Cooke, William (1806-1879), was an English inventor who developed an early telegraph. In 1836, Cooke, in collaboration with Charles Wheatstone, produced a telegraph that worked by electromagnetism. Their receiving instrument had five magnetic needles mounted vertically on a dial on which the letters of the alphabet were printed. A separate wire and a coil that served as an electromagnet controlled each needle. When an electric current passed through one of these wires, it produced a magnetic field in the coil, causing the needle to move. Two needles pointing toward a letter at the same time signaled that letter. In principle, the Cooke-Wheatstone telegraph was a miniature electric semaphore system. A single-needle version was patented in 1845 and was used in the United Kingdom until 1870.
William Fothergill Cooke was born on May 4, 1806, in Ealing, London. He was knighted in 1869. Cooke died on June 25, 1879.
