"Roentgen" induction coils and other X-ray apparatus
A 1904 trade catalogue issued by the James G. Biddle Company of Philadelphia, selling Roentgen induction coils and X-ray apparatus to physicians, hospitals and laboratory buyers. The halftone plates show ebonised coils on oak bases with brass terminals, spark gaps, adjustable electrode standards and wiring, printed on tinted stock; useful for silhouettes of early electrical instruments, brass hardware details and equipment-on-table compositions.
