[ *85 3 
Supplement to the foregoing Paper. 
N deducing the diflance of the fun in 
femidiameters of the earth, and his 
horizontal parallax, from the proportion above con- 
cluded between the fun’s mean diflance and that of 
the moon ; I have fuppofed the latter to be 604. 
femidiameters of the earth, as it is reckoned by Sir 
Ifaac Newton. According to the hypothecs which 
feems to be now generally received, that the denfity 
of the moon is very nearly equal to that of the earth, 
(the French reckon it rather lefs), the moon’s mean 
diflance fhouldbe little more than 60,23207, that is, 
not quite 604. femidiameters of the earth. But from 
fome computations that I have formed with great care ; 
I have reafon to think, that Sir Ifaac Newton’s deter- 
mination is much nearer to the truth ; that the 
denfity of the moon is actually greater than that of 
the earth, in the proportion of 6 to 5 nearly ; and that 
the moon’s mean diflance amounts to 60,441 femi- 
diameters of the earth ; which differs from the 
diflance affigned by Sir Ifaac Newton, by lefs 
than To 4 T of the whole. 
S. Horfley. 
Read June 19, T 
1767. A 
B b 
Vol. LVII. 
Received 
