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Telegraph
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensive and sophisticated as in China, were generally not capable of transmitting arbitrary text messages. Possible messages were fixed and predetermined, so such systems are thus not true telegraphs. The earliest true telegraph put into widespread use was the Chappe telegraph, an optical telegraph invented by Claude Chappe in the late 18th century. The system was used extensively in France, and European nations occupied by France, during the Napoleonic era. The electric telegraph started to replace the optical telegraph in the mid-19th century. It was first taken up in Britain in the form of the Cooke and Wheatstone telegraph, initially used mostly as an aid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Telegraph
Electrical telegraphy is Point-to-point (telecommunications), point-to-point distance communicating via sending electric signals over wire, a system primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems called ''telegraphs'', that were devised to send text messages more quickly than physically carrying them. Electrical telegraphy can be considered the first example of electrical engineering. Electrical telegraphy consisted of two or more geographically separated stations, called telegraph offices. The offices were connected by wires, usually supported overhead on utility poles. Many electrical telegraph systems were invented that operated in different ways, but the ones that became widespread fit into two broad categories. First are the needle telegraphs, in which electric current sent down the telegraph line produces electromagnetic force to move a needle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Telegraph
Electrical telegraphy is point-to-point distance communicating via sending electric signals over wire, a system primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems called '' telegraphs'', that were devised to send text messages more quickly than physically carrying them. Electrical telegraphy can be considered the first example of electrical engineering. Electrical telegraphy consisted of two or more geographically separated stations, called telegraph offices. The offices were connected by wires, usually supported overhead on utility poles. Many electrical telegraph systems were invented that operated in different ways, but the ones that became widespread fit into two broad categories. First are the needle telegraphs, in which electric current sent down the telegraph line produces electromagnetic force to move a needle-shaped pointer into position o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Telegraph
An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals (a form of optical communication). There are two main types of such systems; the semaphore telegraph which uses pivoted indicator arms and conveys information according to the direction the indicators point, and the shutter telegraph which uses panels that can be rotated to block or pass the light from the sky behind to convey information. The most widely used system was the Chappe telegraph, which was invented in France in 1792 by Claude Chappe. It was popular in the late eighteenth to early nineteenth centuries. Chappe used the term ''télégraphe'' to describe the mechanism he had invented – that is the origin of the English word "telegraph". Lines of relay towers with a semaphore rig at the top were built within line of sight of each other, at separations of . Operators at each tower would watch the neighboring tower through a telescop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless Telegraphy
Wireless telegraphy or radiotelegraphy is the transmission of text messages by radio waves, analogous to electrical telegraphy using electrical cable, cables. Before about 1910, the term ''wireless telegraphy'' was also used for other experimental technologies for transmitting telegraph signals without wires. In radiotelegraphy, information is transmitted by pulses of radio waves of two different lengths called "dots" and "dashes", which spell out text messages, usually in Morse code. In a manual system, the sending operator taps on a switch called a telegraph key which turns the transmitter on and off, producing the pulses of radio waves. At the radio receiver, receiver the pulses are audible in the receiver's speaker as beeps, which are translated back to text by an operator who knows Morse code. Radiotelegraphy was the first means of radio communication. The first practical radio transmitters and radio receiver, receivers invented in 1894–1895 by Guglielmo Marconi used radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pavel Schilling
Baron Pavel Lvovitch Schilling (1786–1837), also known as Paul Schilling, was a Russian inventor, military officer and diplomat of Baltic German origin. The majority of his career was spent working for the imperial Russian Ministry of Foreign Affairs as a language officer at the Russian embassy in Munich. As a military officer, he took part in the War of the Sixth Coalition against Napoleon. In his later career, he was transferred to the Asian department of the ministry and undertook a tour of Mongolia to collect ancient manuscripts. Schilling is best known for his pioneering work in electrical telegraphy, which he undertook at his own initiative. While in Munich, he worked with Samuel Thomas von Sömmerring who was developing an electrochemical telegraph. Schilling developed the first electromechanics, electromagnetic telegraph that was of practical use. Schilling telegraph, Schilling's design was a needle telegraph using magnetised needles suspended by a thread over a ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telegraph Code
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. A code consists of a number of code points, each corresponding to a letter of the alphabet, a numeral, or some other character. In codes intended for machines rather than humans, code points for control characters, such as carriage return, are required to control the operation of the mechanism. Each code point is made up of a number of elements arranged in a unique way for that character. There are usually two types of element (a binary code), but more element types were employed in some codes not intended for machines. For instance, American Morse code had about five elements, rather than the two (dot and dash) of International Morse Code. Codes meant for human interpretation were designed so that the characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooke And Wheatstone Telegraph
The Cooke and Wheatstone telegraph was an early electrical telegraph system dating from the 1830s invented by English inventor William Fothergill Cooke and English scientist Charles Wheatstone. It was a form of needle telegraph, and the first telegraph system to be put into commercial service. The receiver consisted of a number of needles that could be moved by electromagnetic coils to point to letters on a board. This feature was liked by early users who were unwilling to learn codes, and employers who did not want to invest in staff training. In later systems, the letter board was dispensed with, and the code was read directly from the movement of the needles. This occurred because the number of needles was reduced, leading to more complex codes. The change was motivated by the economic need to reduce the number of telegraph wires used, which was related to the number of needles. The change became more urgent as the insulation of some of the early installations deteriorat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morse Code
Morse code is a telecommunications method which Character encoding, encodes Written language, text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of the early developers of the system adopted for electrical telegraphy. International Morse code encodes the 26 ISO basic Latin alphabet, basic Latin letters to , one Diacritic, accented Latin letter (), the Arabic numerals, and a small set of punctuation and procedural signals (Prosigns for Morse code, prosigns). There is no distinction between upper and lower case letters. Each Morse code symbol is formed by a sequence of ''dits'' and ''dahs''. The ''dit'' duration can vary for signal clarity and operator skill, but for any one message, once the rhythm is established, a beat (music), half-beat is the basic unit of time measurement in Morse code. The duration of a ''dah'' is three times the duration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Morse
Samuel Finley Breese Morse (April 27, 1791 – April 2, 1872) was an American inventor and painter. After establishing his reputation as a portrait painter, Morse, in his middle age, contributed to the invention of a Electrical telegraph#Morse system, single-wire telegraph system based on European telegraphs. He was a co-developer of Morse code in 1837 and helped to develop the commercial use of telegraphy. Personal life Samuel F. B. Morse was born in Charlestown, Boston, Massachusetts, the first child of the pastor Jedidiah Morse, who was also a geographer, and his wife Elizabeth Ann Finley Breese. His father was a great preacher of the Calvinism, Calvinist faith and supporter of the Federalist Party. He thought it helped preserve Puritan traditions (strict observance of Christian Sabbath, Sabbath, among other things), and believed in the Federalist support of an alliance with Britain and a strong central government. Morse strongly believed in education within a Federalist f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chappe Telegraph
The Chappe telegraph was a French semaphore telegraph system invented by Claude Chappe in the early 1790s. The system was composed of towers placed every 5 to 15 kilometers. Coded messages were sent from tower to tower, with transmission being handled by tower operators using specially designed telescopes. The messages were decoded once they reached their destination city. By the mid 19th century, the network spanned several hundred kilometres and covered most major French cities as well as Venice, Mainz and Amsterdam. The system was dismantled after the introduction of the Electrical telegraph, electric telegraph. Today, about twenty Chappe towers remain, in varying states of repair. Design The Chappe telegraph system embodied varying designs, with the variation partly due to technological improvements made as the system was used. Physical layout of the towers The typical tower's signaling mechanism was visible through specially designed telescopes from a neighboring tower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Telegraph Cable
A submarine communications cable is a cable laid on the seabed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables were laid beginning in the 1850s and carried telegraphy traffic, establishing the first instant telecommunications links between continents, such as the first transatlantic telegraph cable which became operational on 16 August 1858. Submarine cables first connected all the world's continents (except Antarctica) when Java was connected to Darwin, Northern Territory, Australia, in 1871 in anticipation of the completion of the Australian Overland Telegraph Line in 1872 connecting to Adelaide, South Australia and thence to the rest of Australia. Subsequent generations of cables carried telephone traffic, then data communications traffic. These early cables used copper wires in their cores, but modern cables use optical fiber technology to carry digital data, which includes telep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleprinter
A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point (telecommunications), point-to-point and point-to-multipoint communication, point-to-multipoint configurations. Initially, from 1887 at the earliest, teleprinters were used in telegraphy. Electrical telegraphy had been developed decades earlier in the late 1830s and 1840s, then using simpler Morse key equipment and telegraph operators. The introduction of teleprinters automated much of this work and eventually largely replaced skilled labour, skilled operators versed in Morse code with Data entry clerk, typists and machines communicating faster via Baudot code. With the development of early computers in the 1950s, teleprinters were adapted to allow typed data to be sent to a computer, and responses printed. Some teleprinter models could also be used to create punched tape for Compute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
