so8 Of the SOLIDS 



As the tangent of 6 2°. 46' is not far from being double of 

 the radius, therefore the cone of greateft attraction has the ra- 

 dius of its bafe nearly double of its altitude. 



To compare the attraction of this cone with that of a fphere 

 containing the fame quantity of matter, we muft exprefs the 

 attraction in terms of u y the ratio of x to z, which has now been 

 found. 



Because * x (z* — x 2 ) — £m 3 , and z — -,*x(— — xj rr 



x ), and lince - zzu. — r= 



z' z z 



3 



zz2nm.(i — u) y—~ k ; wherefore, A 3 — 8 *' m 3 (1 — u)z 



v J t(i — u) y J 



But if A' be the attraction of a fphere of which the mafs is 



mK on a particle at its furface, A' = m V — -. and A' 3 = 



9 



«3.Zil. Therefore A* : A'» : : 2 4 a' (i - a)* 16 . . 

 9 1 + « 9 



27 ,■ (1 — y . nd conf tl A . A , tf^fcsjf : T .. 



If, in this expreffion, we fubrtitute .45761 for ?/, we fhall 

 have A: A 7 : : .82941 : 1, fo that the attraction of the cone, 



when 



