360 ANNUAL OF SCIENTIFIC DISCOVERY. 



any previous one; its brilliant nucleus and long train, about the time 

 of the perihelion passage, made it a very conspicuous object, and alto- 

 gether the largest and most beautiful comet that has appeared since 

 the great comet of 1843. According to Mr. Hind, of England, the 

 actual diameter of the bright nucleus was 8000 miles, or about equal to 

 that of the earth, while the tail had a real length of 4,500,000 miles, 

 and a breadth of 250,000, rather over the distance separating the moon 

 from the earth. Its nearest distance to the earth at any one time was 

 68,000,000 of miles. 



On the night of Sept. llth, 1853, Mr. C. Bruhns, of Berlin, detected, 

 near the forward paw of the Great Bear, a large, faint, nebulous 

 comet, resembling a star-cluster. Up to Sept. 1 7th, no indications of 

 a tail were visible, and the nucleus continued to present the appearance 

 of an unresolved nebula, with numerous points of light. 



A telescopic comet was discovered on the 25th of November, by 

 Robert Van Arsdale, Esq., of Newark, N. J., in the constellation of 

 Cassiopea. It is of a small, round, bright appearance, with an ex- 

 ceedingly rapid motion in a direction apparently opposite to that of 

 the sun. After only a short observation it changed its place, very 

 perceptibly. 



Biela's Comet. Prof. Hopkins in his address before the British 

 Association has the following notice of this singular body: "This 

 comet has a period of about six years and a half, and has been ob- 

 served a considerable number of times on its periodical return to the 

 neighborhood of the sun. It appeared in November, 1845, and in the 

 following January the phenomenon alluded to was observed for the 

 first time. The comet had become divided into two distinct parts with 

 separate nuclei. Sometimes the one and sometimes the other appeared 

 the brighter till their final disappearance. The elements of the orbits 

 of these twin comets were calculated by Prof. Plantamour, from 

 observations made at Geneva, in 1845-6, assuming them to be unin- 

 fluenced by each other's attractions. The correctness of these ele- 

 ments could be determined only on the next return of the comet, 

 which took place in the autumn of last year, one of the nuclei having 

 been first seen by Signer Secchi, at Rome, on the 25th of August, and 

 the other on the 15th of September. The subsequent observations 

 made upon them show that the elements of the orbits, as previously 

 calculated from the Geneva observations, were far from exact. A 

 complete discussion of all the observations which have been made on 

 these comets during their last and previous appearances, is now in 

 progress by Prof. Hubbard, of the Washington observatory. The 

 distance between the two nuclei was much increased on their last 

 appearance. Judging from the apparent absence of all influence and 

 sympathy between these bodies, it would seem that their physical 

 divorcement, though without known precedent, is final and complete." 



