Electric Heater Case
Electric heating is any process in which electrical energy is converted to heat. Common applications include heating of buildings, cooking, and industrial processes. An electric heater is an electrical appliance that converts electrical energy into heat. The heating element inside every electric heater is simply an electrical resistor, and works on the principle of Joule heating: an electric current through a resistor converts electrical energy into heat energy.
Government Printing Office The Official Gazette of the United States Patent Office (Washington, DC: Government Printing Office, 1895)
Courtesy the private collection of Roy Winkelman