Competition to Edison's Lamp
"If you want to succeed, get some enemies."
(Edison, as quoted in the Ladies Home Journal, April 1898).
Successful inventions spawn competition which, in turn, often stimulates new
inventions. Edison's lighting system was no exception and competitors very quickly
introduced similar products. Some copied what he had done; others used their own
inventive talent to create new ideas and new devices. The competition provoked
controversy and a great deal of activity.
By 1891 there were over 1,300 incandescent lighting central stations in the United
States with a capacity of approximately three million lamps. Towns and cities across the
country competed with each other for the privilege of being the first in their area to gain
access to the new technology.
"The Dream of a Gas Manufacturer," 1883
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Developed in England in the 1790s, gas light technology spread quickly. In 1816 gas
streetlights went into service in Baltimore, and by the time of Edison's 1879 lamp
invention, gas lighting was a mature, well-established industry. The gas infrastructure
was in place, franchises had been granted, and manufacturing facilities for both gas
and equipment were in profitable operation. Perhaps as important, people had grown
accustomed to the idea of lighting with gas.
Edison consciously modeled his plans for an electric lighting system on the gas light
technology. Instead of gas-making plants, he designed generators. Where pipes ran
under the streets distributing gas to end users, he planned to place electrical "mains"
(conductors) to carry current. Since people were able to have gas lamps in many rooms
and control them individually, Edison intended his lamps to be capable of independent
Even before Edison demonstrated a working lamp, gas stocks began to fall in price. In
late 1879 he and his men began making detailed cost studies of gas light in order to
determine price goals that the electric light would have to meet. After the lamp
invention, promotions for the Edison system duly reported deaths and injuries due to
Despite nightmares like the one depicted above, gas manufacturers responded to the
challenge with two major advances. The first was better quality gas. The second was an
incandescent mantle invented by Carl Auer von Welsbach of Austria (who later
invented the first commercial metal filament light bulb). Both innovations resulted in
more brighter, more efficient light.
Gas proved a tough competitor since infrastructure already existed, whereas electric
light could not be used until generating plants were built and wires were strung. Also,
gas could be used for heating and cooking as well as light. In 1910, GE's William
Coolidge invented a tungsten-filament lamp capable of giving 10 lumens per watt.
invention, combined with the growing level of electrification in the country effectively eliminated
competition from gas lighting.
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Edison was neither the first nor the only person trying to invent an incandescent electric
lamp. In the U.S., Moses Farmer, William Sawyer and Albon Man, and Hiram Maxim
were all pursuing the goal, as were St. George Lane-Fox and Joseph Swan in England.
Swan demonstrated a working lamp of the design seen to the left in several early
1879 lectures. But his lamp (like those of the other contenders) used a carbon rod of relatively
low electrical resistance. It was practical only if used in series (where the
current flowed successively through several lamps that would turn and off
together) or if it was close to the power supply (so that the lead wires would
Swan had experimented with carbonized paper filaments for some years, however.
Once he learned that a high resistance filament was needed, he quickly adapted it to
his own lamps and established the Swan Electric Light Company. It should be noted
that Swan had been granted several patents for various lamp features before Edison's
breakthrough. Indeed Swan's patent position in England was strong enough that in mid-1882 a merger was arranged and the Edison & Swan United Company ("Ediswan") was
Hiram Maxim also quickly produced a lamp containing a high-resistance filament
in 1880. One of the reasons Maxim was able to introduce a product
so fast was that he had hired Ludwig Boehm (Edison's glassblower)
away from Menlo Park earlier that year. Maxim soon moved on to other
inventions (such as machine guns), but the United States Electric
Lighting Company installed systems that used the Maxim lamp for
several years. The company was purchased by George Westinghouse
The company Elihu Thomson and Edwin Houston established in 1880 to sell arc
lamp systems became quite successful and diversified into other electrical markets. In
1886 they purchased the Sawyer & Man Electric Co. and began making incandescent
lamps under the Sawyer-Man patents. By 1890, Edison, Thomson-Houston, and
Westinghouse were the "Big 3" of the American lighting industry. In 1892, J. Pierpont
Morgan engineered a merger between the Edison interests and Thomson-Houston. The
resulting company was named General Electric.
George Westinghouse's initial fame stemmed from his invention of an air-brake that
vastly improved railroad safety. In the 1880s he too diversified into electrical
and then into electric lamps. At the time he bought U.S. Electric Lighting Co. and began
making lamps, the company was being sued by Edison for patent infringement. In 1892
the courts decided in Edison's favor and forced Westinghouse to stop production.
However, Westinghouse had obtained rights to the Sawyer-Man patents and quickly
retooled to make non-infringing lamps based on those patents. He produced these
"Stopper lamps" until Edison's patents expired in 1897.
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Critical to any electrical system is the ability to
measure at any moment the flow of electricity (the current) and the force on it
(voltage). These techniques were well known, and it was a relatively simple
matter to design instruments that could deal with the relatively high flow in
lighting circuits (like the Elihu Thomson voltmeter shown here). For a
commercial enterprise, it was also important to know how much energy the
customer was using. Edison designed a chemical meter in which a
portion of the current being supplied caused metal to be deposited on an
electrode. The electrode could then be weighed to give a measure of the energy
consumed. Later electromagnetic meters registered watt-hours directly by
measuring the product of voltage and current over time.
AC Versus DC
Tesla AC motor
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alternating and direct current had been used for arc lights, and both could be
used for incandescent lamps. However, in the early 1880s motors could
function effectively only on DC. There was an expectation that electricity
could be stored in batteries during off-peak hours, and this was possible only
with DC. Finally, there was evidence that at the same voltages AC was more
dangerous than DC. All of this led Edison to prefer a DC system.
An important advantage for AC became apparent with the invention of the transformer
in 1883. This meant that the voltage from an AC generator could be
efficiently increased for transmission and then decreased at the other end for
use in the home or factory. (Electrical energy is proportional to voltage
times current, so that boosting the voltage means that the same amount of energy
can be transmitted with less current flow. Since heat produced in
the line is a function of the current and the resistance, so with less current
the loses are less.) For short lines (of a mile or so) this made little
difference. But for long distances it would be critical.
The Westinghouse and Thomson-Houston companies preferred AC, and their faith was
justified when Nikola Tesla invented a practical AC motor in 1888 (an early
example is shown in the picture). Additional Tesla polyphase patents made
AC systems more efficient. These patents were used by Westinghouse at
Niagara Falls in 1895.
During the 1880s a sometimes fierceand not always
logicalbattle was waged between proponents of AC and of DC. Edison
himself became less involved as he devoted more time to his new laboratory at
West Orange, New Jersey, after 1886, and as he became more involved with his
iron-ore project. The Edison and Thomson-Houston companies merged in 1892
to form General Electric.