Signedsigned: Ruhmkorff a Paris
Inscribedold numbers stamped: 8-63
FunctionFor experimentation and demonstration of the high voltages induced in a secondary winding when the current in the primary windings is abruptly disrupted. With this coil, the spark gap distance was about 1 ".
From card: "The uses of an induction coil are very numerous. Some of these may be classified: Experimental - production of sparks - magnetic deflection - colors from metals of spark points - perforation of solids as plate glass. Shocks - entertainment - medical. Discharges in vacuum - luminous discharge - deflection and rotation - Geissler tube in vacuum tubes - phosphoresce and florescence of materials - stratification - spectra of gases. High Vacuum effects and X-Rays (but not till 1895)."
Primary SourcesThe instrument is illustrated in DuMoncel, Applications de L'Electricite, v2, 1873 and fig.395 in Noad's Manual of Electricity, 1859, (Lib 2803).
ProvenanceUsed in the Physics Department at Harvard University.