American inventor Thomas Alva Edison was a pioneering figure in science whose inventions and innovations forever changed the way people lived the world over.
Thomas Alva Edison is considered one of the greatest inventors of all time. His name is virtually synonymous with the invention of the lightbulb, even though he did not invent it but only modified it. Nonetheless, over his lifetime he was awarded more than thirteen hundred patents--far more than have been credited to any other individual in American history. Among Edison's best-known inventions are the automatic telegraphy machine, the phonograph, motion picture equipment, and a modernized telephone. His major accomplishment in scientific research was the discovery of the emission of electrons from a heated cathode (or conductor), a phenomenon now known as the Edison effect. Edison is widely regarded as a virtual genius who had the ability to master an amazing array of subjects and produce a wide range of inventions.
Attends school for three months
Edison was born in Milan, Ohio, on February 11, 1847, the seventh and youngest child of Samuel and Nancy (Elliott) Edison. When he was seven years old he moved with his family to Port Huron, Michigan, where he attended school for a total of only three months. His teacher, failing to relate to the way Edison's mind worked, dismissed him as being "addled," or retarded. Nancy Edison withdrew her son from school and from that point on educated him at home. Even though there is some evidence that Edison had dyslexia, a problem that makes reading difficult, he did learn to read, under his mother's guidance. She introduced him to natural philosophy, a mixture of physics, chemistry, and other sciences. Edison became especially interested in chemistry and built a chemical laboratory in a corner of the cellar in the family home. By the age of ten, he was conducting his own experiments.
Gets first job
Edison was also fascinated by locomotives and railroads. When he was twelve years old he landed a job as a newspaper and candy salesman on the Grand Trunk Railway, which ran between Port Huron and Detroit, Michigan. During layovers in Detroit, Edison spent his time at the public library. Over time Edison expanded his activities on the train, receiving permission to use an empty part of the baggage car to set up a small chemistry laboratory and later to run a printing press on which he produced a small newspaper, the Weekly Herald.
Loses his hearing
One morning while Edison was running to catch the train, one of the conductors pulled him aboard by grasping his ears. Edison felt something snap inside his head. When he later became deaf he claimed this incident had caused his condition. Evidence to the contrary suggests that his deafness was probably an after-effect of scarlet fever (a severe contagious disease that occurs mainly in children and is characterized by a high fever and scarlet rash on the skin). No matter the cause, this affliction had a profound effect on his life. Edison grew increasingly solitary and studious. He also became more serious about his experiments. One of the lifelong habits he developed during this period was working long hours with only short naps to keep him going. Later in life it was not unusual for Edison to spend twenty out of every twenty-four hours at work.
Another train incident in 1862 led to a new job for Edison. After he bravely pulled the stationmaster's son from the front of an oncoming locomotive, the boy's father offered to teach Edison telegraphy, a means of communicating over a great distance by using coded signals transmitted by wire. Edison soon mastered the art of telegraphy and for the next five years traveled throughout the country as an operator. It was during this time that he first dreamed of becoming an inventor. He spent much of each paycheck on electrical gadgets or chemicals for his laboratory.
Influenced by Michael Faraday
After returning home to Port Huron briefly in 1867, Edison moved to Boston, Massachusetts, where he found a job with the Western Union Telegraph Company. During his free time, he continued studying and inventing. Two books had a particular impact on him. After reading Isaac Newton's 1687 book Philosophiae naturalis principia mathematica ("Mathematical Principles of Natural Philosophy"), Edison decided that he never wanted to do anything that required a knowledge of mathematics. But when he read Experimental Researches in Electricity by Michael Faraday, he noticed that Faraday seemed to conduct most of his experiments without the use of mathematics. Faraday became a model for Edison, who had decided to experiment with electrical inventions.
Receives first patent
While in Boston, Edison rented a corner of William's Electric Shop on Court Street and began to experiment. He invented a device for electronically recording the voice votes taken in a legislative assembly. In 1869, this recorder earned him his first patent (a grant made by the U.S. government that assures an inventor the exclusive right to manufacture, use, and sell an invention for a stated period of time). The machine worked well, but there was just one problem--nobody was interested in buying it. Edison vowed never again to invent something no one wanted.
Goes to New York City
June 1869 marked a turning point in Edison's career as an inventor when he left Boston for New York City. He arrived in the city without a cent in his pockets and was saved by a remarkable stroke of good luck. While he was waiting to interview for a job with Law's Gold Indicator Company, the office's central transmitting machine broke down. Edison quickly found the problem and fixed the machine. The next day the owner of the company, S. S. Laws, offered Edison a job as general manager of the firm, with the then-generous salary of $300 a month.
This job allowed Edison to think more seriously about a career in invention, and he ended up forming his own electrical engineering company. Soon after, the company was bought by the Gold and Stock Telegraphic Company, which paid Edison $40,000 for a device that kept stock tickers working in unison. This was quite a fortune for a twenty-three-year-old man from Port Huron who had essentially no formal education.
Opens first "invention factory"
The profit from the Gold and Stock deal allowed Edison to act on a plan he had been thinking about for some time. First he opened a firm in Newark, New Jersey, which was, as he called it, an "invention factory." The plant operated for six years, turning out a variety of inventions related primarily to improvements in stock tickers and telegraphy equipment. In all, Edison was granted about two hundred new patents for work completed in the Newark laboratories. Then, in 1876, when Edison had outgrown his Newark facilities, he built a new invention factory in Menlo Park, New Jersey. Over the next ten years he produced many important inventions, including three that made him famous: a more modern telephone, the phonograph, and the incandescent lightbulb. Although Alexander Graham Bell was the actual inventor of the first telephone, Edison developed a transmitter that greatly improved the quality of Bell's invention.
Invents the phonograph
In 1877, Edison produced what he himself named his favorite invention: the phonograph, or record player. 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 hand-cranked while a needle traced a groove on it. The phonograph was very popular, and although it was improved over the years, it remained essentially the same.
Improves the lightbulb
Although Edison did not invent the incandescent lightbulb, he found a way to build it so that it would be cheap enough for everyone to buy. English chemist Joseph Wilson Swan had begun working on the lightbulb back in 1848, about thirty years before Edison. The concept of the lightbulb was simple enough: when an electrical current passes through a thin wire (a filament), it encounters resistance that causes the wire to become hot enough to glow, that is, to reach incandescence. Swan had a problem keeping the wire from oxidizing, or burning up. In theory, the solution was to encase the wire in a vacuum (a space absolutely devoid of matter). In Swan's time, however, it was impossible to make a good enough vacuum. As a result, a wire might be brought to incandescence and produce light for a short time, but it quickly burned up and the light went out.
Swan continued to work on the incandescent lightbulb for the next two decades and finally solved the problem at about the same time Edison did. An important key to Edison's success was that much better vacuums were available in 1878. In addition, Edison discovered an ideal material for use as the filament in a lightbulb, a charred length of cotton thread. On October 21, 1879, Edison first demonstrated in public an incandescent lightbulb--made with his charred cotton thread--that burned continuously for forty hours.
The incandescent lightbulb was, of course, a remarkable success, and Edison spent the next few years adapting it for large-scale use. He found it necessary, for example, to invent the generating, switching, and transmitting devices needed to supply electricity to a large number of lightbulbs at the same time. Within three years he had solved many of these problems and was operating the world's first power station on Pearl Street in New York City. When the plant began operation on September 4, 1882, it supplied power to four hundred incandescent lightbulbs owned by eighty-five customers.
Creates the Edison effect
While working on the incandescent lightbulb, Edison made his one and only important scientific discovery. In attempting to modify the construction of the bulb, he introduced a wire into the bulb adjacent to the filament. When the lamp was turned on, Edison observed that electrical current flowed from the filament to the wire. He saw no practical application of this discovery, so he did no further work on it. The Edison effect, as the discovery is now called, later had important applications as a way of directing electrical current.
Invents early motion picture machine
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. Probably the best-known invention to come out of this period 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. However, he soon lost interest in the technology.
Almost wins Nobel Prize
In 1912, Edison was recommended as a corecipient of the Nobel Prize with Nikola Tesla, who had been employed in Edison's lab in the late 1880s. Soon after quitting because of a disagreement with Edison, Tesla achieved great success on his own. At the root of their hostility was their disagreement about how to supply electricity to the public. Tesla favored using a system of alternating current (AC) he had helped to develop, while Edison favored direct current (DC). Even when the superior AC system began to be accepted around the country, Edison stubbornly resisted, something the temperamental Tesla never forgot. When he refused to share the Nobel Prize with Edison, the committee awarded the prize to someone else.
Dabbled in various fields of study
Edison's active nature and inquisitive mind led him to wander from subject to subject. In some cases, he stayed with a project long enough to see it to commercial production. In other instances, he spent time developing the early stages of an idea and then moved on to something new. Among the inventions to which he made at least some contribution were the lead storage battery, the mimeograph machine (a copying machine), the dictaphone, and the fluoroscope (a type of X-ray machine). He also developed an interest in iron mining and processing and in cement production.
Received awards and honors
Edison was married twice, the first time on Christmas Day, 1871, to Mary Stilwell, whom he had met in Newark. They had three children: Marion Estell, Thomas Alva, and William Leslie. Mary Edison died in 1884, and two years later Edison married Mina Miller. Three children--Charles, Madeleine, and Theodore--were born during this marriage. Edison died in West Orange on October 18, 1931. In recognition of his accomplishments, he was elected to the National Academy of Sciences in 1927 and the Hall of Fame for Great Americans in 1960. In addition, he was awarded the Albert Medal of the British Society of Arts in 1892, the John Fritz Medal of the American Engineering Societies in 1908, and the Rumford Medal of the American Academy of Arts and Sciences.
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