65 Observations of a Comet. 



and irregular, especially towards the end ; it is also shorter 

 than the south -preceding one. 



The shape of the unequal length of the sides of the tail, 

 when attentively viewed, is visible in a night glass, and even 

 to the naked eye. 



Oct. 31. 10-feet reflector. The tail continues to be better 

 defined on the south -preceding than on the north-follow- 

 ing side. 



Dec. 6. The length of the tail is now reduced to about 

 23' of a degree. 



Of the Density of the Coma and Tail of the Comet. 



Many authors have said, that the tails of comets arc of so 

 rare a texture, as not to affect the light of the smallest stars 

 that are seen through them. Unwilling to take any thing 

 upon trust, that may be brought to the test of observation, 

 I took notice of many small stars, that were occasionally 

 covered by the coma and the tail, and the result is as follows. 



Oct. 26. 6h. l.i'. Large 10-feet reflector, 24 inches aper- 

 ture. A small star within the coma is equally faint with 

 two other stars that are on the north-following side of the 

 comet, but without the coma. 



7h. 30'. The coma being partly removed from the star, 

 it is now brighter than it was before. 



Oct. 31. 6h. 5'. 10- feet reflector. A star in the tail of the 

 comet, which we will call a, is much less bright than two 

 others, b and c, without the tail. 



Two other stars, d and e, towards the south of h and r, 

 are in the following skirts of the tail, and are extremely 

 faint. 



7h. 20'. The star e is now considerably bright, the tail 

 having left it, while d, which is rather more involved than 

 it was before, is hardly to be seen. 



7h. 50'. The star a, toward which the comet moves, is 

 involved in denser nebulosity than before, and is grown 

 fainter. 



d is involved in brighter nebulosity than before, but 

 being near the margin, it will soon emerge. 



' Sh. 



