Mercury vapor lamp, type H1
date: label: Date made
content: ca 1934
label: date made
content: ca. 1934
name: label: maker
content: General Electric Company
notes: label: Description
content: The type H-1 mercury vapor lamp represented a significant advance in commercial-industrial light sources. Prior to the H-1, mercury lamps contained large amounts of the toxic metal, and most were large and awkward to use. The H-1 featured a small amount of mercury contained in an internal hard-glass "arc-tube" mounted inside the lamp. Compared to previous mercury lamps, the H-1 was a compact and convenient device.
label: Description
content: This particular unit is a first generation model from about 1934. A wire grid seen wrapped around the arc-tube helps the unit to start. Later models used a special small electrode for that task. Use of the internal arc-tube allowed the lamp to operate at high internal pressure, resulting in better energy efficiency. While not the first high-pressure mercury vapor lamp, mass production of the H-1 and its ease of use led to its wide adoption. Today's mercury vapor and metal halide lamps can be considered refinements of the H-1.
label: Description
content: Lamp characteristics: A brass mogul-screw base with glass insulator. Hard-glass arc-tube with mercury drops visible on the inner wall. Two mandrel and re-coiled tungsten electrodes. Dumet and stranded wire leads connect the base to the electrodes. Starting electrode-grid wrapped around arc-tube and connected to frame. There is no starting resistor in this lamp. Welded connectors. Tipless, T-shape envelope. 400-watt rating.
label: Description
content: Mercury vapor lamps are one type of discharge lamp. Other types are fluorescent and neon tubes. They make light by passing an electric current through a gas, and require additional devices called ballasts to operate properly (not seen in the pictures). More information about how discharge lamps operate is on our website <I>Lighting A Revolution</I>.
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Energy & Power
label: Exhibition
content: Lighting a Revolution
label: Exhibition Location
content: National Museum of American History
publisher: label: Related Publication
content: Taylor, A. H.; Kerr, G. P.. Character of Light from Mercury Lamps Alone and in Combination with Tungsten Lamps.
label: Related Publication
content: Bright, Jr., Arthur A.. The Electric-Lamp Industry: Technological Change and Economic Development from 1800 to 1947
label: Related Publication
content: Lighting A Revolution exhibition website
label: Related Web Publication
content: http://americanhistory.si.edu/lighting/
creditLine: label: Credit Line
content: from General Electric Large Lamp Department
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.318195
label: catalog number
content: 318195
label: accession number
content: 232822
objectType: label: Object Name
content: discharge lamp
label: Other Terms
content: discharge lamp; Lighting Devices; Mercury Vapor
physicalDescription: label: Physical Description
content: tungsten (overall material)
label: Physical Description
content: mercury (overall material)
label: Physical Description
content: glass (overall material)
label: Physical Description
content: brass (overall material)
label: Measurements
content: overall: 13 in x 2 in; 33.02 cm x 5.08 cm