NEw SERIES. ai SINGLE CoPIEs, 15 CTs. 
VoL. X. No. 245. FRIDAY, SEPTEMBER 8, 1899. ANNUAL SUBSCRIPTION, $5.00 
(Jueen 
N=-Inch Portable Induction 
Outfit complete with QUEEN Self-Regulating X-RAY 
TUBE, FLUOROSCOPE, BATTERY, Etec. Price, $170 
This Coil, giving a very powerful discharge with heavy spark, is suitable for all classes of X-Ray 
work and at the same time for general laboratory work, setting up powerful oscillations 
when used for wireless telegraphy. 
Pamphlets on INDUCTION CoILs and on QUEEN SELF-REGULATING TUBE sent free on application. 
Queen & @o., in. 
J. G. GRAY, President 
Electrical and Scientific Instrument Works 
ME Yoel Rina nesae 1010 Chestnut St., Philadelphia 
