C 115 3 
V. Observations of a Comet, with Remarks on the Construction of 
its different Parts . By William Herschel, LL.D. F. R. S. 
Read December ig, iBn. 
The comet which has lately visited the solar system has 
moved in ail orbit very favourably situated for astronomical 
observations. I have availed myself of this circumstance, and 
have examined all the parts of it with a scrutinizing attention, 
by telescopes of every degree of requisite light, distinctness, 
and power. 
The observations I have made have been so numerous, and 
so often repeated, that I shall only give a selection of such as 
were made under the most favourable circumstances, and 
which will serve to ascertain the most interesting particulars 
relating to the construction of the comet. 
As my attention in these observations were every night 
directed to as many particulars as could be investigated, it will 
be most convenient to assort together those which belong to 
the same object; and in the following arrangement I shall 
begin with the principal part, which is 
The planetary Body in the Head of the Comet. 
By directing a telescope to that part of the head where with 
the naked eye I saw a luminous appearance not unlike a star; 
I found that this spot, which perhaps some astronomers may 
call a nucleus, was only the head of the comet; but that within 
O 2 
/“W 
