470 Mr. J. M. Kuehne on the Electrostatic 



Hence 



i NOE . 2Q dO 



L=-y — sm 2 ^ 



Zir at 



= NCEn sin 2 0, 

 since dd/dt = 2irn. 



Now the average moment over one complete cycle is 



A A 



Y NCE>i C 2n . ,. , 

 JL = — s 1 sin- 0t70 



NCEn r 



-^ Jo 



= 1/2NCE72. 



Since this formula expresses the moment directly in terms 

 of the magnetic flux and the charge, it would seem to be the 

 most natural one to use. It was in fact employed in all the 

 earlier calculations of the present experiment. The quantities 



-V A 



N and E have to be expressed in terms of measurable 

 quantities as follows : 



E =R v /2E 1 xl0 8 , 



where Ex is the effective E.M.F. in volts impressed on the 

 primary of the transformer, and R is the ratio of transfor- 

 mation. 



A v. dt - ±nN - T 



where n is number of complete cycles per second, and E 2 is 

 the effective E.M.F. in volts induced in a coil of T turns. 

 From this 



* '901E.X10 8 



4nT 



On account of its greater convenience of application to the 

 experimental data the following formula was given the 

 preference in all the later computations. 



Let E 2 = the effective E.M.F. induced in a single turn of 

 a conductor encircling the magnetic field. Then the mean 

 value around the circle of the " effective " electric intensity 

 is 



F=- 2 -. 



2irr 



Also let Ei = the effective charging E.M.F. Then since 



