'''Amos Emerson Dolbear''' (November_10, 1837 – February_23, 1910) was an American Inventor. His patents interfered with Guglielmo_Marconi's planned activities in the US. ==Biography== He invented the first telephone receiver with a permanent magnet in 1865, 11 years before Alexander_Graham_Bell patented his model. Later, Dolbear couldn't prove his claim, so Bell kept the patent. While a student at Ohio Wesleyan, he had made a "talking telegraph" and invented a receiver containing two features of the modern telephone: a permanent magnet and a metallic diaphragm that he made of a tintype. He lost his case before the U. S. Supreme Court, (Dolbear et al. v. American Bell Telephone Company). The June 13, 1881 edition of Scientific American reported: "had [Dolbear] been observant of patent office formalities, it is possible that the speaking telephone, now so widely credited to Mr. Bell would be garnered among his own laurels." In 1882 Professor Amos E. Dolbear was able to communicate over a distance of a quarter of a mile without wires in the Earth. It is interesting to note that the Tufts Professor was ahead of Hertz and Marconi. He received a U.S. patent for a wireless telegraph in March of that year. His device relied on induction, not RF. His set-up used phones grounded by metal rods poked into the earth. His transmission range was a little less than a mile {{fact}}, but he received a patent for it({{US patent|350299}}). But more importantly the Dolbear patent prevented the Marconi Company from operating in the United States. In the end Marconi had to purchase Dolbear's patent, even though it was: A.) Generally inferior to Marconi's model{{fact}}. B.) Untractable in application{{fact}}. In 1868 Dolbear (while a professor at Bethany College) invented the electrostatic telephone. Dolbear also work on converting sound waves into electrical impulses. He also invented the opeidoscope, and a system of incandescent lighting. He authored several books, articles, and pamphlets, including "Matter, Ether, Motion," and was recognized for his contributions to science at both the Paris Exposition in 1881 and the Crystal Palace Exposition in 1882. In 1897, Dolbear published an article "The Cricket as a Thermometer" that noted the correlation between the ambient temperature and the rate at which crickets chirp. The formula expressed in that article became known as Dolbear's_Law. Dolbear was a graduate of Ohio_Wesleyan_University, in Delaware,_Ohio. ==External links== * Amos Dolbear, Tufts faculty as of 1874 * Just Who ''Did'' Invent Radio? * Roxbury's Professor Dolbear * A portrait of Prof. Dolbear {{engineer-stub}} Dolbear, Amos Emerson Dolbear, Amos Emerson Dolbear, Amos Emerson