ASTRONOMICAL PHENOMENA AND PROGRESS. 



51 



Its period is slowly diminishing, having, since 

 1786, shortened 3f days. No satisfactory ex- 

 planation of this diminution has been offered. 

 It passed its perihelion on March 7, 1885. 



Barnard's comet (I, 1885), the first discov- 

 ered of the year, was picked up by Prof. Ed- 

 ward E. Barnard, Assistant Astronomer at 

 Vanderbilt University Observatory, Nashville, 

 Tenn., on July 7. It was observed at the War- 

 ner Observatory on the 8th, and at Harvard 

 College Observatory on the 9th, at 17 h -17 m> 31% 

 G. M. T., in R. A. 17"' 17 ra - 48-4'-, Dec. - 6 1' 

 8". It was at discovery a very faint object, 

 and did not subsequently increase in bright- 

 ness. A short tail, about 2' in length, was on 

 several occasions observed at the Warner Ob- 

 servatory, and perhaps elsewhere. Its promi- 

 nent feature is its great perihelion distance, 

 equal to 2-516, and greater than that of any 

 recorded comet, with the exception of that of 

 1729. Its elements present no similarity to any 

 preceding comet ; hence, if it has before visited 

 our system, it departed unobserved. If its or- 

 bit be a parabola (a fact not ascertained at this 

 writing), it has never previously entered our 

 system, nor will it return again to it, but will 

 remain a wanderer through the stellar worlds, 

 though a denizen of none. The nucleus gave 

 a continuous spectrum over which the usual 

 cometary bands could, with great difficulty be- 

 cause of excessive faintness, be distinguished. 



The following elements of Barnard's comet 

 have been computed by Prof. H. V. Egbert, of 

 the Dudley Observatory: 



Time of perihelion passage, 1885, Aug. 5-2869. 



Distance from node to perihelion = 178 21' 43>' 



Longitude of node = 92 17' 27-" 



Inclination = 80 39' 05" 



Perihelion distance = 2'516 



Tempel's comet (II, 1867), discovered by 

 Prof. Wilhelm Tempel in 1867, was soon found 

 to have an elliptical orbit with a period of 

 about six years. True to prediction, it re- 

 turned in 1873, and again in 1879, and in 1885 

 was again due. M. Raoul Gautier circulated 

 last year a finding ephemeris fixing the date of 

 perihelion passage on Sept. 25, 1884, and of 

 perigee (nearest the earth) on March 31, 1885. 

 The perihelion distance in 1867 was 1,564, the 

 earth's mean distance being taken as unity. 

 These elements show that at perihelion passage 

 in 1885 the distance will have increased by 

 perturbation to 2,073. The nearest approach 

 of the comet to ths earth's orbit occurs at or 

 very near perihelion, and it will appear that, 

 under the most favorable conditions of the 

 orbit of 1885, the theoretical intensity of light 

 will not exceed one sixth of the value it might 

 have attained in 1867. At aphelion in the 

 present orbit the comet approaches that of 

 Jupiter. 



Armed with Gautier's ephemeris, in April of 

 the present year a most determined effort to 

 find it was made by all the great telescopes of 

 the world, though without success. On April 

 6, while engaged in a search for it, Dr. Swift, 

 with the sixteen-inch refractor of the Warner 



Observatory, found a nebulous object in R. A. 

 ll h - 54 m - 40"-, Dec. + 20 3', which, on the even- 

 ing of the 8th, had disappeared. His descrip- 

 tion of it was, " Very faint, pretty large, round, 

 and forms a right-angled triangle with two 

 stars." Though the object was doubtless a 

 comet, it differed a little too much in declination 

 to have been Tempel's, unless, since its last ap- 

 pearance, it had been subjected to a greater 

 perturbation in this co-ordinate than computa- 

 tion had predicted. A diligent though vain 

 search to recover the lost object was made both 

 at the Warner and Cambridge Observatories. 

 The published announcement that the comet 

 had been found in Europe was a mistake. The 

 object seen was one of the many nebulae in the 

 region wherein the comet was looked for. 



Tuttle's comet (II, 1885), unique in one re- 

 spect at least, that it belongs neither to the 

 group of short-period comets nor to those of 

 long period, was found in 1790 by Mechain. 

 Its periodicity was not suspected, and it was 

 not again seen until re-discovered by Tuttle at 

 Harvard College Observatory on Jan. 4, 1858. 

 At its next return, in 1871, it was generally 

 observed. It is now visible in the early morn- 

 ing sky, too near twilight to be well seen. It 

 was first picked up at the observatory at Nice, 

 France, on the morning of Aug. 9, 1885, and, 

 two days later, was found at the Warner Ob- 

 servatory, Rochester, N. Y. 



The annexed table includes all comets that 

 are known to be periodic. Many others are 

 supposed to be of this class. All of those 

 tabulated have made one or more returns to 

 perihelion since discovery, except Barnard's, 

 Wolf's, and Denning's, but that these are peri- 

 odics, with elements differing little from those 

 here given them, is unquestioned. Olbers's 

 comet of 1815, expected this year or the next, 

 will increase the number to seventeen, if we 

 include the comet of Biela, which in 1846 was 

 disrupted into two parts. But, as neither frag- 

 ment has been seen since 1852, it may be con- 

 sidered as irrecoverably lost. 



On the evening of August 31, Mr. W. R. 

 Brooks, an amateur astronomer of Phelps, N. 

 Y., and an indefatigable comet-seeker, found 

 a faint nebulous body in the constellation of 

 the Hunting Dogs Brooks's comet (III, 1885). 

 Its cometary character being strongly sus- 

 pected, he at once telegraphed his discovery to 

 Dr. Swift, director of the Warner Observatory, 

 which, in compliance with the conditions of 

 the Warner prize, he was obliged to do. As 

 there were five nebulae in the immediate vicin- 

 ity of the supposed comet, it was deemed ad- 

 visable to delay the cabling of the intelligence 

 until confirmation could be had. On the even- 

 ing of Sept. 2 it was observed at both the 

 Warner and Cambridge Observatories, where- 

 upon Prof. Pickering, director of the latter in- 

 stitution, promptly cabled it to Kiel, Germany, 

 the European center for astronomical tele- 

 grams. Thence all important astronomical dis- 

 coveries are communicated to all the chief ob- 



