January 0, 1885.] 



SCIENCE. 



31 



tare, is, as a natural consequence, inhabited b}' 

 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 crus- 

 taceans, are examples of these. Naturally 

 the}* 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 b}' 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 pos- 

 sibly 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. Al- 

 though the fish-commission has organized many 

 extensive expeditions for the sole purpose of 

 searching after the tile-fish, not a single speci- 

 men 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 the}' 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 } T ears 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. 



Ralph S. Tarr. 



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 1882, nearly all 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 be- 

 longs properly with the comets of the preceding year, 

 as it passed perihelion on Dec. 25, 1883. It was 

 discovered, however, on Jan. 7, 1884, by Ross, an ama- 

 teur observer, at Elsternwick, near Melbourne, Aus- 

 tralia, — "a faint nebulous object, with an ill-defined 

 central condensation, and a small, tail-like projec- 

 tion." It was not visible in the northern hemisphere, 

 and was under observation for only about a month. 

 The tail was one and a half degrees long on Jan. 18, 

 1884. 



The first comet of 1884, in order of perihelion pas- 

 sage, was that discovered, or rather re-discovered, by 

 Brooks, at Phelps, N. Y., on Sept. 1, 1883. 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 (in. 67). 



The second comet, in both order of perihelion pas- 

 sage and of discovery, was that found by E. E. Bar- 

 nard of Nashville, Tenn., on July 16, 18^4. 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 DeVico'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 is still 

 under observation. In its physical appearance, the 

 comet 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 

 tail. When examined on Nov. 13, with the nine- 

 inch equatorial at the Naval observatory, under a 

 magnifying-power of one hundred and two diame- 

 ters, 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 this disk the stellar nucleus. The line of demar- 

 cation between the disk and the surrounding nebula 

 was, of course, extremely uncertain; but measures 

 made with the filar micrometer gave, roughly, a di- 

 ameter of V 52" for the outer nebula, 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 interest- 

 ing feature of the comet is its orbit. Krueger has 

 assigned a period of about six and seventh-tenths 

 years, but there is no evidence of any previous appear- 

 ance. He remarks that at the returns in 1871 and 1878 

 it was unfavorably situated. In 1891 and 1864 its 

 situation is favorable, if we can suppose that it fol- 

 lows 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 Ju- 

 piter, 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 

 is extremely faint, but will grow somewhat brighter. 

 It will not reach perihelion till March, 1885. 



To complete the list, we should mention a ' sus- 

 pected ' 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, hi., on 

 the morning of May 26, 1884. Unfavorable weather 

 prevented a re-examination of this place till June 17 

 and 18, when the object could no longer be seen, nor 



