ULE IN E 
NEW SERIES. SINGLE COPIES, 15 CTs. 
VoL. X. No. 254. FRIDAY, NOVEMBER 10, 1899. ANNUAL SUBSCRIPTION, $5.00 
A NEW PAMPHLET 
X-RAY APPARATUS 
Describing in detail the most improved and efficient X-Ray Apparatus on the market, 
together with the methods employed by the leading operators throughout the country. 
OUR 
SELF-REGULATING X-RAY TUBE 
POSSESSES UNIQUE FEATURES 
Photometers and Photometric Work = = = Cire. 474 
Cable Testing Apparatus = = = = = Cire. 454 
Queen Portable Testing Set - = = = = Cire. 366 
Any of these Publications Sent Free by Mail on Request 
WE MANUFACTURE ALL KINDS OF 
ELECTRICAL AND SCIENTIFIC INSTRUMENTS 
WE IMPORT THE PRODUCT OF ANY FOREIGN MANUFACTURER 
QUEEN & CO., INc. 
J. G. GRAY, President 
Electrical and Scientific Instrument Works 
59 Fi A s 
ENO iNee You 1010 Chestnut St, Philadelphia 
