HIGH VOLTAGE ' 



By Kakl T. Compton 

 President, Massachusetts Institute of Technology 



[With 1 plate] 



While there is much truth in the statement that necessity is the 

 mother of invention, it has often be€n pointed out that it is far from 

 true that necessity is the mother of discovery. Discoveries come often 

 most unexiDectedly, in the pursuit of knowledge by the curious and 

 observant. The great background of natural phenomena which have 

 thus been discovered form an immense reservoir from which may be 

 drawn natural laws or combinations of phenomena which can be 

 made to work for the solution of men's needs or desires when necessity 

 arises. 



One of the most excellent examples of the fact that necessity is the 

 mother of invention is found in the great number of applications of 

 science which were made during the past war to cope with situations 

 which never before had challenged the ingenuity of man. Such situ- 

 ations were the detection and location of submarines or of airplanes 

 flying by night. There were also the location of underground mining 

 operations or of enemy artillery by sound, or the direction of counter- 

 battery artillery fire, also by sound. Such examples could be multi- 

 plied almost indefinitely, but the interesting feature of them all is 

 that every one was handled by the application of some scientific phe- 

 nomenon which had been known in the laboratory for many years. 

 The necessities of war brought forth the means of applying these 

 phenomena for particular purposes. 



It is to a very recent example of this natural sequence of events 

 that I will call your attention in this paper, an example taken from 

 the field of electricity, the chosen field of Joseph Henry in whose 

 honor this lecture has been named. It is a modern application of 

 one of the oldest branches of electricity, a branch so old that some 

 ultramodern textbook writers have advocated omitting it entirely 

 from textbooks on account of the academic and impractical character 

 of its subject matter. But let me first lay the groundwork for this 

 new development in the field of high-voltage electricity. 



1 The third Joseph Henry lecture delivered before the Philosophical Society of Wash- 

 ington on Mar. 11, 1933. Reprinted by permission from Journal of the Washington 

 Academy of Sciences, vol. 23, no. 6, June 15, 1933. 



249 



