100 



J « 



20 

 10 



15,000 



High- Frequency Induction- Coil. 

 Fkr. 7. 



3:55 

















\ 













































*\ 















-\ 































r - -*js_ 







































20,000 



25,000 



30,000 



Volts. 



No direct measurements were made verifying this frequency. 

 The few spark-photographs made show mainly the hazy light 

 due to the current expressed by the exponential term. 



Substituting the values of capacity and inductances in 

 equations (30) and (31), and reducing from the absolute to 

 the practical system, we get 



i 



i 



l*dt = MJ 



8 x 10- 10 

 R. + -1694R' 



T. if -v» 1-355x10-" 

 l2 ^- v ° R 1 + -1694R 2 - 



Solving for R 1 + '1694R 2 , we get for n=136 

 R 1 + '1694K 2 =l-089xl0-^ 



V 2 

 = 1-845 xl0" 8 =|-. 



v 



Table IV. gives in columns a, V, b, as before, the primary 

 spark-length, the potential corresponding thereto, and the 

 maximum impressed potential. In column c are given the 

 lengths of spark-gaps introduced into the secondary circuit, 

 the spark taking place between brass balls 2 centim. in 

 diameter. Columns I x and I 2 give the observed effective 



