Biography of Thomas Edison:
Thomas Alva Edison was an American inventor who was born in Milan, Ohio on February 11, 1847. He went to school for only three months in Port Huron, when he was 12 years old he began selling newspapers on the Grand Trunk Railway. In 1862 he published a weekly paper known as the Grand Trunk Herald where he printed it in a freight car that was also used as a laboratory. Because he saved the life of a station official’s child he was rewarded by being taught telegraphy. While he worked as a telegraph operator, he made his first invention which was a telegraphic repeating instrument that enabled messages to be transmitted automatically over a second line without the presence of an operator. Edison the went to Boston, Massachussets and devoted all his spare time there to research. When working for the Gold and Stock Telegraph company of New York he greatly improved the company’s apparatus and service. By selling telegraphic appliances, Edison earned 40,000 dollars and with this money he established his laboratory in 1876. Afterwards he devised an automatic telegraph system that made possible a greater speed and range of transmission. Edison invented a carbon telephone transmitter which was important in the developpment of the telephone which was invented by Alexander Bell.
In 1877 Edison invented the gramophone which was an invention where sound could be recorded mechanically on a tinfoil cylinder. Two years later he invented the electric light bulb which was his most important invention. This invention was a huge success. In 1882 he developped and installed the world’s first large central electric-power station, located in New York. In 1887 Edison moved his laboratory from Menlo Park, New Jersey to West Orange, New Jersey where he constructed a large laboratory for his research. In 1888 he invented the kinetoscope which was the first machine to produce films by a rapid movement of pictures. Edison also invented a battery . He also invented a gramophone where sound was no longer stored in cylinders but on discs. By combining his gramophone and kinetoscope he created the first sound film in 1913. In 1915 he was appionted president of the United States Navy Consulting Board.His later work consisted mainly in improving his earlier inventions. He made around 1000 inventions throughout his life. Edison died in West Orange on October 18, 1931
... of Physics, 9th Ed., Wiley 2011  Laboratory manual, General Physics 3, Department of Physics, Map ... length was done already for us by the laboratory assistants. Then, a stopper was inserted in ... invented by German Physicist, August Kundt. Knowing the speed of sound in air, the speed of sound V ... when the temperature increases, the velocity of sound in air also increases. Therefore, the temperature ...