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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.
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 electric telegraph was slower to develop in France due to the established optical telegraph system, but an electrical telegraph was put into use with a code compatible with the Chappe optical telegraph. The Morse system was adopted as the international standard in 1865, using a modified Morse code developed in Germany in 1848. [1]
Myer's code remained in use in the US until 1886 when it was replaced by Morse code for flag signals. [63] It came back into use after 1896, [50] but was officially discontinued in 1912 when International Morse code was mandated for all types of visual signaling. Inconsistently, American Morse code was mandated for Army electrical telegraph ...
A telegraph key, clacker, tapper or morse key is a specialized electrical switch used by a trained operator to transmit text messages in Morse code in a telegraphy system. [1] Keys are used in all forms of electrical telegraph systems, including landline (also called wire) telegraphy and radio (also called wireless) telegraphy .
A wire signal is a brevity code used by telegraphers to save time and cost when sending long messages. The best-known code was the 92 Code adopted by Western Union in 1859. The code was designed to reduce bandwidth consumption over telegraph lines, thus speeding transmissions by utilizing a numerical code system for frequently used phrases.
Electrical telegraphy was the first practical use of current electricity and was developed in the 1840s and 1850s at the same time as the development of railways. The first commercial electrical telegraph was the Cooke and Wheatstone system .
Starting in 1896, [259] the International Telegraph Union (ITU) attempted to control the use of codes in international telegrams to protect telegraph incomes and avoid messages difficult for operators to transmit. In 1875 they reduced the maximum length of a word (telegrams were charged by the word) from seven syllables to ten letters.