produced by Motion in the Electric Field. 



e 

 magnetic force outside and inside =<&e ipt mi 6 -j ; hence 



-8C>£ E (Ou.)-3D^«i = !?. 



da ' da a z 



From (5) we have 



C(E 2 (i\a) + 2E (/\a)) - D(S 2 (V) - 2S (X 1 a)) = 



/a 3 K 

 From these equations we have 



C= i {f^? Ta S o(V)-i^(SKV)-2S„(VO) } ( 6 ) 



D= s{ -*?( E ^ a ) + 2E »(^))-^iE ^a)}, (7) 

 where 

 A = (E,(t\a) + 2E (tXa)^ S (M + ^E (t^a)(S 8 (Xa)-2S (V))). 



Let us first consider the case where \a and X x are both small. 

 In this case E 2 (z\a) is large compared with E (?\a) and 

 S 2 (Xia), very small compared with S (X 1 a) ; hence we see that 



cue 



— -zE Q (i\a) 



D= a 



E 2 (OUi)|;S (X 1 a) 



aa 

 Since E 2 (z\a) = -r^p approximately, and S (Xi«j =1, we have 



-p. _ 0)6 ZJt90-K 

 (2 47T 



The magnetic force outside the sphere parallel to the axis of 

 x equals 



or 



= icoe\e iKa -r ^— . e*' 

 ay ikr ? 



