32 



ON MAGNETISM. 



In Fig. 11 there is force, tending to produce a 

 motion of translation of B from A, represented by 



4 (w + 1) a/3 x ab . c"" 1 " 2 . 



Fig. 13. 

 fl 



Fig. 14. 



ft\ 



In Fig. 12, there is an equal force tending to produce 

 motion of B towards A. 



In Fig. 13, there is force tending to produce motion 

 of B towards A, represented by 



4m . (m + 1) aft x ab . c~ m ~ z . 



In Fig. 14, there is an equal force tending to produce 

 motion of B from A. 



In all these cases, the index of c is - m 2, and the 



