STANDARDIZATION 

 APPARATUS 



FOR BOTH 



DIRECT AND ALTERNATING CURRENT 



We have a fully developed line of apparatus for the 

 standardization of voltmeters, ammeters and wattmeters, 

 either D.C. ; or A.C., also apparatus for the determination of 

 the ratios of both potential and current transformers. 

 The following catalogues sent upon request: 

 The L & N Potentiometer. 

 The A.C., D.C. Comparator. 

 Dynamometers. 



The Leeds & Northrup Co. 



ELECTRICAL MEASURING INSTRUMENTS 

 4901 Stenton Avenue Philadelphia, Pa. 



W. & L. E. GURLE Y 



TROY, N. Y. 



Manufacturers of 



Physical and Scientific Instruments 



For Schools, Colleges and Private Laboratories 



Estimates Free Catalogue on request 



