induction coil
Date1920
Inventory Number0344
ClassificationInduction Coil
Subject
Maker
Thordarson Electric Manufacturing Company
founded 1895
Supplier
Central Scientific Company
1889 - 2000
Cultural Region
Place of Origin
Place of Use
Dimensions27.5 × 21.2 × 40.7 cm (10 13/16 × 8 3/8 × 16 in.)
Material
DescriptionRelatively large Induction coil with pointed spark gap needles and hammer attachment for contact. Thick with square wood ends. The secondary is covered with a rubber wrapping which conceals the secondary windings. A knife reversing switch. The contact breaker is weighted.
From instrument's card:
A short thick coil with square wooden ends. Probably sectionally wound secondary covered with wrapping of thin hard rubber sheet. High terminals mounted on wooden ends. Contact breaker has a heavily loaded knocker that strikes interrupter, knife reversing switch. Rectangular wood box base containing condenser.
From instrument's card:
A short thick coil with square wooden ends. Probably sectionally wound secondary covered with wrapping of thin hard rubber sheet. High terminals mounted on wooden ends. Contact breaker has a heavily loaded knocker that strikes interrupter, knife reversing switch. Rectangular wood box base containing condenser.
Signedon base: Thordarson Electric MFG. Co. / Chicago Illinois 1037789
Inscribedplate on base: Central Scientific Co. / Laboratory Supplies / Apparatus Chemicals / Chicago USA
Curatorial RemarksCard has description of device HU: E-299 info is on a plaque on base: type: 3 inch; volts: 6; distributor: CENCO. "Is the secondary wound in sections?" (Originally in Descriptions)
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 of this coil was about 2.5in to 3in.
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)."
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)."
ProvenanceUsed in the Harvard University Chemistry Department. Given to the collection October 10, 1954.
Ducretet et Lejeune
Date: 1892-1896
Object number: DW0089
C. F. Casella & Co. Ltd.
Date: circa 1920
Accessories: leather carrying case; long leather strap with brass loop at end
Object number: 5100
American
Date: late 19th-early 20th Century
Accessories: tilting arm (0380b)
Object number: 0380a
American
Date: late 19th-early 20th Century
Accessories: goes with reversing switch (0380a)
Object number: 0380b
