666 



Professor J. A. Fleming 



[June 4, 



extremely large. Hence if we form a spark gap consisting of a large 

 number of very small spark gaps in series, say 10 gaps each of • 3 mm., 

 and if we keep the spark surfaces cool, then not only can no arc form 

 between these surfaces, but the condenser spark is immediately 



Fig. 11. — Method of Utilising Waves of Both Frequencies emitted 

 BY Inductively-Coupled Transmitting Antenna. 



Ordinary Spark 



Primary 



\[0^Y^J\})J^^ 



Secondary 



Primary 



Secondary H 



Fig. 11a. — Oscillations in Inductively-coupled Circuits. 



quenched. Moreover, if we supply this spark gap, either from a hi^h 

 frequency alternator, or from a low resistance transformer, we can 

 produce as many as 2000 sparks per second. A form of discharger 

 for this purpose has been devised in Germany, which consists of a 



