98 



Potts — Rowland's New Method. 



\ M. F. standard condenser made by the Troy Electric Co. 



The Bridge. — The bridge was set up permanently on a 

 table ; all connections were soldered ; and the wires used in 

 connecting different parts of the bridge and instruments were 

 !No. 25 cotton-covered copper wire. All wires were made as 

 short as possible and no wires were twisted. 



Investigation. — In fig. 2, is shown the arrangement used in 

 the measurement of electric absorption ; s t , s„ and s s are current 



reversing switches, which were used in testing for induction of 

 one part of the bridge on another. In most cases, however, 

 there was no appreciable error due to this cause, so that it was 

 not usually necessary to take a set of readings for all positions 

 of these switches. M and 1ST are two switches which were 

 used in a later experiment described below. In the measure- 

 ment of electric absorption M and ]S" were in the position a. 

 In the fourth arm of the bridge there was a resistance R 4 . K T 

 is a key to close the circuit through the hanging coil of the 

 electro dynamometer. When K : was not pressed down, it 

 closed the cross-connection of the bridge through a resistance 



