PHILOSOPHICAL 
TRANSACTIONS. 
XII. Observations of a second Comet , with Remarks on its Con- 
struction. By William Herschel, LL. D. F. R. S . 
Read March 12, 1812. 
As we have lately had two comets to observe at the same 
time, I have called that of which the following observations 
are given, the second. Its appearance has been so totally dif- 
ferent from that of the first, that every particular relating to 
its construction becomes valuable ; and notwithstanding the 
unfavourable state of the weather at this time of the year, I 
have been sufficiently successful to obtain a few good views 
of the phenomena which this comet has afforded. 
A short detail of the observations, in the order of their rela- 
tion to the different cometic appearances, is as follows : 
The Body of the Comet. 
January 1, 1812. I viewed the second comet with several 
of my telescopes, and found it to have a considerable nucleus 
surrounded with very faint chevelure. 
Jan. 2. The comet had a large round nucleus within its 
faint nebulosity. Not seeing it very well defined, and of so 
mdcccxii. H h 
