360 Mr Southerns, Experimental Investigation as to Dependence 



which they are attached. The cups F, G are permanently earthed 

 by the wire X. By means of a rocker not shewn in L connections 

 can be made as shewn by the dotted lines, two kinds of dots being 

 used to shew the connections corresponding to the two positions 

 of the rocker. The mercury in the cups B, G, iV, is higher than 

 that in the other cups in order that earth contacts shall always be 

 made before and broken after high potential contacts. It will be 

 seen that the key simply consists of two ordinary six cup reversing 

 keys fastened together. The lever W is used to throw the balance 

 connections in or out as desired. It will easily be seen that the 

 arrangement here described satisfies the condition that the two 

 fields Fj^, F2 of fig. 1 shall be quite distinct from each other. By 

 means of the key J in fig. 3 the multi-cellular voltmeter H can be 

 connected to either of the wires S, T in fig. 5 at pleasure. 



(3) Detailed description of experiments and results. 



The several experiments will now be described in order and 

 their results afterwards discussed. 



1. June 9th, 1909. (Used 1000 volts on each side of balance 

 in all cases except when otherwise stated.) There was very large 

 electrostatic deflection 6, no attempt being made to reduce this. 

 The zero of balance was altering rapidly. In the following tables 

 the observations are numbered, and the arrows shew the position 

 of the rocker of reversing key (refer to fig. 5), The column 

 marked 28 is calculated from three successive readings, it is the 

 difference between the mean of the first and last of the three and 

 the intermediate reading. 



A. Front cover of balance off. 



See Table on p. 369 for values of 5 corrected for sensitiveness. 



