162 



PROCEEDINGS OP THE AMERICAN ACADEMY 



noticed that the curvature near the origin is considerable, but that 

 after about one tenth of a second each line becomes nearly, though not 

 quite, straight. If the internal resistance of the battery is assumed to 

 be 24,000 ohms, the effective electromotive forces in the circuit after 

 one tenth of a second are about 1.2 volts, 4.5 volts, and 7.4 volts, 

 respectively. The electromotive force of the open battery was a little 

 over 16 volts. 



0.1 sec. 0.2 sec. 



Fig. 9. 



0.3 sec. 



The results in Table VI. were obtained with another battery of 20 

 water cells which had been resting for one month. The uumbei's 

 in the body of the table give in microcoulombs the quantity of elec- 

 tricity which passes through the circuit when the poles of the battery 

 were connected for the times named through various external re- 

 sistances. 



TABLE VI. 



After the poles of a battery of these water cells joined up in series 

 have been connected together for a short interval only (say for one 



