Electric light
Edison did not invent the first electric light bulb, but instead invented the first commercially practical incandescent light. Many earlier inventors had previously devised incandescent lamps, including Alessandro Volta's demonstration of a glowing wire in 1800 and inventions by Henry Woodward and Mathew Evans. Others who developed early and commercially impractical incandescent electric lamps included Humphry Davy, James Bowman Lindsay, Moses G. Farmer, William E. Sawyer, Joseph Swan and Heinrich Göbel. Some of these early bulbs had such flaws as an extremely short life, high expense to produce, and high electric current drawn, making them difficult to apply on a large scale commercially.
After many experiments, first with carbon filaments and then with platinum and other metals, in the end Edison returned to a carbon filament. The first successful test was on October 22, 1879; it lasted 13.5 hours. Edison continued to improve this design and by November 4, 1879, filed for U.S. patent 223,898 (granted on January 27, 1880) for an electric lamp using "a carbon filament or strip coiled and connected to platina contact wires".
Although the patent described several ways of creating the carbon filament including "cotton and linen thread, wood splints, papers coiled in various ways", it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1,200 hours. The idea of using this particular raw material originated from Edison's recalling his examination of a few threads from a bamboo fishing pole while relaxing on the shore of Battle Lake in the present-day state of Wyoming, where he and other members of a scientific team had traveled so that they could clearly observe a total eclipse of the sun on July 29, 1878, from the Continental Divide.
In 1878, Edison formed the Edison Electric Light Company in New York City with several financiers, including J. P. Morgan and the members of the Vanderbilt family. Edison made the first public demonstration of his incandescent light bulb on December 31, 1879, in Menlo Park. It was during this time that he said: "We will make electricity so cheap that only the rich will burn candles."
Henry Villard, president of the Oregon Railroad and Navigation Company, had attended Edison's 1879 demonstration. Villard quickly became impressed and requested Edison install his electric lighting system aboard his company's new steamer, the Columbia. Although hesitant at first, Edison relented and agreed to Villard's request. Following most of its completion in May 1880, the Columbia was sent to New York City, where Edison and his personnel installed Columbia's new lighting system. Due to this, the Columbia became Edison's first commercial application for his incandescent light bulb. The Edison equipment was eventually removed from Columbia in 1895.
Lewis Latimer joined the Edison Electric Light Company in 1884. Latimer had received a patent in January 1881 for the "Process of Manufacturing Carbons", an improved method for the production of carbon filaments for lightbulbs. Latimer worked as an engineer, a draftsman and an expert witness in patent litigation on electric lights.
George Westinghouse's company bought Philip Diehl's competing induction lamp patent rights (1882) for $25,000, forcing the holders of the Edison patent to charge a more reasonable rate for the use of the Edison patent rights and lowering the price of the electric lamp.
On October 8, 1883, the US patent office ruled that Edison's patent was based on the work of William Sawyer and was therefore invalid. Litigation continued for nearly six years, until October 6, 1889, when a judge ruled that Edison's electric-light improvement claim for "a filament of carbon of high resistance" was valid. To avoid a possible court battle with Joseph Swan, whose British patent had been awarded a year before Edison's, he and Swan formed a joint company called Ediswan to manufacture and market the invention in Britain.
Mahen Theatre in Brno (in what is now the Czech Republic), which opened in 1882, was the first public building in the world to use Edison's electric lamps, with the installation supervised by Edison's assistant in the invention of the lamp, Francis Jehl. In September 2010, a sculpture of three giant light bulbs was erected in Brno, in front of the theatre.
