Humboldt State University ® Department of Chemistry
Robert A. Paselk Scientific Instrument Museum
Central Scientific Company
HSU Chemistry Department, 1960
Used as a demonstration tool in physics and chemistry and as an arc source for demonstrations etc. According to Wikipedia,
"An induction coil or "spark coil" (archaically known as an inductorium or Ruhmkorff coil after Heinrich Ruhmkorff) is a type of disruptive discharge coil. It is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current (DC) supply. To create the flux changes necessary to induce voltage in the secondary, the direct current in the primary is repeatedly interrupted by a vibrating mechanical contact called an interrupter. Developed beginning in 1836 by Nicholas Callan and others, the induction coil was the first type of transformer. They were widely used in x-ray machines and spark-gap radio transmitters from the 1880s to the 1920s. Today their only use is as the ignition coils in internal combustion engines, and in physics education to demonstrate induction." ("Induction Coil", Wikipedia; http://en.wikipedia.org/wiki/Induction_coil; downloaded 6/28/2012)
The induction coil case has a 14" x 7" base, the wood case is 6 1/2" high. The instrument is as described in the catalog scan available above from Cenco, Cat J-300, General Catalog Laboratory Apparatus & Scientific Instruments, Chicago. (1960?) 968 pp.