﻿816 



Mr. V. E. Pound on the Secondary Rays 



In column 1 is given the voltage applied to the polonium, 

 and in column 2 the charge gained per minute by the brass 

 electrode opposite the polonium, as measured by the quadrant 

 electrometer. A curve representing these results is shown 

 in fig. 2. 



Ffc. 2. 



*60 320 <S0 



Voliocje on Polonium. 



6W 



It is evident from the results given in the Table, and from 

 the curve, that when the polonium was at zero voltage the 

 charge gained by the brass electrode was negative. It is 

 also evident that as the voltage on the polonium was increased 

 positively the charge gained by the electrode increased from 

 a negative charge to a positive one, and that at a potential 

 of about 20 volts the rate of charging became a maximum. 

 This result agrees with the result published by Logeman. 

 This can be seen from the numbers recorded in his paper, a 

 few of which are given in the following table. The results 

 can be readily compared, because the distance between the 

 polonium and the opposite electrode was about the same as 

 that in Logeman's apparatus. 



