Telegraphy

right|upright=0.9|thumb|Replica of a Chappe telegraph on the Litermont near [[Nalbach, Germany]]

thumb|Teletype Corporation|Teletype teleprinters in use in England during [[World War II|alt=|250x250px]] thumb|Example of teleprinter art: a portrait of [[Dag Hammarskjöld, 1962|alt=]]

form of data storage

A telegram is a written or printed message, originally sent through telegraphy. The use of the telegrams was popular for social and business correspondence in the latter half of the 19th and the first half of the 20th century. Even in the telephone age, the telegram remained popular, and spawned its own style of writing that in turn persisted in other media. Telegram services still exist today, though the popularity has largely waned, replaced by other forms of text communication. alt=Western Union telegram sent to President Dwight Eisenhower wishing him a speedy recovery from his heart attack

method of communication

system of visual communication

early system for transmitting text over wires

thumb|Fig. 1: Signaling with a Mance heliograph; Alaska–Canada border, 1910.

pioneering five-bit character encodings

undersea cable

American businessman (1819–1892)

electrical switch used to transmit text messages in Morse code

thumb|right|A NAVTEX receiver prints an incoming message thumb|right|NAVTEX message for the Baltic Sea

device

A duplexer is an electronic device that allows bi-directional (duplex) communication over a single path. In radar and radio communications systems, it isolates the receiver from the transmitter while permitting them to share a common antenna. Most radio repeater systems include a duplexer. Duplexers can be based on frequency (often a waveguide filter), polarization (such as an orthomode transducer), or timing (as is typical in radar).

thumb| thumb|Caselli's pantelegraph mechanism

thumb|right|300px thumb|right|350px|Slight timing errors are compensated for by redundancy (engineering)|printing each line twice.

Ten-codes, officially known as ten signals, are brevity codes used to represent common phrases in voice communication, particularly by US public safety officials and in citizens band (CB) radio transmissions. The police version of ten-codes is officially known as the APCO Project 14 Aural Brevity Code.

thumb|right|TTX11 terminal, in this case being relabeled IBM PS/2. Teletex was ITU-T specification F.200 for a text and document communications service that could be provided over telephone lines. It was rapidly superseded by e-mail; however, the name Teletex lives on in several of the X.500 standard attributes used in Lightweight Directory Access Protocol.

1963–1981 ASCII communications/computer terminal device

thumb|right|An early telautograph machine The telautograph is an ancestor of the modern fax machine. It transmits electrical signals representing the position of a pen or tracer at the sending station to repeating mechanisms attached to a pen at the receiving station, thus reproducing at the receiving station a drawing, writing, or signature made by the sender. It was the first such device to transmit drawings to a stationary sheet of paper; previous inventions in Europe had used a constantly moving strip of paper to make such transmissions and the pen could not be lifted between words. Surpri

heroine of the Franco-Prussian War of 1870 and the first woman to be awarded the Legion of Honor

digital communication media

Othernet Inc. was a broadcast data company. Othernet sold a portable satellite data receiver that combined an amplifier, radio, and CPU in a single unit.

storing sound recordings on film

British politician and industrialist (1816–1896)

Type of electrical telegraph

1884 treaty to protect submarine communications cables

early electrical telegraph system dating from the 1830s

informal name for system of electrical telegraphs that linked the British Empire

Semaphore systems using water-based mechanisms

American politician (1806-1876)

various methods of transmitting more than one telegraph messages simultaneously

clipped language used in telegrams

journalist, telegrapher, inventor (1846–1920)

telegraphic communications system used between Berlin and the Rhine Province from 1832 to 1849

type of electrical telegraph

telegraphy transmission method

American teleprinter manufacturer

one of the character encodings used to transmit information by telegraphy

device for detecting operability in a telegraph