1920] Thermionic Valve in Wireless Telegraphy 6c Telephony 189 



With these brief explanations I must close my stoiy. The 

 development of the thermionic valve has been quite one of the most 

 remarkable things in recent electrical technology. 



It was my good fortune to make the first application of ther- 

 mionic facts to wireless telegraphy in 1904, but the subsequent 

 immense development has been due to the work of many able 

 scientific investigators who were immediately attracted to the new 

 field of research I had opened by its utility and interest. 



Without any exaggeration the thermionic valve in its two- and 

 three-electrode forms may be said to be the foundation stones of 

 modern wireless telegraphy and telephony. An enormous amount 

 of valuable research work has been carried out on the action of the 

 instrument in recent years. Thermionic valves have been used 

 literally by millions during the war, but the experience thus gained 

 is being carried forward into time of peace, and has given us new 

 and wonderful additions to our resources for transmitting intelligence 

 to distances quite impossible by any other means. 



[J. A. F.] 



