Sir yoseph Petavel 195 



of it there are columns of intricate steel apparatus, con- 

 nected by arms with projections from the ceiling. Those 

 six columns support three transformers, forming the high- 

 voltage testing-plant which will play its part in the new 

 national electricity scheme now in course of development. 

 For that plant can produce a current at one million volts 

 and a frequency of fifty cycles a second — that is to say, 

 through that apparatus can be flashed fifty electrical 

 charges of one million volts, backward and forward, in 

 a single second. 



