Friday, 28 March 2014
Nathan B. Stubblefield (November 22, 1860 - March 28, 1928) was an American inventor and Kentucky melon farmer. It has been claimed that Stubblefield demonstrated radio in 1892, but his devices seem to have worked by audio frequency induction or, later, audio frequency earth conduction (creating disturbances in the near-field region) rather than by radio frequency radiation for radio transmission telecommunications.
Though there were contemporaneous experiments by others such as William Preece, Stubblefield has been proposed as a claimant for the invention of wireless telephony, or wireless transmission of the human voice, which would, however conflict with the four documented patents for the photophone, invented jointly by Alexander Graham Bell and Charles Sumner Tainter in 1880. The photophone allowed for the transmission of sound on a beam of light, and on June 3, 1880 Bell and Tainter transmitted the world's first wireless telephone message on their newly invented form of telecommunication.
Stubblefield was the second of seven sons of a lawyer, William "Capt. Billy" Jefferson Stubblefield (1830–1874), and his mother Victoria Bowman (1837-1869) died of scarlet fever. Stubblefield lived in Murray, Kentucky. Stubblefield was tutored by a governess and later attended a boarding school called the "Male and Female Institute" in Farmington, until his father died in 1874, leaving Stubblefield an orphan at 14 years old.
Stubblefield was additionally self-educated by reading whatever publications were available in Murray, such as Scientific American and Electrical World. He married Ada Mae Buchannan in 1881. Stubblefield operated a home school called "The Nathan Stubblefield Industrial School," or "Teléph-on-délgreen Industrial School" built on his 85-acre (340,000 m2) melon farmland. It is now the campus of Murray State University. In 1898,Stubblefield was issued U.S. Patent U.S. Patent 600,457 for an "Electric battery", which was an electrolytic coil of iron and insulated copper wire to be immersed in liquid or buried in the ground, where it could also serve as a ground terminal for wireless telephony.
He continued to experiment with wireless telephony, using large circular conduction coils to transmit voice frequencies to receiving stations. On May 12, 1908, he received U.S. patent 887,357 for his Wireless Telephone, using the voice frequency induction system. He said in the patent that it would be useful for "securing telephonic communications between moving vehicles and way stations". The diagram shows wireless telephony from trains, boats, and wagons. In foreign patents he showed wireless telephony with cars. However, there is no indication that he was using voice-modulated continuous high frequency waves, as used for radio today.
Stubblefield's inventions did not lead directly to radio as the technology works today, but the public demonstrations in 1902 and the press coverage in the newspapers helped to spur public interest in the possibilities of wireless transmission of voice and music. Most other inventors of the era sought to provide point-to-point messaging, to compete with telephone and telegraph companies. Stubblefield in the 1902 was in a sense the "Father of Broadcasting", in that he said to the St. Louis Post Dispatch reporter in 1902, "..it is capable of sending simultaneous messages from a central distributing station over a very wide territory. For instance, anyone having a receiving instrument, which would consist merely of a telephone receiver and a signalling gong, could, upon being signalled by a transmitting station in Washington, or nearer, if advisable, be informed of weather news. My apparatus is capable of sending out a gong signal, as well as voice messages. Eventually, it will be used for the general transmission of news of every description".
List of Patents
Lighting device - November 3, 1885.
Mechanical telephone - February 21, 1888.
Electric battery - March 8, 1898.
Wireless telephone - May 12, 1908.
Wireless Telephone - October 20, 1908.