* 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:
* 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 Holboldt 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 (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 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.
* 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!
* 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)
* 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).
* Very EARLY MIRAGE descriptions (1558) by Antonius de Ferrariis (1444-1517)
* also known as Antonio Galateo, Galateus Antonus, etc.
* 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.
* Thomas Facellus (Tommaso Fazello) briefly mentions mirages
* (Panormi = Palermo)
* Cited by Minasi; and, following him, P&E. 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
* I have not seen this.
* 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 1 Naturae, siue de Morgana Rheginorum in Freto Mamertino,
* siue Siculo" -- here, on p. 801, we have "Vocant autem Rhegini hoc
* spectaculum Morganam," followed by Angelucci's letter.
* 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 paper on
* Harriot.)
* 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."
* 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).
* 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!
*
* 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."
* 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.
* 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.)
* Mather's account enshrined by the poet Longfellow
* (Thanks to Penny Porter for pointing this out!)
* 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.
* (see also "Crocker Land" and "W.H.Lehn" files)
*
* MIRAGE OBSERVATIONS
*
* 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.
* 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.
* 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
* BOSCOVICH translated into French
* The same section numbering is used as in the original. There is a
* detailed map included, showing the region surveyed.
* 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.]
* 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.
* 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."
* 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!
* 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.)
* 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.
* 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.
* 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.
*
* TOBIAS GRUBER's letter
* An amazingly perceptive summary of the salient points: flat, smooth
* ground; the hiding of objects below the "vanishing line"; 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."
* This is actually a Postscript (Nachschrift ) to the Fifth Letter,
* beginning on p. 40, and dated 20 April 1779, from Zirknitz.
* Typographical note: this is all set in Fraktur, with little e's over
* the vowels as umlauts.
*
* Full title page reads:
*
* Herrn Tobias Grubers,
* Weltpriesters und k. k. Bau- und Navigationsdirektors
*
* 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
*
* [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
* 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!
* Here, 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. . . .
* Interestingly, he does invoke total internal reflection (p. 53).
*
* 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, appending notes to it -- 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)
*
* 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.
*
* Special thanks to the ILL people for this one at last!
* 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
* 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.
* 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 .
* 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.
* 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"!
* 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. . . ."
* 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 a 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."
* 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.
* 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".
* 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."
* EARLY OBSERVATION & EXPLANATION OF INFERIOR MIRAGES
* The same, reprinted:
* Note: Nicholson's Journal merged with Phil. Mag. in 1813.
* 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 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."
* 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.)
* 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 crank theory (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 additional 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
* 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 of 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).
* 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, 1797 -- 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!
* 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.]
* 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.
* 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.
* GASPARD MONGE explains the INFERIOR MIRAGE as total internal reflection,
* and reports REFLECTED RAINBOWS
* Cf. Le Gentil (1789) for "se mirer".
* 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!)
* 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.
* EARLY MIRAGES
* summaries of the work of others by Ludwig Wilhelm Gilbert:
* EARLY EXPERIMENTAL DEMONSTRATION OF MIRAGE
* Abbé Tobias Gruber (Grüber?) -- see his 1786 paper.
* QUANTITATIVE MEASUREMENTS of MIRAGES and VARIABLE REFRACTION
* Reinhard Woltman (Not "Woltmann", says Pogg.)
* Gilbert attributes the term "Spiegelung" to Woltman.
* [It seems that Woltman was Brandes's supervisor in 1794-95.]
* 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."
* 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 des
* Wasser um 2° F. kälter als die Luft, so fand Hebung der Strahlen
* und nie eine Spiegelung herabwärts statt."
* Note that Gilbert prints double-s as a long followed by a short s.
* EARLY THEORY OF MIRAGE
* Abbé Tobias Gruber (Grüber?)
* 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.
* 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.
* 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.
* Gilbert's translation of Wollaston's 1800 paper, with copious notes:
* 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".
* 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. 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. [Probably "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.
* 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.
* William Beauford's perceptive review, just before Wollaston's
* Probably this should be the first entry in the FOG file. However, his
* perceptive remarks requite 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 c