ecole NCE 
NEW SERIES. SINGLE COPIES, 15 cTs. 
Vor. XIII. No. 315. FRIpay, JANUARY IW, 1 901. ANNUAL SUBSCRIPTION, $5.00. 
Queen X-Ray Apparatus 
Queen Self-Regulating X-Ray Tube 
QUEEN & CO., INc. 
59 Fifth Avenue, New York J. G. GRAY, President 
480 Monon Blidg., Chicago PH | LADE LPH IA 
