Rotation of the Ring of Saturn, 48 1 
wc fliall be able to give an eafy folution to all the retraining 
obfervations. 
For inftance, let / 3 , 7, S, s, reprefent five fpots on the ring of 
Saturn, iituated as in fig. 2. ; where the ring is fuppoted to be 
divided into 360 degrees, and the foot a placed at 271°, 5 ; /3 at 
po : ,2 ; 7 at 183°, o ; $ at i42°,5 ; and e at 358°,6. Then will 
the ring, with the fpots thus placed, ferve as an epocha for the 
year 1789; by which, with the affidance of a table con» 
ftru&ed upon the before -mentioned period of the rotation of 
the ring, we may calculate their fit nation for any required 
time ; and to render this calculation perfectly convenient, I 
have given a table, ready prepared for the purpofe, at the end 
of the other tables. j 
The following obfervations have all been previoufly cal- 
culated by the tables of fuch of the feven fatellites as were 
not already in views and have been found to belong to neither 
of them; but in the notes that are given with them they have 
been again calculated by the table of the rotation of the ring for 
every time they were obferved ? on a fuppOfition of their being 
fpots adhering to it. 
Obfervations not accounted for by fatellites « 
* . ' \ 
\ . 
July 28. 22 31. I now perceive between the neareft fat. and 
T? , on the f. fide, a fmall lucid point, like an emerging fatel* 
lite (A). 
22 37. 
(A) My furmife of its being an emerging fatellite fo early as the beginning 
of the feafon, when I was ftill unacquainted with the minute phenomena that 
offered themfelves afterwards, fliews plainly, that the lucid point was of a fuiti- 
cient brightnefs to deferve notice. The five old fatellites were in view, and the 
Vol. LXXXo R r r 6th 
