; 



170 Mr. C. 8. Whitehead on the Effect of a Solid 



Therefore 



dx dy dz 



dp 17 ~dl' _ 1 



dy dz dz dx dx dy r 



z j~V-t x ^ z ~r Vi x ~r- 



ds * ds ds ds u ds ds 



Hence 



Xs=e^rf n {kr) C ^ ) 



[. (10) 



~ , t( f i dn n i/a\ 2 "+ 1 ^r / 



Let Xj, X^ be the components of P, Q, K along dsf in the 

 sphere and dielectric respectively. 

 We find as before 



At the surface of the sphere, the normal magnetic in- 

 duction is continuous, and also the tangential magnetic force. 

 Therefore 



Jl s = R d when r = a, 



— T = T. ,, r = a. 

 Therefore 



ip 



- iL </-i(*»)+ n /i( fa )K s= o.+ i 



We see that the first of these equations also arises from the 

 continuity of the tangential electromotive intensity. 

 Eliminating co n , 



{n + i;u — — — - — _ _ — wft . (11) 



Now 



where J w+ i(#?') is Bessefs function. 



