made with a view to investigate its Magnitude, See. 3 59 
comet made its appearance in the telescope, it struck the eye 
as a very conspicuous object. 
The immense tails also of some comets that have been ob- 
served, and even that of the present one, whose tail, on the 
18th of October, was expanded over a space of more than 9 
million of miles,* may be accounted for more satisfactorily, 
by admitting them to consist of radiant matter, such as, for 
instance, the aurora borealis, than when we unnecessarily as- 
cribe their light to a reflection of the sun’s illumination thrown 
upon vapours supposed to arise from the body of the comet. 
By the gradual increase of the distance of our comet, we 
have seen that it assumed the resemblance of a Nebula; and 
it is certain, that had I met with it in one of my sweeps of the 
zones of the heavens, as it appeared on either of the days 
between the 6th of December, and the 21st of February, it 
would have been put down in the list I have given of nebulae. 
This remark cannot but raise a suspicion that some comets 
may have actually been seen under a nebulous form, and as 
such have been recorded in my catalogues ; and were it not 
a task of many years labour, I should undertake a review of 
all my nebulae, in order to see whether any of them were 
wanting, or had changed their place, which certainly would 
be an investigation that might lead to very interesting con- 
clusions. 
Account of a new irregularity lately perceived in the apparent 
Figure of the Planet Saturn. 
The singular figure of Saturn, of which I have given an 
account in two papers, has continued, for several reasons, to 
* 9160542. 
