Dr. Herschel's Observations, &c. 333 
which are contained in this paper. It was an attempt to avail 
myself of the abundant light and high powers of my various 
telescopes, to examine the nature and construction of the bodies 
of the satellites themselves, and of their real magnitudes. Here 
phenomena occurred that will perhaps be thought to be re- 
markable, and even inconsistent or contradictory. So far from 
attempting to lessen the force of such animadversions, I shall 
be the first to point out difficulties, in order that future obser- 
vations may be made to resolve them. 
Perhaps it would have been better to delay the communi- 
cation of these observations, till I had continued them long 
enough to be able to account for things which at present must 
be left doubtful. But as in final conclusions to be drawn from 
astronomical observations, we ought to take care not to be pre- 
cipitate; so on the other hand I am perhaps too scrupulous in 
satisfying myself, and should probably require the observations 
of several years before I could venture to be decisive. It will 
also be seen by the dates of the first observations, that a fur- 
ther delay in the communication cannot be adviseable ; since 
much information may possibly be gained by throwing open, 
to other observers, the road it will be eligible to take for a 
satisfactory investigation of the subject ; especially as we have 
reason to congratulate ourselves on the spirit of observation, 
and increase of large instruments, that seem to have taken place 
in various parts of Europe. 
I shall now transcribe the observations from my journals. 
They are as follows. 
Xx 2 
