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A few two-signal-wire systems lingered on; the Cooke and Wheatstone two-needle system used on British railways, [10] and the Foy-Breguet telegraph used in France. [11] With the reduction in the number of signal wires, the cost of the return wire was much more significant, leading to earth return becoming the standard. [12]
A cablegram was a message sent by a submarine telegraph cable, [4] often shortened to "cable" or "wire". The suffix -gram is derived from ancient Greek: γραμμα ( gramma ), meaning something written, i.e. telegram means something written at a distance and cablegram means something written via a cable, whereas telegraph implies the process ...
Cooke and Wheatstone's five-needle telegraph from 1837 Morse telegraph Hughes telegraph, an early (1855) teleprinter built by Siemens and Halske. Electrical telegraphy is a point-to-point text messaging system, primarily used from the 1840s until the late 20th century.
The history of telecommunication began with the use of smoke signals and drums in Africa, Asia, and the Americas. In the 1790s, the first fixed semaphore systems emerged in Europe. However, it was not until the 1830s that electrical telecommunication systems started to appear. This article details the history of telecommunication and the ...
He shows that a coil of wire carrying a current behaves like an ordinary magnet and suggests that electromagnetism might be used in telegraphy. He mathematically develops Ampère's law describing the magnetic force between two electric currents. His mathematical theory explains known electromagnetic phenomena and predicts new ones.
Before the discovery of electromagnetic waves and the development of radio communication, there were many wireless telegraph systems proposed and tested. [4] In April 1872 William Henry Ward received U.S. patent 126,356 for a wireless telegraphy system where he theorized that convection currents in the atmosphere could carry signals like a telegraph wire. [5]
Wired communication refers to the transmission of data over a wire-based communication technology (telecommunication cables). Wired communication is also known as wireline communication . Examples include telephone networks , cable television or internet access , and fiber-optic communication .
Hills, Jill, The Struggle for Control of Global Communication, University of Illinois Press, 2002 ISBN 978-0-7099-3701-2. Hubbard, Geoffrey, Cooke and Wheatstone and the Invention of the Electric Telegraph, Routledge\, 2013 ISBN 978-1-135-02850-3. Huurdeman, Anton A., The Worldwide History of Telecommunications, Wiley, 2003 ISBN 978-0-471-20505-0.