Observations on the Tails of Hallei/s Comet. 149 



the head ; i. e. it is really in the upper and left part. What ap- 

 peared as a short tail, in a clear sky, appears through the smoke as 

 an eccentric envelope, this term being applied to the nebulous mat- 

 ter which surrounds the nucleus. The angle which the supernume- 

 rary tail makes with the other, is not greater to-night than it was 

 last night. On account of the smoke, the angle cannot be so exactly 

 determined, but is between 100° and 120°. As seen through this 

 eye-piece, the luminous matter on the lower right side of the nu- 

 cleus appears to-night to extend three or four times as far from the 

 nucleus as it did last eve7iing, when k appeared more distinctly as 

 a tail. By the use of the term rmcleus, I do not mean to' affirm, 

 that any solid body was seen, but to express a small bright spot, 

 whose brightness had, on all sides, an abrupt termination, and did 

 not fade away into that of the exterior of the head, by insensible 

 degrees. Those students generally who used the telescope this 

 evening, perceived the eccentric situation of the nucleus. I per- 

 ceived the same after having taken the telescope from the stand, 

 and placed the lower side uppermost. I consider my conclusion in 

 regard to the existence of a supernumerary tail confirmed. The 

 longer tail is directed toward (3 Cephei. 



Oct. 14. — The tail, at 8 P. M., was directed nearly towards r 

 Herculis. The opacity of the air, which appears to be of the same 

 nature as that which frequently prevails in this country in the latter 

 part of autumn, and which is called Indian summer, tends much to 

 obscure the comet this evening. To the naked eye, the tail is about 

 6° or 8° in length, and from 12° to \6°, as seen obliquely. 



The nucleus cannot be seen with the eye tube for terrestrial ob- 

 jects, nor with that of the highest magnifying powers, and but faintly 

 with the two intermediate powers, but more distinctly with the 

 higher of these two. On account of this indistinctness, it is dif- 

 ficult to determine exactly the direction of the supernumerary tail, 

 or (if any one prefers the expression) on which side the nebulous 

 envelope is very much condensed and elongated. But if I might 

 hazard an opinion, the nebulous matter at about 8 or 9 o'clock ap- 

 peared to be elongated downwards in a direction making an angle of 

 perhaps 160° or 170° with the long train. That it was elongated 

 downwards in some direction was evident ; the precise direction being 

 rather uncertain. 



Oct. 15. — The clouds and a kind of fog this evening prevented 

 a good view. The length of the tail appeared less than 2° ; its 

 direction was towards the star ^ in the constellation Hercules. 



