236 - Of the SOLIDS 
Let the body B be cut by two planes, at right angles to AC, 
and indefinitely near to one another, fo as to contain between 
them a flice or thin fection of the body, to which A and A’ 
may be confidered as gravitating, nearly in the direction of the 
line AG perpendicular to that fection. » 
THE gravitation of A, therefore, to the aforefaid fection, will 
be to that of A’ to the fame, as the angular fpace fubtended by 
that feGtion at A, to the angular fpace fubtended by it at A’. 
But thefe angular fpaces, when the diftances are great, are in- 
verfely as the fquares of thofe diftances, and therefore, alfo, the 
eravitation of A toward the fection, will be to that of A’, in- 
verfely as the {quares of the diftances of A and A’ from the 
fection. Now thefe diftances may be accounted equal to CA 
and GA’, from which they can differ very little, wherever the 
feétion is made. 
THE Feast of A and A’ toward the faid fection, are, 
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the gravitation to all the other fections, or laminz, into which 
the body can be divided by planes perpendicular to AC; there- 
fore the fums of all thefe gravitations, that is, the whole grayi- 
tations of A to B, and of A’ to B, will be in that fame ratio, 
therefore, as — And the fame may be proved of 
that is, as —~> or inverfely as the fquares of the di- 
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ftances from C. Q.E.D. 
Ir is evident, that the greater the diftances AC, A'C are, the 
nearer is this propofition to the truth, as the quantities rejected 
in the demonftration, become lefs in refpect of the reft, in the 
fame proportion that AC and A‘C increafe. 
Ir is here aflumed, that the angular {pace fubtended by the 
fame plane figure, is inverfely as the fquare of the diftance. 
This 
