J. Trowbridge — Side Discharge of Electricity. 57 



Art. VIII. — Side Discharge of Electricity ; by John Trow- 

 bridge. 



The installation of a large storage battery of 10,000 to 20,000 

 cells presents many interesting problems in regard to insula- 

 tion ; and modern theories of ionization receive great support 

 from a study of the phenomena observed in the region surround- 

 ing the poles of the battery. There is a great probability of 

 an invisible ionization which is constantly taking place between 

 the earth and the battery. 



A E 



^ 



B 



3? 



Such ionization immediately becomes visible in an interesting 

 form of Geissler tube shown in fig. 1. 



The terminal A is connected permanently with the pole of 

 the battery through a large water resistance (several megohms). 

 The terminal B is connected to the negative pole by a spark gap S. 

 ,5 is connected to the earth. At the instant the spark occurs a 

 brilliant side discharge occurs between E and B. If the nega- 

 tive pole of the battery is permanently connected through the 

 large water resistance to B, and A connected by a spark gap 

 to the positive pole of the battery, the side discharge takes 

 place between E and A. At the same time that these side 

 discharges take place, a discharge passes between A and B. It 

 is evident that the capacity of the region outside the battery, 

 the room, and building charges up under the difference of 

 potential between it and the poles of the battery, a difference 



