induction coil
Date: circa 1899
Inventory Number: 1989-0014
Classification: Induction Coil
Subject:
Maker: Reinhold Rudenberg (1883 - 1961)
Dimensions:
22 × 41.3 × 24.5 cm (8 11/16 × 16 1/4 × 9 5/8 in.)
Description:
Shiny black cover over the windings with exposed and possibly broken secondary wires appear at opposite ends of the top. The coil is ended with black discs and a wood cap nailed over the core, painted black. The base is wood, finished mortered, and may contain the condenser. The contact breaker appears to be incomplete. The iron core is exposed on the contact breaker side of the instrument.
Signedunsigned
FunctionFor experimentation and demonstration of the high voltages induced in a secondary winding when the current in the primary windings is abruptly disrupted.
Historical AttributesBuilt by Reinhold Rudenberg in his youth as a 16-year old boy. He operated it from a home built lead-acid storage battery for the following: 1) to show long sparks 2) Used with borrowed Roentgen x-ray tube 3) Hertzian wave generation 4) In 1906 used as silent wake-up alarm.
ProvenanceFrom Instrument tag: "SPARK COIL (Rukmkorff) ... Made by Reinhold Rudenberg (Harvard Prof) at age 16 in Germany and used with early Roentgen x-ray tube. / Presented in 1962 by Mrs. Rodenberg on permanent loan. / The present Sir Darwin was for a short time pupil of Prof. Rudenberg and recommended to him by F. Klein mathematician".