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The effectiveness of any wire obstacle is greatly increased by planting anti-tank and blast antipersonnel mines in and around it. Additionally, connecting bounding anti-personnel mines (e.g. the PROM-1) to the obstacle with tripwires has the effect of booby-trapping the obstacle itself, hindering attempts to clear it.
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 telegrapher's equations (or just telegraph equations) are a set of two coupled, linear equations that predict the voltage and current distributions on a linear electrical transmission line. The equations are important because they allow transmission lines to be analyzed using circuit theory . [ 1 ]
Part of the Russian–American Telegraph line bearing the single wire of an earth-return circuit, c. 1866. Earth-return telegraph is the system whereby the return path for the electric current of a telegraph circuit is provided by connection to the earth through an earth electrode. Using earth return saves a great deal of money on installation ...
Cooke and Wheatstone 5-wire telegraph cable in a wooden spacer. Cooke and Wheatstone had their first commercial success with a telegraph installed in 1838 on the Great Western Railway over the 13 miles (21 km) from Paddington station to West Drayton. Indeed, this was the first commercial telegraph in the world. [10]
A telegraph message sent by an electrical telegraph operator or telegrapher using Morse code (or a printing telegraph operator using plain text) was known as a telegram. A cablegram was a message sent by a submarine telegraph cable, [4] often shortened to "cable" or "wire".
Contemporary map of the 1858 transatlantic cable route. Transatlantic telegraph cables were undersea cables running under the Atlantic Ocean for telegraph communications. . Telegraphy is an obsolete form of communication, and the cables have long since been decommissioned, but telephone and data are still carried on other transatlantic telecommunication
A telegraph code is one of the character encodings used to transmit information by telegraphy. Morse code is the best-known such code.Telegraphy usually refers to the electrical telegraph, but telegraph systems using the optical telegraph were in use before that.