THEORETICAL EXPLANATION OF INDUCTION. 141 



64. TIie.inductive energy may "be resolved in different 

 directions, in the same manner as statical forces. 



Fig. 52. In Figure 52, let a and b represent 



the separated masses of magnetism of 

 equal intensity produced by one of the 

 small circles in Figure 51. It seems 

 reasonable to suppose that the extent of 

 ^ their separation will be proportional to 

 the external magnetic energy. Take the 

 positions b'a (coincident in space) for 

 two masses of opposite magnetisms, each 

 equal to a or b. These two masses, 

 while coexisting, neutralize each other. 

 But we may conceive b' associated with 

 a and a associated with Z>; and we may 

 consider the pair ab r as the effect of one 

 inducing magnetism in the direction ab', 

 gmv and the pair a'b as the effect of another 

 inducing magnetism in the direction a'b ; 

 and the magnitudes, of the two inducing magnetisms 

 must (by the general assumption mentioned above) 

 be considered proportional to the lengths ab', ab. 

 It is seen here that we have in fact resolved the 

 primary inducing energy into two, according to the 

 laws of resolution of statical forces : and if, in any pro- 

 posed problem, it can be shewn that one of these is 

 inefficient, we may confine our attention to the 

 other : or if the effects of the resolved inductions 

 can be computed more easily than that of the 



