Copyright, 1909 and 1911 

 BY FREDERICK BEDELL 



All rights reserved 



First Edition, September, 1909; November, 1909 



Second Edition (enlarged), July, 1911; (revised), December, 1911 



August, 1912, November, 1912, March, 1914 

 NOTE The first edition was issued under the title 

 " Direct and Alternating Current Testing." 



PRESS OP 



THE NEW ERA PRINTING COMPANY 

 LANCASTER. PA 



