164 MR. GEORGE W. WALKER ON THE INITIAL ACCELERATED 



Referred to the centre of the sphere as a moving origin the steady state is given as 

 before by 



- /? - 



o U , Po 



, 



\J 



Y (^ i*\o v <o 7 <u 



-^V) - ^1 A, )-^, ID --- 5. Ai -- 5 

 die 8y 82 



Proceeding, as before, to a first order approximation, we find that the field due to 

 the disturbance, using condition (1), is conveniently expressed by the system 



vy vz dz By 

 1 u' J (f> j , D-I/;,, , 3 2 </> 



^"^" 1 ' 



t'.' 1 d?/ 



/. 8 2 i//,, _ , _ , 2 s 3^ _ 3 J (/> X; 



~~ L/ ^^ 2 \ ^ I ^ ^ 5Ii T 7 ! 



o/ oar dz U 



??/8z 



where d> is a solution of 



supposed small of the same order as _/! 

 We assume the same forms as before 



The contributions to electric force are 



The tangential component of electric force vanishes at ? = a if 



when ? = a for all values of t. 



