207, 208] CONDUCTION IN DIELECTRICS. 403 



circuit may also be broken. If / is the current in the wire from 

 the plate 2 to plate 1, we have, since whatever charge arrives by 

 the wire is uniformly distributed over the plates 



(1) s-I-yJS- 



(2) 8^ = -I+q 3 S 



(3) S-(fc~ft}<Sf 



The densities are determined by the equations 



(5) 



(6) 



Beside these we have always, taking the line integral of the 

 force plate to plate, the equation 



(7) 



From (l) and (4), (2) and (5) 



and integrating from t = to t = r, 



If F 1 be the greatest value of F^ in the interval t = 0, t = T, we 

 have 



fr F l dt<F 1 r, 



262 



