DEPRIVED OF MONOPOLY.; AN INJUNCTION AGAINST USING THE DUPLEX TELEGRAPH SYSTEM REFUSED. Share full article. Sept. 29, 1885. Credit... The New York Times Archives.

Telegraph lines could carry more than one message at a time if designed cleverly. In 1868, Joseph Stearns devised a method of sending two messages simultaneously on a single line. Called a duplex ...

Bunnell duplex telegraph relay National Museum of American History. Click to open image viewer. CC0 Usage Conditions Apply Click for more information. Click to view download files. Click to view IIIF ...

Electro-Mechanical Duplex Telegraph. Join Our Community of Science Lovers! Sign Up for Our Free Daily Newsletter. Email Address.

This article was originally published with the title “ The Duplex Telegraph Instrument in England ” in Scientific American Magazine Vol. 28 No. 5 (February 1873), p. 65 doi:10.1038 ...