Thomas Alva Edison invented hundreds of devices, including the
phonograph. He also developed a method of organized scientific research
that hastened advances in American technology.
Early years
Thomas Edison was born on February 11, 1847, in Milan, Ohio.
Edison’s father was a jack-of-all-trades, and his mother was a former
teacher. As a child, Edison spent only three months in school. His
mother educated him herself at home. At the age of twelve, he went to
work, selling fruit, candy, and newspapers on the Grand Trunk Railroad.
During his teens, Edison lost his hearing, possibly caused by the scarlet
fever he had as a child.
In 1862, Edison got an opportunity to learn telegraphy, a means of
communicating over a great distance by using coded signals transmitted
by wire. He soon mastered the art and for the next five years traveled
throughout the country as a telegraph operator. During these years, he
dreamed of becoming an inventor. He frequently purchased electrical
gadgets or chemicals for his laboratory. First inventions
Not long after Edison went to work for Western Union Telegraph
Company in Boston, Massachusetts, in 1868, he invented a device for
electronically recording the voice votes taken in a legislative assembly.
For this machine, he obtained his first patent, a grant made by the U.S.
government that assures an inventor the exclusive right to manufacture,
use, and sell the invention for a stated period of time. The machine
worked well, but no one was interested in buying it.
In June 1869, Edison moved to New York City to work for an electrical firm. He soon formed his own electrical engineering company and invented a stock ticker, a machine that printed out stock quotes that came
in through telegraphy. He sold the company, with the ticker, for $40,000.
Invention factories
Using the money from the sale of his company, Edison opened an “invention factory,” a lab for research in Newark, New Jersey. The factory
employed as many as eighty researchers, including chemists, physicists,
and mathematicians. It operated for six years, turning out a variety of inventions related primarily to improvements in stock tickers and telegraphy equipment.
In 1876, Edison built a new invention factory in Menlo Park, New
Jersey. Over the next ten years, he produced many important inventions,
including the phonograph and an improved incandescent lightbulb.
The phonograph
Edison’s most original and lucrative invention, the phonograph, or
record player, was patented in 1877. The idea for the phonograph came
to Edison while he was studying a telephone receiver. He attached a steel
stylus (a hard-pointed, pen-shaped instrument) to the diaphragm (a disk
that vibrates to generate sound waves) of the receiver so he could feel the
sound vibrations with his finger as they were emitted. It dawned on him
that the stylus might “etch” the vibrations onto a piece of moving tinfoil.
He reasoned that a similar point could then trace the grooves left on the
foil and pass the vibrations onto another diaphragm to produce sound.
His original phonograph used a tinfoil-covered cylinder that was handcranked, while a needle traced a groove on it. By 1890, his phonograph
had become a motor-driven machine playing cylindrical wax records.
The incandescent lightbulb
Edison did not invent the incandescent lightbulb, but he designed one
that worked well and was cheap enough for everyone to buy. The concept
of the lightbulb was simple enough: When an electrical current passes
through a thin wire, or filament, it encounters resistance that causes the
wire to become hot enough to glow, that is, to reach incandescence. The
heat caused the wire to burn too quickly, so scientists encased the wire in
a vacuum, a space devoid of matter. Edison tested ideal materials for use
as the filament in a lightbulb. On October 21, 1879, he publicly demonstrated an incandescent bulb that burned continuously for forty hours. The first central electric-light power plant
In 1878, Edison and other investors created the Edison Electric Light
Company, which was later the General Electric Company. At that time,
everyone who used electricity had to have their own dynamo, or generator. Edison opened the first commercial electric station in London in
1882, providing electric power to buildings in the area of the station.
Within months, he opened the Pearl Street Station in New York City,
lighting more than 5,000 lamps for 230 customers. Many towns and
cities soon installed central stations.
A new lab
In 1887, when his laboratories outgrew the facilities at Menlo Park,
Edison built an even larger invention factory in West Orange, New Jersey.
By this time, his labs were so productive that he was receiving an average
of one new patent every five days. The West Orange factory, which
Edison directed from 1887 to 1931, was the world’s most complete research laboratory, the forerunner of modern research and development
laboratories, with teams of workers systematically investigating problems.
Probably the best-known invention of the late 1800s was the kinetograph, a primitive form of the moving picture. Edison developed a
method for arranging a series of photographs on a strip of celluloid film
and then running the film through a projector. He used this technique in
1903 to produce The Great Train Robbery, one of the first moving pictures.
Edison’s active nature and inquisitive mind led him to wander from
subject to subject. Sometimes he stayed with a project long enough to see
it to commercial production, and sometimes he spent time developing
the early stages of an idea and then moved on to something new. Among
the many inventions to which he made a contribution are the lead storage battery, the mimeograph machine (a copying machine), the dictaphone, and the fluoroscope (a type of X-ray machine).
Edison died in West Orange on October 18, 1931.