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PROCEEDINGS OF THE AMERICAN ACADEMY. 



total energy communicated between the circuits was about four times as 

 great with the mercury interrupter as with the spark-gap. The results 

 here given pertain, of course, only to the particular form of circuits and 

 the particular interrupter employed. I have made some experiments 

 with forms of open circuit of the type used in wireless telegraphy, but 

 the results are not yet ready for presentation. 



TABLE I. 



III. Resonance. 



On account of the regularity of the mercury interrupter, it can be 

 employed advantageously in the study of resonance between circuits of 

 high frequency. For example, the closed loops used in this experiment 

 can be quite accurately tuned with the aid of this interrupter and the 

 receiving instruments described above. With a fixed sending circuit 

 the accompanying curve (Figure V) was obtained by a single set of 

 readings when the air condenser in the receiving circuit was varied from 

 six plates up to twenty-one plates. The capacities are represented as 

 abscissas, while the deflections in centimeters are the ordinates. The 

 capacity for each plate of the air condenser is 248 cm. The capacity 



