196 
CONSTRUCTION OF COMETS, &C. 
having rather the appearance of a planet seen through an at- 
mosphere full of haziness. 
Jan. 8. The chevelure consisted of so faint a light that, 
when magnified only 170 times, it was nearly lost. 
Jan. 18. The chevelure was extremely faint and of very 
little extent. 
Jan. 20. The light of the moon, which was up, would 
not admit of further accurate observations on the chevelure. 
The Tail of the Comet. 
9' J an - 1 ‘ a l° w magnifying power, I saw in the 10 feet 
was about 659 reflector an extremely faint scattered light, in opposition to 
thousand 
miles lorn?. 
the sun, forming the tail of the comet. It reached from the 
centre of the double eye-glass half way toward the circum- 
ference. * 
Jan. 8. The narrow, very faint scattered light beyond the 
chevelure remains extended in the direction opposite the 
sun. 
Jan. 18. I estimated the length of the tail by the propor- 
tion it bore to the diameter of the field of the eye-glass, which 
takes in 38' 39", and found that it filled about one quarter of 
it, which gives Q' 40''. 
Jan. 20. On account of moonlight the tail was no longer 
visible. 
From the angle which it subtended in the last observation, 
it will be found that its length must have been about 609 thou- 
sand miles. 
Remarks on the Construction of the Comet . 
Tue body of 
this comet ap- 
proached to 
planetary 
density. 
The method I have taken in my last paper of comparing 
together the phenomena of different comets appears to me 
most likely to throw some light upon a subject which still re- 
mains involved in great obscurity. When the comet of which 
the observations have been given in this paper is compared 
with the preceding one, it will be found to be extremely dif- 
ferent. Its physical construction appears, indeed, to approach 
nearly to a planetary condition. In its magnitude it bears a 
considerable proportion to the size of the planets j the dia- 
meter 
