini model simply.
*      "It does not seem likely that these figures can have any physical
* interpretation. They merely emphasize the fact that a serious part
* of the refraction takes place near the Earth, and not high in the
* atmosphere." (p. 509; quoted approvingly by Plummer, 1931)
* He continues: ". . . it will be seen how rapid is the increase in
* importance of the inner shells as we approach the horizon. . . .      This
* suggests that any influence of meteorological phenomena on astronomical
* refractions must be sought at large Z.D.'s, which is in accordance
* with experience."
* Cites Bakhuyzen.
* The paper was read at the May 8 meeting of the RAS; see
*                    Obs. 31, 225-228 (1908)
* for the interesting discussion at the meeting.


H. Raper
The Practice of Navigation and Nautical Astronomy, 19th edition
(J.D.Potter, London, 1908).

* Lieutenant Henry RAPER's classic
* Nothing here on green flashes, so it's put in General Refraction.
* Paragraph 205 (p.60) explains DIP.
* Paragraph 207 (p.61) explains TERRESTRIAL REFRACTION, and that it
* ". . . is, on the average, about 1/14 of the intercepted arc, or
* distance in miles . . . . This proportion, however, is subject to great
* irregularity, and varies between 1/3 and 1/23 of the intercepted arc.
* The apparent elevations of the summits of high land are thus subject to
* great variations, depending on particular states of the air.
* Paragraph 208 (p.61) explains the temperature effects: "When the sea
* is warmer than the air, the horizon appears below its mean place
* . . . ; when the sea is colder than the air, the horizon appears above
* its mean place . . . ." [Parry is cited in a footnote.]
* Paragraph 209 (p.62) gives credence to claims of "a sensible change in
* the horizontal direction of objects", citing Nautical Mag. (1847).
* The effects of WAVES are discussed in Para. 545 (p.196), where
* Du Petit-Thouars is mentioned.
* The ellipticity due to differential refraction is mentioned in
* Paragraph 852 (p.313).


A. Bemporad
“La teoria della refrazione astronomica direttamente fondata sui risultati della fisica dell'atmosfera,”
Atti della Accademia gioenia di scienzi naturali in Catania, Ser. 5, Vol. 3, Mem. V , (1910).

* BEMPORAD's refraction-calculation paper
*      This paper gives his transformation of the refraction integral.
* He argues that the previous analytic models of the atmosphere are
* unrealistic, and that refraction should be integrated numerically on
* the basis of measured atmospheric profiles. These were known only up to
* about 20 km in his day; but he finds that quite diverse assumptions about
* structure above 20 km leads to inappreciable differences in refraction.
* So he is forced to conclude that ". . . seeing that the most rigorous
* calculations and the most minute observations of the refractions at the
* horizon would not even allow to decide if the atmosphere be 250 or 600
* km high, it seems very problematic that these theories can, as was once
* hoped, cast light on the constitution of the atmosphere at great heights."
* So he gives only the structure tables for 4 seasons (and the yearly
* mean), "to communicate the definitive results afterwards."
*      (Cf. his 1907 paper in Mem.Soc.Spett.)


C.-V.-L. Charlier
“Sur la réfraction terrestre et la constitution de l'atmosphère,”
C. R. 157, 831–834 (1913).

* Charlier's attempt to formulate the inverse theory via integral eqns.
* Note that his new variable x is the reciprocal of nR. Its monotonic
* decrease with R (here called rho) requires the usual condition,
* and a mention (but not citation) of Schmidt's theory.


T. A. Banakhevich
“Tri eskiza po teorii refraktsii,”
Ucheniya Zapiski [Kazan] 82, No. 10, 1–27 (1915).

* Banakhevich's "Three Sketches"; the last devotes a page to GREEN FLASH
* Of these, the first and third are most interesting.
*      The first is "The influence of temperature inversions on refraction".
* It starts out:
*      "All tables of refraction are based on the assumption that the
* temperature decreases with height. But really, as is well known at
* the present time, so-called inversions of temperature are frequently
* observed in the atmosphere at night . . . . We are not speaking here of
* the inversion at a height of about 10 km (stratosphere), discovered by
* Tesseren de Borom [Teisserenc de Bort], which can have no significance
* for the question of refraction (cf. Fabritius - Astronom. Nachr. V. 93,
* p. 17-18); we mean the normal nocturnal inversion of temperature in the
* first kilometer of height." He cites Bauschinger's 2° inversion at
* 200 m, but thinks it isn't as important as Bauschinger did. (In
* particular, it isn't important for the refraction constant.) He shows
* that Bauschinger's inversion has negligible effect out to 84° ZD,
* and is only 3.5 seconds at 87° 56' -- values about an order of
* magnitude smaller than Bauschinger's.
*      The second essay deals with the ZD dependence of image motion.
* It's basically a statistical analysis of meridian-circle errors; he fits
* an empirical formula, but unfortunately chooses sec Z instead of airmass
* as the independent variable, even near the horizon. So it's largely an
* exercise in numerology.
*      The third essay is "Dependence of the refraction on its constant",
* by which he means the refractivity, and the question of its dependence
* on density. There is a good comment on p. 22: "The majority of authors
* assume, without direct explanation, that R is proportional to 2c [i.e.,
* the constant in the refractivity formula]." Gyldén and E. Oppolzer are
* criticised for doing this. He has a nice table on p. 26 showing how
* much larger the fractional change in refraction is than the fractional
* change in surface pressure (keeping the temperature distribution fixed).
* It amounts to nearly 10% for a refraction of 35'.
*      This is followed by remarks on the wavelength dependence of
* refraction: the refraction varies more near the horizon than does the
* refractivity. "This question has interest for the explanation of the
* so-called green light [i.e., the GREEN FLASH] or blue light at sunset
* and sunrise." So he calculates the duration of green after red at sunset
* as 1.75 seconds of time (at 45° latitude), and 3.18 sec. for blue.
* [This is the ONLY calculation I have found that takes the nonlinearity
* of the refraction into account!] He concludes that the length of the
* atmospheric spectra must be 1/120 of the whole refraction, between red
* and green, or 1/67 between red and blue.
* Cites Fabritius, Bauschinger, etc., and refers to Radau's tables.
* Of course this uses the old, pre-Revolutionary alphabet.


G. C. Comstock
“The atmospheric refraction,”
Pop. Astron. 37, 222–231 (1929).

* Comstock's Presidential address at the 41st meeting, Dec. 1928
* (He was president of the AAS from 1925-28.)
* A good review of refraction, from the standard point of view.
* He starts by quoting Newcomb's infamous remark. Many well-known works
* are mentioned, but there are no references. He gives special attention
* to the works of Radau, de Ball, Emden, and Harzer. He recognizes that
* refraction "is almost wholly due to the lower atmospheric strata."
*      "Harzer’s refractions may be described as theoretical results whose
* relation to practical astronomy remains to be determined. A provisional
* comparison between them and the tables of Gyldèn and Radau shows a very
* satisfactory agreement for normal circumstances and moderate zenith
* distances. It should not escape notice that Harzer’s appeal to physics
* and meteorology, as constituting in themselves and without reference
* to astronomical observation an adequate basis for refraction tables,
* has in some respects greatly complicated the problem in hand. In lieu
* of the two, three, or four parameters used by his predecessors, Harzer
* finds need for twice as many. For the computation of his numerical
* refraction in a given case there is required a process much longer and
* more burdensome than that hitherto employed, e.g. these new refractions
* commonly involve and depend upon not only the current temperature and
* barometric pressure at the time and place of observation but require also
* such further elements as the time of day at which the observation was
* made (diurnal variation), the time of year (annual variation), color of
* the star (dispersion effect), wind velocity (effect of, upon barometric
* pressure), and discrimination may be required between observations made
* upon opposite sides of the zenith. The astronomer with long routine
* experience with meridian observations may be unpleasantly impressed by
* such an array of new factors to be considered . . . ." (p. 226)
*      On the next page, he supposes that the Oriani-Laplace theorem still
* applies in the presence of turbulent fluctuations and waves. He also
* mentions possible effects of tilts and atmospheric tides.
*      Then comes a discussion of navigation, and variable dip; he mentions
* the Carnegie observations at sea. As this was done when the conflicting
* evidence had not yet been rationalized by Freiesleben and by Hasse,
* he thinks more observations are needed: "An extended series of
* observations of the time of sunrise or sunset at the sea horizon could
* be made to furnish much pertinent information . . . ". (p. 230)
*      Reprinted in Proc.AAS,vol.6, pp.214-223 (1931)


A. Fletcher
“Note on astronomical refraction,”
M. N. R. A. S. 91, 559–562 (1931).

* Alan Fletcher's first paper
* This seems to be his very first publication, while he was still Smart's
* graduate student. The Cambridge U. library shows the full text (evidently
* never published) was 1/3 of his Ph. D. thesis (1935).
*      Some good things here: he presents an explicit formula for the
* refraction at all zenith distances for a generalized Laplace-type model
* atmosphere in terms of the error function. Unfortunately, most of the
* details are suppressed, so that the answer appears pulled out of a hat.
* His notation is: µ is the index of refraction; ν is the refractivity
* (µ -1); ν' = ln µ = ν - ½ν2 . . . "and differs little from ν" while
* making the notation more confusing. A zero subscript "indicates values
* at the place of observation." Then:
*      "It is well known that the refraction at a given moderate zenith
* distance depends for all practical purposes on the two independent
* variables ν0 and H0, the latter being the ratio l0/r0 of the height
* l0 of the homogeneous atmosphere to r0" [i.e., the radius of curvature
* of the Earth.] He then attributes the 2-term tangent expansion to
* Lord Rayleigh -- who does indeed derive it simply at the end of his 1893
* paper in scintillation, but who also attributes it to Laplace. He says
* "no reasonable theory differs from [this] by more than a few
* thousandths, hundredths, tenths of a second at ζ = 60°, 70°, 75°
* respectively. . . .      At large zenith distances the refraction depends to
* an appreciable extent, and beyond ζ = about 85° to an undue extent for
* practical purposes, on the particular function . . . used [to represent the
* model atmosphere], and no introduction of a third independent variable
* suffices to the same extent; nevertheless, the refraction depends mainly
* on ν0, H0 and the value of dµ/dr in the first few kilometres above
* the ground . . . ."
*      He even deals with the choice between the Laplace and Gladstone-Dale
* formulae for the refractivity in terms of the density, and introduces a
* parameter k that "would be 1/2 or 0 if ρ were proportional to µ2 - 1
* or µ - 1 respectively." (A nice touch.)
*      Unfortunately, he accepts Radau's (1889) treatment of water vapor,
* which requires its mixing-ratio to be constant throughout the
* atmosphere. So his simplification of Radau's results is not all that
* useful. However, he has a good comment on atmospheric structure:
* "For ζ > 85° it becomes of decreasing importance that our fictitious
* atmosphere shall have the right H0, and of increasing importance that
* it shall have the right µ in the first few kilometres; . . . beyond ζ =
* 85° or even less the ability of any theory to predict the amount of
* refraction rapidly dwindles."
*      The scans at ADS lack a few glyphs.  Those in the text on p. 562
* seem to be due to pieces of type that fell out of the forms; they
* are also missing on that page of the copy in your library.
*      The l.c. "l" that is missing on the left side of Eq.(15) is a typo,
* corrected in the Erratum on p. 1009.


H. C. Plummer
“On astronomical refraction,”
M. N. R. A. S. 92, 25–36 (1931).

* Plummer's paper (cited by Horak)
* "The difficulties and complexities of the treatment of astronomical
* refraction on the classical lines laid down by Bessel are well known.
* They are not made more attractive by the fact that the structure of the
* atmosphere . . . is certainly different from what it was formerly supposed
* to be. Hence any attempt to simplify the theory may be justified."
*      The smallness of the variation of nR through the atmosphere gives
* ". . . evidence that r/a differs little from 1, and that the upper
* atmosphere plays a very small part in astronomical refraction."
* He then investigates the assumption that r dn/d(nr) is constant,
* which leads to the Bradley/Simpson model, which gives a horizontal
* refraction about 20% low -- not surprising, he says, as d(ln n)/d(ln nr)
* must go to zero. But simple attempts to model this fail; so he then
* tries the sum of two atmosphere models with different scale heights --
* which he identifies (!) with oxygen and nitrogen. -- cf. Turner (1908)
* (whom he cites). The paper degenerates into numerology.


Z. Horák
“Sur la théorie de la réfraction astronomique,”
A. N. 247, No. 19, 345–350 (1933).

* Horak's first paper
* Here he revives Laplace's notion of orbital motion as an analogue of
* refraction, and finds hyperbolic orbits that reproduce the tables out
* to 83° ZD (!) [Hardly surprising, as his model is similar to the
* Simpson/Bradley/Mayer model.] He notes that the radius of curvature
* of a horizontal ray is about 8 times that of the Earth.
*      Cites Radau, but (strangely) not Laplace.
* Issue Nr. 5923 closed Jan 25. 1933.


Z. Horák
“Sur une formule des réfractions normales,”
A. N. 248, No. 23, 405–410 (1933).

* Horak's second paper
* He introduces the nice form R = (ln n0)(sin Z)/M, and discusses the
* denominator function M, which is roughly cos Z. Noting that M = cos Z
* corresponds to the flat model, which gives too much refraction, and that
* Cassini's model gives M = sqrt(cos2 Z + \delta), which gives too little,
* he proposes to interpolate between them. The straight mean corresponds
* to Mayer's formula, which still gives too little near the horizon.
*      Then he suggests using a weighted mean, which helps; but he gets
* carried away with the idea of adding some constants to the numerator
* and denominator to get an even better fit to the *mean* refraction --
* instead of keeping the analytical values of the parameters, which would
* have given a more useful result. Still, there are useful references
* (including Radau).
* Issue Nr. 5951 closed Mai 16. 1933.


P. de Vanssay de Blavous
“On refraction and refraction tables,”
Hydrographic Review 21, 17–36 (August, 1944).

* Ingénieur Hydrographe Général Pierre de Vanssay de Blavous
* GOOD REVIEW of TABLES for MARINERS
*      This is a thorough review of refraction and dip tables, and also tables
* for correcting geodetic refraction. Both the histories of the tables and
* the bases of their computation are fully described, from early days.
*      Many references to little-known tables for mariners & geodesists.
*      This is now called the International Hydrographic Review.
* Available at:
* https://journals.lib.unb.ca/index.php/ihr/article/view/27073/1882519828
* PDF: dVdB1944.pdf


R. Meyer
“Atmosphärische Strahlenbrechung,” in Handbuch der Geophysik , F. Linke and F. Möller, eds., Band 8, Physik der Atmosphäre I
(Gebr. Borntraeger, Berlin, 1942-1961), Kap. 13, pp.769–821.

* (in Meyer's 1935 GF file) GOOD REVIEW ARTICLE
* (published in sections dated 1955 and 1956)
* geometric interpretation of the refractive invariant (p.774)
* nice proof of "Fraser's theorem" (pp.776/7 and 800)
* The GF section (pp. 804-806) reproduces Lagaaij's drawings in color.


C. A. Whitney and G. Veis
“A flashing satellite for geodetic studies,”
SAO Special Report , No. 19, 9–20 (1958).

* Chuck Whitney & George Veis introduce the term "parallactic refraction"
* In a 3-sentence paragraph on p. 12 we see:
* ". . . there is a small effect, which might be called parallactic
* refraction, arising from the fact that the satellite is much closer than
* the stars."
* This was later reprinted in:
* Smithsonian Contributions to Astrophysics, Vol. 6, pp.17-24 (1963)
* (both available from ADS)


L. Oterma
“Computing the refraction for the Väisälä astronomical method of triangulation,”
Informo , No. 20, 1–28 (1960).

* Liisi Oterma's treatment of parallactic refraction
* Here parallactic refraction is called "rocket refraction" as opposed
* to astronomical refraction. The approach is the usual series expansion,
* following Radau; I think it's not very different from the Saastamoinen
* papers. There are numerical tables that extend to 85 deg. ZD.
* "Informo" was published in Turku, Finland.
* (Cited by Bruin)


F. Wünschmann
“Über den Einfluß nicht-statischer atmosphärer Schichtungen auf die astronomische Refraktion,”
Mitt. Astron. Ges. 1963, 134 (1964).

* only a 1-line abstract, though listed by AJB -- useless
* The full paper was never published, nor does the author ever appear in
* the Citation Index. But his 1938 paper in Gerl. Beitr. Geophys. was
* cited by Sugawa (1956).


J. Saastamoinen
“Contributions to the theory of atmospheric refraction^{(1)},”
Bull. Géodésique , No. 105, 279–298 (Sept., 1972).

* SAASTAMOINEN's papers in BULLETIN GÉODÉSIQUE (1972)
* A gross overdevelopment of the series-expansion approach, with some
* conceptual errors: ". . . it follows from the law of Gladstone and
* Dale that the height integral . . . of the atmospheric refractivity . . .
* is directly proportional to the ground pressure. The refractivity
* integral, therefore, can be determined without detailed knowledge of
* the height distribution of the refractive index . . . ." (p. 279)
* He carries out the series to the tan11 power term, but then substitutes
* approximations for the lower-order ones, beginning with tan3 z.
* (The approximations either assume n = 1, or r/r0 = 1; see p. 281)
* Vertical structure in the lower atmosphere is brushed aside: "But since
* only a small contribution to these integrals comes from the lower levels,
* it will be quite sufficient merely to extend the constant temperature
* gradient of the free troposphere down to the ground level, neglecting
* the small error thus involved." (p. 291)
* The peculiar-looking refraction constant in the abstract (cf. pp. 386
* and 388 of the second part) is due to having divided out T0/p0.
* NOTE: Bull.Géod. was issued in about 4 numbers a year from its founding
* in 1922 to WW II. The issues were numbered and paginated separately.
* After No. 76 (1941/42), a New Series began, ending with No. 118 (1975).
* After that, there are annual volumes -- beginning with Vol. 50 in 1976!
* In 1996, Bull.Géod. merged with manuscripta geodaetica to form
* the Journal of Geodesy (which continued the volumes of BG).


J. Saastamoinen
“Contributions to the theory of atmospheric refraction (2^{ème} Partie) ,”
Bull. Géodésique , No. 106, 383–397 (Dec., 1972).

* Saastamoinen, part 2
*      On the very first page, he assumes a "standard wavelength of 0.574
* microns adopted by Jordan-Kneissl [1970] and others for the average
* starlight". [This refers to the 1970 edition of "Handbuch der
* Vermessungskunde", by Karl Ramsayer.]
*      Then he adopts the obsolete 1966 Edlén dispersion formula (already
* shown to be in error by Owens (1967). (p. 384) [Actually, he uses
* the 1-term approximation of the Edlén formula for 0.405 to 0.705 µ
* that is given in the first line of Table 4 of Edlén's 1966 paper.]
*      This is followed by the "Reduction of Local Gravity to the Centroid
* of the Atmospheric Column" used later by Sinclair. But this centroid
* is only applicable to the region above 70° Z.D. where structure is
* insignificant. Eq.(35) on p. 385 is used in the RGO refraction program.
*      ". . .  any significant variation of the tropospheric contribution,
* whether of regional or seasonal origin, is largely compensated by the
* stratosphere . . . ." (p. 386)
*      Worst of all: "The most direct method of determining the apparent
* colours of the stars is by visual colorimetry, notably employed by
* H. Osthoff [1900] . . . . In the Osthoff catalog, which still [sic!]
* provides a chief source of information . . . ." (p. 388)
*      At the bottom of p. 389 he briefly mentions the effect of atmospheric
* reddening on the effective wavelength.
*      More interesting is his attempt to estimate TILT of the isopycnic
* surfaces from meteorological data (pp. 390 ff.) He finds 1' 52".
* He also claims (p. 395) that tilts of "a few degrees" occur in the
* boundary layer near coasts, due to the land-breeze/sea-breeze effect.
* "Horizontal temperature gradients in the surroundings of the observing
* station probably make one of the most important sources of error in the
* determination of refraction." But his simple model considers only the
* latitudinal gradient of mean temperatures, like Glazenap (1881).
*      ". . .  refraction errors will not be present in ordinary inversion layers
* which lie horizontal, such as the nocturnal ground inversions which are so
* typical of conditions best suited for astronomical observations." (p. 396)
* [But this neglects the effects of wind.]
*      The actual title shown in the PDF on the Bulletin Géodesique pages of
* Springer's website is:
*
*      "Introduction to practical computation of astronomical refraction"
*
* [This is sometimes listed as Journal of Geodesy 46, No.4 (Dec. 1972).]


J. Saastamoinen
“Contributions to the theory of atmospheric refraction. Part II. Refraction corrections in satellite geodesy,”
Bull. Géodésique , No. 107, 13–34 (Mar., 1973).

* Saastamoinen, part 3
* This is all about parallactic refraction, range delays, and the like.
*      On p. 14, he adopts a wavelength of 0.554 microns for "white stars".
* On p.32, he uses a wavelength "of 0.6943 microns for a ruby laser."
* [This is sometimes listed as Journal of Geodesy 47, No.1 (Mar. 1973).]


A. I. Nefed'eva
“Humidity reductions in astronomical refraction tables,”
Sov. Astron. 18, 804–805 (1975).

* A. I. NEFED'EVA discusses the humidity corrections
*      This is the English translation of the paper in Astron.Zh.51, 1346-1347
* (1974). See the translator's note about earlier related papers. The
* translator did not recognize Courvoisier's name, printing "Kurvuaz'e".
* The translation also gives Gyldén's paper the date 1968; it's 1868.
*      Everyone seems to have done it incorrectly.  The 4th edition of the
* Pulkovo Tables (1956) was farther from the truth than the 3rd (1930).
*      "At zenith distances of 88° and 89° the ray curvature is affected very
* strongly by the lowest air layers, where the decline in air density is
* retarded because of the rapid decrease in humidity with height. . . .
* During the cold season an inversion occurs in the layer near the ground,
* while above there is a sharp drop in humidity, . . . .
*      "Thus humidity corrections can be computed to high accuracy for a given
* time only if the distribution of water vapor with height is known."
*      This mentions de Ball's attempt (1906) without citing it.  The
* historical review is informative.


A. A. Mikhailov
“On the correction for astronomical refraction,”
Sov. Astron. Lett. 1, 213–214 (1975).

* Strange note: attributes Oriani's theorem to Newcomb; raises issues
* already raised by Biot about the distance to the upper atmosphere
* when looking near the horizon: "Beyond 60°, however, the state of
* the atmosphere at heights of 10 km and greater begins to exert an
* increasing influence . . . ."
* How did this get published in a Letters journal?
* Original version was Pis'ma Astron.Zh. 1, 46-48 (Oct. 1975)


E. Livieratos
“On the Refraction Problem of Ground Target Photography with Stellar Background as Applied in the 3-D Terrestrial Triangulation by Using Pure Satellite Triangulation Methods,”
Bollettino de Geodesia e Scienze Affini 35, No. 4, 425–432 (1976).

* Another attempt to relate terrestrial and astronomical refraction
* (cf. Faye!)
* Thanks to William M. Robertson for a copy!


I. G. Kolchinskii
“Zametki o teoreme Oriani-Laplaca v teorii refraktsii,”
Astrometriya i Astrofizika (Kiev) 38, 96–103 (1979).

* Kolchinskii on Oriani's theorem
* A clear explanation and derivation, with some discussion of claims
* that the theorem is not adequate to calculate refraction out to 70°.
* He shows that it is -- cf. Green's book (1985).
* Cites Laplace, Bruhns, and Newcomb.


A. I. Nefed'eva
“On the values of the refraction constant adopted in different tables,”
Sov. Astron. 24, 504–505 (1980).

* Nefed'eva infers wavelengths from adopted refraction constants
* [translation of A.Zh.57,878-880(1980).]


G. G. Bennett
“The calculation of astronomical refraction in marine navigation,”
J. Inst. Nav. 35, 255–259 (1982).

* MEAN REFRACTION FORMULAE
* See the comment on this below.


R. Fukaya and M. Yoshizawa
“A numerical approach to the determination of astronomical refraction,”
PASJ 37, No. 4, 747–762 (1985).

* Fukaya & Yoshizawa confirm Nefed'eva's result
* "We conclude that the true effective wavelength of the Pulkovo table is
* close to 595 nm. This conclusion is in good agreement with Nefed'eva's
* (1974)." [p. 756]


Th. Saemundsson
“Atmospheric refraction,”
S&T 72, 70 (1986).

* An inverse for Bennett's formula
* In Roger Sinnott's "Astronomical Computing" column.


H. Yan
“A new expression for astronomical refraction,”
AJ 112, 1312–1316 (1996).

* Recognizes the importance of tropospheric lapse rate; says that height
* of tropopause is also important.
* Probably this should be Hao-Jian Yan, but the name is printed as "Haojian".


R. C. Stone
“An accurate method for computing atmospheric refraction,”
PASP 108, 1051–1058 (1996).

* STONE uses Green's approximation, with the Owens refractivity formula


A. D. Wittmann
“Astronomical refraction: formulas for all zenith distances,”
AN 318, 305–312 (1997).

* Wittmann's comparison of approximate formulae (cf. Fletcher, 1952)
*      He uses the old  (1953) Edlén dispersion formula, and H = 7.632 km
* as the height of the homogeneous atmosphere. On p. 308, he uses the
* numerically unstable solution of a quadratic equation in deriving his
* "new formula" (eq. 10).
*      Refraction below the astronomical horizon is treated superficially;
* giving constants for this to 4 significant figures is absurd.
*      Parallactic refraction is discussed in section 5 (p. 310).  He cites
* the 1838 paper by Hansen here.


P. D. Noerdlinger
“Atmospheric refraction effects in Earth remote sensing,”
ISPRS J. Photogrammetry Remote Sensing 54, 360–373 (1999).

* Peter Noerdlinger's interesting paper on satellite geodesy & sensing
* His main result uses the geometric invariant to locate the *apparent*
* target point on Earth as seen from the satellite. Note the warning
* that topography effects are much larger!
* ISPRS = International Society for Photogrammetry and Remote Sensing
* Thanks to Peter Noerdlinger for a reprint!


S. Y. van der Werf
“Ray tracing and refraction in the modified US1976 atmosphere,”
Appl. Opt. 42, 354–366 (2003).

* SIEBREN VAN DER WERF's refraction program and study
* "There have been many attempts . . . to relate refractions, obtained
* by accurately timing the moment of sunset, with the predictions of
* atmospheric models. This example shows that such studies are sensitive
* to the temperature gradient just above ground or sea level, rather than
* to the global features of the atmospheric model." [Cf. Fletcher's (1931)
* "It is well known. . . " comment.]
*      "This temperature profile is characterized by piecewise constant
* temperature gradients." (p. 356)
* This paper gives the details of his method of integrating the refraction;
* see his 2008 "Comment" paper for further details.
* He has an interesting discussion of the water-vapor corrections, too.
*      Note the erratum on Siebren's website: "In eq. 21 the constant
* 1167917 should be replaced by 167917".
*      Cites Fletcher (1952), but not Fletcher's 1931 paper.


A. T. Young
“Sunset science. IV. Low-altitude refraction,”
Astron. J. 127, 3622–3637 (2004).

* Paper IV
* Where (in the atmosphere) does the refraction come from?
* Shows why structure is really not important out to 75 or 80° Z.D..
* Refutes the errors of Newcomb, O'Connell, etc.
* Cites Biot's invention of the transformed integral.


G. H. Kaplan
Atmospheric Refraction of Light from Nearby Objects in Space
(Defense Technical Information Center, Fort Belvoir, Va, 2014).

* George Kaplan's treatment of parallactic refraction, using the
* old homogeneous model (cf. Bouguer, 1753).
*       Available at https://apps.dtic.mil/sti/pdfs/AD1094247.pdf
* Dated 2014 June 10.


Richard F. Olson , Jr.
“Computing the total atmospheric refraction for real-time optical imaging sensor simulation,”
Proc. SPIE Vol. 9452 , 945211–1 (2015).

* Richard F. Olson, Jr. describes a method based on LOWTRAN 6
*      He gives the method, but not the source code used.  Refractivity is
* the "new" (1966) Edlén formula. The 6 model atmospheres from the
* LOWTRAN-6 report are used. He uses N for (n - 1), and C for
* the refractive invariant, and Thomas & Joseph's Chebyshev quadrature.
* The RGO method is used to show agreement to 1 arcsec with LOWTRAN,
* using 1600 quadrature modes. An example of PARALLACTIC REFRACTION is
* shown.
*      Citations include Ciddor, Dan Bruton's thesis, Smart, TN 63, etc.
*      This is also
* "Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XXVI."
* edited by Gerald C. Holst, Keith A. Krapels.
* DOI: 10.1117/12.2179771


H. Labriji , O. Herscovici-Schiller, and F. Cassaing
“Computation of the lateral shift due to atmospheric refraction,”
Astronomy & Astrophysics 662, A 61, 1–15 (2022).

* RAY SEPARATIONS
* some discussion of parallactic refraction and meteors; mostly
* numerical results. Their "lateral" means "vertical".
* DOI: https://doi.org/10.1051/0004-6361/202142338



*** POLYTROPES and PIECEWISE POLYTROPIC REFRACTION FILE ***

W. Fabritius
“Die astronomische Refraction bei Annahme einer constanten Temperaturabnahme,”
A. N. 93, 17–28 (1878).

* (see also Ivory, 1821, 1824, 1825; Bauernfeind, 1864; Radau, 1882.)
* (also Brocks, 1949)
*
* First use of linear temperature gradient after Bauernfeind (1864)?
* Shows the negligible influence of the upper atmosphere:
* "Auf diese Betrachtungen gestützt, darf man also den Schluss ziehen,
* dass die Constitution der Atmosphaere in den höchsten Schichten ohne
* jeden merkbaren Einfluss selbst auf die Horizontalrefraction sein wird."


Arnaud
“Mémoire sur la Réfraction Atmosphérique,”
Mém. Acad. Sci. Lyon , series 3, 8, 163–178 (1905).

* ARNAUD's papers on astronomical refraction
* Good, clear exposition. He is mainly interested in terrestrial
* refraction, but also deals with astronomical. Good discussion of
* ray curvature and lapse rate.
* Full title is Mémoires de l'Académie des sciences, belles-lettres et
* arts de Lyon. Sciences et letters.


Arnaud
“Sur la réfraction astronomique au voisinage de l'horizon,”
C. R. 155, 612–615 (1912).

* Begins with a formula for ray curvature that involves lapse rate


Arnaud
“Sur la réfraction astronomique sous un angle quelconque,”
C. R. 156, 1962–1964 (1913).

* Astronomers should avoid the region near the horizon
* Finds that beyond 87°, "Il faudrait faire entrer dans les formules
* une variable nouvelle θ, valeur moyenne de (-dt/dz). Les Tables
* devendraient ainsi très compliquées et sans utilisation pratique, étant
* donné que les observations sont rendues incertaines par les phénomènes
* de diffraction.
* Cette région doit être considerée comme interdite aux observations
* de précision."


R. Emden
“Beiträge zur Thermodynamik der Atmosphäre. 1. Mitteilung: Über polytrope Atmosphären,”
Met. Zs. 33, Nr. 8, 351–360 (1916).

* EARLY USE OF POLYTROPIC MODEL
* Robert Emden's first installment in Met. Zs. This is a clear and
* detailed exposition of the structure of a polytropic atmosphere,
* assuming a constant gravitational acceleration. All the classic
* power-law relations are derived. The polytropic index here is n ,
* which he calls its "Klasse".
*      On p. 353, he refers to the earlier mention of his model in Encyc.
* der Math. Wiss., Bd.VI, 1B, Heft 3.
*      On p. 354, he finds the lapse rate requied to produce constant density
* to be 34.2°/km (cf. Fabritius), and cites "Gaskugeln". On the next
* page, he points out that the index for an isothermal atmosphere is
* infinity. Eq. (18) shows that the height of a polytrope is (n+1) times
* the height of the homogeneous atmosphere. There is a nice table of the
* heights and lapse rates for 14 different indices from 0 to ∞ .
* Eqs.(19) give the formulae for the temperature, density, and pressure
* as functions of height, and he immediately shows that the limit for
* n --> ∞ is the exponential law of the isothermal model.
*      On p. 356, he proposes to replace a curve with a piecewise polytropic
* model -- "eine Sehnenzug" or string of chords -- as a better alternative
* to the "usual division into isothermal layers."
*      Then come examples of applications: the polytropic height formula
* instead of the isothermal one; he proposes a polytrope of index 4 [lapse
* rate 6.83 K/km] as a good barometric model. (The Standard Atmosphere
* proposal was still a few years off, remember.)
*      P. 358: he considers the thermal energy in a vertical column, and
* tries to apply this to storms, and to the radiation balance of the
* atmosphere -- again referring to "Gaskugeln".
*      The volume's Index bears the subtitle:
* LI. Band der ,,Zeitschrift der k. k. Österr. Ges. für Meteorologie''


R. Emden
“Beiträge zur Thermodynamik der Atmosphäre. II. Über die Ausbreitung des Schalles in einer windbewegten, polytropen Atmosphäre,”
Met. Zs. 35, 13–29, 74–81, 114–123 (1918).

* Emden's second installment has to do with sound propagation, both with
* and without winds. He makes some toy models with single polytropic
* layers, but admits that these are only rough approximations.
*      I list it here only for completeness; but there are nice ray diagrams
* that resemble optical ray traces for superior mirages (cf. p.81).
* (Note the hidden "shadow" zones, as in optical mirages.) In fact, on
* p.118, he comments on the multiple auditory detections of a single
* detonation, and compares these multiple images with those in mirages,
* citing Pernter's Meteorologische Optik.
*      Notice that the equations are continuously numbered through all 3
* installments; so the first one here is Eq.(27).
*      The first part is in the Jan/Feb issue (Nr.1/2); the second, in
* March/April (3/4); the third in Mai/Juni (5/6).


A. Toussaint
“Étude des performances d'un avion muni d'un moteur suralimenté,”
l'Aeronautique 1, No. 5, 188–196 (Oct., 1919).

* Origin of the STANDARD ATMOSPHERE explained, part 1
* Albert Toussaint's article on supercharged aircraft engines
*      The crudeness of his methods is indicated by his remark that his study
* had been done "en utilisant un abaque de comparaison des avions, qui
* évite des calculs nécessaires au passage des perfomances d'un avion
* ordinaire à celles d'un avion à moteur suralimenté." (and the graphs
* and nomograms in this paper.)
*      "De plus, notre attention avait été attirée sur les caractéristiques
* de l'atmosphère aux très hautes altitudes. et nous avons dû abandonner
* ls lois de Radau, admise jusqu'à ce jour, pour lui substituer une loi
* nouvelle plus conforme, espérons-nous, à la réalité des phénomènes."
* [This refers to Radau's 1901 "Tables Barometriques et Hypsometriques pour
* La Calcul des Hauteurs, Gauthier-Villars, 1901. See Minzer, 1966.]


W. R. Gregg
“The standard atmosphere,”
Monthly Weather Review 48, 272–273 (May, 1920).

* Origin of the STANDARD ATMOSPHERE explained, part 2
* "With the advance of aeronautics and the science of artillery, engineers
* and specialists in these fields have come to require a specific knowledge
* of the varying states of the atmosphere from the ground to very great
* elevations. This has led to the introduction of a conventional term
* commonly known as the standard atmosphere, which pretends to specify the
* normal or average condition. As is well known, the ‘standard atmosphere’
* is never found; that is to say, at no time or place do ‘standard’ or
* average conditions of all the meteorological elements at all altitudes
* simultaneously occur. Nevertheless, it is proper, and in certain fields
* (especially those of aviation and ordnance) it is necessary, to adopt
* so-called ‘standard’ values, and it is desirable to have these represent
* as closely as possible true mean values . . . ."
*      ". . .  Prof. Pericle Gamba . . .  has employed a large number of
* observations in several countries, resulting in a reasonably close
* representation of the average conditions of free air. Prof. Toussaint has
* utilized Gamba's analysis of the meteorological data in the formulation of
* a proposed interallied agreement as to the law of decrease of temperature
* with increase of altitude. Toussaint proposes the adoption of a ‘law’ of
* linear decrease of temperature with altitude, starting at a temperature
* of 15° C. at sea level and attaining -50° C. at an altitude of
* 10,000 meters. This ‘law’ is expressed by the formula t = 15 - 0.0065
* Z , in which t = temperature in ° C. and Z = altitude in meters.
*      "Although the adopted rate of temperature decrease is arbitrary,
* the resulting values nevertheless agree quite well with annual means as
* published by various investigators for Europe and the United States. . . .
* Prof. Toussaint remarks:
*      "It has been found preferable to take a linear law rather than to seek
* an equation approximate to Prof. Gamba's curve, for the following reason:
*      "In order to define the standard atmosphere, what is needed is not
* an exact representation of that curve, but merely a law that can be
* conveniently applied and which is sufficiently in concordance with the
* means adhered to. . . .
*      "The deviation is of some slight importance only at altitudes below
* 1,000 meters, which altitudes are of little interest in aerial navigation.
* The simplicity of the formula largely compensates this inconvenience."
*      Toussaint's paper is:
*
*       A.Toussaint
*       Étude des performances d'un avion muni d'un moteur suralimenté
*       l'Aeronautique 1,No.5,pp.188-196(Oct. 1919)
*
*      Dr. Willis Ray Gregg was the Chief of the Weather Bureau, 1934-1938.
* When he wrote this report, he was Chief of its Aerological Section.
* He was the author of the NACA "Standard Atmosphere", 1922.


W. R. Gregg
Report No. 147: Standard Atmosphere
(NACA, Hampton,VA, 1922).

* Gregg's "Standard Atmosphere" paper (NACA TR-147)
* The pages are numbered 397-409, so this is probably from the Annual Report
* for 1922 that would be dated 1923.
* Available at https://ntrs.nasa.gov/search.jsp?R=19930091212


R. A. Minzer
A Status report on atmospheric density models and observations
(GCA Corp., Bedford, Mass., 1966).

* Origin of the STANDARD ATMOSPHERE explained, part 3
* Gives all the gory details of the various atmosphere models.
* [https://ntrs.nasa.gov/api/citations/19670002897/downloads/19670002897.pdf]


R. Emden
“Beiträge zur Thermodynamik der Atmosphäre. III. Die astronomische Strahlenbrechung in polytropen Atmosphären,”
Met. Zs. 40, 173–177 (1923).

* EARLY USE OF POLYTROPIC MODEL
* The 3rd installment of Emden's series in Met. Zs.
*      Once again, the equations are numbered sequentially from the earlier
* installments; though only the first is mentioned here.
*      See also Brocks (1949) in terrestrial refraction file!


R. Emden
“Über astronomische Refraktion,”
A. N. 219, 45–56 (1923).

* ROBERT EMDEN's important paper on polytropes and refraction
* "Liegt eine beliebig temperierte Atmosphäre vor, so kann dieselbe stets
* in konzentrische Schichten geteilt werden, in der Art, dass innerhalb
* jeder Schicht der Temperaturgradient hinreichend genau konstant angenommen
* werden kann." (p.52)
*      Note that section 10 deals briefly with TILT of layers; he misreads
* Oppolzer's treatment in Valentiner, saying it gives numbers 3000 times
* too big! (He confuses the argument with the value in the ref. table.)
* In fact, his numbers are quite consistent with Oppolzer's.


B. Garfinkel
“An investigation in the theory of astronomical refraction,”
A. J. 50, 169–179 (1944).

* BORIS GARFINKEL's model (original)
* "The trajectory of light will be symmetric about the axis drawn to the
* ‘perigee’. . . . Consequently the refraction . . . along the entire trajectory
* can be obtained . . . ." -- so he shows that refraction below the horizon
* can be computed by doubling half the part below eye level. (p. 171)
*      This paper is an abstract of Garfinkel's Ph.D. thesis, done under
* Dirk Brouwer.


B. Garfinkel
“Astronomical refraction in a polytropic atmosphere,”
A. J. 72, 235–254 (1967).

* GARFINKEL's model (revised)
* His isothermal stratosphere begins at 11 km; this is where RGO got that.
* (Actually, it goes back to Toussaint, 1919.)
*       Note that he uses the term "the ray perigee" for the lowest point.


L. Auer and E. M. Standish
Astronomical Refraction: Computational Method for all Zenith Angles
(Yale University Astronomy Dept., New Haven, 1979).

* AUER & STANDISH PREPRINT
*      This uses the method invented by Biot in 1836.
* NOTE: this paper was not published for 21 years -- but it became a classic!
* You should be able to get a copy from E. Myles Standish at JPL.


S. Mikkola
“Refraction in a piecewise polytropic atmosphere,”
Astron. Astrophys. 94, 20–24 (1981).

* PIECEWISE POLYTROPIC model
*      This gives the details promised in his paper in IAU Symp.89.
* He gives a procedure for calculating the total refraction for a single
* polytropic atmosphere; but then he proposes to treat a polytropic
* layer as the difference of two polytropes. This might be acceptable
* for coarse layers (like Garfinkel's model), but the catastrophic
* cancellation it would cause in a realistic model with thin layers makes
* it hopelessly inaccurate in the real world. Also, the fudge factors that
* were determined by least-squares fits mean this is not very accurate to
* begin with. (Note the remark about errors of "only tenths of a second of
* arc and thus negligible.")
*      The concluding statement that "the present method is probably the most
* convenient known today" means he was unaware of the Auer & Standish work.
*      Is this the last gasp of the analytical approaches?


L. Auer and E. M. Standish
“Astronomical Refraction: Computational Method for all Zenith Angles,”
A. J. 119, 2472–2474 (2000).

* AUER & STANDISH's published paper -- at last!
*      This uses the method invented by Biot in 1836.
* Unfortunately, they chose to evaluate the integrand by using Newton-
* Raphson iterations that diverge where the invariant changes slowly with
* height.


M. Nauenberg
“Atmospheric refraction predictions based on actual atmospheric pressure and temperature data,”
PASP 129, No. 974, 044503 (2017).

* Michael Nauenberg's refraction paper tries to use radiosonde profiles
* This physicist thinks that the nocturnal inversion in the lowest
* kilometer "has been ignored previously." [Cf. Oppolzer (1901);
* Bauschinger (1896); Banakhevich (1915); Saastamoinen, Part 2 (1972); etc.]
* He fits the density profile in the lowest km with a parabola, and
* calculates the refraction for a wavelength of 0.633 micron . . . .



*** ASTRONOMICAL-REFRACTION HISTORY FILE (omitting feebler modern efforts) ***

Delambre
Histoire de l'Astronomie Moderne
(Courcier, Paris, 1821).

*
*
* (See also the 2022/3 Special Issue of C.R.-Physique)
*
* DELAMBRE's "Hist. MODERNE"
* Bruhns leaned very heavily on this, especially for the work of Cassini
* -- see pp. 722-725 of Vol. 2.
* [note that Biot & Arago's saga was also published by Courcier that
* same year!]


Delambre
Histoire de l'Astronomie au Dix-huitième Siècle
(Bachelier, Paris, 1827).

* DELAMBRE's 18th-Century-history book, published posthumously by Mathieu
*      N.B. This is *not* the Mathieu of the Mathieu functions; that is
* Émile Léonard Mathieu.
* Here (see footnote, p. 696) is where Mathieu says the drawings in Biot's
* book are his own. On the next page, he mentions seeing inferior mirages
* "over ice or snow". He also has many interesting comments on Delambre's
* text, including a *long* "Note on refraction" (pp. 774-796). There is
* much interesting discussion of the Simpson/Bradley/Mayer model, as well.
* On p. 339 Delambre shows that Bouguer's scheme is equivalent to this;
* and Mathieu discusses the matter more clearly on pp. 777-779.
*      A few other items of note:
* P. 151 (speaking of Horrebow's Atrium Astronomiæ ): "Un amateur qui
* habitait en Islande, l'assurait que le réfraction au solstice d'hiver
* était d'un degré. Mais il n'avait qu'un quart de cercle de bois, et
* Horrebow doute s'il peut y avoir quelque confiance." [See §17, p. 8
* of Horrebow's 1732 book.]
*      Mathieu does place some emphasis on Oriani's discovery (pp. 790-791).
* So why did Bruhns not pick up on this?
*      Mathieu mentions "great heights" (pp. 793-4); he seems to have been
* influenced by Ivory's concerns about "the height of the atmosphere".
*      Throughout, the emphasis is on the Simpson-Bradley formula, and on
* the development in powers of tan z. There are useful pointers to
* obscure earlier works, such as Legendre's 1772 paper (p. 786) and the
* work of Du Séjour (p. 724, p. 783), who coined the term "Equations
* of condition".
*      Available from Gallica.


C. Bruhns
Die astronomische Strahlenbrechung in ihrer historischen Entwickelung
(Voigt & Günther, Leipzig, 1861).

* Carl Christian BRUHNS's prize essay on HISTORY of ASTRONOMICAL REFRACTION
*      This is a classic, written in a clear and enthusiastic style.
* It was originally a prize essay, and I can see why it won the prize!
*      Based on Delambre's "Hist. Moderne"; and succeeded by Bemporad's 1907
* article in Enz. Math. Wiss.
*      Bruhns divides the history into two periods: before and after Kramp.
* He is much more thorough on the first part; I suspect he ran out
* of time. He treats the second period largely as though only the
* numerical tables resulting from it are worthy of note. In particular,
* the theoretical niceties of Ivory's 1823 paper, and Biot's 1836 monograph,
* are completely missed; Biot's wonderful method of calculating refraction
* for a *real* atmosphere is dismissed as a mere "mechanische Quadratur".
* In particular, he overlooked Biot's important theorem.
*      Consequently, those [like Newcomb (1906) and Mahan (1961)] who rely
* heavily on Bruhns are badly misled. Note that Bruhns was only 31 when
* this was published.
*      However, despite using only secondary sources (Delambre's "Histoire
* de l'astronomie moderne"), he has some useful things to say about
* Cassini -- pointing out the way of solving the equations quadratically,
* which might have been Cassini's own approach. In particular, he says:
* "Man sieht also, dass, wenn die Constanten genau genug bestimmt sind,
* die Cassini'schen Tafeln bis zu z = 74° mit den Laplace'schen
* übereinstimmen müssen." (p. 38)
*      On the other hand, I cannot agree with his remark that "nur Wenige
* waren der irrigen Meinung gewesen, dass die ganze Atmosphäre nicht
* die brechende Kraft besässe" (p. 79). Kepler, the first 3 Cassinis,
* de Mairan, Flamsteed, Bouguer, . . . ?
*      Caution: although he first says Cassini's second altitude was 19°
* (p. 33), he then says ZD = 80° in the sequel. As the refraction at
* this altitude is given as 5' 28'', 80° is certainly correct. [This
* typo is corrected to 10° in the "Verbesserungen" following p. 181]
* The final correction, which refers to p. 183, probably refers to line
* 8 from the bottom of p. 180.
*      Our library has this only on the nearly unreadable Readex Microprint
* cards, but I have managed to get my own copy at last. This was No. 148
* in Carl Bamberg's Geschäfts-Bibliothek; later taken over as 148 in the
* Askania-Werke library. The copy appears hardly to have been read; there
* were no marginal notations, nor were the corrections entered in the text.
*      Cited by Chauvenet, Newcomb, and every writer on refraction history.


A. I. Mahan
“Astronomical refraction – some history and theories,”
Appl. Opt. 1, 497–511 (1962).

* HISTORY OF REFRACTION
* A curious literature survey by an applied physicist with little
* understanding of astronomical refraction. Like most beginners, he
* supposes the upper atmosphere is important.
* Contains some useful early references; misses several important works.


A. I. Sabra
“The authorship of the Liber de Crepusculis, an eleventh-Century work on atmospheric refraction,”
Isis 58, 77–85 (1967).

* An historical correction
* "This article aims to prove that the Liber de crepusculis , which
* has always been attributed to Ibn al-Haytham (Alhazen, d. c. 1039)
* since it was published in 1542, is in fact the work of the Andalusian
* mathematician Abu 'Abd Allah Muhammad ibn Mu 'adh, who lived in the
* second half of the eleventh century."


F. Bruin
“Atmospheric refraction and extinction near the horizon,”
Archive for History of Exact Sciences 25, 1–17 (1981).

* A really bad stab at the history of refraction
* Sample quotes: "Around 1850 it could be said that the subject was
* practically exhausted and that little further improvement could be
* expected." (second sentence, p. 1)
* The usual square-root form is attributed to Lagrange (1772) with no
* citation; Mayer, Simpson, Bradley and Lambert are not mentioned. (p.2)
* The simple tangent formula "is Domenico Cassini's formula for
* atmospheric refraction (1662)." And no citation. (p. 3) "For most
* astronomical observations, therefore, the integral in (1-6) is of no
* great importance." [So what was everyone arguing about the last 200 yrs?]
* Newcomb is credited with Oriani's theorem (p.4), where we find that as
* tan z goes to infinity at the horizon, "the series no longer converges."
* [As if it ever did! Where's Ivory's warning?]
* "The first useful table of atmospheric refractions was constructed
* by Johann Kepler (1604) on the basis of a homogeneous atmosphere of
* given height. Because of this we will call this model atmosphere
* Kepler's model." (No mention of Tycho Brahe, or Ptolemy!)
*      On p. 7 we have "James Bradley's formula (1798)."  (no citation.)
* [Bradley died in 1762; Maskelyne published it in 1763 and 1764.]
* And: ". . . the atmospheric refraction is proportional to (n o - 1)".
*      P.8: we jump from Bradley to Ivory, with no mention of Oriani,
* Kramp, or Laplace; "With Ivory's work the basic problems of atmospheric
* refraction had come to a completion." [. . . as if he did it all himself;
* and what about Biot, who came later?]
*      P.11: He supposes a superior mirage, where "In particular, we may
* see a reflected image of the setting sun." (after mis-using "Fata
* Morgana" to refer to looming.) On p. 12 the "forbidden" strip is
* mentioned, without Wegener's name.
*      P.12: "Systematic work" on stellar photometry "began only after Norman
* Pogson had defined stellar magnitudes (1850) and J. C. F. Zoellner had
* built his visual photometer (1861)." [Pogson's paper was 1857; and
* what about Steinheil, and all the people whose works Pogson was trying
* to reconcile??? But there are no citations for any of these works.]
*      P.15: Now for a real howler: "The fundamental concepts of ray optics
* follow from the observation . . . that light is a periodic phenomenon . . . ."
*      P.16 ". . .  Fermat's principle . . .  is the basis of ray optics."
*      P.16 "It was only in 1621, when Willebrord Snell . . .  found the law
* named after him." [This was written over 20 years after the proof that
* Harriot found it first.]
*      Then there are the typos, like "Williams Chauvenet" (p.1) and "km"
* for meters (p.11) . . . . A sorry sight, indeed. The only possible utility
* is in the fudged variants on Bradley's rule.
*      Frans Bruin was Owen Gingerich's successor at the American University
* in Beirut. He seems to have been trained as an electrical engineer;
* see the 2002 obituary in JHA.
* Thanks to Jed Buchwald for a copy!


A. M. Smith
“Ptolemy, Alhacen, and Ibn Mu'adh and the problem of atmospheric refraction,”
Centaurus 48, 100–115 (2003).

* A. Mark Smith has another shot at Ptolemy
* Despite the title, this really has nothing to do with refraction.
* It's mostly about the Moon Illusion, with a little on the height
* of the atmosphere inferred from twilight. The only connection with
* refraction is the notion of "vapors near the horizon", so it might
* help explain Tycho's idea that refraction occurs only at low altitudes.
* The copy on Blackwell's web site is nearly illegible.


W. H. Lehn and S. van der Werf
“Atmospheric refraction: a history,”
Appl. Opt. 44, 5624–5636 (2005).

* HISTORY of atmospheric refraction
* Not an historian's history, but an account for opticists that leans on
* secondary sources. Only the period from antiquity to Kepler is included,
* so the Moon Illusion gets a lot of attention.
*      There are some slips: the coin-in-the-basin demo is attributed to
* Archimedes (in Note 10) rather than Euclid (or, properly, some unknown
* earlier person); Ptolemy's measured angles of refraction in water and
* glass are "quite accurate by modern standards"; "Ibn Mu'adh expressed
* his result in Italian miles"; "Tycho Brahe was the first to measure
* atmospheric refraction properly" and "Tycho's measurements, the
* first ever made of atmospheric refraction" (no mention of Walther);
* the anaclastic lens is "a paraboloid" (note 36).
*      On the other hand, citing Kepler's rejection of "vapors" is a nice touch.



*** RGO FILE ***

International Association of Geodesy
“Resolutions,”
Bull. Géodésique , No. 70, 389–415 (Dec., 1963).

*
* source of some bad data used by Sinclair
* This is the set of Resolutions approved by the IAG at their 13th
* (1963) General Assembly in Berkeley. Only the first and fourth are
* of interest here:
*      Resolution No. 1 recommends "either the Eflen [sic!] formula . . .
* or the Barrell and Sears formula" for refractivity of air.
* (Unfortunately, Sinclair chose the Barrell and Sears formula.)
* [The French version is even worse, confounding Edlén with Essen of the
* Essen & Froome formula for radio refractivity!]
* (Note that they mean the old (incorrect and obsolete) Edlén formula.)
* The English version is just p. 390.
* NOTE: This was finally revoked in Resolution 3 of the 1999 General
* Assembly; see J. Geodesy 74, pp. 66-67 (2000).
*      Resolution No. 4 says that "the determination of refractive index
* now constitutes a most difficult problem and serious source of error in
* electromagnetic distance measurement; and that further scientific
* research into this problem, in all its aspects and in all conditions,
* is urgently required;" but then veers off into checking via invar tapes,
* rather than direct measurements of refractivity.
*      This is now (retroactively) called Journal of Geodesy 37, No.4.


A. T. Sinclair
The effect of atmospheric refraction on laser ranging data (NAO Technical note number 59, January 1982)
(H.M.Nautical Almanac Office, Royal Greenwich Observatory, 1982).

* RGO MODEL - origin
*      This is no longer on the Web; but I have a paper photocopy from Sinclair
* himself, dated 1/5/95. The TN says (p. 5) that "A more elaborate, and
* presumably more accurate, expression for N" [ i.e., (n - 1) * 106] "is
* given by Owens (1967). However comparisons with the expression above"
* [i.e., the Barrell-Sears formula] "give agreement to within 0.04 % for a
* range of typical pressures and temperatures. Hence we conclude that the
* expression above is adequate for our purposes." Well, 0.04% is 1 part
* in 2500, or about a second of arc in horizontal refraction. Remember,
* this was Jan. 1982. But already in 1972, Peck & Reeder (1972) had made
* good measurements in the IR showing that even the "new" (1966) Edlén
* formula was wrong in the IR. How did Sinclair overlook it?
*      On pp.7 - 9, he adopts a "constant mean value" for the acceleration
* of gravity: 9.784 m/sec². That is Saastamoinen's (1972) value at
* the "height of the centroid of the atmospheric column", 7.3 km.
* But of course we know that the upper part is irrelevant; an effective
* mean value near 1 km height is proper. [See my 2004 AJ paper.] On
* p. 10, he continues to use this value of g in the stratosphere.
*      On p. 13 he shows some "typical" values, including the "effects of
* variations of the parameters of the atmospheric model by amounts typical
* of their uncertainties". The variation of "the" lapse rate is only half
* a degree per km!


C. Y. Hohenkerk and A. T. Sinclair
The computation of angular atmospheric refraction at large zenith angles (NAO Technical Note No. 63, 1985 April)
(H.M.Nautical Almanac Office, Royal Greenwich Observatory, 1985).

* RGO MODEL - development
* Available on the Web at      http://astro.ukho.gov.uk/data/tn/naotn63.pdf
* That seems to be an accurate transcription into PDF format of the
* original TN 63; however, the typeface is different from the original,
* and the figure has been re-drawn and re-labelled. Apart from that,
* the PDF is bug-for-bug compatible with the original: the confusion of
* DELTA and GAMMA in the program listing; the erroneous "respectively"
* in the Conclusion (where the order of the last two items was reversed);
* and the use of an absolute value in the Subroutine AREF, which prevents
* its use with an inverted lapse rate in the troposphere, are all preserved.
*      Much of the text is taken over verbatim in ES II Section 3.281.



*** ATMOSPHERIC ASTIGMATISM FILE ***

Professor Challis
“On the indications by phenomena of atmospheres to the Sun, Moon, and planets,”
M. N. R. A. S. 23, 231–238 (1863).

* (see also Gergonne, 1829, in Mirage Theory file)
* (see also Everett, 1873 in Mirage file, and 1874 in Mirage Theory file)
* (see also Julius, 1900, and Einstein's 1925 obit. of him)
* (see also Hillers, 1914, in Mirage File)
* (see also Nölke, 1917, in Mirage Theory File)
*
* JAMES CHALLIS makes the brightness error
* Challis is notorious as the fellow Airy entrusted with Adams's
* prediction of where to look for Neptune.
* After some unremarkable observations on the apparent enlargement of
* a planet by refraction in its atmosphere, he considers "an eclipse
* of the Sun by the Earth, as seen from the Moon, . . . " [p. 233] and
* continues: "There will, consequently, be a condensation of light . . .
* bordering the Earth's limb . . . ." He also notes the extinction,
* "as is evident from the fact that the Sun's face, when near setting,
* loses so much brightness that it can be looked at with impunity with
* the naked eye."
*      He then asserts [p. 234] that during an eclipse of the Sun by the
* Moon, as seen from Earth, "if there be a lunar atmosphere" there would be
* "a slight condensation of solar light bordering the part of the Moon's
* periphery which crosses the Sun's disk." And he suspects this has been
* observed.
*      Also, [p. 235] he considers the case -- later taken up with much
* fervor by Schmidt and by Julius -- of refractive curvature exceeding
* that of the body: "It is reasonable to suppose that this is the case in
* the Sun's atmosphere . . . ," claiming [p. 236] that "The foregoing
* theory fully explains why the contour of the Sun is generally observed
* to be entirely free from inequalities. This fact is the more remarkable
* because the unevenness of the Sun's surface, as indicated by the mottled
* appearance spread over its whole extent, with the occasional occurrence
* of deep depressions (the spots), surrounded generally by lofty ridges
* (the faculæ), gives reason to expect that inequalities would be
* perceptible on the periphery."
*      Note: This volume of M.N. falls in the group (from vol. 19 to vol. 27)
* that was re-published in 2-column, quarto format, to match that of the
* Memoirs of the R.A.S. and be bound with them. See pp. 239-240 of
* "History of the Royal Astronomical Society", Vol. 1, for details of
* "this curious arrangement". Infotrieve produced a copy from the
* quarto edition for our ILL people.


G. B. Airy
“On the origin of the apparent luminous band which, in partial eclipses of the Sun, has been seen to surround the visible portion of the Moon's limb,”
M. N. R. A. S. 24, 13–19 (1863).

* GEORGE BIDDELL AIRY, Astronomer Royal, refutes Challis's error
* Airy quotes Challis's "condensation" remark, and announces that
* "It is my principal object in this paper to show, by optical
* investigation, that no refraction can cause a change in the apparent
* brightness of the surface viewed." He then goes on to establish the
* Lagrange invariant, "not aware that any optical writer has examined into
* this question . . . ." The treatment is perhaps excessively mathematical,
* which obscures the physics somewhat; but he correctly concludes:
* "And therefore refraction by a lunar atmosphere cannot explain the more
* luminous band which appears to surround the Moon's limb where it crosses
* the Sun." [p. 18]
* He has "no difficulty in explaining to myself the origin of the
* luminous band in question. It is strictly an ocular nervous phenomenon,
* not properly subjective, but sensational -- a mere effect of contrast.
* I have seen it so frequently under circumstances very different from
* these, that I cannot have the smallest doubt on the matter.
*      "A person who stands before a moderately illuminated whitish wall,
* and swings a piece of black cloth upwards between his eye and the wall,
* will almost always see the edge of the black cloth preceded by a broad
* luminous band. I should once have said that such a band is always seen,
* but I find that I do not see it so conspicuously now as formerly."
* (Note that this volume begins with the Nov. 13 meeting.)


Professor Challis
“On the calculation of an optical effect of atmospheric refraction,”
M. N. R. A. S. 24, 49–55 (1864).

* CHALLIS persists in his error
* Here Challis is disputing Airy's (correct) conclusion "that the
* brightness of an object seen through the refracting medium is the same
* as if no medium were interposed, loss of light in the transmission being
* left out of account." (p. 50)
*      "But there remains a fatal objection to the application of this
* result to the question under consideration. No account has been taken
* of the variation of the refractive index (n ) in passing from one point
* to another of the medium. In every investigation respecting the courses
* of rays in atmospheres, . . . " and off he goes! After more talk of
* "rays", we get:
*      "The disk of the Sun, as seen by a spectator on the Earth's surface,
* is diminished by the effect of atmospheric refraction, the lower limb
* being more raised than the upper, and the vertical diameter and parallel
* ordinates being consequently diminished, while the horizontal dimensions
* remain unchanged. Hence [sic!] if no light were lost by passage through
* the atmosphere, the brightness of the Sun, so far as it depends on the
* number of pencils in a given space, would be increased by the refraction."
* (p. 51)
* Issue dated January 8, 1864.


G. B. Airy
“On the bright band bordering the Moon's limb in photographs of eclipses,”
M. N. R. A. S. 24, 188–189 (1864).

* Airy tries again . . .
* Here he argues that a continuously varying medium can be decomposed
* into a series of homogeneous ones, so that the conclusion can be applied
* to each internal boundary in succession -- each time preserving the
* brightness. With the physics thus brought out more clearly, Challis is
* finally convinced (see below).
*      In addition, Airy offers a demonstration using photographs and strips
* of black paper. . . .
* (June 10, 1864 issue)


Professor Challis
“On the bright band bordering the Moon's limb in solar eclipses,”
M. N. 25, 18–21 (1864).

* Challis recants at last!
* "The question is purely mathematical, and one on which two
* mathematicians ought certainly to be able to come to an agreement. . . . It
* is still true that to an eye situated within the medium the apparent
* brightness of an external object may be increased by the refraction;
* but from Mr. Airy's argument it follows that if the eye, and the object
* from which the rays originally proceeded, be in the same medium, the
* brightness of the object cannot be increased by transmission of the light
* through an intervening transparent substance, whatever be its form . . . ."
* Evidently Airy's second paper convinced him.


R. Clausius
“Ueber die Concentration von Wärme- und Lichtstrahlen und die Gränzen ihrer Wirkung,”
Pogg. Ann. Physik 121, 1–44 (1864).

* RUDOLF CLAUSIUS comes up with the same conclusion independently
* Notable for the section that describes the inverse relation between the
* area and solid angle of a beam -- or what we would consider "conservation
* of throughput" today. Of course, this is famous for his connecting the
* optical question with the Second Law of thermodynamics. Clausius cites
* Helmholtz's "Physiol. Optik", p. 50; but goes well beyond Helmholtz.
*      Available via ADS.
*      This is vol. 197 in the whole series; v.121 of Pogg.Ann.


R. Clausius
Abhandlungen über die Mechanische Wärmetheorie
(Friedrich Vieweg und Sohn, Braunschweig, 1864), pp. 322–361.

* Clausius's paper reprinted in the first edition of his Abhandlungen


R. Clausius
The Mechanical Theory of Heat, with its Applications to the Steam-Engine and to the Physical Properties of Bodies
(John van Voorst, London, 1867), pp. 290–326.

* Thomas Archer Hirst's edition of Clausius's reprint in English
* The English translations first appeared in Phil. Mag.
* The paper of interest to us here is the "Eighth Memoir".
* Available at Google Books.


R. Clausius
Die Mechanische Wärmetheorie, Bd.1
(Friedrich Vieweg und Sohn, Braunschweig, 1876), pp. 316–356.

* Clausius's revised, second edition
* (A 3rd edition appeared in 1887, where this is pp. 315-354.)


R. Clausius
The Mechanical Theory of Heat
(MacMillan and Co., London, 1879), pp. 295–331.

* Walter R. Browne's translation of Clausius's second edition
* Now it is Chapter XII.
* Available at Google Books.


F. Dobe
Astigmatismus bei der astronomischen Strahlenbrechung
(C.Schulze & Co., Gräfenhainichen, 1911).

* Friedrich Dobe's thesis
* Dobe finds the focal point is some 500 km behind the observer, for
* *normal* atmospheric structure, in the vertical plane; but over a
* thousand times larger in the horizontal plane. He mistakenly contrives
* to make this out to be a significant effect.


A. Schmidt
“Die Helligkeit astigmatischer Bilder und das Bild der Sonne,”
Phys. Zs. 4, 476–479 (1903).

* Schmidt's mistaken attempt to explain solar limb-darkening as due to
* the astigmatism of refraction in its atmosphere ". . . bei die durch die
* Brechung bewirkte ungleiche Strahlenverteilung . . . ." Unlike most of
* his ilk, he is aware of the solid-angle considerations; but -- alas!
* forgets that area is also involved:
* "Helligkeit ist  S t r a h l e n m e n g e      p r o      E i n h e i t
* d e s      R a u m w i n k e l s  . . ."  So there is talk about rays
* leaving a point, etc. (Typical radiance/irradiance error.)
* (As we have this on a micro-opaque only, I have no hard copy.)


A. B. Fraser and W. H. Mach
“Fata Morgana and Fata Bromosa,”
JOSA 65, 1173 (1975).

* Fraser & Mach introduce the "Bromosa" error
* This is just a 4-line meeting abstract.


A. B. Fraser and W. H. Mach
“Mirages,”
Scientific American 234, no. 1, 102–111 (Jan., 1976).

* NICE PHOTOGRAPHS by Fraser; confusing (and confused) explanations
* This otherwise standard account of mirages is badly marred by the
* authors' insistence that ASTIGMATISM can change image brightness. As
* their discussion on p. 110 shows ("Consider a point source of light . . . "),
* they have made the standard mistake of confusing radiance with
* irradiance. Unfortunately, this theme was taken up again by Fraser's
* disciple Alfred Löw (the "Luftspiegelungen" book).
* The same error was made by the Editor of Met. Mag. -- cf. Bates, 1921.


E. Fabri, G. Fiorio, F. Lazzeri, and P. Violino
“Mirage in the laboratory,”
Am. J. Phys. 50, 517–520 (1982).

* LABORATORY mirage simulations and simple theory
* [filed here because their Fig. 5 nicely shows the effects of ASTIGMATISM.]
* They use a vertical hot plate, and show 3 images in their mural mirage.
* Their lab setup corresponds to Schmidt's theory of 3-image mirages.


Y. Öhman
“Can mirage phenomena explain some of the strange stellar observations made in olden days up chimneys?,”
Q. J. R. A. S. 25, 290–292 (1984).

* Yngve Öhman suggests that mural mirages in chimneys might magnify stars
* The discussion is in terms of magnification in 1 dimension. Cylindrical
* lenses are mentioned, but not astigmatism per se.
* There is a plate showing a mural mirage.
*      Note the resemblance of this idea to Huddart's 1797 suggestion about
* the apparent brightness of lighthouses.
* Available from ADS.


W. Tape
“The topology of mirages,”
Scientific American 252, no. 6, 120–129 (June, 1985).

* WALTER TAPE's "topology" review
* NOTE: The published version was garbled by the editors; this is based
* on the (supposedly) corrected reprint. (see p.6 of the Sept. issue)
* "If no mirage conditions exist, the rays are straight . . . ."
* "I believe the multiple horizontal spikes sometimes seen on the rising
* or setting sun may be multiple images of parts of the sun that have been
* highly demagnified." [So he spotted the mock mirage as a mirage.]
*      Note also the caption to the last figure: "When the transfer mapping
* is smooth, some mirage images must be compressed if there is to be room
* for multiple images. . . ."
*      This paper introduces the concept of "folding" in mirage mapping.


W. Tape
“Die Topologie von Luftspiegelungen,”
Spektrum der Wissenschaft , no. 8, 48–55 (Aug., 1985).

* WALTER TAPE's "topology" review (German version)
* This is a "Scientific American"-level article, centered on the
* odd-number theorem and its basis in topology. The main virtue is the
* collection of excellent mirage photos from the Great Lakes (badly
* reproduced in my photocopy, however). Fraser & Mach are cited, but
* nothing else.
*      "Liegt keine Luftspiegelung vor, so sind alle Lichtstrahlen
* geradlinig . . . ." (p. 50)
*      "Ich glaube, daß die vielfachen horizontalen dünnen Streifen auf
* der Sonne, die manchmal bei Sonnenaufgang oder Sonnenuntergang sichtbar
* sind, Mehrfachbilder von Teilen der Sonne sind, die stark verkleinert
* erscheinen." (p. 55)


A. Löw
Luftspiegelungen
(BI-Wiss.-Verlag, Mannheim, 1990).

* MIRAGE MISCELLANEA
*
*
* ALFRED LÖW's book on mirages
* There is much to be liked about this book; it fills in the gap about
* "Morgana" being derived from the same root as "Margaret" (p. 18), and
* insists on the variety of mirage phenomena; has good examples reproduced
* in color plates; provides a good (but incomplete) list of references; an
* Appendix gives Wegener's theory clearly; the author insists that "Fata
* Morgana" should be restricted to complex displays; and there is a
* chapter on the psychological aspect of mirages.
* On the other hand, it misses some important papers: Hillers, Schmidt,
* Woltmann, and Forel are all missing, and Biot appears only in the text,
* not in the references. Tait is called "französische" (p. 92); Fraser's
* mistake about astigmatism is repeatedly invoked as factual; many
* phenomena are arm-waved away as due to inclined layers; a double-image
* mirage is thought possible without an intervening inverted image
* (p. 82); Raman's nonsense is treated with respect (p. 94), as are some
* of Gordon's more fantastic claims, and "lateral" mirages; and looming
* and sinking are included as varieties of mirage.
* Not for beginners, but a good source for further research.
* Thanks to Rolf-Dieter Auer for bringing this to my attention!


C. Pinney
The Waterless Sea: A Curious History of Mirages
(Reaktion Books, London, 2018).

* Christopher Pinney's book
*      A curious history of mirages, indeed!  There is only one photograph
* of a superior mirage display, and none of the common inferior mirages.
* A variety of 19th-Century artistic efforts to depict mirages are shown,
* some factual but most quite phony (as well as a couple of fakes). No
* effort is made to explain the physics of mirages; though the word
* "refraction" appears a few times in the text, there's no hint of the
* law of refraction, nor any ray diagrams. Fortunately, the sources of
* the various quotations and pictures are documented -- though these are
* often taken from encyclopedias and other secondary sources, not the
* originals. Many obscure old references to mirages are provided.
*      This appears to be a more factual effort to deal with the cultural
* significance of mirages than Marina Warner's fantastic botch. Curiously,
* it cites this bibliography for a reference to her book. It's more of
* a history of mistaken notions about mirages than a history of mirages
* themselves; no effort is made to distinguish fact from fiction.
*      Thanks to Christopher Pinney for a copy of his book!


F. Amery
“'An attempt to trace illusions to their physical causes’: atmospheric mirages and the performance of their demystification in the 1820s and 1830s,”
Brit. J. Hist. Sci. 53, No. 4, 443–467 (December, 2020).

* An historian admires Pinney's effort
*      Fiona Amery calls Pinney's book "the only historical work devoted to the
* history of the mirage". Evidently she's unaware of the works of Biot,
* Erdmann, Tait, Pernter & Exner, Löw, . . . -- not to mention Delambre,
* C. C. Bruhns and his disciple A. I. Mahan, and F. Bruin's sloppy effort.
*      On p. 457, she reproduces Brewster's representation of Vince's 3-image
* mirage, calling the lowest image "the real ship", and the upper images
* "projections".
*      Shows no understanding of optics, but contains some marginally useful
* citations: James Abbott (1844)
*       and
* Henry Hasted,‘Reminiscences of Dr. Wollaston’,in Proceedings of the Bury
* and West Suffolk Archaeological Institute Established March 1848 for the
* Collection and Publication of Information on the Ancient Arts and Monuments
* of the Western Division of Suffolk and Archdeaconry of Sudbury, Bury
* StEdmunds: Barker and Son, 1853, pp. 121–34, 125.
*      (All the references are in English.)
*
* Available at
*
* https://www.cambridge.org/core/services/aop-cambridge-core/content/view/B6987E17A024924D6939138D6AA0A01A/S0007087420000369a.pdf
*



*** GEODESY and RADIUS of CURVATURE FILE ***

F. R. Helmert
Die mathematischen und physikalischen Theorieen der höheren Geodäsie. II. Teil: die physikalischen Theorieen
(B.G.Teubner, Leipzig, 1884).

*
*      Cf. Bouguer (1753) !
*
* GEODETIC REFRACTION (std.work on GEODESY)
* ray can be treated as arc of a circle, pp.553-561
*      See longer comments on Helmert (1884) in GENERAL BOOK file.


V. C. Dragomir, D. N. Ghițau, M. S. Mihailescu, and M. G. Rotaru
Theory of the Earth's Shape
(Elsevier, Amsterdam, 1982), pp. 192–196.

* RADII of CURVATURE


K. Nikolitsas1 and E. Lambrou
“A methodology for correcting refraction in vertical angles for precise monitoring in tunnels,” in Proceedings, 4th Joint International Symposium on Deformation Monitoring, 15-17 May 2019
(Eugenides Foundation, Athens, Greece, 2019).

* Konstantinos Nikolitsas, Evangelia Lambrou


M. Sabzali and L. Pilgrim
“Updated atmospheric modelling of refracted zenith angle using vertical temperature gradient for refraction coefficient,”
Journal of Geosciences and Geomatics 11, no. 1, 11–20 (2023).

* Mansoor Sabzali, Lloyd Pilgrim
*      A useless Master's project, written in badly broken English.
* Some of the text and figures were taken from the 2019 paper by Nikolitsas
* and Lambrou.



*** KURZYNSKA FILE ***

K. Kurzyńska
“Precision in determination of astronomical refraction from aerological data,”
Astr. Nach. 308, 323–328 (1987).

*
* Here is where she shows the rapid transition near ZD 85°
* Cf. Freiesleben (1951)


K. Kurzyńska
“How to improve old astrometric observations by introducing more accurate corrections for astronomical refraction,” in Journees 1991, Systemes de Reference spatio-temporales , N. Capitaine, ed.
(Obs. de Paris, Paris, 1991), pp. 223–228.

* Both these deal with the water-vapor problem. In the second paper, she
* shows that the water-vapor correction given in the Pulkovo tables is wrong.
* However, they seem OK for *DRY* air.


K. Kurzyńska
“Can Pulkovo tables, 5th edition, serve as a standard of pure astronomical refraction?,” in Dynamics and Astrometry of Natural and Artificial Celestial Bodies
(Poznan, Poland, 1994).


I. S. Guseva
“Astronomical refraction calculation and refraction tables compilation on a basis of the atmosphere modelling method,” in Proceedings of the Workshop of Refraction Determination in the Optical and Radioastrometry, Leningrad, USSR, 1985 , G. Teleki, ed.
(Publ.Astr.Obs.Belgrade, Belgrade, 1987), pp. 57–68.

* PULKOVO TABLES - methods of calculation
* methods used for PULKOVO TABLES, 5th ed.
* NOTE:
* ISO adopts g = 980.616 (1 - 0.0026373 cos 2phi + 0.0000059 cos2 2phi)
* which it calls Lambert's eqn. and cites Smithsonian Met.Tables, 1963.
*
* g = g0 (1 - .0026373 cos 2phi + 0.0000059 cos-sq 2phi)
* and
* g0*M/(R*T0) = 1.1855, where
* M = 28.9644 (mol.wt.); R = 8314.32 j/k kmole (gas const.);
* T0 = 288.16 K


O. Struve
Tabulae Refractionum in usum speculae Pulcovensis congestae
(Typis Academiae Imperialis Scientiarum Petropolitanae, Petropoli, 1870).

* PULKOVO REFRACTION TABLES FILE (all editions)
*
* There have been 5 editions, published in 1870, 1905, 1930, 1956 and 1985.
* It may be useful to list them all together here.
*
* FIRST EDITION (1870)
* This is the one that used the calculations of Hugo Gyldén.
* The logarithms of the various factors are tabulated for every minute of
* arc of Z.D.
* Available at Google Books. 39 numbered pages + IV
*


O. Backlund
Tables de refraction de l'Observatoire de Poulkovo
(l'Imprimerie de l'Académie Impériale des Sciences, St.-Pétersbourg, 1905).

* SECOND EDITION (1905)
* Basically a reprint of the first edition, but with an added preface
* by Oskar Backlund; and the table referring exclusively to the Pulkovo
* meridian circle has been omitted. Struve's Latin preface is retained.
* Formerly available at Google Books. Only 26 pages, including covers.
* Currently available at HathiTrust:
*
* https://babel.hathitrust.org/cgi/pt?id=mdp.39015073268875;view=1up;seq=7
*
* https://babel.hathitrust.org/cgi/pt?id=uc1.b5012362;view=1up;seq=1
*


N. Dneprovskii
Refraction Tables of Poulkovo Observatory, Third Edition
(Pulkovo Observatory, Moscow, 1930).

* THIRD EDITION (1930)
* 22 pages + X
* Substantial revisions and corrections, including the addition of
* several tables from Harzer, including the one for star colors on
* Osthoff's visual scale.
*      The back of the title page says it was printed at the request of the
* Main State Astronomical Observatory at Pulkovo (signed by Director A.
* Ivanov); the printing was done at the Dunaev cartographic printing plant
* in Moscow. (They also printed the multi-color maps that are tipped into
* the volumes of the Great Soviet Encyclopedia, or Большая советская
* энциклопедия.) The title page says "Moscow 1930" without naming a publisher.
*      If we follow the rule that the "publisher" is whoever ordered the book
* to be printed, that must be Pulkovo Observatory.


B. A. Orlov
Refraction Tables of Pulkovo Observatory, Fourth Edition
(Izd.AN SSSR, Moscow, 1956).

* FOURTH EDITION (1956)
* 32 pages
* Таблицы рефракции Пулковской обсерватории
* (Изд-во Академии наук СССР, 1956)


V. K. Abalakin
Refraction Tables of Pulkovo Observatory, Fifth Edition
(Nauka, Leningrad, 1985).

* FIFTH EDITION (1985)
* 48 pages
* Таблицы рефракции Пулковской обсерватории, Издание пятое
* (Изд-во «Наука»,Ленинград, 1985)
* P. 39 lacks a page number. The corrections for chromatic refraction
* are on the (unnumbered) inside back cover, following p. 48.



*** GEODESY, GPS, Polar Motion, and refraction FILE ***

P. Melchior
“For a clear terminology in the polar motion investigations,” in Nutation and the Earth's Rotation , E. P Fedorov, M. L. Smith, and P. L. Bender, eds.
(Springer, Dordrecht, 1980), pp. 17–21.

*
* MELCHIOR's jeremiad about terminology
*      "The  useless introduction of  the new words "wobble" and "sway"
* has produced a flourishing rise in confusing terminology in most of the
* recent papers.      These two words even if picturesque are fundamentally
* unprecise."
*      "Because of this new fashion introduced by some geophysicists, many
* astronomers have become really confused and,      instead of keeping the
* very clear Poinsot-Tisserand terminology, started to stammer into the
* following extensive terminologies, never clearly defined, which I. . . ."
*      There is a lucid description of nutation theories; refraction is
* not mentioned.


V. B. Mendes, G. Prates, E. C. Pavlis, D. E. Pavlis, and R. B. Langley
“Improved mapping functions for atmospheric refraction correction in SLR,”
Geophys. Res. Lett. 29, No. 10, 53–1 – 53–4 (2002).

* MENDES et al.
* "The main accuracy-limiting factor in modern space geodetic
* techniques, such as the Global Positioning System (GPS), very long
* baseline interferometry (VLBI), and satellite laser ranging (SLR),
* is atmospheric refraction." (First sentence of Introduction.)
*      NOTE: What the radio people call a "mapping function" is just what
* astronomers and solar-energy people call the "airmass finction";
* see Rapp-Arrarás and Juan M. Domingo-Santos (2008).



*** "SUNSETS --> REFRACTION" FILE ***

J. Hellerich
“Beobachtung der Strahlenbrechung in der Nähe des Horizontes,”
Astr. Nachr. 232, 57–66 (1928).

* REFRACTION FROM SUNSETS and SUNRISES
* Temperature inversions explain the greater refraction and flattening than
* predicted by the Pulkovo tables. Wegener (1918) cited.
* Biggest deviation on a morning in Feb.1920.
* Shows that INVERSIONS of ordinary size can produce the observed effects,
* including Wegener's blank strip.


J. de Kort
“Measurements of the Sun's limb for the determination of refraction between 80° and 90° zenith distance,” in (Georgetown Observatory Monograph No. 17; AFCRL-TN-60-820)
(Georgetown University, WashingtonDC, 1960).

* Jules de Kort, S.J.


A. B. Fraser and R. Hemler
“How to take an atmospheric temperature sounding to a height of 5 km by watching the setting sun,”
J. O. S. A. 65, 1174 (1975).

* REFRACTION FROM SUNSETS


A. B. Fraser
“Solutions of the refraction and extinction integrals for use in inversions and image formation,”
Appl. Opt. 16, 160–165 (1977).

* REFRACTION FROM SUNSETS; MAGNIFICATION rule
* ". . . the squashing of the sun's disk when the sun is on the horizon
* depends only on the temperature and lapse rate at the height of the
* observer's eye."
* ". . . if the sun reaches its minimum aspect ratio above the astronomical
* horizon, γ must decrease with height (to give a lifted inversion)."


V. V. Archangelskij and S. Volshanin
“On the fast determination of astronomical refraction in near-horizon observations,” in Proceedings of the Workshop on Refraction Determination in the Optical and Radio Astrometry, Leningrad, USSR, 1985 , G. Teleki, ed.
(Belgrade Observatory, Belgrade, 1987), pp. 169–172.

* REFRACTION FROM LOW SUN
* This is Pub. Obs. astron. Belgrade No. 35


L. Györi
“Determination of atmospheric refraction from the distortion of the Sun's disc,”
Astron. Astrophys. 278, 659–664 (1993).

* REFRACTION FROM SUNSETS


W. D. Bruton and G. W. Kattawar
“Unique temperature profiles for the atmosphere below an observer from sunset images,”
Appl. Opt. 36, 6957–6961 (1997).

* DAN BRUTON's thesis, published version
* The method is an exact integral equation for the inversion.
* N.B.: the method fails in cases of ducting; cf. Ao (2007).
* This uses my sunset sequence as an example.


W. D. Bruton and G. W. Kattawar
“Unique temperature profiles for the atmosphere below an observer from sunset images: erratum,”
Appl. Opt. 37, 2271 (1998).

* Historical addendum to the previous paper, discussing priority issues


K. P. Gaikovich
Inverse Problems in Physical Diagnostics
(Nova Science Publishers, Inc., Hauppauge, New York, 2004).

* Konstantin P. Gaikovich's monograph
*      Cf. Gaikovich et al (1983) in "Mirage Theory" file for inversion theory.
* Chapter 3, "Gas media. Atmosphere Remote Sensing", is the relevant part
* (pp. 85-189). There is a section (§3.2. Reflection in Atmosphere
* Diagnostics) on ducting (pp. 134-138). The rest of the chapter deals
* with radiometric observations.
*      The list of 264 references at the back includes O'Connell's book and a
* couple of Lehn's papers, but no mention of Link's works.


C. O. Ao
“Effect of ducting on radio occultation measurements: An assessment based on high-resolution radiosonde soundings,”
Radio Science 42, No. 2, RS2008 (2007).

* Chi O. Ao compares radiosonde profile with GPS retrievals
*      Cites papers by Gorbunov (2002,2004) for wave-optical retrieval theory,
* and "failure of Abel inversion when ducting layers (also referred to as
* superrefraction or critical refraction layers) are present". [Intro.]
*      "The radiosonde profiles . . .  retain the very high vertical resolution
* of ≈30m". He denotes the nR function as a .
*      Note that parallactic effects are neglected, "Since the transmitter and
* receiver are located far from the atmosphere in a GPS RÖ.
*      Appendix A shows that "An infinite number of refractive index
* profiles -- of which the Abel inversion offers but one possibility --
* that differ only within and below the duct can be shown to give an
* identical" bending angle profile. [UNIQUENESS problem]
*      He describes the algorithm for finding the top, "middle", and bottom of
* a duct (bottom of p.4). [By "middle" he means the place where nR is a
* local maximum.]
*      The retrieved refractivity profiles are underestimated in and just
* beneath the duct, but are less strongly affected closer to the surface.
*      This is paper number RS2008, paginated from 1-15.
* DOI: https://doi.org/10.1029/2006RS003485



*** Misc. SUNSET PICTURES FILE ***

L. F. Hall
“Atmospheric effects in multiple-exposure and streak photographs of the Sun and Moon,”
Bull. Amer. Meteorol. Soc. 62, 1676–1678 (1981).

* NICE SUNSET PHOTOS in SERIES


M. J. McNamara
“As the Sun goes down,”
Popular Photography , 46 (Aug., 1992).

* Wonderful 7-image mirage of setting Sun by Jay Meisel



*** FAKE MIRAGE SIMULATIONS FILE ***

M. Berger, T. Trout, and N. Levit
“Ray tracing mirages,”
IEEE Computer Graphics and Applications 10, no. 3, 36–41 (May, 1990).

*
* These papers try to simulate mirages numerically. Most use very
* unrealistic models -- often just "internal reflection". The emphasis
* is on making fake images, not realistic simulations of *real* mirages
* as in Lehn's papers.
*
* Layers of constant n used; unrealistic
* The correct terms for mirages are used, but they say the inf. & sup.
* mirages are below/above the "actual position". Based on 2 papers in
* Am. J. Phys. from 1977 & 1982.
*      Fig. 1 shows a typical mis-placed image for an inferior mirage.
* All the images came out a strange dark blue here -- looks as if they
* had trouble preparing the CMYK separations for the journal. The PDF
* on the IEEE website has saturated image simulations (mostly black).


F. Kenton Musgrave
“Ray tracing mirages,”
IEEE Computer Graphics and Applications 10, no. 6, 10–12 (Nov., 1990).

* Response to the previous item, with a GREEN FLASH mention in passing
* Musgrave correctly sees that "if the formation of a mirage were by
* some continuous deformation in the ray path, then we would expect to see
* a different image than if it were formed by some discontinuous process
* such as total reflection." But he is unaware that the continuity of
* the erect and inverted images *is* observed. Then he correctly says
* that "if refraction were the primary engine in mirage formation, then
* we would expect to see the effects of dispersion in a mirage, smearing
* the image into its component colors by a prismatic effect (an important
* factor in the generation of the famous and elusive `green flash' of the
* setting sun)." But then: "My subject experience indicates little to no
* dispersion in mirages observed in nature. Furthermore, as the index of
* refraction of the air at room temperature and pressure is only 1.00025
* versus 1.0 for a vacuum, there is precious little refractive power to
* work with . . . .
*      "This would indicate that the primary `bending agent' in mirage
* formation is total reflection, not refraction . . . ." So, by being
* ignorant of mirage observations, as well as missing the infinite slope
* at grazing incidence in the sine law, he picks the wrong model.


M. Berger
“Berger responds,”
IEEE Computer Graphics and Applications 10, no. 6, 12 (Nov., 1990).

* Berger's reply to Musgrave compounds his errors
* "Ken Musgrave is correct in pointing out that the major contribution
* to the mirage effect is total internal reflection, which results in a
* discontinuity of the first derivative at that point." (See what happens
* when you use layers of constant index?) "In addition, Musgrave's
* observation that a `purely reflective model, without refraction, might
* well be sufficient' is well taken." Yuck.
* [This appears on the last page of Musgrave's paper, above.]


M. Berger, N. Levit, and T. Trout
“Rendering mirages and other atmospheric phenomena,” in Eurographics 90 , C. E. Vandoni and D. A. Duce, eds.
(Elsevier, Amsterdam, 1990), pp. 459–468.

* Layers of constant n used; unrealistic
* ". . . optical illusions brought about by atmospheric refraction."
* "A single image may appear side by side . . . ."
* "Stooping Mirages" and "Towering Mirages" sub-heads . . .
* Meeting was in September, so I assume this followed the previous ref.


J. Sloup
“Visual simulation of refraction phenomena in the Earth's atmosphere,” in Proc. 7th Intl. Conf. on Information Visualization
(IEEE Computer Society, Los Alamitos, CA, 2004), pp. 452–457.

* Jaroslav Sloup has a good idea (circular arcs)
* But his "omega" simulation has unrealistic artifacts, because he
* chooses layers that are too thick.
* Cites Berger (above) and Dan Bruton's thesis.



*** WEGENER FILE ***

A. Wegener
“Über die Ursache der Zerrbilder bei Sonnenuntergängen,”
Beitr. Physik d. freien Atmos. 4, 26–34 (1912).

* qualitative theory: rays are straight lines
* Beiträge zur Physik der freien Atmosphäre


A. Wegener
“Elementare Theorie der atmosphärischen Spiegelungen,”
Annalen der Physik , series 4, 57, 203–230 (1918).

* quantitative mirage theory: rays are circular arcs
* Here is where the BLANK STRIP or "obscured strip" or "reflecting strip"
* was introduced, together with the Nachspiegelung.
* [Note that the horizontal blocking was predicted by Biot (1836).]
*      He simulates inversion sunsets with both supercritical and subcritical
* lapse rates. At the end, he describes a sunset in which the lower edge
* of the strip is below the horizon: "Here the Sun sets behind an invisible
* wall, . . .      at considerable height above the [astronomical] horizon."
* O'C #149


A. Wegener
“Optik der Atmosphäre,” in Müller-Pouillets Lehrbuch der Physik, 11. Auflage , A. Eucken, O. Lummer, and E. Waetzmann, eds.
(Friedr.Vieweg & Sohn, Braunschweig, 1928).

* Wegener's big review article (mostly a re-hash of the earlier papers)
* The GF is item C (section 5), pp.203-204. The standard story is given:
* "Es kann kein Zweifel daran herrschen, daß auch hier die spektrale
* Zerlegung des Lichtes durch die Refraktion die Ursache ist, und daß das
* Spektrum nur aus dem Grunde bei Grün aufhört, weil Blau und Violett, wie
* die rote Farbe der untergehenden Sonne zeigt, am Horizont ausgelöscht
* werden." But: "Indessen bleibt hierbei zunächst unerklärt der
* plötzliche Übergang von Rot zum Grün ohne erkennbaren Durchgang durch
* die dazwischen liegende spektrale Farbenfolge."
* It's nice to see that he has seen GFs himself: "Die Erklärung einiger
* Autoren, nach der es sich nur um ein subjektives Nachbild handelt, ist
* für jeden, der die Erscheinung selbst beobachtet hat, schon wegen ihres
* Glanzes ausgeschlossen . . . ."
* O'C #150


A. Wegener
“Optik der Atmosphäre,” in Lehrbuch der Geophysik , B. Gutenberg, ed.
(Gebrüder Borntraeger, Berlin, 1929), pp. 696–697.

* Wegener's chapter on atmospheric optics
* Section 373 is "Der Grüne Strahl". He quotes Bemporad's dispersion
* table. He gives the textbook explanation, but admits that "Die
* Erscheinung . . . scheint aber außerdem noch an besondere Bedingungen,
* vielleicht hohe Feuchtigkeit, gebunden zu sein." He rejects Julius's
* anomalous-dispersion theory (interestingly, because "die Erscheinung
* zu glänzend ist.") He recognizes that "Auffallend bleibt nur der
* plötzliche Übergang von Rot zum Grün ohne erkennbaren Durchgang
* durch die dazwischen liegenden Farbenfolge," but attributes this to the
* "rain bands": "Hierdurch erklärt sich auch die Unregelmäßigkeit des
* Auftretens." Not a bad try for 1929.


D. Robinson, T. M. Ali, and W. Gallant
“Abnormal refraction, approaching Cape Blanco,”
Marine Obs. 37, 18 (1967).

* SPLENDID DRAWING of SUN above BLANK STRIP, with reflected ship in it !!
* This observation directly contradicts FEENSTRA KUIPER's error.
* STRIP described as "a bank of medium cloud."
* (Cf. Pinkhof, 1933, for a similar ship mirage without the Sun.)
* "Air temp. 71 F, wet bulb 64, sea 68."



*** MIRAGE THEORY FILE ***

J. D. Gergonne
“Recherches sur les réfractions terrestres et particulièrement sur le mirage,”
Notice Travaux Acad. Gard pour 1808, 219–256 (1809).

*
*      See also Biot's monograph, and the works by Bravais, and
* Ao (2007) in "Sunsets --> refraction" file.
*
* Gergonne's obscure 1808 paper: an extended abstract, with a few quoted
* passages from Gergonne's full memoir. He thinks that the mirage is of
* local interest, "le département du Gard étant peut être la seule
* contrée de l'Europe ou le mirage puisse annuellement être observé."
* [Here a footnote explains that the mirage is seen every summer at the
* hottest time of day in the south of Gard.]
*      He begins by citing, and quoting from, Biot's Traité élémentaire
* d'astronomie physique -- but without realizing that Biot took his
* description of the mirage in Egypt almost verbatim from Monge's 1799 account.
* Thus the description on pp. 222-223 is mostly wording taken directly from
* Monge's work (which he says he has not seen, on p. 251).
*      Gergonne realizes that the inverted image means that at least one
* of the two rays from a point has not followed a straight path from the
* object to the eye, which implies that either reflection or refraction
* must be involved. He can't see where the reflecting surface would be,
* or how reflection would not act on objects at all distances, or how the
* concentration of heat could produce a reflection; so, for all the wrong
* reasons, he decides that refraction must be responsible. And, as the
* refracting medium has to be air, which we know is strongly affected by
* heat and cold, he proceeds in that direction. (pp. 223-224)
*      So he develops the theory of refraction in a medium whose refractive
* power varies continuously. (pp. 225 ff.) He derives the differential
* equation of the ray trajectory (p. 227), and treats the atmosphere as
* plane-parallel. Although there is no general solution (because the
* distribution of refractivity with height is not known), Gergonne obtains
* several results from the structure of the differential equation itself.
*      He shows how to make a geometrical construction that relates the
* trajectory to a curve related to the refractivity profile, so that each
* of these curves can be deduced from the other.
*      As a simple example, he assumes the trajectory is a parabola with its
* axis vertical; then the related "regulator" curve is a straight line.
* In a real case, the regulator can be considered as made up of successive
* line segments; and the trajectory, a series of parabolic arcs whose
* slopes match where they join. [We would say it is a spline of parabolic
* segments.] This single observation gives rise to a multitude of results
* that Gergonne develops. (p. 229)
*      For example, if the regulator has a maximum, the trajectory must wind
* back and forth about a horizontal line corresponding to this maximum;
* and its differential equation does not have an algebraic solution.
* [In modern terms, this is a ray trapped in a duct.] (p. 230)
*      This raises the question of how two rays leaving the same point can
* intersect again, so that an eye placed at that intersection sees two
* separate images of the source. Gergonne asserts that a necessary and
* sufficient condition is that the second differences of the refractive
* powers of the different atmospheric layers do not continually have the
* same signs as their first differences. (p.231)
*      Applying this result to a particular example, he finds the condition
* that all the rays of light leaving a certain point are reunited at the
* eye, as "a common focus".  (p. 233)      [This is the Fata Morgana case.]
* He notes that the observer "serait frappé d'une impression semblable à
* celle d'un brouillard qui , empruntant sa couleur de celle du point qui
* en produirait l'apparence, pourrait en changer , lorsque l'œil se
* déplacerait." (p.234)
*      He then asks how many images of a given point are seen, in general.
* He first remarks that for points near the observer, the rays can be
* considered straight, and the spectator sees objects as if they were in a
* vacuum or a homogeneous medium of constant density, and sees only a
* single image of each object. Then his basic equation has only one real
* root; it must be of odd degree; so that whatever the intervening medium
* may be, it can "only give rise to an odd number of images". (p. 235)
*      Besides the number and positions of the images, Gergonne considers
* whether they are erect or inverted. And, because of the unlimited
* variety of possible functions, he considers the "physical constitution"
* of the atmosphere."      (p.240)  He remarks that our ignorance of how heat
* is transferred from one layer to another does not allow us to know how
* the density varies. Nevertheless, when the ground is heated by the sun,
* the small thermal conductivity of air restricts the heating to only
* a small height. So he concludes that, near the ground, the second
* differences of the refractive powers, naturally negative, become null
* or even positive; but that, as the variations are never very rapid, one
* deviates very little from the truth by supposing that the density of the
* air in the lower regions, and consequently it refractive power, is
* constant, or that it varies little, so that the medium is divided by a
* horizontal plane into two parts, in one of which the density varies
* gradually, while in the other it is constant or varies in a different
* way. This corresponds to assuming that the regulator is a straight line,
* or that it is made of two lines with different slopes, which means that
* the trajectory is linear or parabolic, or that it is formed of part of
* a parabola, following the tangents at its ends, or following the arcs
* of another parabola. (p.243)
*      Gergonne analyses all these different cases in detail.  Most of
* them produce no remarkable phenomena. The case where the density is
* constant near the earth and then decreases upward, and that in which
* the density initially increases upward and then becomes constant,
* give rise to three images, provided that the eye and the object are not
* both in the variable medium. (p. 244)      Of the three images, one of
* the extremes which is direct, and the intermediate one which is inverted,
* are both visible, while the third, which is formed beyond the spectator,
* cannot be seen. . . . The same things occur in the case of a medium composed
* of two parts varying in density according to two different progressions,
* provided that the eye is in one of these media, and the object in the
* other; but if they are both in the same medium, the number of images can
* rise to five . The multiplicity of images can only occur for objects
* suitably placed. Finally, Gergonne remarks that in the case where the
* density decreases toward the ground, the ray paths have their convexity
* turned from upward to downward; some of them can be intercepted by the
* ground: a circumstance that necessarily reduces the effective number of
* images, and can make it much less than the theory indicates.
*      Gergonne finishes by considering the case where the regulator is a
* parabola with its axis horizontal, so that the refractive power decreases
* with the squares of the distances of the atmospheric layers from a
* certain plane. Then, in general, each object has only a unique image;
* however, whatever the situation of the spectator, there is always a set
* of isolated points whose rays reach the eye in all sorts of directions,
* so that the observer must see these points everywhere. (p. 245)
*      Gergonne compares the various cases with the description of the mirage
* quoted from Biot (i.e., Monge's description), and says: (p. 246)
*      "il n'est pas difficile de reconnaître à laquelle de ces
* hypothèses ce phénomène doit être rapporté. Voici donc de
* quelle manière il me semble devoir être expliqué. Le matin ,
* lorsque le sol n'est pas encore échauffé , la densité de l'air
* va croissant vers la terre, mais d'une manière si peu sensible que ,
* dans les limites qui embrassent l'œil et les objets qu'il peut
* apercevoir , il est permis de la considérer comme constante ; alors
* donc l'aspect du pays est tel que le comporte la disposition
* réelle des objets et leur éloignement ; mais , lorsque le sol s'est
* échauffé par la présence du soleil , il communique une partie
* de la chaleur qu'il a acquise , à l'air qui est en contact avec lui ;
* et cette chaleur , se transmettant de proche en proche , dilate le milieu
* jusqu'à une certaine hauteur , probablement peu considérable , au-delà
* de laquelle sa densité est sensiblement uniforme, tandis qu'au contraire
* elle décroît continuellement vers la terre. Il arrive donc que ,
* parmi les rayons de lumière qui partent des objets suffisamment
* éloignés du spectateur , et placés à une hauteur con venable ,
* ceux qui , à raison de leur inclinaison , ont une vitesse verticale
* peu con sidérable , venant à pénétrer les couches inférieures de
* l'air , sont attirés par les couches supérieures , plus denses , dont
* l'action parvient bientôt à éteindre cette vitesse , et à leur en
* faire ensuite acquérir une autre de bas en haut ; il arrive donc que
* ces rayons , dont la direction était d'a bord sensiblement rectiligne ,
* après avoir décrit dans le milieu variable une courbe convexe vers la
* terre , se relèvent et repassent dans le milieu constant où ils prennent
* de nouveau la direction rectiligne , selon laquelle ils parviennent enfin
* à l'oeil du spectateur. Dans le cas le plus ordinaire , le spectateur
* recevra par cette voie une image renversée de l'objet : indépendamment
* de l'image directe qui lui parviendra; par l'entremise des rayons de
* lumière entièrement situés dans le milieu constant ; il verra donc
* simplement au-dessous de chaque objet , son image renversée , comme elle
* paraitrait effectivement dans l'eau ; et comme cette double impression ne
* pourra avoir lieu que pour des objets suffisamment distans du spectateur ,
* il arrivera qu'à mesure qu'il avancera , les limites de l'inondation
* apparente s'éloigneront ; mais alors le phénomène se reproduira pour
* d'autres objets plus éloignés ; et , ce qui achèvera sur-tout de
* compléter l'illusion , c'est que l'air , près du sol , étant dans une
* agitation continuelle , l'image renversée qu'on observera au-dessous
* de chaque objet , au lieu d'être immobile comme l'objet même ,
* éprouvera une sorte de mouvement d'ondulation , pareil à celui que
* produit l'agitation de la surface de l'eau , sur les images des corps
* qui s'y réfléchissent." (p. 248)
*      He then discusses the third image that is formed behind the observer,
* and is therefore invisible.
*      Gergonne then points out that this model implies that the heated part
* of the air should not extend to the height of the observer's eye, and
* that the limits of the apparent inundation should contract as the heating
* increases, "so that one could, in a way, measure the extent of the
* phenomenon by means of a thermometer suspended freely a few inches
* from the ground." (p.249)
*      Furthermore, the mirage should be seen daily in places with smooth flat
* land, during the summer, in the hot part of the day. (p. 250)
*      "Je sais que M. Monge a traité le même sujet, dans le premier volume
* de la décade égyptienne ; mais n'ayant pu encore me procurer cet ouvrage,
* j'ignore absolument quel rapport il peut y avoir, sur ce point, entre mes
* idées et celles de cet illustre géomètre." (p.251)
*      As Gergonne's memoir was accompanied by many plates, the editors have
* thought they should put at least one at the end of this extract, showing
* the simplest case where the mirage can occur. Pp. 253 ff. give the
* explanation of this plate.
*      This seems to be the earliest work after "EMERITUS" (1807) in which the
* POSITION of the image is considered. (Nölke took it up again in 1917.)
*      These are the proceedings of the Academy at Gard.  Notice the spelling
* "Nismes" throughout.
*
* Title page reads:
*
*              N O T I C E
*
* DES TRAVAUX DE L'ACADÉMIE
*
*                  DU GARD,
*
* PENDANT L'ANNÉE 1808.
*
* Available (with the figure mutilated) at
* https://books.googleusercontent.com/books/content?req=AKW5QacmcKk4_gN4ijpaPfon4Zd6_rSVDZh5NmLFmAy7RfjZ0-8FW18Qtip-W_bhVltSdHdvlrCnPlH_IxCbR93QG3vAsN7iB3B7pF2BXd--Uo3fDbBhwhioYGseQyNm4HLeRpQu3cQZkTpnXEWgCIKws5OxpwsyDFwpdjikAo1mEAGMRdZwOCXs4vPylmpSFYr-IqBuTQMmhlwYFASuwywr03Ru173miapJesrook4DuyNDhAcJ4alx-SKsLe0nRoKAdcZvrrTXYqTohNT-ONUSy2pGj_oDyUTDCS5CaTnIQYAf7yJLPOk
*
* The figure is available in the copy at Gallica:
* https://gallica.bnf.fr/ark:/12148/bpt6k486370q/f220.item
*
* The text is clearer at Google, but the figure is only readable at Gallica.
*      Thanks to Eric Frappa for locating these PDFs!


J. D. Gergonne
“Du mouvement de la lumière dans un milieu transparent, dont la densité varie , dans tous les sens , suivant une loi mathématique quelconque,”
Annales de Mathématiques Pures et Appliquées 19, 257–285 (1829).

* Gergonne's paper in Vol.19 (1829)
*      This contains his comments on Monge's "wretched" abstract!
* "Plusieurs années avant que M. Biot eût fait paraître son ouvrage
* sur les Réfractions extraordinaires qui ont lieu près de l'horizon ,
* et à l'occasion d'une pitoyable explication du phénomène du Mirage ,
* que j'avais rencontrée dans la Décade philosophique , je m'étais
* déjà occupé de la recherche des lois du mouvement de la lumière
* et de la vision , dans un milieu transparent de densité variable.
* Bien qu'alors le phénomène du mirage fût connu et observé depuis
* long-temps , dans diverses contrées de l'Europe , personne néanmoins,
* n'avait songé à en déduire l'explication mathématique des lois
* connues de l'optique. La route dans laquelle je n'engageais n'était
* donc point encore frayée. Je n'avais jamais eu l'occasion d'observer le
* phénomène que j'entreprenais de soumettre à l'analyse ; il ne m'était
* même connu que par la courte description qu'en avait donné M. Biot ,
* dans ses Elémens d'astronomie ; cependant je fus assez heureux pour
* parvenir à des résultats que l'observation directe , elle-même ,
* n'avait fait apercevoir qu'assez tardivemeni à M. Monge , durant
* son séjour en Egypte , comme on en peut juger par le post-scriptum
* de son Mémoire sur le mirage , inséré d'abord dans la Décade
* égyptienne , et reproduit postérieurement par M. Hachette , dans son
* Programme d'un cours de physique . Le mémoire de Monge parait , au
* surplus , beaucoup moins écrit pour les géomètres que pour les hommes ,
* en très-grand nombre , qui aspirent uniquement à prendre une teinture
* superficielle des causes des phénomènes variés que le spectacle de la
* nature peut offrir à notre observation ; ce mémoire ne m'aurait donc
* pu être d'aucun secours pour mon travail , qui était terminé depuis
* plus d'un an , lorsqu'il me tomba pour la première fois sous la main ."
*      Here he actually cites his 1808 paper; then he proposes to treat
* the subject from a completely general point of view. He adopts the
* Newtonian emission theory in much the same form used by Laplace, and
* "derives" the sine law for refraction. Then the equations look just
* like Biot's.
*      On p. 278, he applies his general theory to the spherically
* symmetrical case. Other symmetries are also considered. The paper
* ends with a promise to consider mirages in a following paper.
*      The reference to "Décade philosophique" is apparently to its abstract
* of Monge's paper in An VII, No.10 (cited by Bravais, 1853). That is
* a 1-page summary on pp. 4 and 5 of that issue, where the meeting of 11
* Fructidor is described. That text is nearly identical to the Ann. Chim.
* abstract.
*      This paper is referenced several times in the sequel on mirages
* in vol. 20.
*      The signature footers say "1.er mars 1829."


J. D. Gergonne
“Essai analytique sur le phénomène du mirage,”
Annales de Mathématiques Pures et Appliquées 20, 1–31 (1829).

* Gergonne computes the image locations for Biot's simple analytic examples
* (He was the editor and publisher of this series.)
*      This paper fills in some of the analytical development that was
* omitted from the 1808 summary.
*      Possibility of MULTIPLE DENSITY MAXIMA and PREDICTIONS:
* "Il ne serait même pas impossible que, dans des circonstances
* probablement fort rares, la densité des couches fût alternativement
* croissante et décroissante, de manière à présenter, le long d'une
* même verticale, plusieurs maxima et minima ; or , ce sont toutes
* ces variétés de circonstances, comme nous le verrons bientôt,
* qui donnent naissance à cette multiplicité d'images d'un même
* objet qui constitue proprernent le phénomène du mirage, ainsi qu'à
* beaucoup d'autres phénomènes non moins piquans, dont quelques-uns,
* à la vérité, n'ont point encore été observés, mais que le calcul,
* dévançant ici l'observation, comme en tant d'autres rencontres, ne
* nous montre pas moins comme très-possibles." (p. 2)
*      The first few pages reprise in detail some of his mostly unpublished
* 1808 memoir; e.g., on p. 7 here he discusses the ducted ray. On p. 8
* he shows that maxima and minima of the density correspond to points of
* inflection of the ray. He also suggests that the inverse problem can be
* solved: given the path of a ray, find the structure of the medium.
* For example, he shows that his theory can infer a constant density if
* the rays are straight, and a density changing linearly with height if
* the rays are parabolas with vertical axes. (pp. 10-11)
*      He then proceeds to consider the location of the image of an object
* point: it is the center of curvature of the ray normals [i.e., the
* wavefronts] at the eye. (p. 16) If the image is behind the observer, the
* rays are converging at the eye. He also considers whether the image is
* erect or inverted (pp. 21-22), and the number of images (p. 23). Finally,
* there is the question of double roots of his equation, corresponding to
* the place where two images meet (p. 24). If the two images are distinct,
* we have the phenomenon of mirage (p. 25).
*      Prediction of BIFURCATIONS in the ray diagrams:
*      "Les rayons émanés du point lumineux pourront donc ne pas occuper
* en totalité, le plan qui les contient ; ou du moins ils pourront
* ne pas concourir, en même nombre, en tous les points de ce plan ;
* ces rayons pourront donc avoir une ou plusieurs courbes limites ou
* enveloppes communes, lesquelles diviseront le plan qui les contient en
* plusieurs régions, telle qu'en passant d'une région à celle qui lui
* sera consécutive, le nombre des rayons concourant en un même point,
* et par suite, le nombre des images du point rayonnant qui pourront
* être aperçus par un oeil situé en ce point, augmentera ou diminuera
* d'une unité." (p.23)
*      He then says these were called "déterminatrices" in his 1808 memoir.
*      In elaborating the parabolic ray paths in the atmosphere with a
* linear density gradient, he finds an illustration of Biot's theorem
* about the locations of the ray vertices. (pp. 26-27) In a footnote,
* he points out the analogy between the two ray paths connecting the eye
* with their common source point, and the two elevations of a gun that
* send its projectile to the same target.
*      The signature footers say "1.er juillet 1829."
*      Google's scan shows that the plate follows p. 36 (but does not show the
* plate itself).


J. D. Everett
“Atmospheric refraction,”
Nature 7, No. 166, 163 (Jan. 2, 1873).

* Everett is preparing for his mirage reviews
*      He cites Scoresby's works, and mentions Latham, Vince, Wollaston, and
* Monge's "Annales de Chimie" paper, and Gorsse in the same volume; adding
* papers in Nature in July 28 and Aug. 25, 1870, and Aug. 25, 1872. Then:
* "If any of your readers can inform me os any important contributions to
* the literature of Mirage besides those above mentioned I shall be greatly
* obliged."


A. Ramsay
“Mirage,”
Nature 7, No. 174, 322 (Feb. 27, 1873).

* A reader responds to Everett's appeal for references
*      More than a dozen good references, including the elusive 1808 memoir
* by Gergonne (though its page digits are transposed) and other obscure
* publications.


J. D. Everett
“On mirage,”
Proc. Belfast Nat. Hist. Phil. Soc. , 20–35 (1874).

* Prof. Joseph David Everett's descriptive lecture (1872)
*      This is the run-up to his more technical papers of 1873.  The text
* here appears to be exactly the same as its reprint in Nature (1874).
*      Here he gives an account of the well-known observations, identifying
* Scoresby's observations of "a mural precipice of great elevation" as
* essentially the same as the "magnificent columns . . . of the Fata Morgana,
* at the Straits of Messina". (p. 28)
*      The treatment is all qualitative.  He gives Monge credit for "the
* earliest explanation for mirage," but raises the objection that "it
* seems to imply not a curvature, but an angle in the course of the rays,"
* which would require a perfectly sharp transition" in density; "no such
* harsh supposition is necessary." (pp. 30-31)
*      He then discusses at some length the distinction between reflection
* and refraction, and introduces "quasi reflection". (p.33) This leads
* into a 3-liquid tabletop demonstration, using alum on the bottom, pure
* water on top, and "Scotch whiskey mixed with enough sugar to make its
* specific gravity intermediate between those of the other two liquids."
*      The title page says:
* "Proceedings of the Belfast Natural History and Philosophical Society
* for the Session 1872-73"; the paper is dated November 27th, 1872.


Professor Everett
“On the optics of mirage,”
Phil. Mag. , series 4, 45, No. 299, 161–172 (1873).

* Everett's technical papers; cf. the Nature (1874) ones.
* He starts by deriving the radius of curvature of the ray in terms of
* the refractive-index gradient along the wave-front. "This proof is due
* to Professor James Thomson, who gave it in a paper to Section A at the
* recent meeting of the British Association at Brighton." (Cf. Thomson's
* 1872 paper in the "HORIZONTAL-RAY PARADOX" file.) From this he obtains
* the harmonic motion of a ray about a plane of maximum refractivity, and
* the resulting focusing property: "It thus appears that . . . every object
* will yield a series of real images, alternately inverted and erect . . . .
* It is of course to be understood that the images are formed in one
* dimension only, like those formed by a cylindrical lens." (p. 165)
*      On p. 167, he discusses ray trapping, and the critical angle, between
* regions of constant index joined by a continuous transition region.
*      In section VI on that page, he allows the surfaces of constant index
* to be curved, so as to follow the curve of the Earth. Then the rays
* oscillate about the level where the ray curvature matches the Earth's.
*      Section VII (p. 169) relates the refractivity to the state variables
* (using the work of Biot & Arago): "Hence, when the diminution of
* temperature per foot of ascent is 1/96 of a degree Centigrade, the
* density of the air is uniform and the rays are straight." He finds
* the ratio of curvatures to be 5.2 at 0° C and 5.6 at 10°. (p. 170)
* Then the curvatures are equal if the temperature increases 1 C in 29.4
* ft., or 1 F in 16.3 ft. "Any portion of the earth with such a state of
* things prevailing over it will appear plane, distant objects being no
* longer hidden by the intervening convexity. A still more rapid increase
* will make the surface of the earth appear concave."
* [Note observation of CONCAVE surface.]
*      [The concave appearance is also described by Forel (1895), p. 541.]
*      Section VIII takes up looming and mirages.  "The inverted images are
* formed by rays incident from below . . . at such an obliquity that . . .
* they cannot get through, but are compelled to descend again, and thus
* undergo a kind of reflection." (p. 171) He attributes multiple images
* to either multiple inversions, or irregularities on a single one,
* rather than multiple "reflections". He attributes the Fata Morgana
* and Scoresby's Greenland mirages to "the vertical magnification of
* real objects." The inferior mirage is attributed to rays concave
* upward "and a quasi reflection," as for the superior mirage.
*      Section IX (p. 172): "In the transmission of rays through a medium of
* continuously varying index, no proper distinction can be taken between
* refraction and reflection. They shade insensibly into one another;
* or rather, I should perhaps say, both names are equally inappropriate
* in this application."
*      In section X, he comments on the HORIZONTAL-RAY paradox: "The
* mistake of supposing that a ray can pursue a straight course parallel to
* planes of equal index in a continuously varying medium. The contrary
* was pointed out so long ago as 1799 and 1800 by Vince and Wollaston in
* the Philosophical Transactions, but appears to have since dropped out
* of mind."
*      No references are cited.
* Available at the HathiTrust site:
*
*      https://babel.hathitrust.org/cgi/pt?id=uc1.b3728171;view=1up;seq=188
*
* In the March 1873 issue; the next paper is from the April issue.


Professor Everett
“On the optics of mirage (Second Paper),”
Phil. Mag. , series 4, 45, No. 300, 248–260 (1873).

* Everett's second paper (April issue)
* Here he extends the work beyond mirages, to gradient-index lenses.
* He begins with cylindrical symmetry (in section XI), and proceeds to
* spherical symmetry, which applies to the atmosphere again:
*      "Required the law of index-variation which will cause all circles
* described about the common centre to be paths of rays." Of course,
* this produces the nR = Const. condition. (p. 251)
*      After again doing a cylindrical case, he considers plane surfaces
* of constant index, and shows that the rays are circular arcs if the
* index is inversely proportional to distance from a fixed plane. This
* "might have been deduced at once from the undulatory theory without
* any application of analysis. For if μ is inversely as the distance
* from a fixed plane, velocity is directly as this distance . . . . Hence
* the wave-front will swing round the line of intersection like a door
* upon its hinges, and each point in the wave-front will describe a
* circular arc, which will be the path of a ray." (p. 256)
*      Various other analytically elegant but physically improbable cases
* are explored in the remainder of the paper, which casts little light
* on mirages.


A. Schmidt
“Die cyklische Refraction,”
Programm des Königl. Realgym. Stuttgart , 1–31 (1878).

* Schmidt's clear mirage explanation, with the MINT quote:
* There is a lot of nonsense here in which Schmidt tries to explain
* aberration by the "piling-up" of the luminiferous aether in front of the
* moving Earth. The useful parts are section II ("Die cyklische
* Refraction") and III ("Die Luftspiegelung"). The best part is the
* elegant construction in Fig. 5, p. 10, in which he shows how the
* change in density gradient is responsible for the triple-image mirage.
* He has some penetrating remarks about textbook accounts: Biot's theory
* "ist wegen der Allgemeinheit der Behandlung des Problems mit einem zu
* grossen geometrischen Apparat verbunden, es scheint unmöglich, ohne
* genaue Kenntniss der caustischen Linie in die Geheimnisse der
* Erscheinungen einzudringen. Daher ist diese Theorie nicht gut
* popularisirbar, sie ist eine Barre edlen Metalls, das seit 70 Jahren im
* Gewölbe der Münzstätte ruht, das Niemand in courante Münze umsetzt.
* Die Lehrbücher der Physik, welche sie kennen, wie z. B. Biot's
* Experimentalphysik selbst, berichten wohl die Erscheinungen, verweisen
* aber in Betreff der Erklärung einfach auf obige Abhandlung, und
* diejenigen, welche sie nicht kennen, behelfen sich mit der Erklärung
* durch totale Reflexion. Für die Theorie der mehrfachen Bilder, ihrer
* relativen Annäherung, ihrer Verzerrung ist damit nichts gewonnen, das
* aufrecht Bild über dem umgekehrten soll durch mehrfache Reflexion
* entstehen, das aufrechte Bild eines Schiffes (Fig. 4) z. B. soll das
* Bild des Bildes im Meere sein.
*      "Eine populäre Erklärung der Erscheinungen der Luftspiegelung wird
* es sein, wenn man unter Annahme einfacher Verhältnisse einen
* Specialfall schafft, welcher die Erscheinungen, so wie sie gewöhnlich
* sich darstellen, in der Natur und im Experiment, mit möglichst
* elementaren geometrischen Vorstellungen zum Verständniss bringt.
* Diess glaube ich im Folgenden zu leisten." (And he does!) (p. 9)
*      On p. 11, he derives the magic number of 1° 23' for the limiting
* extent of mirages.
*      He also points out the ease with which the inferior and superior
* mirages can be confused, if only 2 images appear. But (p. 16) he
* thinks that 5-image mirages involve both superior and inferior ones
* simultaneously, and tries to explain the observations of Biot and
* Arago of the signal fire on "Iviza" as seen from Desierto de las
* Palmas.
*      Quoting the German translation of Flammarion's book, he comments on
* the frequent reports of images well above the horizon: "Wir müssen
* daran festhalten, dass die Höhe des Bildes über der geraden Luftlinie
* nach dem Gegenstande den Betrag von 1° 23' wohl nie erreichen wird.
* Was darüber hinausgeht, gehört entweder in das Reich der Fabel oder
* ist es nicht mehr die Wirkung der Refraction, sondern die einer
* wirklichen Reflexion." (p. 17)
*      In discussing the terrestrial refraction constant, he notes that
* Glaisher's balloon data show a very different lapse rate than that
* required to produce the usual values of refraction, and suggests using
* the optical measurements to determine the lapse rate (p. 20).
*      Section V on parabolic refraction compares the two upper images of
* the triple-image mirage to the two ballistic trajectories reaching the
* same target for a given muzzle velocity.
*      According to Kleinschmidt's obituary, this was Schmidt's very first
* publication!
*      N.B.: cited by Hillers.  The mirage model is very similar to that
* proposed by Thomas Young (1807).


A. Garbasso
“Il Miraggio,”
Memorie della accademia reale delle Scienze di Torino, vol. 58, Ser. 2, 1–59 (1906).

* ANTONIO GARBASSO's papers on mirages: 1
* This is the paper discussed by Bemporad in his 1907 paper, where it
* is cited as "Memorie della accademia reale delle Scienze di Torino,
* Anno 1906-1907".
* The title page of the volume says "1908".
* P. 1 says "Approvata nell'adunanza del 2 Dicembre 1906."
* The date at the end of p. 57 is "Ottobre 1906".
* The text ends on p. 57; but the "due Tavole" occupy pp. 58 and 59.
*      This is a broad review of mirages; there is an extended abstract,
* outlining the paper, followed by a good review of the observations
* (pp. 4-11), and another review of the theory (pp. 12-18); He calls
* Biot's mirage monograph "the first truly important theoretical work,"
* explicitly passing over Monge. But he seems not to have read through
* Biot's work, and gives the most credit to Tait's.
*      Then he turns to "the experiments of Wollaston," and later laboratory
* experiments on diffusion in liquids (pp. 18-21) by Macé de Lépinay and
* Perot, by Wiener, and by Wood.
*      Now comes Garbasso's own contribution, beginning with a statement of
* the problem in curvilinear coordinates (Chapter 4). This he applies to
* Wollaston's experiments (Ch. 5, p. 29). He finds (p. 31) that "the
* index of refraction is propagated with the laws found by Fourier in
* the analytical theory of heat." Then the index is described by a Fourier
* series, and the ray path is expressed in elliptic integrals. The
* subsequent numerical results become more complicated and less
* interesting, as Bemporad showed (see below).
*      On p. 47, he returns to mirages, beginning with "the mirage of Monge".
* Unfortunately, he is still thinking in terms of diffusion; so he comes
* up with an error function for the refractivity profile. So he tries to
* force the laboratory simulation to fit the geophysical situation.


A. Garbasso
“Il Miraggio,”
Nuovo Cimento , series 5, 14, 411–420 (1907).

* ANTONIO GARBASSO's papers on mirages: 2
* This is the paper "presentato al Congresso di Parma della Società
* Italiana di Fisisa." [sic]
*      Here, he is more hesitant about real mirages than he was in the
* previous paper, which concluded with the flat assertion that there are two
* kinds of mirages. Now, instead of Pernter's two kinds, we have three:
* "the mirage of Monge" (2 images); "the mirage of Vince", with 3 images;
* and "the mirage of Parnell", with 5 images. [But Kelly (1846) saw
* five images 23 years before Parnell (1869) did.]
*      He is even harder on Monge than before: "Monge truly had a very
* rudimentary concept of the matter; he thought of two superimposed and
* sharply separated layers of air, and made a total reflection occur
* at the limiting surface." (p. 412)
*      After referring to the principles of Huygens and Fermat, and Lagrange,
* and Hamilton, he criticizes the models of Biot and Tait for "not having
* any experimental basis." (p. 416) So he comes back again to the lab
* model -- i.e., diffusion. "The mirage of Monge can be reproduced with
* this artifice," he says, citing his earlier paper. So it's back to the
* error-function refractivity profile, and Fourier series again. "In
* reality, in suitable conditions, it is experimentally verified that the
* rays are rigorously parabolic." (And he cites his earlier paper.)
*      P. 418: He claims the experiment of Wollaston provides a satisfactory
* explanation of the mirage of Vince. On the next page, he cites Rolla's
* simulation as explaining the mirage of Parnell. Then we get arm-waving:
* "In nature, the process comes according to all probability from the
* presence of two layers of air, differing in thermal conditions and
* hygrometric state." (p. 420) But "The analytic theory encounters
* material difficulties . . . ."
*      This paper is dated "Settembre 1907"; he cites his first paper as
* "Mem. R. Acc. di Torino, (2), 58, 1906, 1."
*      There is a third paper on the wave surface in N.C. 18, 25-32 (1909).


A. Bemporad
“Saggio di applicazione dei metodi di calcolo dell' astronomia teorica a problemi di fisica matematica,”
Mem. Soc. Spett. Ital. 36, 79–87 (1907).

* BEMPORAD's note, criticizing Garbasso's 1906 paper on mirage theory
* Sub-titled: "A proposito della Memoria del Prof. A. Garbasso sul
* MIRAGGIO"
*      He starts from the recent papers of Boccara on the Fata Morgana,
* regarded from the point of view of Garbasso's curvilinear theory.
* The equations are numbered as in Garbasso's first paper.
*      Here again, Bemp. notes that numerical integration is less work than
* series expansions; cf. his 1907/1913 Encyc. article.
* PDF available at ADS.


Fr. Nölke
“Zur Theorie der Luftspiegelungen,”
Physik. Zs. 18, 134–144 (1917).

* This is the paper Lehn et al. (1978) called "the first adequate analysis";
* I am not so impressed. Nölke was not familiar with the literature of
* atmospheric refraction, or he would not say: "Ist es jemals bemerkt
* worden, daß sich bei der Wüstenspiegelung der Horizont senkte und
* bei der Seespiegelung hob? Hat man beobachtet, daß bei der
* Wüstenspiegelung gelegentlich nur die Kronen der Palmen und unmittelbar
* unter ihnen ihr Spiegelbild erschien? Hat man festgestellt, daß bei der
* Annäherung an das Gegenstand Bild und Spiegelbild immer weiter
* auseinanderwuchsen, bei der Entfernung aber sich von der Basis her
* verkurtzen und schließlich ganz verschwanden? Von derartigen
* Beobachtungen wird nicht berichtet . . . ." [How about Huddart (1796),
* Woltman (1798), Gruber (1798, 1800), Atkinson (1830/31), Kelly (1846), . . . !]
* Likewise, of multiple-image mirages, he says: ". . . so umfassen
* die Bilder nur beschränkte Teile des Gegenstandes. Auf diese
* unvollständigen, vielfachen Bilder scheint man noch nicht aufmerksam
* geworden zu sein . . . ."
*      His introductory complaints about the earlier mirage literature are
* well taken -- "Auch die vielfach zur Illustration der Naturerscheinungen
* ausgeführten Versuche, bei denen man durch Übereinanderschichten
* verschiedener Flüssigkeiten die atmosphärischen Verhältnisse
* nachzuahmen sucht, haben keinen grossen Wert, da es sehr Zweifelhaft
* ist, ob die durch Diffusion der Flüssigkeiten sich herausbildenden
* Verhältnisse mit den in der Atmosphäre vorliegenden Ähnlichkeit
* besitzen. . . . Die anschauliche, geometrische Art der Erklärung ist nun
* zwar schon lange, besonders in populären Lehrbüchern der Physik, üblich
* gewesen, aber die Darstellung ist meistens eine sehr oberflächliche,
* nicht selten sogar fehlerhafte." -- but he himself fails to meet these
* objections. His whole treatment is based on Tait's "vertex" approach
* --- which was actually discovered by Biot!
*
* His insistence on the flat-Earth approximation leads him astray from the
* correct explanation of multiple-image mirages, so that he thinks a 5-image
* mirage requires two "refracting layers" (cf. Garbasso, 1907).
*
* Finally, though the paper is entirely based on Tait's method, there is
* no mention of Tait (or Biot!); the only papers cited are those of Hillers.
*
* Despite all these weaknesses, the paper has some unique virtues: "Je
* dünner die lichtbrechende Schicht ist, desto kürzer ist der Weg, den die
* in der Nähe ihrer oberen Grenzfläche umkehrenden Strahlen in derselben
* zurücklegen, desto mehr nähert sich also auch das umgekehrte Bild einem
* einfachen Spiegelbilde" is a good point often overlooked. And "Im
* allgemeinen haben die Bilder nicht dieselbe Entfernung vom Beobachter wie
* der Gegenstand." This IMAGE LOCATION problem tripped up Hofmann (1902).
*      Cf. Gergonne (1809, 1829), who also treated the image POSITION.
* (Of course it is more easily treated by lens theory.)


O. Haug
“On the theory of superior mirage,”
Meteorologiske Annaler 3, 295–310 (1953).

* Odd Haug: Multiple images solved analytically in an elevated duct
*      The theory resembles Schmidt's 2-layer model.  A modified refractivity
* m = (n-1) + h/R      is used to trace rays, so a piecewise-linear profile
* of (n-1) is assumed; obviously, this is a sort of dip-diagram scheme.
* The altitude of the ray is used, instead of Z.D. Both the observer and
* the miraged object are assumed to be in the lower part of the duct,
* below the inversion base. To simplify the problem, both object and
* observer are assumed to be at the same height (cf. Dettwiller, 2019).
* The periodic motion is emphasized, and the period used to locate
* image distances.
*      Multiple-image mirages are attributed to multiple reflections in
* the inversion. Despite the analytical results, only qualitative
* comparisons are made with Vince, Scoresby, and Parnell.


E. Khular, K. Thyagarajan, and A. K. Ghatak
“A note on mirage formation,”
Am. J. Phys. 45, 90–92 (1977).

* FLAT EARTH ASSUMED (no refs. to P&E nor Wegener)


K. P. Gaykovich, A. S. Gurvich, and A. P. Naumov
“On a reconstruction of meteorological parameters from intra-atmospheric measurements of optical refraction of cosmic sources,”
Izv. Atmos. Ocean. Phys. 19, 507–512 (1983).

* SUNSET (sunrise!) SIMULATIONS showing Mock Mirages
* This and the next paper really belong in the "Sunsets --> refraction" file


S. V. Zagoruyko and V. Kan
“Reconstruction of the profile of the index of refraction and of the temperature from measurements of optical refraction,”
Radio Eng. Electron. Phys. 29, 95–99 (1984).

* THEORY for rapid decrease of influence of structure above eye level
* OMEGA shapes shown over warm water


M. V. Berry
“Disruption of images: the caustic-touching theorem,”
JOSA A 4, 561–569 (1987).

* Sunsets from satellites (cf. Link's book)


W. H. Lehn
“Exact temperature for the hillingar mirage,”
Am. J. Phys. 69, 598–600 (2001).

* Quadratic approximation to T(h) required for ray curvature = Earth's.
* This condition gives unit magnification. The treatment is restricted
* to heights of 100 m and altitudes of 15' because "based on long-term
* experience in observing mirages . . . heights above 15 arcmin are
* extremely rare."
* At STP he gets the critical gradient of 0.1127 K/m.


B. D. Nener, N. Fowkes, and L. Borredon
“Analytical models of optical refraction in the troposphere,”
JOSA A 20, 867–875 (2003).

* Explicit theory for linear and quadratic refractivity profiles
* Basically a repeat of Biot's work, 2 centuries later. Useless.
* (not copied)


A. T. Young
“Inferior mirages: an improved model,”
Appl. Opt. 54, no. 4, B170–B176 (Feb. 1, 2015).

* My inferior-mirage model


L. Dettwiller
“Some theorems on “arctic mirages”: hillingar effect and superior mirages,”
JOSA A 35, 1997–2004 (2019).

* Luc Dettwiller's analytical treatment
*      Makes good use of Biot's transformation of the refraction integral!
* Many instructive results are produced for unrealistically simple models.
*      This is restricted to objects at eye height, and so does not apply
* directly to Fata Morgana mirages.



*** HORIZONTAL-RAY PARADOX FILE ***

A. Bravais
“Optique. Réfraction,”
L'Institut 21, 193 (1853).

*
*      See Everett's comment on this, in his March, 1873, Phil. Mag. paper.
*
* The notice of Bravais's paper on horizontal turning points (see below)
* This is in the account of the Société Philomathique de Paris,
* Séance du 21 mai 1853.
*      The remark on Grunert in the last paragraph refers to G.'s 1850 paper
* in the Beiträge reviews (see the Clausius entry here.)


A. Bravais
“Explication, par le système des ondes, d'un cas remarquable de la refraction de la lumière,”
Ann. Chim. Phys. , series 3, 46, 492–501 (1856).

* Symmetry at vertex; "paradox" of ray optics resolved (cf. Raman)
* This is the full paper announced in 1853.


J. Thomson
“On atmospheric refraction of inclined rays, and on the path of a level ray,”
Brit. Assoc. Adv. Sci. Report 42, 41–45 (1872).

* JAMES THOMSON (elder brother of Sir William Thomson, later Lord Kelvin)
* Shows that the horizontal ray has maximum curvature; nice paper for
* treating the problem both by ray and wave optics.


C. V. Raman & S. Pancharatnam
“The optics of mirages,”
Proc. Indian Acad. Sci. A 49, 251–261 (1959).

* RAMAN & PANCHARATNAM
* Much concern about inadequacy of geom.optics -- cf. Bravais (1856)
* and Thomson (1872) who already resolved this paradox a century earlier!
* Rediscovers Gruber's use of a cold breeze to enhance the experimental
* effect.
* Mentions "caustics" but not Biot; has "Hiller" for Hillers.
* A curiously deficient paper in many respects, re-inventing many a wheel.


C. V. Raman
“The optics of mirages,”
Current Sci. 29, 309–313 (1959).

* RAMAN
* A shorter version of the previous paper


R. T. Bush and R. S. Robinson
“A note on explaining the mirage,”
Am. J. Phys. 42, 774–775 (1974).

* Bush & Robinson paper on teaching mirages
* This only briefly touches on the horizontal-ray problem; but the next
* two papers dwell on that issue, in commenting on this one. So, it's here.


P. L. Dyson
“Comment on explaining the mirage,”
Am. J. Phys. 45, 879–880 (1977).

* Dyson's comment on Bush & Robinson
* ". . . it is important . . . that the students' difficulty with the ray
* picture is due to a lack of understanding of ray theory and not, in this
* instance, to any inadequacy of ray theory itself."


G. P. Sastry
“Teaching mirages,”
Am. J. Phys. 46, 765 (1978).

* Sastry's further comment on Bush & Robinson


M. V. Berry
“Raman and the mirage revisited: confusions and a rediscovery,”
Eur. J. Phys. 34, 1423–1437 (2013).

* Michael Berry's correction of Raman



*** TERRESTRIAL REFRACTION FILE ***

William Roy
“Experiments and observations made in Britain, in order to obtain a rule for measuring heights with the barometer,”
Phil. Trans. Roy. Soc. 67, 653–787 (1777).

*
*       See similar references in the DIP FILE.
*
*
* Colonel WILLIAM ROY's study in Scotland
* Little mention of refraction here; but Atkinson (1826) made much use of
* these data. Atkinson cites him as "General Roy", but he had only just
* been promoted to Colonel at this time.
*      Note that one of the places he measured was Dunsinane-hill. . . .
* Cites and uses many of Bouguer's observations in Peru. See Clarke's
* "Geodesy" (1880) for Cassini de Thury's 1783 role in connecting the French
* meridian to the Survey of England and Wales.
*      Available as a 169MB PDF at:
* https://royalsocietypublishing.org/doi/10.1098/rstl.1777.0035


Le Gentil
Voyage dans les mers de l'Inde,Vol.1
(Impr.royale, Paris, 1779), pp. 701–707.

* LE GENTIL's terrestrial refraction observations
* Not much of interest here, as all the objects were fairly nearby. He
* finds more variation over land than over the sand dunes of the coast,
* and mentions earlier observations made by Picard. There is a remark
* about a considerable change in the dip (p. 705).
* The footnote says:
* "Ces Observations ont été lûes à l'Académie Royale des Sciences,
* le 29 Novembre 1775."


L. W. Gilbert
“Beobachtungen des General Roy's, Dalby's und mehrerer Astronomen über die Grösse der irdischen Strahlenbrechung und die Vertiefung des Seehorizonts, mit Bemerkungen des Herausgebers,”
Gilberts Ann. Physik 3, 281–289 (1800).

* GILBERT's review


H. W. Brandes
“Beobachtungen über die Strahlenbrechung,”
Gilberts Ann. Physik 17, 129–182 (1804).

* Lots of observations; not much useful


Dr. Brandes
“Von Herrn Dr. Brandes zu Eckwarden,”
Gilberts Ann. Physik 18, 432–433 (1804).

* Brandes bemoans his lack of decent help
* "Meine Absicht war, zugleich durch ein Nivellement die wahre Höhe
* einiger jener Gegenstrände zu bestimmen, um die Grösse der Erhebung
* kennen zu lernen. Aber dieses an sich schon nicht leichte Unternehmen
* wurde dadurch ganz unausführbar, dass es mir an einem nur mässig
* brauchbaren Gehülfen fehlte: Personen, die ein Paar Zolle für etwas
* ganz unbedeutendes halten, und von Viertelzollen als von etwas unendlich
* kleinem sprechen, sind bei solchen Untersuchungen schlechte Helfer."


Delcros
“Nivellement barométrique du profil du Jura sur la ligne Genève – Lons-le-Saunier,”
Bibliotheque Universelle 7, 164–179 (1818).

* The original French version of the Delcros paper
*      Here the subtitle is:
* par des observations successives ; comme aussi par leurs correspondantes
* faites à Genève, à Strasbourg, et à Paris, employées simultanément ;
* exécuté en 1813, avec un baromètre de Fortin, pendant le cours d'une
* reconnoissance géodésique; et examen critique des nivellemens
* baromètriques et de ceux qu'on obtient par les distances au zénith.
* Communiqué aux Rédacteurs par Mr. Delcros, capitaine au Corps Royal
* des Ingénieurs-géographes français, Membre de plusiers Sociétés savants,
* (avec fig.)
*      The first few pages have the continuation of a very long footnote from
* the previous paper.
*      The part written by Delcros ends on p. 177, whereupon the Editors'
* commentary begins. A footnote on p. 178 explains that Broussaud was
* "Chef d'escadron au corps des Ingénieurs-géographes, occupé des travaux
* exécutés sous la direction dû dépôt de la guerre pour rattacher le
* Mont-Blanc à la méridienne de Dunkerque." The editorial addition ends
* on p. 179, where the legend for the Plate appears. The Plate itself is
* at the end of the issue, following p.228. (image 260 of the BHL pdf.)
*      Available from the BHL.
*      PDF saved to ~/images/PDF/bibliothqueuni07univ.pdf


[J. ] Delcros
“A Barometrical Measurement of the Profile of Mount Jura, on the Line of Geneva, – Lons-le-Saunier, . . . ,”
Annals of Philosophy 12, No. 5, 355–368 (Nov., 1818).

* Delcros: refraction variations at Mount Jura (English translation)
* "Translated from the Bibliotheque Universelle, vii. 164, for March, 1818."
*      The "Bibliothèque universelle des sciences, belles-lettres, et arts"
* was published in Geneva, from 1816. It became Arch. Sci. Genève in 1947.
* Delcros was Captain of the Royal Corps of French Geographical Engineers.
*      Little is known about him; but there are numerous letters from both
* "F.J.Delcros" and "J.F.Delcros" to Rudolf Wolf in the "Notizen" of the
* Vierteljahrsschrift der Naturforschenden Gesellschaft in Zürich,
* Zweiunddreissigster Jahrgang, 1887. (This was the Wolf of sunspot
* numbers, and also Maurer's thesis adviser.) These letters make very
* interesting reading, and give a picture of the lives of astronomers in
* the middle of the 19th Century.
*      That VJS is available from:      https://libsysdigi.library.uiuc.edu
* [My copy is filed in ~/images/PDF/vierteljahrsschr32natu.pdf ]
*
*      The interesting part for us here is on p. 364:
* "The coefficient of the refraction is a quantity so variable and so
* vague, that I cannot express a sufficient degree of astonishment that a
* constant value is employed for it, applicable in all circumstances and
* seasons. Each mathematician gives his own according to his ideas and
* his experiments. I have also attempted to form one ; and after having
* combined a great number of good zenith distances, I have satisfied myself
* that there is nothing constant in the coefficient but its inconstancy.
* I have seen it vary between 0.06 and 0.21 of the terrestrial arc.
* The different times of the day and the changes of the seasons occasion
* this enormous difference. I believe that sufficient attention has not
* been paid to the influence of the time of day."
*      There is a fine Plate illustrating the DIURNAL VARIATIONS in dip of the
* apparent land horizon from early morning to just before sunset, between
* p.364 and 365. The key to its features is on pp.367-368.
* The signature at the end is dated Feb.15, 1818; the observations were
* made in 1813. It is followed by an "Appendix by the Editors of the
* Bibliotheque Universelle" on pp. 366-367, confirming that hypsometry
* is generally more reliable than trigonometric surveys, unless the latter
* use "reciprocal and very numerous observations, made with excellent
* instruments and by very skilful persons, with all the conveniences and
* all the time requisite for such operations."
*      The Annals of Philosophy was a short-lived technical journal that was
* merged into Phil. Mag. in 1827 -- see its Wikipedia entry.
*      This is Article V., with an excessively long subtitle, concluding:
* "With a Critical Comparison of the Barometrical Measurements with those
* obtained by Zenith Distances." [These long subtitles seem to be the
* seeds of Abstracts, which became common later.]
* Available from BHL and archive.org
*      FILED at ~/images/PDF/annalsofphilosop12phil.pdf


Biot
“Mémoire sue la mesure théorique et expérimentale de la réfraction terrestre, avec son application à la détermination exacte des différences de niveau, d'après les observations des distances zénithales simples ou réciproque,”
Additions a la Connaissance des Temps . . . pour l'An 1842 , 3–80 (1839).

* BIOT's monograph on terrestrial refraction
* Contains some astute remarks on DIP at the end (pp. 70-??):
* "Toutefois, on ne peut se dissimuler qu'il est très difficile de
* déterminer la température propre et réelle de l'air en contact avec
* la surface de la mer . . . ." (p. 75)
* My copy is missing pp. 78-79.


[P. M. Hossard]
“Observations faites par M. Hossard pour déterminer les variations diurnes de la réfraction .,”
Mémorial du Dépôt Général de la Guerre, vol. 9, 451–455 (1853).

* Paul Michel HOSSARD's DIURNAL VARIATIONS in summer, 1844
*      The figure on p. 455 shows a very abrupt change in the refraction at
* dawn. The line of sight was just a few meters above the ground.
*      Published by Maulde & Renou, Paris (Dec. 1853)


Colonel J. T. Walker
Account of the Operations of the Great Trigonometrical Survey of India, Vol. II. History and General Description of the Principal Triangulation and of its Reduction
(Survey of India, Dehra Dun, 1879).

* Col. Walker's detailed measurements of terrestrial refraction at 2 heights
* A brief treatment is in Chapter IV, "The Measurement of the Angles",
* sections 3 and (especially) 5. The details are in Appendix No. 3,
* "On Observations of Terrestrial Refraction at certain stations situated
* on the plains of the Punjab," by Colonel Walker.
* NOTE: the Appendices begin anew at p. 1, following the 426 pages of
* main text. So App. 3 (dated 5th October 1874) starts on p. 77 of the
* Appendices.
*      "Probably all observers, who are familiar with the phenomena of
* refraction over heated plains, will readily recall instances in which
* a distant signal, seen standing well above the ground while the sun was
* behind a belt of clouds, has suddenly sunk down to the ground when the
* clouds passed away and the sun shone out fiercely." (App. p. 91)


H. Hartl
“Ueber den Zusammenhang zwischen der terrestrischen Strahlenbrechung und den meteorologischen Elementen,”
Meteorologische Zs. 16, 129–140 (1881).

* HARTL -- temperature gradient "most important"
* Heinrich Hartl, k.k. Hauptmann im Militär-geographischen Institute
* ``Auf Grund der . . . rein empirischen, von keiner Hypothese beeinflussten
* Untersuchungen glaube ich zu dem Ausspruche berechtigt zu sein: Die
* Temperaturabnahme mit der Höhe ist der w e s e n t l i c h s t e
* Factor in der täglichen und jährlichen Periode der terrestrischen
* Refraktion, die anderen meteorologischen Elemente sind nur von
* sekundärem Einflusse.'' (p.134)
* (actually, all in italics from colon to comma, not just "wesentlichste".)


E. P. Audouard
“Recherche expérimentale de la réfringence de l'air au bord de la mer,”
Bull. Soc. Acad. Brest 13, 209–226 (1888).

* OBSERVATIONS of refraction at the seashore
* Audouard was concerned with the applicability of military rangefinders
* in seacoast positions. He begins with a summary of Biot's work, and
* includes as one of Biot's conclusions that "Lorsque la mer est plus
* chaude que l'air, la densité des couches atmosphériques va en
* augmentant de bas en haut jusqu'à une certaine hauteur à partir de
* laquelle elle va en décroissant normalement.  . . .      Le point d'inflexion
* est vers 8 or 10 mètres au-dessus de la mer." [An early determination
* of the Obukhov length!] (p. 213)
*      He makes extensive observations, hoping to show that rangefinders are
* useful despite the peculiar refraction at the shore. One result is that
* "Il semble . . . que la réfraction est un peu plus forte lorsque la surface
* de la mer est nette, c'est-à-dire débarrassée de cette légère brume
* qui la recouvre souvent, même par un beau temps." (p. 225)
*      The refraction is found to be larger than over land, which he
* attributes to the colder water.
* This paper is an ANNEXE to the main publication.


J. Maurer
“Zur Geschichte der terrestrischen Refraktion,”
Met. Z. 22, 262–265 (1905).

* Summary of HEINRICH DENZLER's remarkable unpublished 1843 treatise
* Much emphasis on the importance of the vertical temperature gradient


J. de Graaff Hunter
Professional paper - No. 14: Formulæ for atmospheric refraction and their application to terrestrial refraction and geodesy
(Survey of India, Dehra Dun, 1913).

* J. de GRAAFF HUNTER's varied effort
* Definitely a mixed bag; but it contains several interesting items:
*
* Chapter IV (pp. 65ff.) deals with diurnal changes in refraction.
*
* Chapter V (p. 80) is an attempt to use astronomical refraction to
* determine terrestrial refraction -- the reverse of Faye's folly, but
* subject to similar criticisms. He proposes using 4 stars at different
* altitudes to find the necessary adjustable constants, apparently not
* realizing that there is no information at altitudes above 10 degrees.
* Of course it all depends on the atmosphere being representable by a
* low-degree polynomial and series expansions.
*
* The magic Z.D. of 88° 38' appears on p. 86.
*
* Allowing for his use of μ instead of n for refractive index, we
* see our old friends nR and [R(dn/dR) + n] on p.88; he sets x = nR,
* and then does the path-length integral with x as independent variable.
*
* Notice his comment that "In India the pole star is often hard to
* discern at latitudes not lower than . . . 13° and it is probable that
* these equations will not have a chance of application for [Z.D.] greater
* than 85°." (p.92)
*
* The best part is his derivation of the correct DIP formula (p. 99),
* with the realization that the WAVES cut off the line of sight; but he
* just misses seeing that there is a Kimmfläche (p. 100). He does
* consider the super-refracting case, and says that "For more rapid
* increase of temperature the sea surface will appear concave and there
* will be no true horizon." [This wording appears to have been lifted
* from Professor Everett's 1873 paper in Phil. Mag.]
*      Again (p. 110): "I think the term horizon in this case has no
* strict meaning. With the ray of light of greater curvature than that
* of the earth it would be possible to see all round the earth where there
* were no obstacles above sea-level, were it not for absorption of light.
* This limitation would not give a sharp horizon."
* [Note observation of CONCAVE surface.]
* He does catch a flaw in Chauvenet's argument (p. 99).
*
*      He repeatedly notes the effects of the waves at sea: ". . .  we must
* remember that we see only the crests of the waves at the horizon.
* Accordingly we are concerned with the difference of level of the points
* of observations and the crests of the waves, not of the mean
* water-level.
*      ". . .  r  is the radius of the sea-level surface or, more strictly, of
* the sphere which envelops the crests of the waves, and h is the height
* of the point of observation above this sphere." (p.97)
*      "Now the ray of light to the horizon is obviously tangential to the
* water at the horizon. (p. 97)
*      "In my opinion the temperatures which affect the problem are the
* temperature at the height of the eye and that at the level of the crests
* of the waves: and the difference of height of the eye and wave crests is
* the other quantity concerned." (p. 111)
*
* On p. 102, he refers to "the fact that refraction in a horizontal
* plane is in general so small as to be scarcely measurable." He also
* associates the afternoon minimum refraction with the adiabatic lapse
* rate: "The rate . . . can hardly be exceeded, except momentarily, for
* convection must be set up if it is; and this adjusts the gradient. The
* adiabatic gradient is found then to give a natural minumum refraction."
*
* There is a tantalizing reference to General Walker's observations of
* "other curious effects" (p. 105) -- presumably, mirages.
* Regarding temperature corrections for dip, he quotes Raper's 10th ed.
* (1870); and cites "Navigation" in 10th ed. E.B. as saying "The effect
* of refraction in displacing the apparent sea horizon was partially
* investigated by the French about a century ago," leading to the temp.
* effects, as mentioned by Raper.
*
* The author is listed as ``Mathematical adviser to the Survey of India.''
* According to Bomford's obituary of him, this was his second position
* after serving as Lord Kelvin's assistant; and this was his first
* major publication. He was John Eccles's successor there. Bomford
* (1967) says the results here "cannot yet be bettered."


A. Gülland
“Ueber den theoretischen Refraktionskoeffizienten aus meteorologischen Elementen,”
Z. f. Vermessungswesen 43, 369–385 (1914).

* DIURNAL & ANNUAL VARIATIONS in TERRESTRIAL REFRACTION


J. Würschmidt
“Elementare Theorie der terrestrischen Refraktion und der atmosphärischen Spiegelungen,”
Ann. Physik , series 4, 60, 149–180 (1919).

* followup to Wegener


J. H. Cole
Systematic error in spirit levelling, Departmental Paper No.35 (Ministry of Finance, Egypt: Survey of Egypt)
(Government Press, Cairo, 1919).

* Systematic errors due to drift of refraction with time;
* contains useful data on the run of temperature gradient with time of day


Anon.
“Effects of the diurnal variations of temperature in surveying,”
Met. Mag. 55, 23–24 (1920).

* Summary of COLE's paper, with comments:
* ". . . it might be profitable to set up telescopes with the object of
* measuring the variation of the lapse-rate near the ground as part of the
* routine of a meteorological observatory." [cf. McAdie's remarks on Fisher!]
* "The difficulty in direct measurement of air temperatures is so great that
* an indirect method would be of great service."


A. Mallock
“Atmospheric refraction,”
Nature 107, 456–457 (1921).

* A peculiar exchange; apparently Mallock independently "discovers"
* terrestrial refraction, but insists it has a particular value.
* J. de Graaff Hunter then tries to educate him, but Mallock won't listen.


J. de G. Hunter
“Atmospheric refraction,”
Nature 107, 745 (1921).

* A surveyor points out that Mallock's value is rather larger than is
* employed in surveying -- but I suppose this is because the surveyors
* choose to work when the atmosphere is convective and so less refracting
* than for the Std. models.


A. Mallock
“Atmospheric refraction,”
Nature 107, 745 (1921).

* Mallock nit-picks at minor points while ignoring the main thrust of his
* critic.


J. Ball
“Atmospheric refraction,”
Nature 109, 8 (1922).

* Ball and Baker enter the fray:
* Ball introduces the factor of 2 . . .


T. Y. Baker
“Atmospheric refraction,”
Nature 109, 8–9 (1922).

* Baker's first letter, mentioning DIP and DISTANCE to HORIZON
* . . . while Baker complains the ray is not a circular arc, because
* "The temperature-gradients in the first 30 ft. (the average height of
* the bridge of a ship above the sea) are very frequently greater than any
* of the gradients mentioned above, and show wide variations in that space."
* "Measurements made by Blish off the coast of California showed that a
* zero dip is quite possible. In the Red Sea the sea horizon is often
* refracted above the true horizontal." But he thinks the ray is actually
* tangent to the surface in such cases, as Lutz Hasse has not yet invented
* the concept of the Kimmfläche.
* [Note observation of CONCAVE surface.]


T. Y. Baker
“Atmospheric refraction,”
Nature 109, 105 (1922).

* Baker's second letter
* Reduces Ball's claim of difference in refraction for plane and spherical
* waves to an absurdity.
* Cites Herman's "Geometrical Optics", p.305; and Heath, "Geom.Optics",
* p.329, for the relation involving the perpendicular to the ray.
* ". . . we can only admit uniform curvature [of the ray] if we are prepared
* to admit that the density of the air in its lowest levels is a linear
* function of the height. To such an admission I take the strongest
* exception. It is quite insufficient to account for a refraction of the
* visible sea horizon above the true horizontal -- a phenomenon which, as
* every seaman knows, is by no means uncommon."
* [Note observation of CONCAVE surface.]


J. Ball
“Atmospheric refraction,”
Nature 109, 444 (1922).

* John BALL finally sees where the problem lies:
* "It is only under isothermal conditions, such as seldom or never occur
* in practice, that Mr. Mallock's result can be even approximately true;
* it was evidently incorrect to consider, as Mr. Mallock did in his reply to
* Dr. Hunter, that temperature effects could produce merely a difference in
* the result of 1 or 2 per cent. per 1000 ft. The mistake of assigning an
* insignificant part to temperature considerations is one which is very
* easily fallen into by anyone who first considers the isothermal condition
* with its accompanying relation between density and pressure, because of
* the small effect which the existence of a temperature gradient has on the
* rate of decrement of pressure as distinguished from density."


J. de G. Hunter
“Atmospheric refraction,”
Nature 109, 549–550 (1922).

* Hunter has another go at Mallock, pointing out that his model "is
* incorrect as regards the density and refractivity gradients, except in the
* special case when the temperature gradient is zero."


Thos. Y. Baker
“Atmospheric refraction,”
Nature 109, 550 (1922).

* Baker responds to Hunter
* Now Baker attacks Hunter's formula for dip (much discussion of rays with
* zero dip -- i.e., rays that remain in a level surface):
*      "The fact is that in an atmosphere where the layers of uniform
* refractive index are spheres concentric with the earth, the dip can
* only be zero, if at all, at one height. Below that height the dip
* will be positive with a maximum value at some lower level; above that
* height no ray tangential to the earth's surface can be seen at all,
* and the depression or elevation of the sea horizon requires an entirely
* different explanation."
*
* ". . . in such a case a ray once horizontal would remain horizontal for a
* complete circuit of the Earth."
* Of course by now Kummer's 1860 paper is long forgotten!


N. K. Johnson and O. F. T. Roberts
“The measurement of the lapse rate of temperature by an optical method,”
Q. J. Roy. Met. Soc. 51, 131–138 (1925).

* LAPSE RATE and REFRACTION


K. Brocks
“Eine Methode zur Beobachtung des vertikalen Dichte- und Temperaturgefälles in den bodenfernen Atmosphärenschichten,”
Met. Zs. 57, 19–26 (1940).

* LAPSE RATE and REFRACTION
* Brocks's early review, citing Brandes (1804)
* Shows that temp. gradient is far more important than T itself.
* (cf. Kurzyńska)


K. Brocks
“Die terrestrische Refraktion in polytropen Atmosphären,”
Deutsche Hydrog. Zs. 2, 199–211 (1949).

* followup to EMDEN
* "Es ist eine bekannte aerologische Erfahrung, dass die Lufttemperatur
* ausserhalb der bodennahen Störungsschicht sich im allgemeinen in der
* Weise mit der Höhe ändert, dass der vertikale Temperaturgradient in
* mehr oder weniger ausgedehnten Höhenbereichen annähernd konstant ist
* und sich nur an den Schichtgrenzen unstetig ändert."
* [Actually, more like an assumption than an experimental fact.]
* "Hierbei bewirkt der Beobachtungsfehler des vertikalen
* Temperaturgradienten mehr als 90% der Fehlerquadratsumme. . . " (p.202)
* CONDITION FOR CIRCULAR ARCS:
* "Für  γ = 1.71° /100 m ist der lokale Refraktionskoeffizient
* mit der Höhe konstant, d.h. die Lichtstrahlen sind kreisbogenförmig."
* (p.203) -- so in general, the curvature is greatest in the lowest parts.


R. G. Fleagle
“The optical measurement of lapse rate,”
Bull. Am. Met. Soc. 31, 51–55 (1950).

* Robert G. Fleagle cites Brocks, and Johnson & Roberts
*      See also Freiesleben, 1950 & 1951


J. de Graaff-Hunter
“The geodetic uses of gravity measurements and their appropriate reduction,”
Proc. Roy. Soc. A 206, 1–17 (1951).

* J. de Graaff-Hunter again
* Notable for section 5 (pp.12-15), which discusses refraction, and
* concludes that "There is scope for fuller inquiry into the refraction
* question."


J. de Graaff-Hunter
“Various determinations over a century of the height of Mount Everest,”
Geographical J. 121, 21–26 (1955).

* J. de Graaff-Hunter once again
* Notable for the historical discussion of refraction corrections in geodesy.
* E.g.: ". . . diurnal variation of refraction . . . had been well known
* to Colonel Everest . . . , for in his reconnaissance for the Great Arc of
* triangulation at the crossing of the featureless plains north of Agra
* he was making use of maximum  refraction . . . :      'The extent of view at
* time of maximum refraction; this varies from midnight to sunrise and
* is generally about 3 o'clock . . . .' (p. 21). And:
* ". . . General J. T. Walker was investigating refraction in the Punjab
* plains where extreme and even negative refraction was encountered --
* diurnal variation of refraction of the kind that makes the observer feel
* as though in a saucer at dawn, later on seeing objects sinking below
* the horizon as receding ships at sea!" (p. 22)
* [Note observation of CONCAVE surface.]


R. H. Phillimore
Historical Records of the Survey of India, Vol. IV, 1830 to 1843: George Everest
(Survey of India, Dehra Dun, 1958).

* The SURVEY OF INDIA records cited in proof by de Graaff-Hunter (1955)
* The passage excerpted by de Graaff-Hunter is on p. 23. Other good quotes:
* P. 41: "The marvels . . . of refraction which were experienced by Captain
* Waugh . . . were of a similar kind to those of which I have before spoken
* . . . , but of a still more astounding extent. . . . Instances [included] . . .
* two stations 20 miles and upwards asunder, the observed vertical angle
* and its reciprocal were both elevations at the same instant." [Everest]
*      On p. 93, Phillimore says that Everest tried to obtain simultaneous
* observations of vertical angles from both ends of each arc. "He did
* not insist on observation at the hours of minimum refraction when --
* with his long rays -- signals were often below the line of sight."
* [He means, below the horizon.] Everest continues:
* ". . . vertical angles . . . have been observed at all hours of the day,
* generally, however, in the morning. . . . I have not been able to infer
* that the elevations and depressions of distant stations were affected
* in any certain way by the change of temperature at different hours."
* Everest was evidently aware, however, that there is a regular diurnal
* variation in refraction; he recommended measuring from opposite ends
* of the same arc at the same time of day, when only one observer was
* available. He says: "About 3 or 4 in the afternoon is generally . . . the
* instant of minimum, and the same hour after midnight . . . that of maximum.
* In certain conditions the difference is immense."
*      The main discussion of refraction is on pp. 105 - 107.  It begins with
* Phillimore's remark about "the vagaries of terrestrial refraction,
* whereby a distant point which is entirely out of sight during the day
* may become clearly visible after dark, provided there is a lamp or fire
* to mark its position." Here are some of Everest's comments:
* ". . . the disk of the Godhna heliotrope made its appearance very late
* on the evening of the 25th November. It was then obviously rising very
* rapidly. . . . When seen it was at a depression of between 7 and 8 minutes,
* and had probably risen 2 minutes, thus standing at the time of minimum
* refraction at a depression of 10 minutes.
*      "At 3 hours 55 minutes after midnight on the 25th November the Godhna
* lamp stood at an elevation of 2' 55'', and on the 27th November at the
* same hour, at a depression of 18'', thus shewing a discrepancy . . . of 13
* minutes or more between the after noon and after midnight refraction,
* and an uncertainty . . . of 3' 13'' . . . at the same hour. . . . The vast
* difference . . . between observations made at the same hour without any
* visible cause baffles all computation."
*      P. 106: "At Nojhili on the 27th November 1835, at 8 a.m., the
* phenomenon was first noted of the heliotrope assuming the columnar form,
* in which that of Dahera shewed itself tall, slim, and erect. The same . . .
* has since occurred so frequently as to have become a matter of common
* notoriety. . . ." [cf. Biot & Arago (1810); Hodges (1953)! ]
*      "Between 3 and 4 p.m. is the hour of minimum, and the same hour after
* midnight is the period of maximum refraction."
*      "In some instances in the month of January the image of the distant
* heliotrope had its periodic hour of rising before sunset, but was never
* seen at any other hour of the day. In the months of March and April,
* however, the heliotropes at sunrise, and for sometimes an hour after,
* were seen projected high up on the sky, and frequently in the form of
* a tall column.
*      "The afternoon rise of the distant heliotrope is curious and
* beautiful. The first rays spread themselves like a running fire along
* the surface of the obstructing land, . . . the light then descends and
* re-ascends, till after a few oscillations it ultimately rises into a
* clear round disk, and remains visible till the rays of the sun become
* too feeble for reflection.
*      [p. 107] "The descent in the morning is equally remarkable.
* In favorable weather the round disk appears immediately subsequent to
* sunrise, projected high up in the sky, and after . . . a short time it
* gradually descends . . . or . . . suddenly vanishes as if by an explosion."
* [This would be the disappearance in the inferior mirage at the surface.]
*       Later, Everest says: "Every observation is made . . .  through a medium
* of very uncertain consistency and variable temperature. . . . The smoke
* and vapours which are perpetually rising from the earth have palpably
* not an uniform density at a given height above the surface. . . ."
* [What a Ptolemaic remark!]
*      "The state of the atmosphere immediately after sunrise . . .  is rarely
* to be depended on; . . . the disk of the heliotrope then often shows small
* and round . . . near the horizon, like a candle shining dimly through a
* hole in a curtain, but, even whilst the observer is . . . intersecting this
* object, another image exactly similar to it rises to the right or left,
* above or below, after which the first disappears, . . . ."


M. S. Sodha, A. K. Aggarwal, and P. K. Kaw
“Image formation by an optically stratified medium: optics of mirage and looming,”
Brit. J. Appl. Phys. 18, 503–511 (1967).

* cites a few references; comments on the range-finder method of
* Fleagle (1956) and IMAGE POSITION.
*      Unfortunately, they assume an incorrect (exponential!) analytic form for
* the refractivity profile; so the results are only qualitative.
* Cites the 1966 note by Aggarwal and Kaw for the image position idea.
* [Cf. Gergonne (1809, 1829) and Nölke (1917).]


A. K. Aggarwal and P. K. Kaw
“Optical measurement of atmospheric refractive index gradient over a curved cold surface,”
JOSA 57, 963 (1967).

* correction to their earlier note


A. K. Aggarwal and P. K. Kaw
“Optical measurement of the atmospheric refractive index gradient,”
Brit. J. Appl. Phys. 18, 1485–1489 (1967).

* cites a few references; comments on the range-finder method of
* Fleagle (1956)


D. Paperlein
“Lichtstrahlkrümmungsmessungen mit einem Artillerieentfernungsmesser in der bodennahen Luftschicht,”
Arch. Met. Geoph. Biokl., Ser. A 24, 347–359 (1975).

* Many REFS to literature; 12 to methods for extracting Tgrad data.
* Full title: Archives of Meteorology, Geophysics and Bioclimatology
* This journal became "Meteorology and Atmospheric Physics" in 1986.


S. Church
“Atmospheric mirage and distortion modeling for IR target injection simulations,” in Targets and Backgrounds: Characterization and Representation II , W. R. Watkins and D. Clement, eds., (SPIE Proc. 2742)
(SPIE, Bellingham, Washington, 1996), pp. 122–135.

* IR mirages; examples shown; multiple horizon inside surface duct
* from elevated inversion.
* Steve Church, Arete Associates, P.O.Box 6024,Sherman Oaks, CA 91413
* church@arete.com (another reprint in the mirage file)
* TEMPERATURE PROFILES (and refraction) FILE
*
* See also ABBE (1886) in TILT file.
*
*
* HUGO GYLDÉN's 1866 paper on refraction and atmospheric structure.
*
* Two different copies have been scanned and are available on the Web:
*
* The Google scan at
* https://babel.hathitrust.org/cgi/pt?id=umn.31951d00011877d;view=1up;seq=9
* lacks OCR text. A better scan at
*      https://www.biodiversitylibrary.org/item/112869#page/7/mode/1up
* has generally good OCR text, but some of the text on the first page
* is missing. (It's the Harvard scan from the MCZ copy.)
*
* The text begins on image 15 of the Harvard scan (p.1 of the paper).
* some of its content is not OCR'd properly. (Later pages are largely OK.)
*
* He begins by considering the atmospheric structure. His word for the
* lapse rate is "Temperaturabnahme". Already on p. 2 he says that
* "Untersuchungen, in wiefern merkliche Veränderungen in der
* Temperaturabnahme mit veränderter geographischer Lage des Punktes, von
* welchem an dieselbe gerechnet wird, hervorgehen, nicht unwichtig sein."
*      Then he considers time variations: the daily and annual periodic ones,
* which can be inferred from "aeronautic expeditions". But the short
* duration of these flights makes it difficult to distinguish the regular
* variations from "accidental" ones, such as "discontinuities"; of which,
* Gyldén says:
*             "Einige bei den Luftfahrten gemachte Wahrneh-
* mungen deuten darauf hin, dass in einiger Entfernung
* von der Erdoberfläche die Wärmeabnahme plötzlich klei-
* ner wird, und sodann wieder rascher vor sich geht.
* Diese Erscheinung ist indessen noch nicht sicher genug
* festgestellt, um berücksichtigt werden zu können."
* (footnote on p. 4)
* or:
* Some observations made in flight indicate that the lapse rate suddenly
* decreases at some distance from the surface, and then increases faster
* again. However, this phenomenon is not yet certain enough to be considered.
* (This seems to be an early hint of the ubiquitous "sheets and layers".)
*      He continues: 'If these circumstances exert an appreciable influence
* on the refraction . . . , the mean refraction would not depend on the
* zenith distance alone.'
*
*      On pp.5 and 6, he comes to the heart of the matter:


H. Gyldén
“Untersuchungen über die Constitution der Atmosphäre und die Strahlenbrechung in derselben,”
Mémoires de l'Académie impériale des Sciences de St.-Pétersbourg 10(7), No. 1, 1–82 (1866).

*      "Die jetzt allgemein gebrauchten Refractionstafeln von Bessel beruhen
* auf einer Voraussetzung über die Temperaturabnahme, welche bekanntlich
* den Thatsachen sehr ungenügend entspricht. Die von ihm angenommene
* Wärmeabnahrae ist nehmlich eine viel geringere, als die wirklich
* stattfindende mittlere Temperaturabnahme, und dem entsprechend sind die
* Refractionen, wie sie aus seinen Tafeln berechnet werden, für grosse
* Zenithdistanzen zu gross. Die Gründe, welche Bessel bewogen hatten,
* dieses falsche Temperaturgesetz anzuwenden, können wir aus seinem
* lehrreichen Aufsatze «Einige Resultate aus Bradleys Beobachtungen»1)
* ersehen. Bradley hatte nehmlich einige sehr tief stehende Sterne
* beobachtet, und die aus diesen Beobachtungen gefolgerten Refractionen
* wollte Bessel durch seine Theorie darstellen. Die fraglichen
* Beobachtungen waren aber meistens bei Nacht und im Winter angestellt,
* wesshalb die aus ihnen folgenden Refractionen grösser ausfallen mussten,
* als diejenigen, welche man unter Berücksichtigung der Veränderlichkeit
* der Temperaturabnahme mit der Zeit erhalten haben würde. Um nun diese
* grossen Refractionen darstellen zu können, wählte Bessel diejenige
* Hypothese, welche auch jetzt nach ihm benannt wird, und welche, wie er
* selbst zugab, nicht die Temperaturabnahme an der Erdoberfläche darstellt."
*      (The footnote cites "Königsberger Archiv für Naturwissenschaften und
* Mathematik. I. Bd." as Bessel's instructive treatise.)
*      So his aim was to find a realistic temperature profile that would
* reproduce observed refractions. Of course, this is easy to do; as Ivory
* had found; there are lots of profiles that work well in the region of
* small and moderate Z.D. Today we know that where the ray is so nearly
* straight that the local ZD hardly depends on atmospheric structure, the
* refraction depends almost entirely on the refractivity at the observer.
*      The matter is quite different near the horizon.  Gyldén struggled to
* produce analytical results for the horizon region, but did manage to get
* approximations for the horizon itself, using all the standard calculus
* tricks (series expansions, integration by parts, partial fractions, etc.)
* Having read Ivory's papers, he was aware of convergence problems; the term
* "halb-convergirende Reihe" is on p. 46. Kramp is mentioned on pp. 57 ff.
* Hypergeometric series, p.61,63.
*
* The concluding paragraph on p. 80 is:
*      "Eine Vergleichung der Tafeln mit den beobachteten Refractionen wird
* hier nicht gegeben, da eine solche mit den aus Argelander's Beobachtungen
* gefolgerten Mittelwerthen in den Tab. Reg. ohne Weiteres auszuführen ist,
* hauptsächlich aber, weil eine von Herrn Abbe in Pulkowa, eigens zu
* diesem Zwecke angestellte Beobachtungsreihe, welche sicherlich einen
* sehr werthvollen Beitrag zu unseren Kenntnissen der Refractionen in
* grossen Zenithdistanzen liefern wird, noch nicht geschlossen ist."
*
*      In English, this says:
*
*      "A comparison of the tables with the observed refractions is not given
* here, since such a comparison can easily be carried out using the mean
* values deduced from Argelander's observations in the Tab. Reg., but
* mainly because a series of observations made by Mr. Abbe in Pulkovo
* specifically for this purpose, which will certainly make a very valuable
* contribution to our knowledge of refractions at large zenith distances,
* has not yet been completed."
*      But Abbe's observations were never published.
*
* NOTE: Gyldén's paper was presented to the Academie on 20. April 1865,
* and has a cover page dated 1866; it is written in German. and was printed
* by Buchdruckerei der Kaiserlichen Akademie der Wissenschaften, although
* Gyldén's German pages have a signature footer that says "Mémoires de
* la Acad. Imp. des Sciences, VIIme Série".
*       The volume as a whole is dated 1867, as the other numbers in it were
* set in type later. Some of them are in German, some in French, and
* some in Latin. Most are medical, botanical, or biological.


K. Brocks
“Über den täglichen und jährlichen Gang der Höhenabhängigkeit der Temperatur in den unteren 300 Metern der Atmosphäre und ihren Zusammenhang mit der Konvektion,” in Ber.Deutsch.Wetterdienst.US-Zone,Nr.5
(Deutscher Wetterdienst, Bad Kissingen, 1948).

* lowest 300 m, including details of lowest 50 cm for INFERIOR MIRAGES
* review article


K. Brocks
“Eine räumlich integrierende optische Methode für die Messung vertikaler Temperatur- und Wasserdampfgradienten in der untersten Atmosphäre,”
Arch. Meteor. Geophys. Bioklim. A 6, No. 3/4, 370–402 (1954).

* KARL BROCKS
* Mostly a theoretical discussion of inverting measured terrestrial
* refractions; but he has tried it at the mouths of the Elbe (!) and
* recommends symmetrical targets rather than the corners of towers and
* other objects. He allows for targets at a different height from the
* observer, and finds that the method is so sensitive to height errors
* that precision levelling is necessary. A tripod is not stable enough
* as a theodolite support; he used stone pillars in the mountains, and
* concrete or stone parapets at the North Sea. The theodolite must be
* protected from solar heating.
*      The results of the actual measurements will be published elsewhere.


G. Bomford
Geodesy (3rd edition)
(Clarendon Press, Oxford, 1971).

* BOMFORD: GEODESY (3rd edition, 1971)
* TEMPERATURE PROFILE OVER WATER: pp.63-66.
*      His treatment of refraction is vastly better than in the first (1952)
* edition. Here it is on pp. 300 and 301, where he quotes from (but does
* not cite) Bessel's error table from the 1823 A.N. discussion (col. 385),
* and mentions the tilt effect.


E. E. Gossard, J. E. Gaynor, R. J. Zamora, and W. D. Neff
“Finestructure of elevated stable layers observed by sounder and in situ tower sensors,”
J. Atmos. Sci. 42, 2156–2169 (1985).

* GOSSARD et al. (1985) on fine structure at the Boulder 300m tower
*      Note: they use "sheets" for the stable inversions, and "layers"
* sometimes for the convectively unstable (nearly or super-adiabatic)
* regions of high turbulence between the "sheets". Also, their examples all
* have very slow winds (< 2 or 3 m/s; see Figs. 4-6 and 9), and weak shear.
* ". . . such observations have not been reported . . . because the
* temperature and humidity sensors used in radiosondes have had inadequate
* response for the usual rates of ascent of balloons . . . ." [p. 2156]
*      There is also discussion of "over-the-horizon" (i.e., concave apparent
* surface) radio propagation.
*      Figs. 8-10 show very steep elevated inversions (typically 5°C in 5 m) at
* heights on the order of 100m. These would cause very strong superior
* mirages. Cf. Fig. 5 (p.2162).
* There is some insteresting discussion on p.2168:
* "The observations show that active wave development occurs when the
* macroscopic Richardson Number is large and that mechanical turbulence
* is weak and dying under these conditions. Wave development and breaking
* then creates a turbulent zone of convective mixing. As the cooler air
* above mixes with the warm air below, the superadiabatic lapse rate is
* erased and is eventually replaced by a slightly stable turbulent zone of
* downward heat flux entraining warmer air from the zone above into its
* upper boundary (and entraining cooler air at its lower boundary). . . .
* Both the entrainment process and the pattern of heat convergence and
* divergence, shown by the solid arrows, tend to sharpen the gradients
* within the bounding sheets."
*      The most interesting Conclusions are:
*       1) Thermally stable elevated atmospheric layers are
* commonly made up of thin transition zones of very
* high gradients of wind, humidity and temperature.
*      4) The profiles sometimes adjust to nearly evenly
* spaced layers that persist over long periods.
* [NOTE: these multiple layers were discussed by Tait (1883).]
*      In Conclusion 5, they argue that "Simple and quite general reasoning
* leads to a ratio of sheet-to-layer thickness" that is the ratio of
* critical Richardson numbers for starting and stopping turbulence --
* i.e., about 4. [Cf. van de Wiel et al. (2012); Grachev et al. (2013);
* Lan et al. (2018); Srivastava & Sharan (2019).] For a more recent look
* at "sheet & layer" structure, see Doddi et al (2022) in the BLMrefs.
*      Most of the figures are replays of their 1984 paper in Radio Sci.


H. Savijärvi
“Radiative and turbulent heating rates in the clear-air boundary layer,”
Q. J. R. Met. Soc. 132, 147–161 (2006).

* RADIATIVE effects
* The first sentence of the Introduction is:
* "The structure of the stable nocturnal boundary layer (NBL) is not well
* known." He finds that radiative exchange tends to smooth the profiles
* in the lowest few meters, as well as pulling the lowest layers closer
* to the surface temperature. "When the surface winds fall below about
* 1 - 1.5 m/sec . . . the Monin-Obukhov theory should be revised to include
* radiative effects." [Abstract] For moderate winds (6 m/s at the
* geostrophic level) the "simulated potential-temperature profiles are
* fairly logarithmic in z in the lowest 5 - 10 m down to the ground." (p.155)
* "An alternative analytic representation for the near-surface NBL
* temperature profile is that the temperature deficit between the surface
* and 2 m decays exponentially upwards with a scale height of about 1 m."
* (p. 159)


C. Hirt, S. Guillaume, A. Wisbar, B. Bürki, and H. Sternberg
“Monitoring of the refraction coefficient in the lower atmosphere using a controlled setup of simultaneous reciprocal vertical angle measurements,”
J. Geophys. Res. 115, D21102 (2010).

* Christian Hirt et al. introduce the method of multiple total stations
*      Measurements are expressed in terms of the ratio k  of ray curvature
* to Earth curvature "around 1.8 m above the grass surface".
* "For mostly sunny days, we found wave-like and sawtooth-like
* fluctuations of the refraction coefficient with amplitudes of 1--1.5 at
* time scales of 10--30 min. On cloudy days, the amplitudes of fluctuations
* were on the order of 0.5. Our refraction experiments show a variation
* range of k between -4 and +16 near the ground on sunny summer days. This
* equates to vertical temperature gradients between -0.5 and -0.1 K/m
* during the day and 1--2 K/m shortly after sunset. Cloud cover reduces
* the variability of k to a range of -2 to +5. Our results show that the
* frequently used Gaussian refraction coefficient of +0.13 is not suited
* for describing refraction effects in the lower atmosphere." (Abstract)
*      NOTE: Their terminoogy is far from the usual meteorological usage:
* "We follow a frequently used model concept that subdivides the
* atmosphere into three different regions, i.e., the higher, intermediate,
* and lower atmosphere [Brocks, 1948; Wunderlich, 1985]. (p. 2)
*      "For the higher atmosphere,  some 100 m above the ground and higher,
* the vertical temperature gradient is fairly independent of the temperature
* of Earth's surface. The vertical temperature gradient ∂T/∂z is about
* -0.006 K/m, . . . " (p. 3)
*       "The intermediate atmosphere,  about 20--30 m to some 100 m [cf. Webb,
* 1984; Wunderlich, 1985], is weakly influenced by the temperature of the
* surface and characterized by temperature gradients frequently of about
* -0.01 K/m, [cf. Bomford, 1980]. This gradient equates to a refraction
* coefficient of +0.15. Also, the Gaussian refraction coefficient of
* +0.13 refers to the intermediate atmosphere and is appropriate for dry
* adiabatic conditions."
*      "In contrast to the higher and intermediate atmosphere, the thermal
* characteristics of the air strata of the lower atmosphere (lowest
* 20--30 m) are strongly subjected to the varying thermal properties of
* the surface [e.g., Angus-Leppan, 1969]."
*      There are extensive references to older measurements in the geodetic
* literature, and subsections devoted to refraction below 3 m, below 1 m,
* and refraction over ice and water. (But no mention of the 19th-Century
* and earlier works.)
*      Figs. 5 and 7 show time-plots of k  that include an abrupt peak at
* sunset on sunny days. But there are no wind data, so it's not possible
* to do a MOST analysis.
*      [Cites my 2006 tutorial, but also the unreliable Thomas & Joseph paper
* (1996).]
* DOI: doi:10.1029/2010JD014067


S. C. McCluskey
“Archaeoastronomical refraction reconsidered,”
Mediterranean Archaeology and Archaeometry, Vol. 18, No. 4, 477–484 (2018).

* Stephen C. McCluskey's 2018 paper, citing Bomford (among many others)
* Nice distinction of astronomical, terrestrial, and "archaeoastronomical"
* refractions. As in Marcel Tschudin's 2019 paper, he emphasizes the
* rapid changes in the effects of atmospheric structure close to the
* horizon; these changes explain the discrepancies between the repeatable
* observations at elevated foresights and the wildly varying observations
* at a sea horizon. (Cf. Kayser, 1877)


A. Doddi, D. Lawrence, D. Fritts, L. Wang, T. Lund, W. Brown, D. Zajic, and L. Kantha
“Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL): high-resolution in situ observations and modeling in and above the nocturnal boundary layer,”
Atmos. Meas. Tech. 15, 4023–4045 (2022).

* Layer/Sheet structures studied with new technology
* (See the 2018 paper by Balsley et al. in "capping" for an earlier report.)
*      Intensive campaign at Dugway Proving Ground in 2017, using drones and
* fast-response 5-micron Pt wires. The Intro. says:
*      "Under stable conditions, the vertical structure of the atmosphere is
* characterized by thin, strongly stable non-turbulent “sheets” separated
* by thicker, less stable, and often weakly turbulent “layers”. . . ."
*      Preliminary results (p. 4032): "Following the criterion described
* by Muschinski and Wode (1998) and Dalaudier et al. (1994), temperature
* gradients on the order of 17Γ (Γ --- adiabatic lapse rate) were used
* to identify the edges of stable sheets. A total of 58 individual stable
* sheet structures roughly 25 to 50 m thick were identified from the DH2
* measurements in this campaign. Stability ducts, consisting of large
* N2 sheets constraining weakly stable and weakly turbulent layers as
* deep as 400 m, were also prevalent (see ε in Figs. 11 and 13). Such
* structures, often persisting up to 5 h under very stable conditions,
* were commonly observed near the peak altitude of Granite Mountain (850
* to 900 m a.g.l.). . . .       Temperature gradients as steep as 0.18 K m(-1)
* or ~ 18Γ (with tropospheric dry adiabatic lapse rate Γ ~ 9.8 × 10(-3)
* K m(-1) ) were typically observed across most sheets." [These would
* produce super-refraction and superior mirages.]
* PAIRED INVERSIONS: They continue: "A shallow nocturnal boundary layer
* (200 m deep), with recurring sheet activity at the mountaintop (850 m)
* and higher aloft (1450-1600 m) separated by deep, intermittent
* turbulent layers (600-800 m deep), was the general theme underlying the
* observations at FS1. Escalation of shear at altitudes coincidental with
* the undulating sheet pairs may be responsible for their recurring decay,
* providing intermittent forcing for the turbulence inside the layers."
* And the Conclusion begins:
*      "Sheet and layer (S&L) structures appear to be ubiquitous in the
* nocturnal boundary layer under relatively quiescent conditions, often
* extend to higher altitudes in the lower troposphere, and have parallels
* extending to much higher altitudes at larger spatial scales."
*      Abhiram Doddi, Dale Lawrence, David Fritts, Ling Wang, Thomas Lund,
* William Brown, Dragan Zajic, Lakshmi Kantha
* PDF: amt-15-4023-2022.pdf downloaded; mv to Doddiet al amt-15-4023-2022.pdf
* DOI: https://doi.org/10.5194/amt-15-4023-2022


S. Giudici
“A long range sighting and terrestrial refraction,”
Eur. J. Phys. 43, No. 4, 045301:1–11 (2022).

* Nice pedagogical use of ray curvature, lapse rate, etc. by Sergio Giudici
* DOI: https://doi.org/10.1088/1361-6404/ac6d29



*** POLAR AXIS and REFRACTION FILE ***

C. Davidson
“On the apparent diurnal motion of stars in relation to the adjustment of the polar axis of a telescope,”
M. N. Roy. Astron. Soc. 58, 4–9 (1897).

* "At Greenwich the polar axes of the photographic equatorials have been
* adjusted so that when the instrument is pointed to, or near, the Pole, and
* the clock is rated to sidereal time, no elongation of the image occurs.
* This implies that the polar axis of the telescope does not point to the
* true, but to the apparent Pole (as affected by refraction)."
* Nov. 1897 issue


A. R. Hinks
“On some attempts to counteract by instrumental adjustments certain effects of refraction in stellar photography,”
M. N. Roy. Astron. Soc. 58, 428–440 (1897).

* Discussion of field rotation and distortion due to differential
* refraction
* June 1898 issue, but still vol.58


E. S. King
“Forms of images in stellar photography,”
Ann. Harvard Coll. Obs. 41, 153–187 (1901).

* Edward S. KING's classic paper
* ". . . the adjustment on the refracted pole is commended . . . ."



*** NAVY PUBS. FILE ***

R. A. Paulus
“Validation of the bulk method for overwater optical refractivity,” in (NOSC TR 1462)
(NOSC, San Diego, 1991).

*
* papers from Juergen Richter at NCCOSC
*
* "multiple images were commonly observed. Of the 7 days, 2 had
* an optical duct. . . . The remaining days had subrefractive
* conditions. . . ." (i.e., inferior mirages).
* This uses a *model* to calculate the refractivity profile from surface
* conditions!


J. S. Hornstein, R. G. Priest, E. H. Takken, and D. Baukman
“Models of refraction in the marine atmospheric surface layer,” in (NRL/FR/7227--93-9547)
(Naval Research Lab, Washington DC, 1993).

* Badly flawed by (a) assumption of Monin-Obukhov theory where it isn't
* valid; and (b) confusion between radiance & irradiance (much garbage about
* attenuation by ray divergence in discussing radiance).
*      However, they do describe the separation of ducted from escaping rays
* as a "bifurcation".


R. Feinberg et al.
“Marine boundary layer refractive effects in the infrared,” in (NCCOSC TD 2706, previously published as TN 555, Oct.1978)
(NCCOSC, San Diego, 1994).

* (contains several badly-reproduced mirage photos)
* "For air temperature gradients less than -1degC/m, it was demonstrated
* that a severe shortening of the optical and infrared horizons consistently
* occur."


R. Feinberg and H. G. Hughes
“Marine boundary layer refractive effects in the infrared,”
Appl. Opt. 18, 2532 (1979).

* the same stuff, condensed.


(No editor named)
Propagation assessment in coastal environments (AGARD Conf.Proc. 567, Feb.'95)
(AGARD, Neuilly-sur-Seine, 1995).

* as in all the other references, a constant temperature gradient with
* height is assumed. This is certainly contrary to our observations!)


© 1999 – 2024 Andrew T. Young