FREE ESSAY ON THOMAS EDISON

THOMAS EDISON

Thomas Alva Edison is considered one of the greatest inventors in history. He was born in
Milan, Ohio on February 11, 1847 and died in 1931. During his life he patented 1,093
inventions. Many of these inventions are in use today and changed the world forever. Some
of his inventions include telegraphy, phonography, electric lighting and photography. His
most famous inventions were the phonograph and the incandescent light bulb. Edison did
some of his greatest work at Menlo Park. While experimenting on an underwater cable for
the automatic telegraph, he found that the electrical resistance and conductivity of
carbon varied accordingly to the pressure it was under. This was a major theoretical
discovery, which enabled Edison to invent a "pressure relay" using carbon rather than
magnets, which was the usual way to vary and balance electrical currents. In February of
1877 Edison began experiments designed to produce a pressure relay that would amplify and
improve the audibility of the telephone, a device that Edison and others had studied but
which Alexander Graham Bell was the first to patent, in 1876. By the end of 1877 Edison
had developed the carbon-button transmitter that is still used today in telephone
speakers and microphones. Many of Thomas Edison's inventions including the carbon
transmitter were in response to demands for new products and improvements. In 1877, he
achieved his most unique discovery, the phonograph. During the summer of 1877 Edison was
attempting to devise for the automatic telegraph a machine that would transcribe a
signals as they were received into a form of the human voice so that they could then be
delivered as telegraph messages. Some researchers had theorized that each sound, if it
could be graphically recorded, would produce a distinct shape resembling short hand, or
phonography, as it was known then. Edison hoped to make this concept real by employing a
stylus-tipped carbon transmitter to make impressions on a strip of paraffined paper. To
his amazement, the barley visible indentations generated a vague sound when the paper was
pulled back beneath the stylus. In December 1877 Edison unveiled the tinfoil phonograph,
which replaced the strip of paper wrapped in tinfoil. Many people would not believe what
they were hearing including a leading French scientist who declared it to be a trick
device of a ventriloquist. The public's amazement was quickly followed by universal
approval. Edison became famous all around the world and was dubbed the Wizard of Menlo
Park, although ten years passed before the phonograph was transformed form a laboratory
curiosity into a commercial product. His most famous and most commonly used invention is
the incandescent light bulb. American scientists including Samuel Langley needed a highly
sensitive instrument that could be used to measure minute temperature changes in heat
emitted from the Sun's corona during a solar eclipse along the rocky mountains on July
29,1878. To please those needs Edison invented a "microtasimeter" employing a carbon
button. This was a time when great advances were being made in arc lights so that
electricity could be used for lighting in the same fashion as with small, individual gas
"burners". The basic problem seemed to be to keep the burner, or the bulb, from being
consumed by preventing it from overheating. Edison thought he would be able to solve this
by coming up with a microtasimeter-like device to control the current. He proclaimed that
he would invent a safe, mild, and inexpensive electric light that would replace the
gaslight. Inventors had been attempting to devise the incandescent light bulb for fifty
years, but Edison's reputation and past achievements commanded respect for his bold
prediction. As a result, a group of leading financiers, including J.P. Morgan and the
Vanderbilts, established the Edison Electric Light Company, and advanced him $30,000 for
his research and development. Edison's idea was to connect his lights in a parallel
circuit by subdividing the current so that the failure of one light bulb would not cause
the whole circuit to fail. Some well-known scientists predicted that such a circuit could
never be possible, but their findings were based on systems of lamps with low resistance
(the only successful type of electrical light at the time). Edison, however, determined
that a bulb with high resistance would serve his purpose, and he began his search for a
suitable one. By the summer of 1879 Edison and Francis Upton had made enough progress on
a generator that considered offering a system of electric distribution for power, not
light. By October Edison and his staff had achieved encouraging results with a complex,
regulator-controlled vacuum bulb with a platinum filament, but the cost of the platinum
would have made the incandescent light bulb to costly. While experimenting with an
insulator for the platinum wire, they discovered that, in the greatly improved vacuum
they were now achieving through advances made in the vacuum pump, carbon could be
maintained for a longer amount time without complicated devices. Edison found that a
carbon filament provided a good light with the simultaneous high resistance required for
subdivision. Steady progress ensued from the first breakthrough in mid-October until the
initial demonstration for the backers of the Edison Electric Light Company on December 3.
In the summer of 1880 Edison determined that carbonized bamboo fiber made a satisfactory
material for the filament. The first commercial land-based "isolated" incandescent system
was placed in the New York printing firm of Hinds and Ketcham in January 1881. In the
fall a temporary, demonstration central power system was installed at the Holborn Viaduct
in London, in conjunction with an exhibition at the Crystal Palace. Edison supervised the
laying of the mains and installation of the world's first permanent, commercial central
power system in lower Manhattan, which became operative in September 1882. Although the
early systems had problems and years passed before incandescent lighting powered by
electricity from central stations began to replace gas lighting. Isolated lighting plants
for such enterprises as hotels, theatres, and stores flourished, so did Edison's
reputation as the world's greatest inventor. Edison's inventions were often discovered by
chance while working on practical experiments and problem solving. This resulted in 380
patents for electric light and power, 195 for the phonograph, 150 for the telegraph, 141
for storage batteries, and 34 for the telephone. Until that point scientists had
primarily been involved in pure research. Edison's approach was to find useful and
helpful ways of applying his inventions. Today you can walk into a store and find light
bulbs that can last for two years. In 1991 Philips developed a light bulb that uses
magnetic induction to excite a gas to emit light. There are no parts to wear out in this
design, so the expected lifetime is 60,000 hours. In the future there will probably be
light bulbs that never burn out. Edison's role as a machine shop operator and small
manufacturer was crucial to his success as an inventor. Unlike other scientists and
inventors of the time, who had limited means and lacked a support organization, Edison
ran an inventive establishment. He was the antithesis of the lone inventive genius,
although his deafness enforced on him isolation conductive to conception. His lack of
managerial ability was, in an odd way, also a stimulant. As his own boss, he plunged
ahead on projects more prudent men would have shunned, then tended to dissipate the
fruits of his own inventiveness, so that he was both free and forced to develop new
ideas. Few men have matched him in the positiveness of his thinking. Edison never
questioned whether something might be done, only how. Edison's career, the fulfillment of
the American dream of rags-to-riches through hard work and intelligence, made him a folk
hero to his countrymen. In temperament he was an uninhibited egotist, at once a tyrant to
his employees and their most entertaining companion, so that there was never a dull
moment with him. He was charismatic and courted publicity, but he had difficulty
socializing and neglected his family. His shafts at the expense of the "long-haired"
fraternity of theorists sometimes led formally trained scientists to depreciate him as
anti-intellectual; yet he employed as his aides, at various times a number of eminent
mathematical physicists, such as Nicole Tesla and A.E. Kennelly. The contradictory nature
of his forceful personality, as well as such eccentricities as his ability to catnap
anywhere, contributed to his legendary status. By the time he was in his middle 30s
Edison was said to be the best-known American in the world. When he died he was the
venerated and mourned as the man who, more than any other, had laid the basis for the
technological and social revolution of the modern electrical world.