Instigated by the reluctance of politicians to use the machine, he decided that in the future he would not waste time inventing things that no one wanted. Edison moved to New York City in mid-1869. Edison was driven to perfect an efficient and commercially practical incandescent bulb following the invention by the English inventor Humphry Davy of the first electric arc lamp early in the 19th century. The government asked Edison to head the Naval Advisory Council, which examined inventions submitted for military use. Most of the work was completed in May 1880 and the Columbia moved to New York City, where Edison and his staff installed Columbia's new lighting system.
Edison was involved in a long rivalry with Nikola Tesla, an academically trained engineering visionary who worked at Edison's company for a time. Early in his career, he worked as a telegrapher, which inspired some of his first inventions. He died on October 18, 1931 in West Orange, New Jersey), an American inventor who, individually or together, held a world record of 1,093 patents. Edison moved from Menlo Park after the death of his first wife, Mary, in 1884, and bought a house known as Glenmont in 1886 as a wedding gift for his second wife, Mina, in Llewellyn Park in West Orange, New Jersey.
After buying the patent from Woodward and Evans and making improvements to its design, Edison obtained a patent for his own improved bulb in 1879. From their laboratories and workshops, the phonograph, the transmitter with carbon buttons for the telephone's speaker and microphone, the incandescent lamp, a revolutionary generator of unprecedented efficiency, the first commercial system of light and electrical energy, an experimental electric railway and key elements of cinematographic devices, as well as a number of other inventions, emanated from their laboratories and workshops. The Mahen Theater in Brno (in what is now the Czech Republic) opened in 1882 and was the first public building in the world to use Edison electric lamps. The two separated in 1885 and would publicly clash in the War of the Currents over the use of direct current, which Edison preferred, and became involved in snake oil products and in shady, fraudulent companies that produced products that were sold to the public as Edison's latest discovery. After years of heated legal battles with his competitors in the fledgling film industry, Edison had stopped working with motion pictures in 1918. Alexander Graham Bell was one of the main inventors of the telephone, he did important work in the field of communication for the deaf and obtained more than 18 patents.
In 1877, Edison developed the carbon transmitter, a device that improved the audibility of the telephone by allowing voices to be transmitted at a higher volume and more clearly. At the time of his death, according to one estimate, some fifteen billion dollars of the national economy came from his inventions alone.
