COMPARISON OF CAPACITIES WITH RESISTANCES. 



471 



In order that the current shall be null in the branch r' in the two 

 experiments, the compensating resistance R x must be null; in this 

 case we have simply 



i rr' 



P ~ 



2nC~ r + r 1 



Instead of bringing the currents to the same value, we may 

 determine the intensity I of the primitive current and the intensities 



/ and /' of the current in the two branches when the commutator is 

 at work; we have in that case 



E - V= 



The mean intensity of the discharge current is 



I = 2^CE = - = I -. 

 P P 



If I' and I - 1' are the discharge currents in the wires r' and 

 we have 



l'r' = (l-l')r, 

 or 



The mean currents during the action of the commutator are 



