One of two Ruhmkorff Coils made by Queen & Co. The output with about 650 Watts of current in the primary was a torrent of sparks 45 inches in length.
INDUCTION COILS
How to Make, Use, and Repair Them
INCLUDING
RUHMKORFF, TESLA, AND MEDICAL COILS,
ROENTGEN RADIOGRAPHY, WIRELESS
TELEGRAPHY, AND PRACTICAL INFORMATION
ON PRIMARY AND
SECONDARY BATTERY
BY
H. S. NORRIE
(NORMAN H. SCHNEIDER)
SECOND EDITION, REVISED AND MUCH ENLARGED
NEW YORK:
SPON & CHAMBERLAIN, 12 Cortlandt St.