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tore, is, as a natural consequence, inhabited by a different fauna: in fact, by a tropical deep-sea fauna. an extension of that of the West Indies. Not only the tile-fish, but certain crustaceans, are examples of these. Naturally they would be sensitive to cold. During the spring of 1882, violent and long-continued easterly and northerly winds prevailed, and numerous icebergs stranded on the George's Banks just north of the belt. We have every reason for believing that these winds carried the inshore waters, which were naturally cold, but whose temperature had been lowered by the stranded bergs, across the border-line and into the warm area. If this were the case. such delicate animals as the tile-fish could not possibly stand the sudden change which their more hardy neighbors could easily live through. So it was that the tile-fish and a few other species were exterminated from these grounds. Although the fish-commission has organized many extensive expeditions for the sole purpose of searching after the tile-fish, not a single specimen has since been found, either of the tile-fish or the other species. Whether or not they still exist in waters more southern is an open question; but we understand that Professor Verrill believes they will be found there. At any rate, it is certain that they are entirely absent from their former haunts, and that, if they do exist elsewhere. many years must elapse ere they inhabit this bank again in abundance. Such sudden changes as these, and local extinction of several species by such simple means, cannot help throwing much light upon paleontological geology.
COMETS AND ASTEROIDS OF 1884.
While the year 1884 has brought no comets of remarkable brilliancy or popular interest, compared with the comets of 1881 or 1889, nearly ell the comets of the year will claim more than ordinary attention at the hands of astronomers, on account of the interest which attaches to the Investigation of their orbits. Of the five comets seen, four have been periodic.
The first comet which was discovered in 1884 belongs properly with the comets of the preceding year, as it peassd perihelion on Dec. 35, 1883. It was discovered, however, on Jan. 7, 1884, by Roas, an amateur observer, at Elsternwiek, near Melbourne, Australia,—" a faint nebulous object, with an ill-defined central condensation, and a small, tail-like projection." It was not visible in the northern hemispheres, and was under observation for only about a month. The tail was one and a hslf degrees long on Jan. 18, 1894.
The first comet of 1884, in order of perihelion passage, was that discovered, or rather re-discovered, by Brooks, at Phelps, N. Y., on Sept. 1, 1888. It has been commonly known as the Pons-Brooks comet, or Pons comet of 1812, having been originally discovered by Pons at Marseilles In that year. An account of this comet has already appeared in Science (iii. 67). The second comet, in both order of perihelion passage and of discovery, was that found by E. E. Barnard of Nashville, Tenn., on July 10, 1884. At the time of discovery It was a nebulous object, slightly condensed near the centre, and tolerably bright. It was found to move In an elliptical orbit with a period of about five and a half years, the elements bearing a very close resemblance to those of DeVlco's comet (1844, i.). The comets do not, however, appear to be identical. The nearest approach to the sun was on Aug. 16.
The third comet of 1884 was discovered on Sept. 17, by Wolf, a student at Heidelberg, and le still under observation. In its physical appearance, the cornet has changed very little since discovery. As far as I know, it has not at any time been visible to the naked eye, nor has it shown any indications of a tall. When examined on Nov. 13, with the nine-inch equatorial at the Naval observatory, under a magnifying-power of one hundred and two diameters, it presented the appearance of a 'slightly oval, nebulous object.' Near the centre of the nebula was a bright disk nearly circular, and in the centre of the disk the stellar nucleus. The line of demarcation between the disk and the surrounding nebula was, of course, extremely uncertain; but measures made with the far micrometer gave, roughly, a diameter of 1′52″ for the outernebula, and a diameter of 18″ for the central disk. Using the distances given in Krueger's ephemeris, these measures would represent distances of forty-seven thousand and seventy-five hundred miles respectively. By far the most Interesting feature of the comet in its orbit. Krueger has assigned a period of about six and seventh-tenths years, but there is no evidence of any previous appearance. He remarks that at the returns in 1871 and 1878 it was unfavorably situated. In 1891 and 1804 its situation is favorable, if we can suppose that it follows the same path as at present. Krueger points out, furthermore, that In the early part of 1875 the comet must have suffered considerable perturbation by Jupiter, and before that time It may have been following an entirely different orbit. Perihelion was passed on Sept. 26.
Encke's comet, the most interesting short-period comet, has just been reported by Professor Young. It le extremely faint, but will grow somewhat brighter. It will not reach perihelion till March, 1885.
To complete the list, we would mention a 'suspected' comet to which some interest is attached. A faint, round, nebulous object was found by Spitaler with the twenty-seven inch refractor of the Vienna observatory, while searching for comet 1858, iii., on the morning of May 20, 1884. Unfavorable weather prevented a re-examination of this place till June 17 and 18, when the object could no longer be seen, nor