SCIENCE 



New Series. 

 Vol. XI. No 271. 



Friday, March 9, 1900. 



Single Copies, 15 CTS. 

 Annual Subscription, $6.00 



QUEEN INSTRUMENTS 



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Queen Projection Galvanometer 



An Instrument designed for Lecture Table and Lantern Work. Scale frame fits the ordinary pro- 

 jection Lantern and deflections can be shown on screen. 



The Galvanometer is of the D'Arsonval type, suiBciently sensitive to show Induction and Thermo 

 effects. The current produced by one volt through 500,000 ohms will produce a deflection of one scale division. 

 Resistance about 600 ohms. With key (not shown in cut) mounted on Galvanometer the motion is dead-beat. 



We direct attention to our latest forms of Photometers, Portable Testing Sets, Cable Testing Instruments, 

 X-Ray Apparatus. Descriptive circulars free. We make a Specialty of Testing Incandescent Lamps. 



QUEEN & CO., Inc. 



J. G. GRAY, President 



ELECTRICAL AND SCIENTIFIC INSTRUMENTS 



59 Fifth Avenue, New York 



1010 Chestnut St., Philadelphia 



