197, 198] DIELECTRICS AND MAGNETIZABLE BODIES. 379 



the cylinder, substituting spherical for circular harmonics. Let us 



FIG. 78. 



again suppose that the bodies producing the undisturbed field are 

 outside, so that at the outer surface of the sphere 



(i) Fo = F (^) + F 1 ( 



Accordingly for r < a, 



(2) 



(3) 

 (4) 

 (5) 



(6) 

 (7) 



The potential of the induced polarization is given by 



n> r>a, 



p- (n+ v)Y n , a>r>b, 

 n, r<b. 



The conditions of continuity of Vi give as before 



