MR. J. BAXENDELL^S OBSERVATIONS OF COMET I. 1861. 3 



side. The tapering elongation of last night was now a 

 narrow and shghtly fan-shaped tail of 2| degrees in length, 

 but apparently separated from the nebulosity of the head 

 by a remarkable and comparatively dark interval, as shown 

 in the sketch which accompanies this paper. The point of 

 origin of this singular tail was estimated to be from 12 to 

 15 minutes distant from the centre of the head; and its 

 breadth at this part was about 4.^ minutes, and at its ex- 

 tremity about 15 minutes. Its axis was perfectly straight ; 

 and its brightness was greatest at the narrow end, where 

 it was equal to that of the nebulosity of the head at two- 

 thirds of the radius from the centre. 



May 5th. At 10^ i6°» 59^-7 G.M.T., six comparisons 

 with Lalande's 19,168 gave the comet^s apparent place 

 R.A. 9^ 39«^ 37^82, Dec. +41° 21' 34''-5. 



The sky to-night was not very favourable for the obser- 

 vation of faint objects ; but the general features of the 

 comet did not appear to have undergone any material 

 change. Last night it occurred to me, after leaving the 

 observatory, that the axis of the tail was not exactly in 

 the direction of the comet's radius vector, and to-night 

 I found its angle of position at 13^ 35"^ sidereal time to 

 be 96°' 7. At this time the position of the sun and comet 

 were — 



The sun R.A. 42° 54' ; N.P.D. 73° 33'. 



The comet. . R.A. 144° 50'; N.P.D. 48° 43'. 



From these data we find that the angle of position of a 

 prolongation of the comet's radius vector was 69°"9. The 

 apparent deviation of the axis of the tail was therefore 26°- 8 

 in the direction of the comet's motion. 



May 7th. At 12^ G.M.T. the comet appeared to the 

 naked eye to be nearly equal to fju Leonis, and equal to, if 

 not brighter than, 38 Lyncis. 



May 9th. Three comparisons with Lalande's 17,987 



B 2 



