254 The Great Comet of 1861. 
ing to the B. A. Catalogue these stars are Nos. 8496, 8358, 3968, 
and 4347. 
It broke off, or suddenly became faint, before it reached the 
distance of Alpha Draconis, at about 20° from the nucleus. 
From that point the tail continued as a much fainter milky 
band, decreasing very gradually in luminosity, and varying 
but little in apparent breadth. This breadth was less than 
one-half the breadth of the extremity of the brighter portion, 
which was about 8°. The southern edge of the narrower and 
fainter stream passed through Alpha Draconis, and grazed the 
stars Tau, Sigma, and Eta Herculis. The decreasing light 0 
this stream vanished in the immediate vicinity of the Milky 
Way, to the east of 6 Ophiuchi. The extreme length of the 
tail was about 95°. The train of the comet was apparently 
made up of two distinct streams of luminous matter, differing 
greatly in width and length. The northern edges of the two 
were in the same line, but the extreme breadth of the shorter 
stream was much greater than that of the other. Its southern 
edge was badly defined, and somewhat concave outward. A 
very faint diffused light, rapidly widening out, could be traced 
far beyond the point where the sudden falling off of brightness 
occurred. This diffused light extended, on the evenings of July 
4th and 5th, to the vicinity of Corona Borealis, or more than 
40° from the nucleus, and attained to a width of 12° or 15°. 
Its southern edge passed just to the north of the star Theta 
Bootis. The breadth of the tail, as distinctly seen, at its broad- 
est part, was about 3°. On the evening of June 280th, the esti- 
mated breadth was 5°; but a faint light on the south side was 
traced 5° farther, giving an extreme breadth of 10°. On July 
4th, the tail was visibly forked about 2° below the star Alpha 
Draconis, or 15$° from the nucleus. On the following evenmg 
the point of forking was 3° or 4° above the same star. The nu- 
cleus had advanced 54° toward it in the interval. 
It was also observed, on the evening of July 4th, that by ex- 
amining carefully it could be discerned that the long narrow 
stream increased in breadth about in proportion to the distance 
om the nucleus. At the point where first seen as a distinct 
stream its breadth was about 14°. : 
Since July 5th the tail of the comet has decreased, from night 
to night, in brightness, as well as in length and breadth. 
2. Observations at Washington. ” 
The following places of the comet as observed at the U. S. 
Naval Observatory, Washington, have been communicated by 
Lieut. J. M. Gilliss, Superintendent of the Observatory. The 
pi rey were made by Mr. Ferguson with the large equ 
torial. 
