SCIENCE— ADVERTISEMENTS 



A LABORATORY EQUIPMENT 



FOR 



CONDUCTIVITY MEASUREMENTS 



Tliis equipment is of unusual convenience in that it may be 

 oj)erated on an ordinary lighting circuit of 110 volts, either 

 25 or 60 cycles. This has been made possible by the develop- 

 ment of the alternating current galvanometer which is used 

 to detect the position of balance. With this detector, noise 

 cannot interfere with securing a balance. 



A very satisfactory degree of accuracy, of the order of 

 0.?)% may be secured when working with the usual labora- 

 tory solutions. 



Tlie equipment includes the following items: 



4760 Wheatstone Bridge $63.00 



2370 A. C. Galvanometer 60.00 



(Specify 25 or 60 cycles) 



3700 Single Contact Key 3.00 



4917 Dip Cell 26.00 



$152.00 



LEEDS & NORTHRUP COMPANY 



ELECTRICAL MEASURING INSTRUMENTS 

 4901 Stenton Ave., Philadelphia, Pa. 



