When most people think of lighting and lamps,
they think of the incandescent
developed by Thomas Edison and other inventors.
Incandescent light bulbs work by using electricity and a
filament. Heated by electricity, the filament inside the light bulb exhibits
resistance that results in high temperatures that causes the filament to glow and emit light. Arc or vapor lamps work
in a different way (fluorescents fall under this category), the light is not created from heat, the light is created
from the chemical reactions that occur when electricity is applied to
different gases enclosed in a glass vacuum chamber.
In 1857, the French physicist Alexandre
E. Becquerel who had investigated the
phenomena of fluorescence and phosphorescence, theorized about the building of
fluorescent tubes similar to those made today. Alexandre Becquerel
experimented with coating electric discharge tubes with luminescent materials,
a process that was further developed in later fluorescent lamps.
American, Peter Cooper Hewitt (1861-1921) patented (U.S.
patent 889,692) the
first mercury vapor lamp in 1901. The low pressure mercury arc lamp of Peter
Cooper Hewitt is the very first prototype of today's modern fluorescent lights.
A fluorescent light is a type of electric lamp that excites mercury vapor to
The Smithsonian Institute states that, "Electrical
inventor, Peter Cooper Hewitt built on the mid-19th century work of German
physicist Julius Plucker and glassblower Heinrich
Geissler. By passing an electric current through a glass tube containing
tiny amounts of a gas, Plucker and Geissler found they could make light.
Peter Cooper Hewitt began developing mercury-filled tubes in the late 1890s,
and found that they gave off an unappealing bluish-green light. The amount of
light, however, was startling. Hewitt realized that few people would want his
lamps in their homes, and so concentrated on developing a product for other
uses." That purpose turned out to be lighting for photographic studios
and industrial use. George
Westinghouse and Peter Cooper Hewitt formed the Westinghouse-controlled
Cooper Hewitt Electric Company to produce the first commercial Mercury lamps.
Marty Goodman in his History of Electric Lighting
states, "In 1901, a now-forgotten inventor named
Peter Cooper Hewitt invented an arc lamp that used mercury vapor. The vapor
was enclosed in a glass bulb. This was the first enclosed arc-type lamp using
metal vapor. In 1934, a high pressure variant of this was developed [by Edmund
Germer], which could handle a lot more power in a smaller space...
...The low pressure mercury arc lamp of Peter
Cooper Hewitt is the very direct parent of today's modern fluorescent lights.
It was found that these low pressure [mercury] arc lamps would put out large
amounts of ultra-violet light. Folks then figured that if they coated the
inside of the light bulb with a fluorescent chemical (one that absorbed UV
light and re-radiated that energy as visible light) they could make an
efficient light source."
Meyer, Hans Spanner, Edmund Germer - fluorescent lamp patent U.S.
Germer (1901 - 1987) invented a high pressure vapor lamp, his
development of the improved fluorescent lamp and the high-pressure mercury-vapor
lamp allowed for more economical lighting with less heat. Edmund Germer was born
in Berlin, Germany, and educated at the University of Berlin, earning a
doctorate in lighting technology. Together
with Friedrich Meyer and Hans Spanner, Edmund Germer patented an experimental
fluorescent lamp in 1927.
Edmund Germer is credited by some historians
as being the inventor of the first true fluorescent lamp. However, it can be
argued that fluorescent lamps have a long history of development prior to
George Inman and Richard Thayer - The
First Commercial Fluorescent Lamp
George Inman lead a group of General Electric
scientists researching an improved and practical fluorescent lamp. Under
pressure from many competing companies the team designed the first practical
and viable fluorescent lamp (U.S. Patent No. 2,259,040) that was first sold in
1938. It should be noted that General Electric bought the patent rights to
Edmund Germer's earlier patent.
According to The GE Fluorescent Lamp
Pioneers, "On Oct 14, 1941 U.S. Patent No. 2,259,040 was issued to
George E. Inman; the filing date was Apr 22, 1936. It has generally been
regarded as the foundation patent. However, some companies were working on the
lamp at the same time as GE and some individuals had already filed for
patents. GE strengthened its position when it purchased a German patent that preceded
Inman's. GE paid $180,000 for U.S. Patent No 2,182,732 that had been
issued to Friedrich Meyer, Hans J. Spanner and Edmund Germer. While one might
argue the real inventor of the fluorescent lamp, it is clear that GE was the
first to introduce it."
Several other inventors patented versions of the fluorescent lamp
Edison filed a patent (U.S. Patent 865,367)
on May 9, 1896 for a fluorescent
lamp that was never sold. However, he did not use mercury vapor to excite
the phosphor. His lamp used x-rays.
with >>> The
History of Lighting.