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Westinghouse tantalum filament "mill" lamp

Westinghouse tantalum filament "mill" lamp

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Description (Brief)
Most incandescent lamps were designed for general use in homes and businesses. However, some required special features for use in particular locations. Westinghouse engineers designed this so-called mill lamp for use in factories and other areas subject to high levels of vibration. An intricate internal support structure absorbed vibrations and kept the filament intact for the life of the lamp. Lamps of this type were later sold as rough-service lamps. The filament itself is made from the element tantalum. Invented in 1902, tantalum filament lamps sold in the U.S. until about 1910 when tungsten lamps were introduced.
Description
Westinghouse tantalum filament "mill" lamp, circa 1908. Brass medium-screw base with skirt, two glass insulators. Two drawn tantalum filaments (in series) with 12 upper, 22 center, and 10 lower copper support hooks. Crimp connectors, Siemens seal, cotton insulator. Tipped straight-sided envelope. Westinghouse label on lamp reads: “Westinghouse Tantalum [inked 223] V 50 W, patent label in stem: “The manufacturer of this lamp is licensed under patent noted on other side.” “Mar-20-94 516,800 APR-16-95 537,493 APR-28-03 726,293 AND OTHERS H.P.5036”. Stamped on base-skirt: “-PA[T Nov. 08 1]904 [Nov. 22] 1904”. “T” inked on stem, “X22 50” on press, “222- [V?]” in base. Label on top is inked: “47D3 1”.
Object Name
light bulb
incandescent lamp
date made
ca 1908
maker
Westinghouse Electric Corporation
Physical Description
glass (overall material)
metal (overall material)
tantalum (overall material)
brass (overall material)
cotton (overall material)
porcelain (overall material)
Measurements
overall: 7 in x 3 in; 17.78 cm x 7.62 cm
ID Number
2014.0058.05
accession number
2014.0058
catalog number
2014.0058.05
See more items in
Work and Industry: Electricity
American Enterprise
Energy & Power
Exhibition
American Enterprise
Exhibition Location
National Museum of American History
Data Source
National Museum of American History
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