telegraph

1832: On a see travel, painter Samuel Morse develops the concept of a single wire telegraph.

1837: The first commercial electrical telegraph is constructed by Sir William Cooke. Cooke and Charles Wheatstone patented it in May 1837 as an alarm system. It was first successfully demonstrated by Cooke and Wheatstone on 25 July 1837 between Euston and Camden Town in London.

Samuel F. B. Morse independently developed an electrical telegraph in 1837, an alternative design that was capable of transmitting over long distances using poor quality wire. His assistant, Alfred Vail developed the Morse code signalling alphabet with Morse.

1844: On May 24, Morse made the first public demonstration of his telegraph by sending a message from the Supreme Court Chamber in the U.S. Capitol in Washington, D.C. to the B&O Railroad "outer depot" in Baltimore.

1858: Première ligne de télégraphie transatlantique. «They put a cable in place between Ireland and Newfoundland. But for all of the reasons mentioned earlier, it hardly worked at all. Queen Victoria managed to send President Buchanan a celebratory message, but it took a whole day to send it.» (Neal Stephenson)

On October 24, 1861, the first transcontinental telegraph system is established. Spanning North America, an existing network in the eastern United States is connected to the small network in California by a link between Omaha and Carson City via Salt Lake City. The slower Pony Express system ceases operation two days later.

1866: The Atlantic Cable is finally successfully laid. The broken cable from the previous year's attempt is raised and repaired; soon two cables are operational.

1866 - 26 November: The first encrypted telegraphic message is sent from Washington et Paris.

1974: Thomas Edison invents the quadruplex telegraph, which can send four simultaneous telegraph signals over the same wire.

1880: By 1880, an estimated one hundred thousand miles of undersea telegraph cable have been laid.

Sources:
http://en.wikipedia.org/wiki/Electrical_telegraph

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