CorreBion of the Theory of tkMbti^ 
on of theSsLtdkc of Saturn, hy that In* 
%^^:.^^on6mcT Mr5^.,jED m u wn 
1 j^criicnd you m^Jiro^omical aecomt ofthemoft remote of all 
:;hie Piams out Vortex^ and withal of the moft inconfiderable, 
1 mean of the Satellite of SatHrny difcoveredin the year 165 5; by 
Monfiem Chrlfiim Hugens of Znllchem , who in that accurate Trea- 
tife of his Syftema Saturmum^ from fag, 2 5 to 3 4 gives us the Theorjf 
of its Motion as well as the (hortnefs of the interval of time between 
his Ohfervations admit ; and fince him 1 know nonethac 
have gone about to improve the faid Theory, 
The late QonjmBlons of Jupiter and SAturn giving me frequent 
occafions of viewing them both, with a Telefcofe that 1 have of about 
24 foot , and pretty good of that length, 1 eafily remarqued this Sa^ 
tallire oi Saturfi^ and haveing found it, in a convenient polidbn to de- 
termine its place , I percieved that H4igm\ numbers were ^ronfi- 
deratty runout, and about i j^^ffrr^i in twenty years too fwifc^ 
this made me refolve more nicely toenquireintolts/^nWj and ac- 
cordingly 1 waited till I had gotten a competent number of Ohferva^ 
tnm^ the moft confiderable whereof ar^ th^fc.^^^ ^ ^ 
' '1^82. Novefnber I3° i3* oo'PM; the'-S^^t^^/rrappca^^^^ tie 
ISfonh fide- of Saturn^ znA ^ferpe^jdicffiar let falVf^om it on tlift traijC- 
verfs diameter of the Rlrig , fell upon the middle of the dark fpacc 
of the following Anf<z i and the fame' nighr .1.9*' co* ic had paft 
xh&Qonjm^ioti, and the fW/^«/f2r feH ^ 
of the <j lobe of SatHrn , as in 7aL 2 . Figure '2.^ The Norihem^^x-- 
tude, and retrograde motion, made it evident that the SMllite^ls 
then in Perig^o, 
Again 
