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phenomena, and nothing that will serve as a basis of any physical investigations; but, on the 12th of May, of the last-mentioned year, there happened a total eclipse of the sun, which was observed at several places in Europe by astronomers who gave more particular attention to its effect on animals, and to the appearances presented by the sun and moon.
At Montpellier, where it was observed by MM. Plantade and Capiés, the total obscuration lasted 4' 10". The corona of light around the moon was observed; and the planets Venus, Mercury, and Saturn; Aldebaran and several other of the fixed stars were observed by the naked eye. “The bats flew about as at dusk; the fowls and pigeons betook themselves in great haste to their resting-places; the little birds, which sung in cages, were silent, and put their heads under their wings; the animals, which were at labor, stood still.” * In several parts of the city of Geneva, “there were seen persons prostrate on the ground, and offering up prayers, under the impression that the last day had come.”+
During the total eclipses of the sun of the 22d of May, 1724, and of the 2d of May, 1733, the corona, or luminous circle, around the moon, was distinctly seen. Several of the planets and the larger stars were visible to the naked eye. During the last-mentioned eclipse, "three or four spots, of a reddish color, were also perceived near the limb of the moon, but not in immediate contact with it." +
On the 24th of June, 1778, there occurred a total solar eclipse, which was observed at sea by Don Antonio Ulloa, the Spanish Admiral, while passing from the Azores to Cape St. Vincent. The period of totality was four minutes. The luminous ring around the moon presented an appearance that was very beautiful. Before it became very conspicuous the stars of the second magnitude were distinctly visible; but after attaining its greatest brilliancy it obscured all but those of the first. “The darkness was such, that persons who had been asleep in the afternoon, having awoke, imagined, to their
* Mem. Acad. des Sciences, 1706, p. 113. † Phil. T' rans. 1706, p. 2241.
| Phil. Trans., 1733, p. 135. $ Phil Trans., 1779, p. 105, et seq.
great astonishment, that the night was already far advanced. The fowls, birds, and other animals on board, took their usual positions for sleeping, as if it had been night.” The total obscuration commenced at three o'clock forty-four minutes in the afternoon.
A total eclipse occurred on the 16th of June, 1806, which was visible in this country. The Spanish astronomer, Don Joachim Ferrers observed it at Kinderhook, state of New York. The period of totality was 4' 37". The corona was . visible. Professor Olmsted says that during this eclipse, “which was one of the most remarkable on record, the time of total darkness, as seen by him, was about mid-day. The sky was entirely cloudless, but as the period of total obscuration approached, a gloom pervaded all nature. When the sun was wholly lost sight of, planets and stars came into view; a fearful pall hung upon the sky, unlike both to night and to twilight; and the temperature of the air rapidly declining, a sudden chill came over the earth. Even the animal tribes exhibited tokens of fear and agitation.” There was a slight fall of dew during total obscuration.
Several large eclipses of the sun occurred from 1830 to 1810, but the next great solar eclipse which deserves our attention is that which took place on the 8th of July, 1842. It so rarely happens that the astronomer has an opportunity of witnessing so sublime a celestial phenomenon as a total eclipse of the sun by remaining in any particular place,t that he has, especially of late years, removed as nearly as practicable to the central line of totality, there to make his observations. As the total eclipse of 1842 was approaching, an intense interest was excited, and astronomers from most parts of Europe betook themselves to those localities suitable for observation, over which calculations had shown that the moon's shadow was to pass. The eclipse was total to parts of Italy, France, Germany, and Russia. M. Arago observed it at Pepignan, and he has given a very fine description of
Astronomy, p. 161. + We have already stated that 575 years passed before another total solar eclipse was visible at London after that of the year 1140.
what he saw, but it has been too frequently quoted for us to reproduce it here. * M. Valz was at Marseilles; the late Mr. Baily, at Pavia ; Professor Airy, astronomer royal, was at the Superga, near Turin; MM. Otto Struve and Schiellewsky, at Lipesk; and various others at other places.
The period of totality during this eclipse, was comparatively short, being not quite two and a half minutes at several of the places, and only 3'5" at Lipesk.fBesides the phenomena to which we have referred as having been seen during former total eclipses of the sun—the luminous ring around the moon, and the effect on terrestrial things-rosecolored protuberances were seen, which seemed to be projected out from the margin of the sun's disk. Professor Airy says: “The appearance of the moon can never be forgotten. It was like a deep black disk fixed in the heavens, and surrounded by a brilliant luminous ring, whose breadth was estimated at about one-eighth the diameter of the moon. The color of this ring was nearly white, in my judgment inclining a little to a reddish hue, while its illuminating power was very great.”+ But the most wonderful circumstances, says Mr. Francis Baily, “in connection with this appearance, was the outbursting of three large protuberances from the edge of the moon, yet evidently a part of the crown of light. They had the appearance of mountains of considerable heights. Their color was red, changing to violet and purple, and perhaps better represented by the color of the peach blossom. They resembled the snow-capped summits of the Alps when illuminated by the rays of the rising or the setting sun. In another respect, they resembled the tops of the Alps, inasmuch as the light was quite steady, while the other part of the crown was rapidly flickering.” §
All the other observers of the total eclipse, saw the same, or nearly the same things, and described them in similar
* Annuire for 1846, p. 303. For information respecting this eclipse, see volume xiv. of the Memoirs of the Royal Astr. Society; volume iv. of the Giornah dell Instituto Lombardo; Nos. 457 and 470 of the Astronomischi Nachrichters, and the Annaire for 1846. | Professor 0. M. Mitchel's Sidereal Messenger, vol. I., p. 24.
$ Ibid, pp. 24 and 25.
terms. Our observer states that“ the thin crescent of light was suddenly changed to a line of luminous points, which appeared to wave from the extremities to the centre of the crescent, like a device in gas swept over by a strong breeze;' and other observers have seen more or less perfectly similar phenomena.
During total eclipses of the sun, the moon's disk is sometimes faintly illuminated by a doubtful kind of light, during the totality, and on one occasion spots were distinctly observed by Vassenius at Gottenberg.+ Both M. Arago and Professor Airy state that the moon's disk was uniformly illumined during the eclipse of 1812, but though they sought diligently for irregularities on the lunar surface, they could see none. In 1806, however, irregularities were noticed by Ferreré..
The light which renders the moon visible on such occasions, undoubtedly is the sunlight reflected from the earth, as it renders visible the moon's disk when the part directly illuminated is but a slender crescent. This is the explanation given of it by Kepler.Ş This lumière cendriée, as the French term it, or ash-colored light, comes from the sun to the earth, is reflected to the moon, and thence reflected to the earth. The fact that sometimes it renders the irregularities of the moon's surface visible, and sometimes not, shows us that its intensity is variable, being sometimes interfered with by what M. Arago calls the lumière atmosphérique.
A curious phenomenon was noticed at Washington by Mr. F. R. Hassler, during the progress of the partial eclipse of the sun, of February 12th, 1831. He saw the inequalities upon the moon distinctly painted" by the reflected light and shade upon its disk, and presenting apparently elevations brilliantly illuminated, and intervals shaded in an ash-colored shade, more or less dark and distinct, as they were nearer to or farther from the sun, the edge of the moon toward the sun being always fully dark.”li The appearance began when about one-eighth of the sun's diameter was immersed, ex
* Hind's Solar System, p. 94. + Phil. Trans. 1733, p. 135. Truns. Amer. Phil. Society, vol. vi., p. 267. $ Epit. Astronomia, p. 895.
| Trans. Am. Phil. Soc., New Series, vol. iv., p. 131.
tended itself with some variations to about one-third of the moon's diameter, and then faded into indistinctness, and the whole of the moon's disk appeared equally dark. The same phenomenon was repeated in an inverted order toward the end of the eclipse.
No very satisfactory explanation has been given of this singular phenomenon. Grant thinks it may possibly be owing to the action of the lumière cendriće and the lumière atmosphérique * Arago noticed a somewhat similar phenomenon during the eclipse of 1842. Forty minutes after the commencement of the eclipse, while a considerable portion of the sun was still visible, he observed the dark contour of the moon projected upon the bright sky. It corresponded exactly with that portion of the moon visible upon the sun's disk.t M. Arago thinks this phenomenon is owing to the projection of the moon upon the solar atmosphere, “the brightness of which, by an effect of contrast, rendered the outline of the moon's dark limbs discernible.”
The next great eclipse of the sun occurred on the 28th of July, 1851. The phenomena observed during the total eclipse of 1842, had awakened in the minds of astronomers a great deal of interest, and the total eclipse of 1851 was looked to with much interest. The line of totality passed through Norway and Sweden, whither several English and American astronomers repaired to observe the phenomenon. The late Professor Bond was stationed at Lilla Edet, in Sweden. He says that “the contour of the lunar mountains was exhibited in great beauty. Towards the south side, they were quite high enough to produce a visible distortion of the cusps.” # He gave his attention more especially to the south cusp; and just before the eclipse was total this cusp “was divided into beads of light, which moved slowly toward the point of the cusp, and disappeared.” He thinks the appearance is such as could not be accounted for by the mountains on the moon's edge.t. On removing the screen, after totality had commenced, he says that he was filled with inexpressible
* Hist. Phys. Ast., p. 402, note.
Gould's Ast. Jour., vol ii.,
Annaire, 1846, p. 372. 49. $ Ibid.