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Edison, Thomas (Alva)

electricity invented light prolific

(1847–1931) US physicist and prolific inventor.

Edison received virtually no formal education, having been expelled from school as retarded, and was educated by his mother. During the American Civil War he worked as a telegraph operator, during which time he invented and patented an electric vote recorder. Some 3 years later, in 1869, he invented the paper tape ‘ticker’, used for communicating stock exchange prices across the country, sold it for $30 000 and opened an industrial research laboratory. He was thereafter to apply himself full-time to inventing, filing a total of 1069 patents before his death. His more notable inventions include the carbon granule microphone, to improve telephone, the phonograph (a device for recording sound on a drum covered in tin foil, invented in 1877) and the electric light bulb. The latter required an extraordinary amount of trial and error testing, using over 6000 substances until he found a carbonized bamboo fibre that remained lit for over 1000 hours in a vacuum. This led in turn to improved electricity generators (he increased their efficiency from 40% to over 90%), power cables, the electricity meter and the revolutionizing of domestic lighting and public electricity supply. During his work on light bulbs he also discovered the Edison effect, that electricity flows from a heated filament to a nearby electrode but not in the reverse direction, which was later to form the basis of the thermionic diode. Edison’s impact on 20th-c life was immense and his reputation as a prolific inventive genius remains unrivalled.

T A Edison, aged 14. Already an entrepreneur, he was working a 14-hr day as a newsboy and food-vendor on the railway, making $20 weekly profit. He soon set up a spare freight car as a laboratory and printery for his Grand Trunk Herald , most of it written by him; at 16 he became a telegraphist and began his career as an inventor.

Edison, Thomas Alva (1847-1931) [next] [back] Edison, Thomas - Overview, Personal Life, Career Details, Chronology: Thomas Edison, Social and Economic Impact

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