Experimental fluorescent lamp

The development of practical fluorescent lamps took decades, and many researchers contributed. Julius Plucker and Heinrich Geissler made glowing glass tubes in the 1850s, about the time George Stokes discovered that invisible ultraviolet light made some materials glow or "fluoresce." Alexandre Edmond Becquerel put fluorescent materials in a Geissler tube in 1859, though his tubes did not last long. Carbon dioxide-filled tubes by D. McFarlan Moore and mercury vapor tubes by Peter Cooper Hewitt around 1900 gave practical experience with gas-filled, discharge lamps and inspired the neon tubes of Georges Claude.
In 1926 Friedrich Meyer, Hans Spanner, and Edmund Germer of Germany patented an enclosed glass tube containing mercury vapor, electrodes at either end, and a coating of fluorescent powders called phosphors. This incorporated all of the features we see in modern fluorescent tubes, but their employer did not pursue development. William Enfield of General Electric saw phosphor-coated neon tubes in France in the early 1930s, and heard that European researchers were developing a fluorescent lamp. An especially urgent 1934 letter from a consultant, Nobel-laureate Arthur Compton, coming on the heels of European breakthroughs in low-pressure sodium and high-pressure mercury lamps, spurred both GE and its licensee Westinghouse into combined action.
Enfield created a team led by George Inman, and by the end of 1934 they made several working fluorescent lamps, including the one seen here. To save time, the team adopted the design of an existing tubular incandescent lamp in order to make use of available production equipment and lamp parts. Speed was important. In addition to European competitors, American companies like Sylvania were also working on fluorescents. A second GE group under Philip Pritchard worked on production equipment. Other GE groups in Schenectady and in Ft. Wayne assisted in developing ballasts and resolving problems of circuit design.
In 1936 GE and Westinghouse demonstrated the new lamp to the U.S. Navy (that lamp is in the Smithsonian's collection). The public finally saw fluorescent lamps in 1939 at both the New York World's Fair and the Golden Gate Exposition in San Francisco. These early lamps gave twice the energy efficiency of the best incandescent designs. Production of fluorescent lamps, slow at first, soon soared as millions were installed in factories making equipment for the American military during World War 2.
Lamp characteristics: Double-ended without bases. Flat presses with an exhaust tip near one press. A tungsten electrode, CC-6 configuration coated with emitter, is set at either end. A mercury pellet is loose inside the lamp. The clear T-7 glass envelope has a phosphor coating covering about 3 inches (8 cm) of the lamp near the center.
date made
ca. 1934
Date made
ca 1934
General Electric
Place Made
United States: Ohio, Cleveland
Physical Description
glass (overall material)
mercury (overall material)
tungsten (overall material)
overall: 14 1/2 in x 7/8 in; 36.83 cm x 2.2225 cm
ID Number
accession number
catalog number
Credit Line
from General Electric Lighting Company, thru Terry K. McGowan
See more items in
Work and Industry: Electricity
Industry & Manufacturing
Energy & Power
Data Source
National Museum of American History


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