OUTLINES OF NATURAL PHILOSOPHY, 



This follows readily from the preceding. The chief 

 application of the proposition is to spherical or 

 spheroidal crusts. 



A spheroid is a solid bounded by a surface generated 

 by the revolution of an ellipsis about either axis. 



The matter of which the solids consist, is supposed in 

 these propositions to be homogeneous. 



. A particle placed any where without a 

 sphere, of which the parts attract, as in the last 

 article, will be urged to the centre of the sphere, 

 with a force that is as the quantity of matter 

 in the sphere, divided by the square of the dis- 

 tance from its centre. 



Princip. Math. lib. i. prop. 74*. SIMPSON'S Fluxions^ 

 $ 380 f 



If m be the mass of the sphere, x the distance of a 



particle from the centre, the attraction is . 



x 



If the radius of the sphere = r > and the density of 

 the matter contained in it = d, the quantity of 



matter, or m = , and so the attraction 



When 



