The Great Comet of 1861. 261 
four hundred miles. On July 2d the breadth of the head at the 
nucleus was 156,000 miles, the height of the inner envelope 
11,500 miles, and the length of the tail about 15,000,000 miles. 
The comet was seen between one and two o'clock on Sunday 
morning, June 30th, by Dr. Briinnow, at the Observatory of 
Ann Arbor. This is the earliest authentic account of its visi- 
bility which has come to my notice. The head could not have 
seen on Friday evening, although observations to that 
effect have been reported. The extremity of the tail, however, 
must have been within view for some time previous, though too 
faint to attract notice. 
he reports current of the identity of the comet with those of 
1264 and 1556 are without any foundation. 
4, Continuation of Account of Comet IT, 1861; by G. P. Bonn, Director 
of the Observatory of Harvard College. 
With the exception of a single cloudy night, observations were 
made at this Observatory, on every evening from the 2d to the 
21st July inclusive. A like succession of clear skies rarely occurs 
here. At the latter date, the comet had become much fainter, and 
Was besides obscured by the moonlight. In the region near the 
nucleus, the outlines of the envelope could no longer be discerned 
—the distribution of the brighter portions of the nebulosity, 
however, could be seen to resemble that of the earlier jets. This 
peculiarity has been preserved up to the beginning of August. 
The tail during the last days of July, as seen through an ops 
era-glass or comet-seeker, has continued to show the narrow ray, 
now reduced to about 12° in length. : 
Near the head it forms the right hand side of the tail (as pre- 
sented in the evening), which is the brightest and best defined. 
Further on, it seems to bend to the right hand with a decided 
brightness, Mr. Safford has computed the follow- 
ing elements from observations : 
Harvard College 
Elements of Comet IT, 1861. 
T= June 11.5018, Washington m. t. 
og. g= 9.9150 
n—Q==  $80°20'48""1) ay a, 
ie 278 58 40 *3 ¢ 19619 
85 37 7 0 
a = 
June 30th, Greenwich. 
July 8th and oe Observatory of 
July 18th. . 
