Thomas Edison

Thomas Alva Edison was an American inventor and businessman, the most famous of his age. He developed the phonograph, a practical electric light bulb and the first central power station, and his laboratories produced early motion-picture equipment and much else. He held 1,093 US patents, but his most lasting innovation was perhaps the organised research laboratory itself, where teams of workers turned ideas into marketable products.

Edison was born on 11 February 1847 in Milan, Ohio, the youngest of seven children of Samuel and Nancy Edison. In 1854 the family moved to Port Huron, Michigan. He attended school for only a few months; his mother, a former teacher, taught him at home, and he read widely on his own. From about the age of twelve he began losing his hearing, probably as a result of scarlet fever and ear infections, and he was nearly deaf for the rest of his life.

At twelve or thirteen he was selling newspapers and snacks on trains of the Grand Trunk Railway between Port Huron and Detroit, and printed his own small newspaper on board. He learned telegraphy, by tradition after saving a station agent's young son from a train, and from 1863 worked as an itinerant telegraph operator in the American Midwest and in Canada, often on night shifts during which he experimented with equipment.

In 1868 he went to Boston, and in 1869 received his first patent, for an electric vote recorder for legislatures, which no one wanted to buy. He took the lesson that he should invent only things for which there was a market. Moving to New York, he improved the stock ticker and sold his rights for a sum that set him up in business in Newark, New Jersey. In 1874 he developed the quadruplex telegraph, which could send four messages over one wire at once. In 1871 he married Mary Stilwell; they had three children before her death in 1884.

In 1876 Edison built a laboratory in the village of Menlo Park, New Jersey, staffed with machinists, chemists and draughtsmen. Often described as the first industrial research laboratory, it aimed to produce a small invention every ten days and a big one every six months. For Western Union he developed a carbon transmitter that made Alexander Graham Bell's telephone much clearer; versions of it were used in telephones for a century.

In 1877 he invented the phonograph, the first machine that could both record and play back sound. A needle cut the vibrations of a voice into tinfoil wrapped round a turning cylinder, and the first words recorded were a recitation of "Mary Had a Little Lamb". The invention astonished the public and earned him the nickname the Wizard of Menlo Park, though it was not a commercial success until improved versions appeared a decade later.

He then took on electric light. Incandescent lamps, in which a thin filament glows when current passes through it, had been made by others, including Joseph Swan in the United Kingdom, but they burned out quickly. Edison's team tested thousands of materials. In October 1879 a carbonised cotton-thread filament in a near-vacuum glowed for about thirteen and a half hours, and later carbonised bamboo filaments lasted more than 1,200 hours. Just as important, Edison designed a complete system around the lamp: generators, cables, meters, switches and fuses. On 4 September 1882 his Pearl Street Station in lower Manhattan began supplying direct current to customers, the first commercial central power station in the United States. In Britain, Edison and Swan merged their rival interests.

Direct current (DC) at low voltage could only be sent about a mile from a power station. Alternating current (AC), which could be stepped up by transformers to high voltages and sent long distances, was promoted by George Westinghouse, using motor patents bought from Nikola Tesla, who had briefly worked at an Edison company in 1884 and 1885. In the late 1880s Edison and his allies campaigned that AC was deadly. The electrical engineer Harold P. Brown, with help from Edison's laboratory, publicly killed dogs and other animals with AC, and Edison backed the adoption of an AC-powered electric chair, first used on the prisoner William Kemmler at Auburn Prison, New York State, in 1890.

Two popular stories need correcting. The 1903 electrocution of Topsy, an elephant at Coney Island, was filmed by Edison's film company, but Edison was not involved in the killing, and the War of the Currents had ended a decade earlier. And the notion of a lifelong personal feud with Tesla is largely modern; the commercial contest was with Westinghouse. In 1892 the financier J. P. Morgan merged Edison's electric companies with a rival to form General Electric, which dropped his name and soon made AC equipment itself.

In 1886 Edison married Mina Miller, and they had three children. In 1887 he opened a far larger laboratory at West Orange, New Jersey, which with its factories grew to employ thousands. There he perfected the wax-cylinder phonograph and the recording industry that followed. His employee William Kennedy Laurie Dickson did much of the work on the Kinetoscope, a peep-show motion-picture viewer that opened in commercial parlours in 1894, and films were shot in the Black Maria, a revolving studio on the grounds. Edison left the film business in 1918.

Some ventures failed badly. An attempt in the 1890s to extract iron from low-grade ore with magnets consumed much of his fortune. His Portland cement company eventually made money, and his nickel-iron storage battery, developed over a decade, became one of his most profitable products. During World War I he chaired the US Navy's Naval Consulting Board and worked on detecting submarines. In his last years, encouraged by his friends Henry Ford and Harvey Firestone, he searched for a plant that could provide rubber in the United States.

Edison died at his home, Glenmont, in West Orange on 18 October 1931, aged 84. On the evening of his funeral, at the request of President Herbert Hoover, many Americans dimmed their lights for a minute in his honour.

Edison was a gifted self-promoter, and his public image as a lone genius obscures how much depended on the skilled teams he directed and on investors' money. He could also be ruthless towards competitors and employees. Yet his combination of invention, engineering and business shaped the electrified world that emerged from the later Industrial Revolution. His remark that genius is one per cent inspiration and ninety-nine per cent perspiration summed up the method he made famous.