12 Dr. Herschel’s Obfervations 
Caober, at 19 h. 56' 46", when thefe two fatellites were 
placed as in fig. 7. the firft, notwithftanding it was nearer the 
planet than the fixth, was (till vifibly brighter than the latter. 
It would, however, be worth while to try whether a good 
achromatic telefcope, of a large aperture, might not poifibiy 
(he;v it at the time of its greateft diftance from the planet, 
and when no other fatellite is near; that is, provided it will 
(hew the other five fatellites with great eafe, asotherwife there 
will be no reafon to expedt it Ihould Ihew the fixth. 
In the period of this fatellite I have employed the obferva- 
tion of the 19th of Auguft, 1 7 ^ 7 ’ as ’ * roin °ther calcula- 
tions, it feems the revolution is determined near enough to 
reach back fo far. 
The moft diftant obfervations of the feventh fatellite, being 
compared together, Ihew, that it makes one fidereal revolution 
in 22 hours, 40 minutes, and 46 feconds : and, by the lame 
data which ferved to afeertain the dimenfion of the orbit of 
the fixth, we have the diftance of the feventh, from the cen- 
ter of Saturn, no more than It is incomparably fmal- 
ler than the fixth ; and, even in my forty-feet reflector, ap- 
pears no bigger than a very fmall lucid point. I lee it, how- 
ever, alfo very well in the twenty-feet refloftor ; to which the 
exquifite figure, of the Ipeculum not a little contributes. It 
muft neverthelefs be remembered, that a fatellite once dilco- 
. vered is much eafier to be leen than it was before we were 
acquainted with its place. 
The revolution of this fatellite is not nearly fo well afeer- 
tained as that of the former.. The difficulty oi having a num- 
ber of obfervations is uncommonly great ; for, on account of 
the fmallnefs of its orbit, the fatellite lies generally before and 
behind the planet and its ring, or at leaft fo near them that, 
except 
