Nathan Stubblefield

Nathan Beverly Stubblefield (born November 22, 1860 in Murray , † March 28, 1928 there ) was an American inventor and melon farmer. Among other things, he received the US patent for inductive wireless voice transmission in 1908 and founded what was probably the world's first radio operator called the Wireless Telephone Company of America .

Biographical

Stubblefield, second son of Judge William “Capt. Billy “Jefferson Stubblefield and his wife Victoria Bowman Stubblefield grew up in Murray. His mother died in 1869, and so did his father in 1874. He received his school education first from a tutor and then until his father's death at the Male and Female Institute , a boarding school in Farmington . In addition, he trained himself further by reading available publications, including articles in Scientific American and Electrical World . In 1881 he married Ada Mae Buchannan, with whom he had a total of nine children, some of whom died in their childhood.

Stubblefield's first experiments with "wireless" voice transmission took place in 1902. He used an "earth battery" he had developed. In fact, the voice transmission took place without a cable connection, but it was not a radio transmission, as Stubblefield used the earth between two iron stakes as a conductor, as was the case with the earth telegraphs or the fullerphone in the First World War . In the period from 1907 to 1911 he taught on his melon farm in the private school he founded, which he referred to as "The Nathan Stubblefield Industrial School" or "Teléph-on-délgreen Industrial School" and which later became the Murray State campus University emerged .

Stubblefield's second invention, patented in 1908, used electromagnetic induction to transmit speech or music over short distances. His concept envisaged installing a multi-core cable on telegraph poles on both sides of rivers, roads or railroad lines, the cores of which should form a very elongated coil following the traffic route . A strong voltage is applied to this coil via an interposed microphone, so that the electrical field of the coil induces a voltage in a smaller coil which is mounted on the roof of a vehicle traveling on the traffic route. You should be able to hear the message there. Unlike the in the radio technology used radio waves Stubblefield took advantage of low-frequency currents and therefore could be realized from a few meters only reach. This and the enormous effort involved in setting up the coils along the receiving paths prevented the concept from being implemented.

Stubblefield, who spawned a multitude of inventions and was able to patent some of them, was later booted out by his investors, reacted bitterly and from then on experimented in his shed near Almo in Calloway County . In 1928 he died of starvation.

Patents

• Patent US329864 : Lighting device. Published November 3, 1885 . ‌
• Patent US378183 : Mechanical telephone. Published February 21, 1888 . ‌
• Patent US600457 : Electric battery. Published May 12, 1908 . ‌
• Patent US887357 : Wireless telephone. Published May 12, 1908 . ‌
• Patent CA114737 : Wireless Telephone. Published October 20, 1908 (Not available from esp @ cenet . CIPO Link: CA114737 ). ‌

Web links

• 100 years of mobile phones (tagesschau.de archive), Tagesschau.de from May 15, 2008
• Nathan Stubblefield Murray State University, College of Science, Engineering and Technology
• Stubblefield's Wireless