C M7 ) 
fmal), but yet at all given Diftances is ftill fonie thing, 
tho' the Effect become infenfible. At the diftance of 
the Moon (which I will fuppofe 60 Semidiameters of 
tne Earch) 3600 Pounds weigh but one Pound, and 
the fall of Bodies is but ^^^^ of a Foot in a (econd, or 
16 Foot in a minute ; that is, a Body fo far off defcends 
in a Minute no more than the fame at the Surface of the 
Earth would do in a Second of Time. 
As was faid before, the fame force decreafing after 
the fame manner is evidently found in the Sun^ Moon, 
and all the Planets ; but more efpecially in the Sun, 
whofe Force is prodigious ; becoming (enfible even in 
the immenfe diftance of This gives room to 
fufpeft, that the force of Gravity is in the Celeftial 
Globes proportional to the quantity of Matter in each^ 
of them : And the Sun being at leaft ten Thoufand times 
as big as the Earth, its Gravitation or attrafting Force, 
is found to be at leaft ten Thoufand times as much as 
that of the Earth, adingon Bodies at the fame diftances. 
This Law of the dccreafe of Gravity being demon- 
ftratively proved, and put paft contradiftion the Au« 
thor with great Sagacity, inquires into the neceffary 
Confequences of this Suppofition ; whereby he finds the 
genuine Caufe of the feveral Appearances in the Theo- 
ry of the Moon and Planets, and difcovers the hitherto 
unknown Laws of the Motion of Comets, and of the 
Ebbing and Flowing of the Sea. Each of which are 
Subjects that have hitherto taken up much larger Vo- 
lumes ; but Truth being uniform, and always the fame, 
it is admirable to obfervc how eafily we are enabled to 
make out very abftrufe aftd difficult Matters, when once 
true and genuine Principles are obtained : And on the 
other hand it may be wondred, that, notwithftanding 
the great facility oftruth,and the perplexity and noncon- 
(equenccs that always attend erroneousSuppofitions,the(e 
Xxx X great 
