Radioactivity and Ionization of the Atmosphere. 707 



The method of winding is shown in fig. 1, where the frame 

 A is seen in position inside the testing cylinder B. The 

 testing cylinder was of metal, about 150 cms. long and 

 30 cms. diameter. The outside cylinder was connected to a 



Fiff. 1. 





n 



□ 



c 



A— 



&lffTH 



r 



jf/f/pr/, 



battery of 100 volts. In order to ensure that there was no 

 conduction current between B and A over the supports the 

 insulator CD was cut into two parts and separated by a metal 

 ring connected to earth. The arrangement can be clearly 

 seen from the figure. 



3 A 2 



