﻿716 Profs. Wellisch and Bronson on the Distribution of 



are given in fig. 1. The test-vessel A was supported by 

 brass clips mounted on ebonite; these clips were connected 



to the battery through carbon resistances R, R', the changes 

 of potential being effected by means o£ the adjustable con- 

 tacts s, s', and the key L. B represents a parallel plate 

 vessel which was employed in order to communicate definite 

 induced charges to the electrometer system whenever occasion 

 arose. C is a capacity consisting of two thin sheets of tinfoil 

 separated by a thin sheet of mica ; this capacity, together 

 with that of B, could be added to the system by means of 

 the key K, and the total capacity of the system was then 

 increased 21i times. The electrometer was of the Dolezalek 

 pattern with a platinum suspension. The needle was charged 

 to a potential of 120 volts, and with this potential the" 

 sensitiveness was 180 mm. per volt on a scale about 1 metre 

 distant. 



The R on i gen -ray bull), which was enclosed in a lead- 

 covered box and which was employed whenever it was 



