36 Mr. Micuey on the Means of difcovering the 
has not been fuggefted by any one elfe) left, for want of being 
aware of the ufe, which may be made of them, they fhould 
neglect to make the proper obfervations, when in their power 3 
I fhall therefore beg the favour of: you to prefent the following 
RAPER on this fubject to the Royal Society. — 
Tam, &c. 
THE very great number of ftars that have been difcovered 
to be double, triple, &c. particularly by Mr. Herscuet *, if 
we apply the doctrine of chances, asI have heretofore done in 
my ‘*‘ Enquiry into the probable Parallax, &c. of the Fixed 
‘¢ Stars,” publifhed in the Philofophical Tranfaétions for the 
year 1767, cannot leave a doubt with any one, who 1s properly 
aware of the force of thofe arguments, that by far the greateft 
part, if not all of them, are fyftems of ftars fo near to each 
other, as probably to be liable to be affected fenfibly by their 
mutual gravitation ; and it is therefore not unlikely, that the 
periods of the revolutions of fome of thefe about their princi- 
pals (the fmaller ones being, upon this hypothefis, to be con- 
fidered as {atellites to the others) may fome time or other be 
difcovered. hee 
2. Now the apparent diameter of any central body, round 
which any other body revolves, together with their apparent 
diftance from each other, and the periodical time of the revolv- 
* See his Catalogue of Stars of this kind, publifhed in the Philofophical Tranf-- 
actions for the year 1782, which is indeed a moft valuable prefent to the aftrono- 
mical world.’ By a happy application of very high magnifyiug powers to his 
telefcopes, and by a moft perfevering induftry in obferving, he has made a very 
wonderful progrefs in this branch of aftronomy, in which almoft nothing of any 
confequence had been done by any one before him, 
ing 
