!7s 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



in the shortest charging interval secured in the experiment. In other 

 words, we shall assume that the small throws obtained after this 

 shortest charging interval are due wholly to the difference in "free 

 charge capacity " of the two condensers. After all, since we find it 

 so difficult to know the actual amount of the residual charge, we must 

 temporarily content ourselves with the differences in residual charge 



TABLE II. (Figure 2.) 

 " Mica A " vs. Am. 

 64 volts. Total Throw = 46.5 cms. 



formed for varying charging intervals. When ballistic throws are in 

 favor of the air condenser, they will be regarded as positive ; when 

 the test condenser's charge prevails, we shall record the throws as 

 negative. With these explanations we may now tabulate the results. 

 (Tables I, II, III.) 



If the principle of superposition, or in this case the simple propor- 

 tionality of residual charge to the electromotive force applied to the 

 condenser, held true for the range of potential used in this experiment, 



