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A semaphore telegraph is a system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the mechanical elements; it is read when the shutter is in a fixed position. The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries.[1][2][3] Lines of relay towers with a semaphore rig at the top were built within line-of-sight of each other, at separations of 5 to 20 miles. Operators at each tower would watch the neighboring tower through a spyglass, and when the semaphore arms began to move spelling out a message. they would pass the message on to the next tower. This system was much faster than post riders for conveying a message over long distances, and also had cheaper long-term operating costs, once constructed. Semaphore lines were a precursor of the electrical telegraph, which would replace them half a century later, and would also be cheaper, faster, and more private. The line-of-sight distance between relay stations was limited by geography and weather, and prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. Modern derivatives of the semaphore system include flag semaphore (a flag relay system) and the heliograph (optical telegraphy using mirror-directed sunlight reflections).

Contents

1 Etymology and terminology 2 History

2.1 Early designs 2.2 Chappe system

2.2.1 Development 2.2.2 Technical operation

2.3 Other systems

3 Use in various countries

3.1 France 3.2 Sweden 3.3 United Kingdom 3.4 Other countries

4 In popular culture 5 See also 6 References 7 Further reading 8 External links

Etymology and terminology[edit] The word semaphore was coined in 1801 by the French inventor of the semaphore line itself, Claude Chappe.[4] He composed it from the Greek elements σῆμα (sêma, "sign"); and from φορός (phorós, "carrying"),[5] or φορά (phorá, "a carrying") from φέρειν (phérein, "to bear").[6] Chappe also coined the word telegraph. The word semaphoric was first printed in English in 1808: "The newly constructed Semaphoric telegraphs", referring to the destruction of telegraphs in France.[7] The word semaphore was first printed in English in 1816: "The improved Semaphore has been erected on the top of the Admiralty", referring to the installation of a simpler telegraph invented by Sir Home Popham.[citation needed] Semaphore telegraphs are also called "optical telegraphs", "shutter telegraph chains", "Chappe telegraphs" or "Napoleonic semaphore". History[edit]

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Early designs[edit]

Illustration showing Robert Hooke's proposed system. At top are various symbols that might be used; ABCE indicates the frame, and D the screen behind which each of the symbols are hidden when not in use.

Optical telegraphy dates from ancient times, in the form of hydraulic telegraphs, torches (as used by ancient cultures since the discovery of fire) and smoke signals. Modern design of semaphores was first foreseen by the British polymath Robert Hooke, who gave a vivid and comprehensive outline of visual telegraphy to the Royal Society
Royal Society
in a 1684 submission in which he outlined many practical details. The system (which was motivated by military concerns, following the recent Battle of Vienna
Battle of Vienna
in 1683) was never put into practice.[8][9]

Sir Richard Lovell Edgeworth's proposed optical telegraph for use in Ireland. The rotational position of each one of the four indicaters represented a number 1-7 (0 being "rest"), forming a four-digit number. The number stood for a particular word in a codebook.

One of the first experiments of optical signalling was carried out by the Anglo-Irish landowner and inventor, Sir Richard Lovell Edgeworth in 1767.[10] He placed a bet with his friend, the horse racing gambler Lord Marsh, that he could transmit knowledge of the outcome of the race in just one hour. Using a network of signalling sections erected on high ground, the signal would be observed from one station to the next by means of a telescope.[11] The signal itself consisted of a large pointer that could be placed into eight possible positions in 45 degree increments. A series of two such signals gave a total 64 code elements and a third signal took it up to 512. He returned to his idea in 1795, after hearing of Chappe's system. Chappe system[edit]

Demonstration of the semaphore

Credit for the first successful optical telegraph goes to the French engineer Claude Chappe
Claude Chappe
and his brothers in 1792, who succeeded in covering France
France
with a network of 556 stations stretching a total distance of 4,800 kilometres (3,000 mi). Le système Chappe was used for military and national communications until the 1850s. Development[edit] During 1790–1795, at the height of the French Revolution, France needed a swift and reliable communication system to thwart the war efforts of its enemies. France
France
was surrounded by the forces of Britain, the Netherlands, Prussia, Austria, and Spain, the cities of Marseille
Marseille
and Lyon
Lyon
were in revolt, and the British Fleet held Toulon. The only advantage France
France
held was the lack of cooperation between the allied forces due to their inadequate lines of communication. In the summer of 1790, the Chappe brothers set about devising a system of communication that would allow the central government to receive intelligence and to transmit orders in the shortest possible time. On 2 March 1791 at 11am, they sent the message “si vous réussissez, vous serez bientôt couverts de gloire” (If you succeed, you will soon bask in glory) between Brulon and Parce, a distance of 16 kilometres (9.9 mi). The first means used a combination of black and white panels, clocks, telescopes, and codebooks to send their message. The Chappes carried out experiments during the next two years, and on two occasions their apparatus at Place de l'Étoile, Paris
Paris
was destroyed by mobs who thought they were communicating with royalist forces. However, in the summer of 1792 Claude was appointed Ingénieur-Télégraphiste and charged with establishing a line of stations between Paris
Paris
and Lille, a distance of 230 kilometres (about 143 miles). It was used to carry dispatches for the war between France and Austria. In 1794, it brought news of a French capture of Condé-sur-l'Escaut
Condé-sur-l'Escaut
from the Austrians less than an hour after it occurred.[12] The first symbol of a message to Lille
Lille
would pass through 15 stations in only nine minutes. The speed of the line varied with the weather, but the line to Lille
Lille
typically transferred 36 symbols, a complete message, in about 32 minutes. Another line of 50 stations was completed in 1798, covering 488 km between Paris
Paris
and Strasbourg.[13] Technical operation[edit]

Diagram showing the Chappe system, as used simply for signalling letters and numbers (though it could also be used in an encoded form)

The Chappe brothers determined by experiment that it was easier to see the angle of a rod than to see the presence or absence of a panel. Their semaphore was composed of two black movable wooden arms, connected by a cross bar; the positions of all three of these components together indicated an alphabetic letter. With counterweights (named forks) on the arms, the Chappe system was controlled by only two handles and was mechanically simple and reasonably robust. Each of the two 2-metre-long arms could display seven positions, and the 4.6-metre-long cross bar connecting the two arms could display four different angles, for a total of 196 symbols (7×7×4). Night operation with lamps on the arms was unsuccessful. To speed up transmission and to provide some semblance of security, a code book was developed for use with semaphore lines. The Chappes' corporation used a code that took 92 of the basic symbols two at a time to yield 8,464 coded words and phrases. The revised Chappe system of 1795 provided not only a set of codes but also an operational protocol intended to maximize line throughput. Symbols were transmitted in cycles of "2 steps and 3 movements."

Step 1, movement 1 (setup): The indicator arms were turned to align with the cross bar, forming a non-symbol. The crossbar was then moved into position for the current symbol. Step 1, movement 2 (transmission): The indicator arms were positioned for the current symbol. The operator then waited for the downline station to copy it. Step 2, movement 3 (completion): The cross bar was turned to a vertical or horizontal position, indicating the end of a cycle.

In this manner, each symbol could propagate down the line as quickly as operators could successfully copy it, with acknowledgement and flow control built into the protocol. A rate of 2-3 symbols per minute was typical.[14][15] Other systems[edit] From 1803 on, the French also used the 3-arm Depillon semaphore at coastal locations to provide warning of British incursions.[1] Many national services adopted signaling systems different from the Chappe system. For example, the UK and Sweden
Sweden
adopted systems of shuttered panels (in contradiction to the Chappe brothers' contention that angled rods are more visible). In Spain, the engineer Agustín de Betancourt developed his own system which was adopted by that state. This system was considered by many experts in Europe better than Chappe's, even in France. Use in various countries[edit] France[edit]

The Chappe Network in France

After Chappe's initial line (between Paris
Paris
and Lille), the Paris
Paris
to Strasbourg
Strasbourg
with 50 stations followed soon after (1798). By 1824, the Chappe brothers were promoting the semaphore lines for commercial use, especially to transmit the costs of commodities. Napoleon Bonaparte saw the military advantage in being able to transmit information between locations, and carried a portable semaphore with his headquarters. This allowed him to coordinate forces and logistics over longer distances than any other army of his time. However, because stations had to be within sight of each other, and because the efficient operation of the network required well trained and disciplined operators, the costs of administration and wages were a continuous source of financial difficulties. Only when[when?] the system was funded by the proceeds of its own lottery did costs come under control.[clarification needed][citation needed]

A Chappe semaphore tower near Saverne, France

In 1821 Norwich Duff, a young British Naval officer, visiting Clermont-en-Argonne, walked up to the telegraph station there and engaged the signalman in conversation. Here is his note of the man's information:

The pay is twenty five sous per day and he [the signalman] is obliged to be there from day light till dark, at present from half past three till half past eight; there are only two of them and for every minute a signal is left without being answered they pay five sous: this is a part of the branch which communicates with Strasburg and a message arrives there from Paris
Paris
in six minutes it is here in four.

The network was reserved for government use but in 1834 two bankers, François and Joseph Blanc, devised a way to subvert it to their own ends.[16] Sweden[edit]

A replica of an optical telegraph in Stockholm, Sweden

At the same time as Chappe, the Swedish inventor Abraham Niclas Edelcrantz experimented with the optical telegraph in Sweden. In 1794 he inaugurated his telegraph with a poem dedicated to the Swedish King on his birthday. The message went from the Palace in Stockholm
Stockholm
to the King at Drottningholm. Edelcrantz eventually developed his own system which was quite different from its French counterpart and nearly twice as fast. The system was based on ten collapsible iron shutters. The various positions of the shutters formed combinations of numbers which were translated into letters, words or phrases via codebooks. The telegraph network consisted of telegraph stations positioned at about 10 kilometres (6.2 mi) from one another. Soon telegraph circuits linking castles and fortresses in the neighbourhood of Stockholm
Stockholm
were set up and the system was extended to Grisslehamn and Åland. Subsequently, telegraph circuits were introduced between Gothenburg and Marstrand, at Helsingborg and between Karlskrona
Karlskrona
and its fortresses. Sweden
Sweden
was the second country in the world, after France, to introduce an optical telegraph network. The Swedish optical telegraph network was restricted to the archipelagoes of Stockholm, Gothenburg
Gothenburg
and Karlskrona. Like its French counterpart, it was mainly used for military purposes.[citation needed] United Kingdom[edit]

Diagram of UK Murray six-shutter system, with shutter 6 in the horizontal position, and shutters 1-5 vertical

In Ireland, Richard Lovell Edgeworth
Richard Lovell Edgeworth
returned to his earlier work in 1794, and proposed a telegraph there to warn against an anticipated French invasion; however, the proposal was not implemented. Lord George Murray, stimulated by reports of the Chappe semaphore, proposed a system of visual telegraphy to the British Admiralty
British Admiralty
in 1795.[3] He employed rectangular framework towers with six, five feet high octagonal shutters on horizontal axes that flipped between horizontal and vertical positions to signal. [17] The Rev. Mr Gamble also proposed two distinct five-element systems in 1795: one using five shutters, and one using five ten foot poles.[3] The British Admiralty accepted Murray's system in September 1795, and the first system was the 15 site chain from London
London
to Deal.[18] Messages passed from London to Deal in about sixty seconds, and sixty-five sites were in use by 1808.[18]

St. Albans
St. Albans
High Street in 1807, showing the shutter telegraph on top of the city's Clock Tower. It was on the London
London
to Great Yarmouth line[19]

Chains of Murray's shutter telegraph stations were built along the following routes: London—Deal and Sheerness, London—Great Yarmouth and London— Portsmouth
Portsmouth
and Plymouth.[19] The shutter stations were temporary wooden huts, and at the conclusion of the Napoleonic wars they were no longer necessary, and were closed down by the Admiralty in March 1816.[20] A replacement system was sought, and of the many ideas and devices put forward the Admiralty chose the simpler semaphore system invented by Sir Home Popham.[2][3] A Popham semaphore was a single fixed vertical 30 foot pole, with two movable 8 foot arms attached to the pole by horizontal pivots at their ends, one arm at the top of the pole, and the other arm at the middle of the pole.[1][2] The signals of the Popham semaphore were found to be much more visible than those of the Murray semaphore.[1] Popham's 2-arm semaphore was modeled after the 3-arm Depillon French semaphore.[1] An experimental semaphore line between the Admiralty and Chatham was installed in July 1816, and its success helped to confirm the choice.[20] Subsequently, the Admiralty decided to establish a permanent link to Portsmouth
Portsmouth
and built a chain of semaphore stations. Work started in December 1820[20] and the line was operational from 1822 until 1847, when the railway and electric telegraph provided a better means of communication. The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations - Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort
Lumps Fort
(Southsea), and Portsmouth
Portsmouth
Dockyard. The semaphore tower at Chatley Heath, which replaced the Netley Heath station of the shutter telegraph, has been restored by Surrey
Surrey
County Council and is open to the public. The Board of Port of Liverpool
Port of Liverpool
obtained a Private Act of Parliament
Private Act of Parliament
to construct a chain of Popham optical semaphore stations from Liverpool— Holyhead
Holyhead
in 1825.[21] A semaphore-based successor for the London
London
to Plymouth
Plymouth
shutter telegraph chain, branching much closer to London, at Chatley Heath
Chatley Heath
in Surrey, was started but abandoned before completion. Many of the prominences on which the towers were built (telegraph hills) are known as ' Telegraph
Telegraph
Hill' to this day. As in France
France
the network required lavish amounts of money and manpower to operate and could only be justified as a defence need. Other countries[edit]

Optical telegraph
Optical telegraph
in the harbour of Bremerhaven, Germany

Former optical telegraph tower on the Winter Palace
Winter Palace
in Saint Petersburg, Russia

Once it had proved its success, the optical telegraph was imitated in many other countries, especially after it was used by Napoleon to coordinate his empire and army. In most of these countries, the postal authorities operated the semaphore lines. In Portugal, the British forces fighting Napoleon in Portugal
Portugal
soon found that the Portuguese Army had already a very capable semaphore terrestrial system working since 1806, giving the Duke of Wellington
Duke of Wellington
a decisive advantage in intelligence. The innovative Portuguese telegraphs, designed by Francisco Ciera, a mathematician, were of 3 types: 3 shutters, 3 balls and 1 pointer/moveable arm (the first for longer distances, the other two for short) and with the advantage of all having only 6 significant positions. He also wrote the code book "Táboas Telegráphicas", with 1554 entries from 1 to 6666 (1 to 6, 11 to 16,... 61 to 66, 111 to 116,... etc.), the same for the 3 systems. Since early 1810 the network was operated by "Corpo Telegráfico", the first Portuguese military Signal Corps. In Canada, Prince Edward, Duke of Kent established the first semaphore line in North America. In operation by 1800, it ran between the city of Halifax and the town of Annapolis in Nova Scotia, and across the Bay of Fundy
Bay of Fundy
to Saint John and Fredericton
Fredericton
in New Brunswick. In addition to providing information on approaching ships, the Duke used the system to relay military commands, especially as they related to troop discipline. The Duke had envisioned the line reaching as far as the British garrison at Quebec City; however, the many hills and coastal fog meant the towers needed to be placed relatively close together to ensure visibility. The required labour to build and continually man so many stations taxed the already stretched-thin British military and there is doubt the New Brunswick
New Brunswick
line was ever in operation. With the exception of the towers around Halifax harbour, the system was abandoned shortly after the Duke's departure in August 1800.[22][23]

The Semaphore Tower at Khatirbazar, Andul in Howrah district of West Bengal.

In 1801, the Danish post office installed a semaphore line across the Great Belt
Great Belt
strait, Storebæltstelegrafen, between islands Funen
Funen
and Zealand
Zealand
with stations at Nyborg
Nyborg
on Funen, on the small island Sprogø in the middle of the strait, and at Korsør
Korsør
on Zealand. It was in use until 1865.[24] The Kingdom of Prussia
Prussia
began with a line 750 kilometres (470 mi) long between Berlin
Berlin
and Coblenz
Coblenz
in 1833, and in Russia, Tsar Nicolas I inaugurated a line between Moscow
Moscow
and Warsaw
Warsaw
of 1,200 kilometres (750 mi) length in 1833; it needed 220 stations manned by 1,320 operators.

Ta' Kenuna Tower, a semaphore tower in Nadur, Gozo, Malta, built by the British in 1848

The British military authorities began to consider installing a semaphore line in Malta
Malta
in the early 1840s. Initially, it was planned that semaphore stations be established on the bell towers and domes of the island's churches, but the religious authorities rejected the proposal. Due to this, in 1848 new semaphore towers were constructed at Għargħur and Għaxaq on the main island, and another was built at Ta' Kenuna on Gozo. Further stations were established at the Governor's Palace, Selmun Palace
Selmun Palace
and the Giordan Lighthouse. Each station was manned by the Royal Engineers.[25] In the United States
United States
the first optical telegraph was built by Jonathan Grout. It was a 104 kilometres (65 mi) line connecting Martha's Vineyard with Boston, and its purpose was to transmit news about shipping. One of the principal hills in San Francisco, California
California
is also named " Telegraph
Telegraph
Hill", after the semaphore telegraph which was established there in 1849 to signal the arrival of ships into San Francisco Bay. The semaphores were successful enough that Samuel Morse failed to sell the electrical telegraph to the French government; however, France
France
finally committed to replace semaphores with electric telegraphs in 1846. Electric telegraphs are both more private and almost completely unaffected by weather; they also work at night. Many contemporaries predicted the failure of electric telegraphs because "they are so easy to cut."[26] The last stationary semaphore link in regular service was in Sweden, connecting an island with a mainland telegraph line. It went out of service in 1880. In popular culture[edit]

A cartoon strip of "Monsieur Pencil" (1831) by Rodolphe Töpffer

The Chappe telegraph appeared in contemporary fiction and comic strips. In "Mister Pencil" (1831), comic strip by Rodolphe Töpffer, a dog fallen on a Chappe telegraph's arm and its master attempting to help provoke an international crisis by involuntarily transmitting disturbing messages. In "Lucien Leuwen" (1834), Stendhal
Stendhal
pictures a power struggle between Lucien Leuwen
Lucien Leuwen
and the prefect M. de Séranville with the telegraph's director M. Lamorte. In Chapter 60 ("The Telegraph") of Alexandre Dumas' The Count of Monte Cristo
The Count of Monte Cristo
(1844), the title character describes with fascination the semaphore line's moving arms. "I had at times seen rise at the end of a road, on a hillock and in the bright light of the sun, these black folding arms looking like the legs of an immense beetle."[27] He later bribes a semaphore operator to relay a false message in order to manipulate the French financial market. Dumas also describes in details the functioning of a Chappe telegraph line. In Hector Malot's novel Romain Kalbris (1869), one of the characters—a girl named Dielette, describes her home in Paris
Paris
as "...next to a church near which there was a clock tower. On top of the tower there were two large black arms, moving all day this way and that. [I was told later] that this was Saint-Eustache church and that these large black arms were a telegraph."[28] The system was referenced in later works such as C. S. Forester's Hornblower and the Hotspur (1962), where the destruction of a French semaphore tower and a shore battery is a key plot point. A similar event is also the focus of the seventh episode of the television series. Interference with the French semaphore system is also an important plot element in Ramage's Signal by Dudley Pope. In the young adult fiction book Death Cloud
Death Cloud
by Andy Lane (2010), Mycroft Holmes
Mycroft Holmes
tells 14-year-old Sherlock Holmes about semaphore stations, commenting about his school beforehand, saying "All the Latin a boy can cram into his skull, but nothing of practical use." Fictional versions of the telegraph also appear in literature. In the alternative history novel, Lest Darkness Fall (1939), by L. Sprague de Camp, the protagonist, a twentieth century man who time travels into Dark Age
Dark Age
Rome, develops a semaphore system to warn of invasion. To make it practical, he also invents the telescope. Pavane (1968), an alternate history novel by Keith Roberts, features a society where long distance communication is by a network of semaphores operated by the powerful Guild of Signallers. Terry Pratchett's Discworld
Discworld
novels (from The Fifth Elephant, 1999, onwards) describe a system of eight-shutter semaphore towers, known as Clacks, which occupy a similar role to that of the Internet. Using advanced clack coding, it is possible not only to send very fast telegrams, but also to encode pictures and send them long-distance, and shopping and banking via the clacks is also mentioned. In David Weber's Safehold
Safehold
series (2007), a worldwide semaphore system is used by the Church to help them maintain their dominion over the world. In Alastair Reynolds' Terminal World (2010), the distant-future terrain is criss-crossed with semaphore lines relaying information between the one remaining city, Spearpoint, outlying communities and the airborne community Swarm. See also[edit]

History of telecommunication Optical communication Railway signalling Semaphore Flag Signaling System Signal lamp Telegraph
Telegraph
Hill, for a list of telegraph hills

References[edit]

Citations

^ a b c d e Chapter 2: Semaphore Signalling ISBN 978-0-86341-327-8 Communications: an international history of the formative years R. W. Burns, 2004 ^ a b c Telegraph
Telegraph
Vol 10, Encyclopædia Britannica, 6th Edition, 1824 pp. 645–651 ^ a b c d Telegraph, Volume 17 of The Edinburgh Encyclopaedia, pp. 664–667, 1832 David Brewster, ed. ^ Groundbreaking Scientific Experiments, Inventions & Discoveries of the 18th Century, Jonathan Shectman, p. 172 ^ Oxford English Dictionary. ^ Webster's Unabridged Dictionary. ^ 500 Years of New Words, Bill Sherk ^ "The Origin of the Railway Semaphore". Mysite.du.edu. Retrieved 2013-06-17.  ^ "History of the Telephone part2". Ilt.columbia.edu. Retrieved 2013-06-17.  ^ Rees, Abraham, ed. (1802–1820). "Telegraph". Cyclopædia. 35. London: Longman, Hurst, Rees, Orme & Brown. Unpaginated work: pages 9-11 of the article entry.  ^ Burns, Francis W. (2004). Communications: An International History of the Formative Years. IET. Retrieved 2013-02-07.  ^ How Napoleon's semaphore telegraph changed the world, BBC News, Hugh Schofield, 16 June 2013 ^ http://www.ieeeghn.org/wiki/images/1/17/Dilhac.pdf ^ Holzmann, Gerard J.; Pehrson, Bjorn (2003). The Early History of Data Networks.  ^ https://web.archive.org/web/20140202183712/http://chappe.ec-lyon.fr/message.html ^ https://www.inc.com/magazine/19990915/13554.html ^ Lieutenant Watson's Telegraph
Telegraph
Mechanics' magazine, Volume 8 No. 222, Knight and Lacey, 1828, pages 294-299 ^ a b F.B. Wrixon (2005), ISBN 978-1-57912-485-4 Codes, Ciphers, Secrets and Cryptic Communication pp. 444-445 cover Murray's shutter telegraph in the U.K., with codes. ^ a b [1] ^ a b c Military Signals from the South Coast, John Goodwin, 2000 ^ Faster Than The Wind, The Liverpool
Liverpool
to Holyhead
Holyhead
Telegraph, Frank Large, an avid publication ISBN 0-9521020-9-9 ^ Raddall, Thomas H. (1971), Warden of the North, Toronto, Canada: McClelland and Stewart Limited  ^ Rens, Jean-Guy (2001), The invisible empire: A history of the telecommunications industry in Canada, Montreal, Canada: McGill-Queen's University Press  ^ The Age of Invention 1849–1920, Post & Tele Museum Danmark, website visited on May 8, 2010. ^ "Semaphore Tower". Għargħur Local Council. Archived from the original on 4 March 2016.  ^ Holzmann, Gerard. "Data Communications: The First 2,500 Years" (PDF). Retrieved 28 June 2011.  ^ Page 84 in ^ See second paragraph in

Bibliography

Crowley, David and Heyer, Paul (ed) (2003) 'Chapter 17: The optical telegraph' Communication in History: Technology, Culture and Society (Fourth Edition) Allyn and Bacon, Boston
Boston
pp. 123–125

Further reading[edit]

The Victorian Internet, Tom Standage, Walker & Company, 1998, ISBN 0-8027-1342-4 The Old Telegraphs, Geoffrey Wilson, Phillimore & Co Ltd 1976 ISBN 0-900592-79-6 Faster Than The Wind, The Liverpool
Liverpool
to Holyhead
Holyhead
Telegraph, Frank Large, an avid publication ISBN 0-9521020-9-9 The early history of data networks, Gerard Holzmann and Bjorn Pehrson, Wiley Publ., 2003, ISBN 0-8186-6782-6 Semaphore Signaling, Chapter 2 of: Communications: an international history of the formative years, R.W. Burns, Institution of Electrical Engineers, 2004 ISBN 978-0-86341-327-8

External links[edit]

Chappe's semaphore (an illustrated history of optical telegraphy) Webpage including a map of England's telegraph chains Diagrams and maps of Murray's U.K. semaphore stations Chart of Murray's shutter-semaphore code Photo and diagrams of Popham's U.K. semaphore stations Map of visual telegraph (semaphore) and electrical telegraph lines in Italy, 1860 (in Italian) Details on the history of the Blanc brothers fraudulant use of the Semophore line

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Luo Lycian Lydian Manchu Mandaic Medefaidrin Molodtsov Mongolian Mru Neo-Tifinagh New Tai Lue N'Ko Ogham Oirat Ol Chiki Old Hungarian Old Italic Old Permic Orkhon Old Uyghur Osage Osmanya Pau Cin Hau Runic

Anglo-Saxon Cipher Dalecarlian Elder Futhark Younger Futhark Gothic Marcomannic Medieval Staveless

Sidetic Shavian Somali Tifinagh Vagindra Visible Speech Vithkuqi Wancho Zaghawa

Non-linear

Braille Maritime flags Morse code New York Point Semaphore line Flag semaphore Moon type

Ideograms/Pictograms

Adinkra Aztec Blissymbol Dongba Ersu Shaba Emoji IConji Isotype Kaidā Míkmaq Mixtec New Epoch Notation Painting Nsibidi Ojibwe Hieroglyphs Siglas poveiras Testerian Yerkish Zapotec

Logograms

Chinese family of scripts

Chinese Characters

Simplified Traditional Oracle bone script Bronze Script Seal Script

large small bird-worm

Hanja Idu Kanji Chữ nôm Zhuang

Chinese-influenced

Jurchen Khitan large script Sui Tangut

Cuneiform

Akkadian Assyrian Elamite Hittite Luwian Sumerian

Other logo-syllabic

Anatolian Bagam Cretan Isthmian Maya Proto-Elamite Yi (Classical)

Logo-consonantal

Demotic Hieratic Hieroglyphs

Numerals

Hindu-Arabic Abjad Attic (Greek) Muisca Roman

Semi-syllabaries

Full

Celtiberian Northeastern Iberian Southeastern Iberian Khom

Redundant

Espanca Pahawh Hmong Khitan small script Southwest Paleohispanic Zhuyin fuhao

Somacheirograms

ASLwrite SignWriting si5s Stokoe Notation

Syllabaries

Afaka Bamum Bété Byblos Cherokee Cypriot Cypro-Minoan Ditema tsa Dinoko Eskayan Geba Great Lakes Algonquian syllabics Iban Japanese

Hiragana Katakana Man'yōgana Hentaigana Sogana Jindai moji

Kikakui Kpelle Linear B Linear Elamite Lisu Loma Nüshu Nwagu Aneke script Old Persian Cuneiform Vai Woleai Yi (Modern) Yugtun

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Braille
Braille
 ⠃⠗⠁⠊⠇⠇⠑

Braille
Braille
cell

1829 braille International uniformity ASCII braille Unicode
Unicode
braille patterns

Braille
Braille
scripts

French-ordered scripts (see for more)

Albanian Amharic Arabic Armenian Azerbaijani Belarusian Bharati

Devanagari
Devanagari
(Hindi  / Marathi  / Nepali) Bengali Punjabi Sinhalese Tamil Urdu etc.

Bulgarian Burmese Cambodian Cantonese Catalan Chinese (Mandarin, mainland) Czech Dutch Dzongkha (Bhutanese) English (Unified English) Esperanto Estonian Faroese French Georgian German Ghanaian Greek Guarani Hawaiian Hebrew Hungarian Icelandic Inuktitut (reassigned vowels) Iñupiaq IPA Irish Italian Kazakh Kyrgyz Latvian Lithuanian Maltese Mongolian Māori Navajo Nigerian Northern Sami Persian Philippine Polish Portuguese Romanian Russian Samoan Scandinavian Slovak South African Spanish Tatar Taiwanese Mandarin (largely reassigned) Thai & Lao (Japanese vowels) Tibetan Turkish Ukrainian Vietnamese Welsh Yugoslav

Reordered scripts

Algerian Braille
Braille
(obsolete)

Frequency-based scripts

American Braille
Braille
(obsolete)

Independent scripts

Japanese Korean Two-Cell Chinese

Eight-dot scripts

Luxembourgish Kanji Gardner–Salinas braille codes (GS8)

Symbols in braille

Braille
Braille
music Canadian currency marks Computer Braille
Braille
Code Gardner–Salinas braille codes (GS8/GS6) International Phonetic Alphabet
Alphabet
(IPA) Nemeth braille code

Braille
Braille
technology

Braille
Braille
e-book Braille
Braille
embosser Braille
Braille
translator Braille
Braille
watch Mountbatten Brailler Optical braille recognition Perforation Perkins Brailler Refreshable braille display Slate and stylus Braigo

Persons

Louis Braille Charles Barbier Valentin Haüy Thakur Vishva Narain Singh Sabriye Tenberken William Bell Wait

Organisations

Braille
Braille
Institute of America Braille
Braille
Without Borders Japan Braille
Braille
Library National Braille
Braille
Association Blindness organizations Schools for the blind American Printing House for the Blind

Other tactile alphabets

Decapoint Moon type New York Point Night writing Vibratese

Related topics

Accessible publishing Braille
Braille
literacy RoboBraille

v t e

Electronic writing systems

Emoticons Emoji iConji Leet Unicode

v t e

Internet
Internet
slang dialects

3arabizi Alay (Indonesia) Denglisch Doge Fingilish (Persian) Greeklish Gyaru-moji (Japan) Jejemon (Philippines) Leet
Leet
("1337") Lolspeak / LOLspeak / Kitteh Martian language (Chinese) Miguxês (Portuguese) Padonkaffsky jargon
Padonkaffsky jargon
(Russian) Translit Volapuk

See also English internet slang (at Wiktionary) SMS language

v t e

Telecommunications

History

Beacon Broadcasting Cable protection system Cable TV Communications satellite Computer network Drums Electrical telegraph Fax Heliographs Hydraulic telegraph Internet Mass media Mobile phone Optical telecommunication Optical telegraphy Pager Photophone Prepay mobile phone Radio Radiotelephone Satellite communications Semaphore Smartphone Smoke signals Telecommunications history Telautograph Telegraphy Teleprinter
Teleprinter
(teletype) Telephone The Telephone Cases Television Timeline of communication technology Undersea telegraph line Videoconferencing Videophone Videotelephony Whistled language

Pioneers

Edwin Howard Armstrong John Logie Baird Paul Baran Alexander Graham Bell Tim Berners-Lee Jagadish Chandra Bose Vint Cerf Claude Chappe Donald Davies Lee de Forest Philo Farnsworth Reginald Fessenden Elisha Gray Erna Schneider Hoover Charles K. Kao Hedy Lamarr Innocenzo Manzetti Guglielmo Marconi Antonio Meucci Radia Perlman Alexander Stepanovich Popov Johann Philipp Reis Nikola Tesla Camille Tissot Alfred Vail Charles Wheatstone Vladimir K. Zworykin

Transmission media

Coaxial cable Fiber-optic communication

Optical fiber

Free-space optical communication Molecular communication Radio waves Transmission line

Network topology and switching

Links Nodes Terminal node Network switching (circuit packet) Telephone exchange

Multiplexing

Space-division Frequency-division Time-division Polarization-division Orbital angular-momentum Code-division

Networks

ARPANET BITNET Cellular network Computer CYCLADES Ethernet FidoNet Internet ISDN LAN Mobile NGN NPL network Public Switched Telephone Radio Telecommunications equipment Television Telex WAN Wireless World Wide Web

.