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Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters, originally by changing something that could be observed from a distance . Radiotelegraphy or wireless telegraphy transmits messages using radio Radio

Radio is the wireless transmission of signals [i], by modulation [i] of electromagnetic waves [i] ... 

. Telegraphy includes recent forms of data transmission such as fax Fax

Fax is a telecommunications [i] technology used to transfer copies of documents, especially using affor ... 

, email E-mail

Electronic mail is a store and forward [i] method of composing, sending, storing, and receiving message ... 

, and computer network Computer networking

Computer networking is the scientific [i] and engineering [i] discipline concerned with communic ... 

s in general. Wireless telegraphy is also known as CW, for continuous wave . Telegraphy messages sent by telegraph Electrical telegraph

The electrical telegraph is a telegraph [i] that uses electric signal [i]s.... 

 operators using Morse code Morse code

Morse code is a method for transmitting information, using standardized sequences of short and long mark... 

 were known as telegrams or cablegrams, often shortened to a cable or a wire message.

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Timeline

1837   Samuel Morse Samuel F. B. Morse

Samuel Finley Breese Morse was an American [i], inventor [i] of the Morse Code [i] and painter [i] ... 

 patents telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

1839   The world's first commercial electric telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

 line comes into operation alongside the Great Western Railway Great Western Railway

The Great Western Railway was a British railway company [i] a ... 

 line from Paddington station Paddington station

Paddington station is a major National Rail [i] and London Underground [i] station complex in the Paddington [i] ... 

 to West Drayton.

1852   French replace semaphore Semaphore

The semaphore or optical telegraph is an apparatus for conveying information by means of visual si... 

s with Morse telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

s

1854   Texas Texas

Texas is a state [i] in both the Southern [i] and Western [i] ... 

 is linked by telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

 with the rest of the United States United States

The United States of America, also known as the United States, the U.S., the U.S.A., a... 

, when a connection between New Orleans New Orleans, Louisiana

New Orleans is a major United States [i] port city and historically the largest city in the U.S. state [i] ... 

 and Marshall, Texas Marshall, Texas

Marshall is a major city of the northeastern [i] region of the U.S. state [i] of Texas [i] ... 

 is completed.

1858   Cyrus West Field Cyrus West Field

Cyrus West Field was an American [i] businessman and financier who led the Atlantic Telegraph Company [i] ... 

 and others complete the first transatlantic telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

 cable after several unsuccessful attempts. The service ends on September 1 due to weak current.

1858   US President James Buchanan James Buchanan

James Buchanan was the 15th president of the United States [i] . ... 

 inaugurates the new trans-Atlantic telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

 cable by exchanging greetings with Queen Victoria of the United Kingdom Victoria of the United Kingdom

Victoria was the Queen [i] of the United Kingdom of Great Britain and Ireland [i] ... 

. However, a weak signal will force a shutdown of the service in a few weeks.

1866   The Atlantic Cable Transatlantic telegraph cable

The Transatlantic telegraph cable was a telegraph [i] cable [i] that crossed the Atlantic Ocean [i] from ... 

 is successfully completed, allowing transatlantic telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

 communication for the first time.

1876   Lars Magnus Ericsson Lars Magnus Ericsson

Lars Magnus Ericsson was a Swedish [i] inventor [i] and founder of telephone [i] equipment manuf ... 

 and Carl Johan Andersson start a small mechanical workshop in Stockholm Stockholm

Stockholm is the capital [i] of Sweden [i], and consequently the site of its Government [i] ... 

, Sweden Sweden

The Kingdom of Sweden is a Nordic country [i] in Scandinavia [i]. ... 

, dealing with telegraphy equipment, which grows into the world-wide company Ericsson Ericsson

Ericsson is a Swedish [i] telecommunication [i]s equipment manufacturer, founded in 1876 [i] as ... 

.

1892   Thomas Edison Thomas Edison

Thomas Alva Edison was an American [i] inventor [i] and businessman [i] who developed man ... 

 receives a patent Patent

A patent is a set of exclusive right [i]s granted by a state [i] to a patentee for a fixed period of time [i] ... 

 for a two-way telegraph Telegraphy

Telegraphy is the long-distance transmission of written messages without physical transport of letters,... 

.



Encyclopedia



Telegraphy is the long-distance transmission of written messages without physical transport of letters, originally by changing something that could be observed from a distance . Radiotelegraphy or wireless telegraphy transmits messages using radio Radio

Radio is the wireless transmission of signals [i], by modulation [i] of electromagnetic waves [i] ... 

. Telegraphy includes recent forms of data transmission such as fax Fax

Fax is a telecommunications [i] technology used to transfer copies of documents, especially using affor ... 

, email E-mail

Electronic mail is a store and forward [i] method of composing, sending, storing, and receiving message ... 

, and computer network Computer networking

Computer networking is the scientific [i] and engineering [i] discipline concerned with communic ... 

s in general. Wireless telegraphy is also known as CW, for continuous wave .

Telegraphy messages sent by telegraph Electrical telegraph

The electrical telegraph is a telegraph [i] that uses electric signal [i]s.... 

 operators using Morse code Morse code

Morse code is a method for transmitting information, using standardized sequences of short and long mark... 

 were known as telegrams or cablegrams, often shortened to a cable or a wire message. Later, telegrams sent by the Telex Teleprinter

A teleprinter is a now largely obsolete electro-mechanical typewriter [i] which can be used to communic... 

 network, a switched network of teleprinter Teleprinter

A teleprinter is a now largely obsolete electro-mechanical typewriter [i] which can be used to communic... 

s similar to the telephone network, were known as telex messages. Before long distance telephone services were readily available or affordable, telegram services were very popular. Telegrams were often used to confirm business dealings and, unlike e-mail, telegrams were commonly used to create binding legal documents for business dealings.

Wire picture or wire photo was a newspaper picture that was sent from a remote location by a facsimile telegraph.

Optical telegraphs and smoke signals

First telegraph were [optical telegraph]s, including the use of smoke signals and beacon Beacon

Beacons are fires lit on hills or high places, used either as lighthouse [i]s for navigation [i] at sea, ... 

s. These have existed since ancient times. A semaphore Semaphore

The semaphore or optical telegraph is an apparatus for conveying information by means of visual si... 

 network invented by Claude Chappe Claude Chappe

Claude Chappe was a French inventor who in 1792 [i] demonstrated a practical semaphore [i] sys ... 

 operated in France from 1792 through 1846. It helped Napoleon Napoleon I of France

Napoleon I Bonaparte, Emperor of the French, King of Italy, Mediator of the Swiss Confederation and Prot... 

 enough that it was widely imitated in Europe and the U.S. The last commercial semaphore link left operation in 1880.

Semaphores were able to convey information more precisely than smoke signals and beacons and consumed no fuel. Messages could be sent at much greater speed than post rider Post riders

Post riders or postriders describes a horse [i] and rider postal [i] delivery system that existed ... 

s and could serve entire regions. However, like beacons and smoke signals, they were dependent on good weather to work. They required operators and towers every 30 km , and could only accommodate about two words per minute. This was useful to governments, but too expensive for most commercial uses other than commodity price information. Electric telegraphs Electrical telegraph

The electrical telegraph is a telegraph [i] that uses electric signal [i]s.... 

 were to reduce the cost of sending a message thirtyfold compared to semaphore.

Electrical telegraphs


In 1775 Francisco de Salva offered an electrostatical telegraph. Samuel T. Soemmering constructed his electrochemical telegraph in 1809. Also as one of the first, an electromagnetic telegraph Electrical telegraph

The electrical telegraph is a telegraph [i] that uses electric signal [i]s.... 

 was created by Baron Schilling in 1832. Carl Friedrich Gauß and Wilhelm Weber Wilhelm Eduard Weber

Wilhelm Eduard Weber was a noted physicist [i].
... 

 built and used for regular communication the first electromagnetic telegraph in 1833 in Göttingen Göttingen

Gttingen is a city [i] in Lower Saxony [i], Germany [i]. ... 

.The first commercial electrical telegraph Electrical telegraph

The electrical telegraph is a telegraph [i] that uses electric signal [i]s.... 

 was constructed by Sir Charles Wheatstone Charles Wheatstone

Sir [i] Charles Wheatstone was a British [i] scientist [i] and inventor [i] of ... 

 and Sir William Fothergill Cooke and entered use on the Great Western Railway Great Western Railway

The Great Western Railway was a British railway company [i] a... 

. It ran for 13 miles from Paddington station Paddington station

Paddington station is a major National Rail [i] and London Underground [i] station complex in the Paddington [i] ... 

 to West Drayton and came into operation on April 9, 1839. It was patent Patent

A patent is a set of exclusive right [i]s granted by a state [i] to a patentee for a fixed period of time [i] ... 

ed in the United Kingdom United Kingdom

The United Kingdom of Great Britain and Northern Ireland is a country and sovereign state [i] tha ... 

 in 1837.
In 1843 Scottish physician Alexander Bain Alexander Bain

Alexander Bain was a Scottish [i] philosopher [i] and educationalist. ... 

 invented a device that could be considered the first facsimile machine Fax

Fax is a telecommunications [i] technology used to transfer copies of documents, especially using affor ... 

. He called his invention a "recording telegraph". Bain's telegraph was able to transmit images by electrical wires. In 1855 an abbot, Giovanni Caselli, in Italy also created an electric telegraph that could transmit images. Caselli called his invention "Pantelegraph". Pantelegraph was successfully tested and approved for a telegraph line between Paris Paris

native_name = Ville de Paris
|common_name = Paris
... 

 and Lyon Lyon

Lyon is a city in east central France [i]. ... 

.


An electrical telegraph was independently developed and patented in the United States United States

The United States of America, also known as the United States, the U.S., the U.S.A., a... 

 in 1837 by Samuel Morse Samuel F. B. Morse

Samuel Finley Breese Morse was an American [i], inventor [i] of the Morse Code [i] and painter [i] ... 

. His assistant, Alfred Vail Alfred Vail

Alfred Lewis Vail was a machinist [i] and inventor [i].... 

, developed the Morse code Morse code

Morse code is a method for transmitting information, using standardized sequences of short and long mark... 

 signalling alphabet Alphabet

An alphabet is a complete standardized set of letters [i] — basic written symbols &mda ... 

 with Morse. America's first telegram was sent by Morse on January 6, 1838, across two miles of wiring. The message read "A patient waiter is no loser." On May 24, 1844, he sent the message, "What hath God wrought?," from Washington to Baltimore, using repeater technology. The Morse/Vail telegraph was quickly deployed in the following two decades.

The first transatlantic telegraph cable Transatlantic telegraph cable

The Transatlantic telegraph cable was a telegraph [i] cable [i] that crossed the Atlantic Ocean [i] from ... 

 was successfully completed on July 27, 1866, allowing transatlantic telegraph communications for the first time. Earlier submarine cable transatlantic cables installed in 1857 and 1858 only operated for a few days or weeks before they failed. The study of underwater telegraph cables accelerated interest in mathematical analysis of these transmission line Transmission line

A transmission line is the material medium [i] or structure that forms all or part o... 

s.


Another advancement in telegraph technology occurred on August 9, 1892, when Thomas Edison Thomas Edison

Thomas Alva Edison was an American [i] inventor [i] and businessman [i] who developed man ... 

 received a patent for a two-way telegraph. He received , "Duplex Telegraph".

Radiotelegraphy

Nikola Tesla Nikola Tesla

Nikola Tesla he United States [i], Tesla's fame rivaled that of any other inven ... 

 and other scientists and inventors showed the usefulness of wireless telegraphy, radiotelegraphy, or radio Radio

Radio is the wireless transmission of signals [i], by modulation [i] of electromagnetic waves [i] ... 

, beginning in the 1890s. Alexander Stepanovich Popov Alexander Stepanovich Popov

Alexander Stepanovich Popov was a Russia [i]n physicist [i] who was the first to demonstrate the practic ... 

 demonstrated to the public his receiver of wireless signals, also used as a lightning detector, on 7 May, 1895. It is considered that Guglielmo Marconi Guglielmo Marconi

Although Guglielmo Marconi is widely credited as the "Inventor of Radio", for some this title is contr... 

 sent and received his first radio in Italy Italy

Italy, officially the Italian Republic , is a Southern European [i] country. ... 

 up to 6 kilometres in 1896. Around the turn of the century, it is reported that he broadcast signals across the English Channel English Channel

The English Channel is the part of the Atlantic Ocean [i] that separates the island [i] of Great Britain [i] ... 

 and, shortly thereafter, Marconi radiotelegraphed the letter "S" across the Atlantic Ocean Atlantic Ocean

The Atlantic Ocean is the second-largest ocean [i], covering approximately one-fifth of the Earth [i]'s ... 

 from England England

England is the largest and most populous constituent country [i] of the United Kingdom [i]. ... 

 to Newfoundland Newfoundland

Newfoundland is a large island off the east coast of North America [i], and the most populous part o ... 

.

In 1898 Popov accomplished successful experiments of wireless communication between a naval base and a battle ship Battleship

Battleship was the name given to the most powerfully gun-armed [i] and most heavily armor [i] ... 

. In 1900 the crew of the Russian battle ship General-Admiral Apraksin as well as stranded Finnish fishermen were saved in the Gulf of Finland Gulf of Finland

The Gulf of Finland is an arm of the Baltic Sea [i] that extends between Finland [i] and Estonia [i] a ... 

  because of exchange of distress telegrams between two radiostations, located at Gogland island Hogland

Hogland is an island [i] in the Gulf of Finland [i] of the Baltic Sea [i], located some 180 km [i] west ... 

 and inside a Russian naval base in Kotka Kotka

Kotka is a town [i] and municipality [i] of Finland [i].
... 

. Both stations of wireless telegraphy were built under Popov's instructions.

Albert Einstein Albert Einstein

Albert Einstein was a German [i]-born theoretical physicist [i]. ... 

 famously described radiotelegraphy by saying,
"Wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. And radio operates exactly the same way. The only difference is that there is no cat."

Radiotelegraph proved effective in communication for rescue work when a sea disaster Disaster

For the Star Trek: The Next Generation episode, see Disaster [i]. ... 

 occurred. Effective communication was able to exist between ships and from ship to shore.

Telegraphic improvements

A continuing goal in telegraphy has been to reduce the cost per message by reducing hand-work, or increasing the sending rate. There were many experiments with moving pointers, and various electrical encodings. However, most systems were too complicated and unreliable. A successful expedient to increase the sending rate was the development of telegraphese.

With the invention of the teletypewriter Teleprinter

A teleprinter is a now largely obsolete electro-mechanical typewriter [i] which can be used to communic... 

, telegraphic encoding became fully automated. Early teletypewriters used Baudot code Baudot code

The Baudot code, named after its inventor [i] mile Baudot [i], is a character set [i] ... 

, a 5-bit code. This yielded only thirty two codes, so it was over-defined into two "shifts," "letters" and "figures." An explicit, unshared shift code prefaced each set of letters and figures.

The airline industry still communicates with Teletype messages over the SITA SITA

SITA is a multinational [i] information technology [i] company specialising i ... 

 or AFTN networks. For example, The British Airways British Airways

British Airways is the largest airline [i] of the United Kingdom [i]. ... 

 operations computer system as of 2004 2004

2004 was a leap year starting on Thursday [i] of the Gregorian calendar [i].
... 

 still used teletype to communicate with other airline computer systems. The same goes for PARS  and IPARS that used a similar shifted 6-bit Teletype code, because it requires only 8 bits per character, saving bandwidth and money. A teletype message is often much smaller than the equivalent EDIFACT or XML message.

A standard timing system Asynchronous start-stop

Asynchronous start-stop describes an asynchronous [i] transmission protocol in which a start signal is s ... 

 developed for telecommunications. The "mark" state was defined as the powered state of the wire. In this way, it was immediately apparent when the line itself failed. The characters were sent by first sending a "start bit" that pulled the line to the unpowered "space" state. The start bit triggered a wheeled commutator run by a motor with a precise speed . The commutator distributed the bits from the line to a series of relays that would "capture" the bits. A "stop bit" was then sent at the powered "mark state" to assure that the commutator would have time to stop, and be ready for the next character. The stop bit triggered the printing mechanism. Often, two stop bits were sent to give the mechanism time to finish and stop vibrating.

Telex





By 1935, message routing was the last great barrier to full automation. Large telegraphy providers began to develop systems that used telephone-like rotary dialing Telephone exchange

In the field of telecommunications [i], a telephone exchange or telephone switch is a system of el ... 

 to connect teletypes. These machines were called "telex". Telex machines first performed rotary-telephone-style pulse dialing, and then sent baudot code Baudot code

The Baudot code, named after its inventor [i] mile Baudot [i], is a character set [i] ... 

. This "type A" telex routing functionally automated message routing.

The first wide-coverage telex network was implemented in Germany Germany

Germany , officially the Federal Republic of Germany , is a country [i] in central Europe [i]. ... 

 during the 1930s. The network was used to communicate within the government.

At the then-blinding rate of 45.5 bits per second, up to 25 telex channels could share a single long-distance telephone channel, making telex the least expensive method of reliable long-distance communication.

In 1970, Cuba Cuba

Cuba, officially the Republic of Cuba, consists of the island of Cuba, the Isle of Youth [i] and a ... 

 and Pakistan Pakistan

[i] located in [[South Asia]... 

 were still running 45.5 baud type A telex. Telex is still widely used in some developping countries' bureaucracies, probably because of its low costs and reliability. The UN United Nations

name = United Nations
Nations Unies
... 

 asserts that more political entities are reliably available by telex than by any other single method.

Around 1960[?], some nations began to use the "figures" baudot codes to perform "Type B" telex routing.

Telex grew around the world very rapidly. Long before automatic telephony was available, most countries, even in central Africa Africa

Africa is one of the greatest sized continents of the Earth.... 

 and Asia Asia

Asia is the largest and most populous continent [i] or region, depending on the definition.... 

, had at least a few high-frequency telex links. Often these radio links were the first established by government postal and telegraph services . The most common radio standard, CCITT R.44 had error-corrected retransmitting time-division multiplexing of radio channels. Most impoverished PTTs operated their telex-on-radio channels non-stop, to get the maximum value from them.

The cost of telex on radio equipment has continued to fall. Although initially specialized equipment was required, many amateur radio Amateur radio

Amateur radio, often called ham radio, is a hobby [i] and public service enjoyed by about 3 millio ... 

 operators now operate TOR with special software and inexpensive adapters from computer sound cards to shortwave radios.

Modern "cablegrams" or "telegrams" actually operate over dedicated telex networks, using TOR whenever required.

In Germany alone, more than 400,000 telex lines remain in daily operation. Over most of the world, more than three million telex lines remain in use.

A major advantage of Telex was that the receipt of the message by the recipient could be confirmed with a high degree of certainty by the "answerback". At the beginning of the message, the sender would transmit a WRU code, and the recipient machine would automatically initiate a response which was usually encoded in a rotating drum with pegs, much like a music box. The position of the pegs sent an unambiguous identifying code to the sender, so the sender was sure that he was connected to the correct recipient. The WRU code would also be sent at the end of the message, so a correct response would confirm that the connection had remained unbroken during the message transmission. This gave Telex a major advantage over other unreliable forms of communications such as telephone and fax.

The usual method of operation was that the message would be prepared off-line, using paper tape Punched tape

Punched tape or paper tape is a largely obsolete form of data storage [i], consisting of a long st... 

. All common Telex machines incorporated a 5-hole paper tape reader and paper tape punch. Once the paper tape had been prepared, the message could be transmitted in minimum time. Telex billing was always by connected duration, so minimizing the connect time saved money. However, it was also possible to connect in "real time", where the sender and the recipient could both type on the keyboard and these characters would be immediately printed on the distant machine.

TWX


Almost in parallel with Germany's telex system, AT&T AT&T

AT&T Inc. is the largest provider of both local and long distance telephone services, wireless service, ... 

 in the 1930s decided to go telex one better, and began developing a similar service called "Teletype Wide-area eXchange" . AT&T, also known as the Bell system, acquired the Teletype Corporation Teleprinter

A teleprinter is a now largely obsolete electro-mechanical typewriter [i] which can be used to communic... 

 in 1930 and used its teleprinter Teleprinter

A teleprinter is a now largely obsolete electro-mechanical typewriter [i] which can be used to communic... 

s for TWX.

TWX originally ran 75 bits per second, sending Baudot code and dial selection. However, Bell later developed a second generation of "four row" modems called the "Bell 101 dataset", which is the direct ancestor of the Bell 103 modem Modem

A modem is a device [i] that modulates [i] an analog carrier [i] ... 

 that launched computer time-sharing. The 101 was revolutionary because it ran on ordinary subscriber lines that could be routed to special exchanges called "wide-area data service". Because it was using the public switched telephone network, TWX had special area codes: 510, 610, 710, 810 and 910. With the demise of TWX service, these codes were re-provisioned as standard geographic NPAs in the 1990s.

Bell's original consent agreement limited it to international dial telephony. Western Union Western Union

Western Union is a financial services and communications company [i] based in the United States [i] ... 

 Telegraph Company had given up its international telegraphic operation in a 1939 bid to monopolize U.S. telegraphy by taking over ITT's PTT business. The result was deemphasis on telex in the U.S. and a cat's cradle of small U.S. international telex and telegraphy companies. These were known by regulatory agencies as "International Record Carriers".

  • Western Union Western Union

    Western Union is a financial services and communications company [i] based in the United States [i] ... 

     Telegraph Company developed a spinoff called "Cable System." Cable system later became Western Union International.
  • ITT's "World Communications" was amalgamated from many smaller companies: "Federal Telegraph," "All American Cables and Radio," "Globe Wireless," and a common carrier division of Mackay Marine.
  • RCA communications had specialised in crossing the Pacific. It later joined with Western Union International to become MCI.
  • Before World War I, Tropical Radiotelegraph put radio telegraphs on ships for its owner, The United Fruit Company, in order to deliver bananas to the best-paying markets. Communications expanded to UFC's plantations, and were eventually provided to local governments. TRT Telecommunications eventually became the national PTT of many small Central American nations.
  • The French Telegraph Cable Company had always been in the U.S. It laid cable from the U.S. to France. It was formed by "Monsieur Puyer-Quartier". This is how it got its telegraphic routing ID "PQ".
  • Firestone Rubber developed its own IRC, the "Trans-Liberia Radiotelegraph Company". It operated shortwave from Akron OH to the rubber plantations in Liberia. TL is still based in Akron.


Bell telex users had to select which IRC to use, and then append the necessary routing digits. The IRCs converted between TWX and Western Union Western Union

Western Union is a financial services and communications company [i] based in the United States [i] ... 

 Telegraph Co. standards.

Arrival of the Internet


As of 2006, most telegraphic messages are carried by the Internet in the form of e-mail.

Around 1965, DARPA commissioned a study of decentralized switching systems. Some of the ideas developed in this study provided inspiration for the development of the ARPANET ARPANET

The Advanced Research Projects Agency Network developed by ARPA [i] ... 

 packet switching research network, which later grew to become the public Internet Internet

The Internet is the worldwide, publicly accessible network of interconnected computer network [i]s that ... 

.

The Internet was a radical break in three ways. First, it was designed to operate over any digital transmission media. Second, routing was decentralized. Third, large messages were broken into fixed size packets, and then reassembled at the destination. All previous networks had used controlled media, centralized routers and dedicated connections. As the Internet grew, it used progressively faster digital carrier links, employing the digital systems that had been developed for the PSTN.

As the PSTN became a digital network, T-carrier T-carrier

In telecommunication [i]s, T-carrier is the generic designator for any of several digitally multiplexed [i]... 

 "synchronous" networks became commonplace in the U.S. A T-1 line has a "frame" of 193 bits that repeats 8000 times per second. The first bit, called the "sync" bit, alternates between 1 and 0 to identify the start of the frames. The rest of the frame provides 8 bits for each of 24 separate voice or data channels. Customarily, a T-1 link is sent over a balanced twisted pair, isolated with transformers to prevent current flow. Europeans adopted a similar system of 32 channels .

Later, SONET and SDH  were adapted to combine carrier channels into groups that could be sent over optic fiber Optical fiber

An optical fiber or fibre is a thin, transparent [i] fiber [i], usually made of glass [i]... 

. The capacity of an optic fiber is often extended with wavelength division multiplexing Wavelength-division multiplexing

In fibre optic [i] telecommunication [i]s, wavelength-division multiplexing is a technology which multiplexes [i] ... 

, rather than rerigging new fibre. Rigging several fibres in the same structures as the first fibre is usually easy and inexpensive, and many fibre installations include unused spare "dark fibre", "dark wavelengths", and unused parts of the SONET frame, so-called "virtual channels."

Currently , the fastest well-defined communication channel used for telegraphy is the SONET standard OC-768, which sends about 40 gigabits per second.

The theoretical maximum capacity of an optic fiber is more than 10^12 bits per second. No current encoding system approaches this theoretical limit, even with wavelength division multiplexing.

Since the Internet operates over any digital transmission medium, further evolution of telegraphic technology will be effectively concealed from users.

E-mail displaces telegraphy


E-mail E-mail

Electronic mail is a store and forward [i] method of composing, sending, storing, and receiving message ... 

 was first invented for Multics in the late 1960s. At first, e-mail was only possible between different accounts on the same computer. UUCP allowed different computers to be connected to allow e-mails to be relayed from computer to computer. With the growth of the Internet, E-mail began to be possible between any two computers with access to the Internet.

Various private networks had e-mail from the 1970s, but subscriptions were quite expensive for an individual, $25 to $50 a month, just for E-mail. Internet use was then limited to government, academia and other government contractors until the net was opened to commercial use in the 1980s.

In 1992, computer access via modem combined with cheap computers, and graphic point & click interfaces to give a radical alternative to conventional telex systems: personal e-mail.

Individual e-mail accounts were not widely available until local ISPs were in place, although demand grew rapidly, as e-mail was seen as the Internet's killer app Killer application

A killer application is a computer program [i] that is so useful or desirable that it proves the value o... 

. The broad user base created by the demand for e-mail smoothed the way for the rapid acceptance of the World Wide Web World Wide Web

The World Wide web is a global, read-write information [i] space. ... 

 in the mid-1990s.

Telegraphy as a legacy system


International Telex remains available via e-mail ports. It is one's e-mail address with numeric or alpha prefixes specifying one's International Record Carrier and account.
Telex has always had a feature called "answerback" that asks a remote machine to send its address. If one is using telex via e-mail, this address is what a remote telex user will want in order to contact an e-mail user.

On January 27, 2006, Western Union of its telegram services; due to the lack of sales. 20,000 telegrams were sent in 2005, compared with 20 million in 1929. According to Western Union, which still offers money transfer services, its last telegram was sent Friday, February 3, 2006.

Telegram service in the United States and Canada is still available, operated by International Telegram. Some companies, like Swedish Telia TeliaSonera

TeliaSonera AB is the dominant telephone company [i] and mobile network operator [i] in Sweden [i] and Finland [i] ... 

 still deliver telegrams, but they serve as nostalgic Nostalgia

Nostalgia describes a longing for the past, often idealized [i] and unrealistic. ... 

 novelty items rather than a primary means of communication. The international telegram service formerly provided by British Telecom has been spun off as an independent company which promotes their use as a retro greeting card or invitation.

In the Netherlands, telegram operations ceased in 2004. In Belgium though, services continue through Belgacom Belgacom

... 

, most astonishing is that business is still flourishing.

In Japan, NTT provides a telegram service that is today used mainly for special occasions such as weddings, funerals, graduations, etc. Local offices offer telegrams printed on special decorated paper and envelopes.

See also


  • Optical telegraph
  • Electromagnetic telegraph Electrical telegraph

    The electrical telegraph is a telegraph [i] that uses electric signal [i]s.... 

  • Electrical telegraph Electrical telegraph

    The electrical telegraph is a telegraph [i] that uses electric signal [i]s.... 

  • Morse code Morse code

    Morse code is a method for transmitting information, using standardized sequences of short and long mark... 

  • Samuel Morse Samuel F. B. Morse

    Samuel Finley Breese Morse was an American [i], inventor [i] of the Morse Code [i] and painter [i] ... 

  • Telegraph code
  • Broadband
  • Baudot Baudot code

    The Baudot code, named after its inventor [i] mile Baudot [i], is a character set [i] ... 

  • Baron Schilling
  • The Daily Telegraph The Daily Telegraph

    The Daily Telegraph was founded in 1855 [i], and is one of only two remaining daily British [i] ... 

    , the London newspaper
  • John H. Emerick
  • Clacks, a fictional, semaphore-based, communications system used in Terry Pratchett Terry Pratchett

    Terence David John Pratchett OBE [i] is an English fantasy author [i], best ... 

    's Discworld Discworld

    Discworld is a series [i] of thirty-four fantasy novels, a number of short stories, and ... 



External articles and references

;Citations

;Further reading
  • Jeffrey L. Kieve — The Electric Telegraph: a Social and Economic History David and Charles ISBN 0-7153-5883-9
  • Tom Standage — The Victorian Internet Berkley Trade, ISBN 0-425-17169-8


;Websites
  • J. Munro, "".






;Archives
  • Archives Center, National Museum of American History, Smithsonian Institution.
  • Archives Center, National Museum of American History, Smithsonian Institution.


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