Signedend of coil marked: A. P. Gage & Son, Boston
Inscribedend of coil: Guaranteed 3/4 inch spark; bottom marked: fra[...]
FunctionFor experimentation and demonstration of the high voltages induced in a secondary winding when the current in the primary windings is abruptly disrupted. The spark gap for this coil was ``guaranteed 3/4 inch spark''.
Old exhibit card reads: this coil will generate a spark 3/4" long from a 6 volt battery.
From #0343's file 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)."
ProvenanceFrom old exhibit card of instrument 1997-1-0678: "These instruments were originally used in the Harvard Physics and Chemistry laboratories. They are now part of the Collection of Historical Scientific Instruments".