Images(4)

induction coil

Dateafter 1851

Inventory Number0338

ClassificationInduction Coil

Subject

Supplier A. P. Gage and Son ca. 1880 - 1910

Maker French ?

User Department of Physics, Harvard University founded 1884

User Department of Chemistry, Harvard University founded 1791

Cultural Region

Place of Origin

Place of Use

Dimensions14.7 x 27 x 13.8 cm (5 13/16 x 10 5/8 x 5 7/16 in.)

Material

DescriptionA coil with square ends of hard rubber on which are mounted the high terminals. Probably simple layer winding. A horizontal contact breaker and knife reversing switch. Mounted on a box containing a condenser made from tin foil and old ledger paper.

Signedend of coil marked: A. P. Gage & Son, Boston

Inscribedend of coil: Guaranteed 3/4 inch spark; bottom marked: fra[...]

Curatorial RemarksThe style and form of this device were contrived by Heinrich Rumkorff (1803-77) in 1851. Part of Crooke's Tube exhibit; 1 flat case 2.5 x 6; 2/28/57 SMP and DPW The exhibit card will be found with the Geissler tube described on the same exhibit card that has been given the inventory number 1997-1-0678 (the schematic sketch of the exhibit's layout shall also be found with this inventory number's file).

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".