242 Of the SOLIDS 

 AK or a\ we have the whole attraction of the folid, or F = 

 « a — f/a — £ Log — ==— • X , 



— (3 Log — X ,- 



p 6 v/^ + ^ * + •** + *" 



If, in this value of F, we invert the ratios, in order to make 

 the logarithms affirmative, and write like quantities, one under 

 the other, we have F = jj a — q'a' 



The fir ft two terms of this expreflion deferve particular at- 

 tention, as n is an arch, fuch that fin n r= fin B AE X fin B AC ; 

 therefore, by what has been before demonflrated, q is the mea- 

 fure of the angular fpace fubtended at A by the rectangle BD. 

 The nrft term in the value of F, therefore, is the product of the 

 diftance AB, into the angular fpace fubtended by the rec- 

 tangle BD. In like manner, the fecond term, or jjV, is the 

 product of the diftance AK, into the angular fpace fubtended by 

 the rectangle KF. 



The relation of the quantities expreffing the ratios, in the 

 two logarithmic terms, will be belt conceived by fubftitu- 

 ting for the algebraic quantities the lines that correfpond 

 to them m the diagram. Becaufe c 1 zz b z -f- |3* zz EB* -f- 



BC- 



