1884.] 



self-induction of the galvanometer. 



215 



What we are at present considering is the whole current 

 through the galvanometer due to the charging of the condenser. 



Let us therefore make abstraction of the electromotive force of 

 the battery and the whole system of steady currents due to it. 



This system of currents entails a difference of potentials between 

 B and D which we may call E t . 



When therefore the condenser is really discharged, it is on our 

 present supposition charged to a potential — E x ; and when it is 

 really charged, it is on our present supposition discharged. 



Hence we have to investigate the whole current through G in 

 the arrangement represented in the second figure when the con- 

 denser, which is initially charged to a potential — E v discharges 

 itself. 



If a be infinite the arrangement becomes identical with that 

 already considered. 



We have the equations 



bx + a (x — y — z) + d (x — y) = 



y _ 



(5), 



-a{x-y-z)+c(y+z)-d(x-y)+^=-E 1 (6), 



-a(x-y-z)+c (y + z)+gz + Lz = (7). 



Eliminating x between (5) and (7), we get an equation of the 

 form Ay + Bz + L'z = 0, 



where A and B are independent of L. 



