126 PROCEEDrNGS OF THE [Nov., 1886. 



The Identity of the Comets 1886 h, 1844 h, and 1678. 



By LEWIS R. GIBBES, M. D., Professor of Astronomy in the College of Charleston, S. C. 



The number of Nature for 14th October last, mentions the discovery of a 

 Comet on 26th September, by Mr. Finlay, of the Cape of Good Hope Observa- 

 tory, and gives the Elements of its parabolic orbit, as calculated by Dr. Hol- 

 etschek, which we copy in the table below. The remark is added, that "it 

 appears to be probably identical with Comet 1844 5," but the writer omitted 

 to add that Comet 1844 h is almost certainly identical witb the Comet of Aug., 

 1678. 



In Oct., 1844, I received from Mr. Sears C. Walker of Philadelphia, a slip 

 from the PhiladelpJila Gazette, announcing the discovery of a Comet, on tbe 

 10th of that month, by Mr. Hamilton L. Smith, of Cleveland, Ohio, and con- 

 taining Smith's observed places of the Comet, from the 10th to the 22d, when 

 the brightness of the moon rendered it invisible. From these observations I cal- 

 culated the Elements of its Parabjlio Orbit and published them in the Charles- 

 ton Mercury of Oct. 18th of same year, at the same time pointing out their 

 similarity to those of the Comet of 1678, and saying that "I feel confident 

 that the Comet of Aug., 1678, and Ihe'Comet of Aug., 1844, are one and the 

 same," with a revolution of 166 years or of some aliquot part of that number, 

 if it should have been unobserved at some intermediate return to the Sun. 



In a week or two the news arrived from Europe, that the Comet was first 

 discovered hj DeVico, at Rome, Italy, on the 22d Aug., nineteen days before 

 Mr. Smith, and hence has always been called DeVico's Comet. Several para- 

 bolic orbits were obtained by different calculators, and the elements of DeVico's 

 orbit (as given in Encke's edition of Olber's Ahhaiidlung,) differ but little from 

 my own, except in the Longitude of the Perihelion, which is greater than mine 

 by 10°, and consequently his date of Perihelion passage is ten days later than 

 mine ; he doubtless had a longer arc at his command, as his first observation 

 was nearly three weeks earlier than Smith's. It is unnecessary to give either 

 his orbit or mine, as they were soon entirely superseded, by more accurate re- 

 sults derived from a still more extended arc of the Comet's orbit, for it was 

 presently found, that a parabolic orbit would not satisfy the observations made 

 as the Comet travelled onwards in its path. 



Several elliptic orbits were then computed, agreeing closely with each other, 

 and giving a periodic time for the C'omet of about five and a half years, a short- 

 er period than any Comet then known except Encke's, and each of these short 

 period comets is found to move direct, that is, in the same direction as the 

 Earth around the Sun. In these ellijjtic orbits, the Inclination and Perihe- 

 lion distance are less, and the Longitude of Node is greater than in the para- 

 bolic orbits. The Longitude of Perihelion is also greater and therefore the 

 time of Perihelion passage is later ; of these we give Briinnow's orbit in the ad- 

 joiiiiiin t;il)lc. 



