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An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals. 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 invented in 1792 in France by
Claude Chappe Claude Chappe (; 25 December 1763 – 23 January 1805) was a French inventor who in 1792 demonstrated a practical semaphore system that eventually spanned all of France. His system consisted of a series of towers, each within line of sight of ...
, and was popular in the late eighteenth to early nineteenth centuries. This system is often referred to as ''semaphore'' without qualification. 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
telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...
, 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. Half a century later, semaphore lines were replaced by the
electrical telegraph Electrical telegraphs were point-to-point text messaging systems, 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 ...
, which was cheaper, faster, and more private. The line-of-sight distance between relay stations was limited by
geography Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, an ...
and weather, and prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. A modern derivative of the semaphore system is flag semaphore, signalling with hand-held flags.


Etymology and terminology

The word ''semaphore'' was coined in 1801 by the French inventor of the semaphore line itself,
Claude Chappe Claude Chappe (; 25 December 1763 – 23 January 1805) was a French inventor who in 1792 demonstrated a practical semaphore system that eventually spanned all of France. His system consisted of a series of towers, each within line of sight of ...
. He composed it from the Greek elements σῆμα (sêma, "sign"); and from φορός (phorós, "carrying"), or φορά (phorá, "a carrying") from φέρειν (phérein, "to bear"). Chappe also coined the word ''tachygraph'', meaning "fast writer". However, the French Army preferred to call Chappe's semaphore system the ''telegraph'', meaning "far writer", which was coined by French statesman André François Miot de Mélito. The word ''semaphoric'' was first printed in English in 1808: "The newly constructed Semaphoric telegraphs (...) have been blown up", in a news report in
The Naval Chronicle The ''Naval Chronicle'' was a British periodical published monthly between January, 1799 and December, 1818 (Huntington). It contained information about the Royal Navy of the United Kingdom, including biographies, histories, news, and essays on ...
. The first use of the word ''semaphore'' in reference to English use was 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 Rear Admiral Sir Home Riggs Popham, KCB, KCH (12 October 1762 – 20 September 1820), was a Royal Navy commander who saw service against the French during the Revolutionary and Napoleonic Wars. He is remembered for his scientific accomplishme ...
. Semaphore telegraphs are also called, "Chappe telegraphs" or "Napoleonic semaphore".


Early designs

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 A polymath ( el, πολυμαθής, , "having learned much"; la, homo universalis, "universal human") is an individual whose knowledge spans a substantial number of subjects, known to draw on complex bodies of knowledge to solve specific pro ...
Robert Hooke, who gave a vivid and comprehensive outline of visual telegraphy to the
Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
in a 1684 submission in which he outlined many practical details. The system (which was motivated by military concerns, following the
Battle of Vienna The Battle of Vienna; pl, odsiecz wiedeńska, lit=Relief of Vienna or ''bitwa pod Wiedniem''; ota, Beç Ḳalʿası Muḥāṣarası, lit=siege of Beç; tr, İkinci Viyana Kuşatması, lit=second siege of Vienna took place at Kahlenberg Mo ...
in 1683) was never put into practice. One of the first experiments of optical signalling was carried out by the Anglo-Irish landowner and inventor, Sir Richard Lovell Edgeworth in 1767. He placed a bet with his friend, the
horse racing Horse racing is an equestrian performance sport, typically involving two or more horses ridden by jockeys (or sometimes driven without riders) over a set distance for competition. It is one of the most ancient of all sports, as its basic pr ...
gambler Lord March, 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 A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...
. 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.


Prevalence


France

Credit for the first successful optical telegraph goes to the French engineer
Claude Chappe Claude Chappe (; 25 December 1763 – 23 January 1805) was a French inventor who in 1792 demonstrated a practical semaphore system that eventually spanned all of France. His system consisted of a series of towers, each within line of sight of ...
and his brothers in 1792, who succeeded in covering France with a network of 556 stations stretching a total distance of . ''Le système Chappe'' was used for military and national communications until the 1850s.


Development in France

During 1790–1795, at the height of the
French Revolution The French Revolution ( ) was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in November 1799. Many of its ideas are conside ...
, France needed a swift and reliable
military communications Military communications or military signals involve all aspects of communications, or conveyance of information, by armed forces. Military communications span from pre-history to the present. The earliest military communications were delivered ...
system to thwart the war efforts of its enemies. France was surrounded by the forces of Britain, the Netherlands,
Prussia Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an e ...
, Austria, and Spain, the cities of
Marseille Marseille ( , , ; also spelled in English as Marseilles; oc, Marselha ) is the prefecture of the French department of Bouches-du-Rhône and capital of the Provence-Alpes-Côte d'Azur region. Situated in the camargue region of southern Fra ...
and
Lyon Lyon,, ; Occitan: ''Lion'', hist. ''Lionés'' also spelled in English as Lyons, is the third-largest city and second-largest metropolitan area of France. It is located at the confluence of the rivers Rhône and Saône, to the northwest of ...
were in revolt, and the
British Fleet The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Fr ...
held
Toulon Toulon (, , ; oc, label= Provençal, Tolon , , ) is a city on the French Riviera and a large port on the Mediterranean coast, with a major naval base. Located in the Provence-Alpes-Côte d'Azur region, and the Provence province, Toulon is th ...
. The only advantage France held was the lack of cooperation between the allied forces due to their inadequate lines of communication. In mid-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. Chappe considered many possible methods including audio and smoke. He even considered using electricity, but could not find insulation for the conductors that would withstand the high-voltage electrostatic sources available at the time. Chappe settled on an optical system and the first public demonstration occurred on 2 March 1791 between Brûlon and Parcé, a distance of . The system consisted of a modified pendulum clock at each end with dials marked with ten numerals. The hands of the clocks almost certainly moved much faster than a normal clock. The hands of both clocks were set in motion at the same time with a synchronisation signal. Further signals indicated the time at which the dial should be read. The numbers sent were then looked up in a
codebook A codebook is a type of document used for gathering and storing cryptography codes. Originally codebooks were often literally , but today codebook is a byword for the complete record of a series of codes, regardless of physical format. Cryptog ...
. In their preliminary experiments over a shorter distance, the Chappes had banged a pan for synchronisation. In the demonstration, they used black and white panels observed with a telescope. The message to be sent was chosen by town officials at Brûlon and sent by René Chappe to Claude Chappe at Parcé who had no pre-knowledge of the message. The message read "si vous réussissez, vous serez bientôt couverts de gloire" (If you succeed, you will soon bask in glory). It was only later that Chappe realised that he could dispense with the clocks and the synchronisation system itself could be used to pass messages. The Chappes carried out experiments during the next two years, and on two occasions their apparatus at Place de l'Étoile,
Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Si ...
was destroyed by mobs who thought they were communicating with
royalist A royalist supports a particular monarch as head of state for a particular kingdom, or of a particular dynastic claim. In the abstract, this position is royalism. It is distinct from monarchism, which advocates a monarchical system of gov ...
forces. Their cause was assisted by Ignace Chappe being elected to the Legislative Assembly. In the summer of 1792 Claude was appointed ''Ingénieur-Télégraphiste'' and charged with establishing a line of stations between Paris and
Lille Lille ( , ; nl, Rijsel ; pcd, Lile; vls, Rysel) is a city in the northern part of France, in French Flanders. On the river Deûle, near France's border with Belgium, it is the capital of the Hauts-de-France region, the prefecture of the No ...
, 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 from the Austrians less than an hour after it occurred. The first symbol of a message to Lille would pass through 15 stations in only nine minutes. The speed of the line varied with the weather, but the line to 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 and
Strasbourg Strasbourg (, , ; german: Straßburg ; gsw, label= Bas Rhin Alsatian, Strossburi , gsw, label= Haut Rhin Alsatian, Strossburig ) is the prefecture and largest city of the Grand Est region of eastern France and the official seat of the ...
. From 1803 on, the French also used the 3-arm Depillon semaphore at coastal locations to provide warning of British incursions.


Chappe system technical operation

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 In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communicati ...
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 operator turned the indicator arms to align with the cross bar, forming a non-symbol, and then turned the cross bar into position for the next symbol. * Step 1, movement 2 (transmission): The operator positioned the indicator arms for current symbol and waited for the downline station to copy it. * Step 2, movement 3 (completion): The operator turned the cross bar 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 symbol sent from Paris took 2 minutes to reach Lille through 22 stations and 9 minutes to reach Lyon through 50 stations. A rate of 2–3 symbols per minute was typical, with the higher figure being prone to errors. This corresponds to only 0.4–0.6 wpm, but with messages limited to those contained in the code book, this could be dramatically increased.


History in France

After Chappe's initial line (between Paris and Lille), the Paris to
Strasbourg Strasbourg (, , ; german: Straßburg ; gsw, label= Bas Rhin Alsatian, Strossburi , gsw, label= Haut Rhin Alsatian, Strossburig ) is the prefecture and largest city of the Grand Est region of eastern France and the official seat of the ...
with 50 stations followed soon after (1798).
Napoleon Bonaparte Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader wh ...
made full use of the telegraph by obtaining speedy information on enemy movements. In 1801 he had Abraham Chappe build an extra-large station to transmit across the English Channel in preparation for an invasion of Britain. A pair of such stations were built on a test line over a comparable distance. The line to
Calais Calais ( , , traditionally , ) is a port city in the Pas-de-Calais department, of which it is a subprefecture. Although Calais is by far the largest city in Pas-de-Calais, the department's prefecture is its third-largest city of Arras. Th ...
was extended to
Boulogne Boulogne-sur-Mer (; pcd, Boulonne-su-Mér; nl, Bonen; la, Gesoriacum or ''Bononia''), often called just Boulogne (, ), is a coastal city in Northern France. It is a sub-prefecture of the department of Pas-de-Calais. Boulogne lies on the C ...
in anticipation and a new design station was briefly in operation at Boulogne, but the invasion never happened. In 1812, Napoleon took up another design of Abraham Chappe for a mobile telegraph that could be taken with him on campaign. This was still in use in 1853 during the
Crimean War The Crimean War, , was fought from October 1853 to February 1856 between Russia and an ultimately victorious alliance of the Ottoman Empire, France, the United Kingdom and Piedmont-Sardinia. Geopolitical causes of the war included the ...
. The invention of the telegraph was followed by an enthusiasm concerning its potential to support
direct democracy Direct democracy or pure democracy is a form of democracy in which the electorate decides on policy initiatives without elected representatives as proxies. This differs from the majority of currently established democracies, which are repres ...
. For instance, based on Rousseau's argument that direct democracy was improbable in large constituencies, the French Intellectual Alexandre-Théophile Vandermonde commented: The operational costs of the telegraph in the year 1799/1800 were 434,000 francs ($1.2 million in 2015 in silver costsRodney Edvinsson
Historical Currency Converter, accessed 8 January 2021.
/ref>). In December 1800, Napoleon cut the budget of the telegraph system by 150,000 francs ($400,000 in 2015) leading to the Paris-Lyons line being temporarily closed. Chappe sought commercial uses of the system to make up the deficit, including use by industry, the financial sector, and newspapers. Only one proposal was immediately approved—the transmission of results from the state-run lottery. No non-government uses were approved. The lottery had been abused for years by fraudsters who knew the results, selling tickets in provincial towns after the announcement in Paris, but before the news had reached those towns. In 1819 Norwich Duff, a young British Naval officer, visiting
Clermont-en-Argonne Clermont-en-Argonne (, literally ''Clermont in Argonne''; formerly Clermont-sur-Meuse, literally ''Clermont on Meuse'') is a commune in the Meuse department in Grand Est in north-eastern France. The former towns of Auzéville-en-Argonne, Jubé ...
, walked up to the telegraph station there and engaged the signalman in conversation. Here is his note of the man's information: The network was reserved for government use, but an early case of wire fraud occurred in 1834 when two bankers, François and Joseph Blanc, bribed the operators at a station near
Tours Tours ( , ) is one of the largest cities in the region of Centre-Val de Loire, France. It is the prefecture of the department of Indre-et-Loire. The commune of Tours had 136,463 inhabitants as of 2018 while the population of the whole metro ...
on the line between Paris and
Bordeaux Bordeaux ( , ; Gascon oc, Bordèu ; eu, Bordele; it, Bordò; es, Burdeos) is a port city on the river Garonne in the Gironde department, Southwestern France. It is the capital of the Nouvelle-Aquitaine region, as well as the prefectu ...
to pass Paris stock exchange information to an accomplice in Bordeaux. It took three days for the information to travel the 300 mile distance, giving the schemers plenty of time to play the market. An accomplice at Paris would know whether the market was going up or down days before the information arrived in Bordeaux via the newspapers, after which Bordeaux was sure to follow. The message could not be inserted in the telegraph directly because it would have been detected. Instead, pre-arranged deliberate errors were introduced into existing messages which were visible to an observer at Bordeaux. Tours was chosen because it was a division station where messages were purged of errors by an inspector who was privy to the secret code used and unknown to the ordinary operators. The scheme would not work if the errors were inserted prior to Tours. The operators were told whether the market was going up or down by the colour of packages (either white or grey paper wrapping) sent by mail coach, or, according to another anecdote, if the wife of the Tours operator received a package of socks (down) or gloves (up) thus avoiding any evidence of misdeed being put in writing. The scheme operated for two years until it was discovered in 1836. The French optical system remained in use for many years after other countries had switched to the
electrical telegraph Electrical telegraphs were point-to-point text messaging systems, 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 ...
. Partly, this was due to inertia; France had the most extensive optical system and hence the most difficult to replace. But there were also arguments put forward for the superiority of the optical system. One of these was that the optical system is not so vulnerable to saboteurs as an electrical system with many miles of unguarded wire. Samuel Morse failed to sell the electrical telegraph to the French government. Eventually the advantages of the electrical telegraph of improved privacy, and all-weather and nighttime operation won out. A decision was made in 1846 to replace the optical telegraph with the Foy–Breguet electrical telegraph after a successful trial on the Rouen line. This system had a display which mimicked the look of the Chappe telegraph indicators to make it familiar to telegraph operators. Jules Guyot issued a dire warning of the consequences of what he considered to be a serious mistake. It took almost a decade before the optical telegraph was completely decommissioned. One of the last messages sent over the French semaphore was the report of the fall of Sebastopol in 1855.


Sweden

Sweden was the second country in the world, after France, to introduce an optical telegraph network.David Greene, ''Light and Dark: An Exploration in Science, Nature, Art and Technology'', p. 159, CRC Press, 2016 . Its network became the second most extensive after France. The central station of the network was at the Katarina Church in
Stockholm Stockholm () is the capital and largest city of Sweden as well as the largest urban area in Scandinavia. Approximately 980,000 people live in the municipality, with 1.6 million in the urban area, and 2.4 million in the metropo ...
. The system was faster than the French system, partly due to the Swedish control panelHolzmann & Pehrson, pp. 104–105 and partly to the ease of transcribing the octal code (the French system was recorded as
pictogram A pictogram, also called a pictogramme, pictograph, or simply picto, and in computer usage an icon, is a graphic symbol that conveys its meaning through its pictorial resemblance to a physical object. Pictographs are often used in writing and ...
s).Holzmann & Pehrson, p. 180 The system was used primarily for reporting the arrival of ships, but was also useful in wartime for observing enemy movements and attacks.Holzmann & Pehrson, p. 117 The last stationary semaphore link in regular service was in
Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...
, connecting an island with a mainland telegraph line. It went out of service in 1880.


Development in Sweden

Inspired by news of the Chappe telegraph, the Swedish inventor Abraham Niclas Edelcrantz experimented with the optical telegraph in Sweden. He constructed a three-station experimental line in 1794 running from the royal castle in Stockholm, via
Traneberg Traneberg is a residential district in western Stockholm ( Västerort) and part of the Bromma borough. For the 1912 Summer Olympics, Tranebergs Idrottsplats hosted some of the football Football is a family of team sports that involve, to v ...
, to the grounds of Drottningholm Castle, a distance of . The first demonstration was on 1 November, when Edelcrantz sent a poem dedicated to the king, Gustav IV Adolf, on his fourteenth birthday. On 7 November the king brought Edelcrantz into his Council of Advisers with a view to building a telegraph throughout Sweden, Denmark, and Finland.


Edelcrantz system technical operation

After some initial experiments with Chappe-style indicator arms, Edelcrantz settled on a design with ten iron shutters. Nine of these represented a 3-digit octal number and the tenth, when closed, meant the code number should be preceded by "A". This gave 1,024 codepoints which were decoded to letters, words or phrases via a codebook. The telegraph had a sophisticated control panel which allowed the next symbol to be prepared while waiting for the previous symbol to be repeated on the next station down the line. The control panel was connected by strings to the shutters. When ready to transmit, all the shutters were set at the same time with the press of a footpedal. The shutters were painted matte black to avoid reflection from sunlight and the frame and arms supporting the shutters were painted white or red for best contrast. Around 1809 Edelcrantz introduced an updated design. The frame around the shutters was dispensed with leaving a simpler, more visible, structure of just the arms with the indicator panels on the end of them. The "A" shutter was reduced to the same size as the other shutters and offset to one side to indicate which side was the most significant digit (whether the codepoint is read left-to-right or right-to-left is different for the two adjacent stations depending on which side they are on). This was previously indicated with a stationary indicator fixed to the side of the frame, but without a frame this was no longer possible. The distance that a station could transmit depended on the size of the shutters and the power of the telescope being used to observe them. The smallest object visible to the human eye is one that subtends an angle of 40 seconds of arc, but Edelcrantz used a figure of 4 minutes of arc to account for atmospheric disturbances and imperfections of the telescope. On that basis, and with a 32× telescope, Edelcrantz specified shutter sizes ranging from 9 inches () for a distance of half a
Swedish mile A Scandinavian mile ( Norwegian and sv, mil, [], like "meal") is a unit of length common in Norway and Sweden, but not Denmark. Today, it is standardised as 1 being , but it had different values in the past. The word is derived from the same ...
() to 54 inches () for 3 Swedish miles (). These figures were for the original design with square shutters. The open design of 1809 had long oblong shutters which Edelcrantz thought was more visible. Distances much further than these would require impractically high towers to overcome the curvature of the Earth as well as large shutters. Edelcrantz kept the distance between stations under 2 Swedish miles () except where large bodies of water made it unavoidable. The Swedish telegraph was capable of being used at night with lamps. On smaller stations lamps were placed behind the shutters so that they became visible when the shutter was opened. For larger stations, this was impractical. Instead, a separate tin box matrix with glass windows was installed below the daytime shutters. The lamps inside the tin box could be uncovered by pulling strings in the same way the daytime shutters were operated. Windows on both sides of the box allowed the lamps to be seen by both the upstream and downstream adjacent stations. The codepoints used at night were the complements of the codepoints used during the day. This made the pattern of lamps in open shutters at night the same as the pattern of closed shutters in daytime.


First network: 1795–1809

The first operational line, Stockholm to Vaxholm, went into service in January 1795. By 1797 there were also lines from Stockholm to Fredriksborg, and Grisslehamn via Signilsskär to Eckerö in
Åland Åland ( fi, Ahvenanmaa: ; ; ) is an autonomous and demilitarised region of Finland since 1920 by a decision of the League of Nations. It is the smallest region of Finland by area and population, with a size of 1,580 km2, and a populat ...
. A short line near Göteborg to Marstrand on the west coast was installed in 1799. During the War of the Second Coalition, Britain tried to enforce a blockade against France. Concerned at the effect on their own trade, Sweden joined the
Second League of Armed Neutrality The Second League of Armed Neutrality or the League of the North was an alliance of the north European naval powers Denmark–Norway, Prussia, Sweden, and Russia. It existed between 1800 and 1801 during the War of the Second Coalition and was ...
in 1800. Britain was expected to respond with an attack on one of the Nordic countries in the league. To help guard against such an attack, the king ordered a telegraph link joining the systems of Sweden and Denmark. This was the first international telegraph connection in the world. Edelcrantz made this link between Helsingborg in Sweden and Helsingør in Denmark, across the Öresund, the narrow strait separating the two countries. A new line along the coast from Kullaberg to
Malmö Malmö (, ; da, Malmø ) is the largest city in the Swedish county (län) of Scania (Skåne). It is the third-largest city in Sweden, after Stockholm and Gothenburg, and the sixth-largest city in the Nordic region, with a municipal popul ...
, incorporating the Helsingborg link, was planned in support and to provide signalling points to the Swedish fleet. Nelson's attack on the Danish fleet at
Copenhagen Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan a ...
in 1801 was reported over this link, but after Sweden failed to come to Denmark's aid it was not used again and only one station on the supporting line was ever built. In 1808 the Royal Telegraph Institution was created and Edelcrantz was made director. The Telegraph Institution was put under the jurisdiction of the military, initially as part of the Royal Engineering Corps.Holzmann & Pehrson, p. 120 A new code was introduced to replace the 1796 codebook with 5,120 possible codepoints with many new messages. The new codes included punishments for delinquent operators. These included an order to the operator to stand on one of the telegraph arms (code 001-721), and a message asking an adjacent station to confirm that they could see him do it (code 001-723). By 1809, the network had 50 stations over of line employing 172 people. In comparison, the French system in 1823 had of line and employed over three thousand people. In 1808, the Finnish War broke out when Russia seized Finland, then part of Sweden. Åland was attacked by Russia and the telegraph stations destroyed. The Russians were expelled in a revolt, but attacked again in 1809. The station at Signilsskär found itself behind enemy lines, but continued to signal the position of Russian troops to the retreating Swedes. After Sweden ceded Finland in the Treaty of Fredrikshamn, the east coast telegraph stations were considered superfluous and put into storage. In 1810, the plans for a south coast line were revived but were scrapped in 1811 due to financial considerations. Also in 1811, a new line from Stockholm via Arholma to Söderarm lighthouse was proposed, but also never materialised. For a while, the telegraph network in Sweden was almost non-existent, with only four
telegraphist A telegraphist (British English), telegrapher (American English), or telegraph operator is an operator who uses a telegraph key to send and receive the Morse code in order to communicate by land lines or radio. During the Great War the Royal ...
s employed by 1810.


Rebuilding the network

The post of Telegraph Inspector was created as early as 1811, but the telegraph in Sweden remained dormant until 1827 when new proposals were put forward. In 1834, the Telegraph Institution was moved to the Topographical Corps. The Corps head, Carl Fredrik Akrell, conducted comparisons of the Swedish shutter telegraph with more recent systems from other countries. Of particular interest was the semaphore system of Charles Pasley in England which had been on trial in Karlskrona. Tests were performed between Karlskrona and Drottningskär, and, in 1835, nighttime tests between Stockholm and Fredriksborg. Akrell concluded that the shutter telegraph was faster and easier to use, and was again adopted for fixed stations. However, Pasley's semaphore was cheaper and easier to construct, so was adopted for mobile stations. By 1836 the Swedish telegraph network had been fully restored. The network continued to expand. In 1837, the line to Vaxholm was extended to Furusund. In 1838 the Stockholm-
Dalarö Dalarö is a locality situated in Haninge Municipality, Stockholm County, Sweden with 1,199 inhabitants in 2010. It is situated south-east of Stockholm and is part of Metropolitan Stockholm and serves as a recreational summer spot for Stockholmer ...
-
Sandhamn Sandhamn ( Swedish for "Sand Harbour") is a small settlement in the central-peripheral part of the Stockholm Archipelago in central-eastern Sweden, approximately 50 km (30 mi) east of Stockholm. Sandhamn is located on the island San ...
line was extended to Landsort. The last addition came in 1854 when the Furusund line was extended to Arholma and Söderarm. The conversion to electrical telegraphy was slower and more difficult than in other countries. The many stretches of open ocean needing to be crossed on the Swedish archipelagos was a major obstacle. Akrell also raised similar concerns to those in France concerning potential sabotage and vandalism of electrical lines. Akrell first proposed an experimental electrical telegraph line in 1852. For many years the network consisted of a mix of optical and electrical lines. The last optical stations were not taken out of service until 1881, the last in operation in Europe. In some places, the heliograph replaced the optical telegraph rather than the electrical telegraph.}


United Kingdom

In Ireland, 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 The Admiralty was a department of the Government of the United Kingdom responsible for the command of the Royal Navy until 1964, historically under its titular head, the Lord High Admiral – one of the Great Officers of State. For much of i ...
in 1795. He employed rectangular framework towers with six five-foot-high octagonal shutters on horizontal axes that flipped between horizontal and vertical positions to signal.Lieutenant Watson's Telegraph
Mechanics' magazine, Volume 8 No. 222, Knight and Lacey, 1828, pages 294-299
The Rev. Mr Gamble also proposed two distinct five-element systems in 1795: one using five shutters, and one using five ten-foot poles. The British Admiralty accepted Murray's system in September 1795, and the first system was the 15 site chain from London to
Deal A deal, or deals may refer to: Places United States * Deal, New Jersey, a borough * Deal, Pennsylvania, an unincorporated community * Deal Lake, New Jersey Elsewhere * Deal Island (Tasmania), Australia * Deal, Kent, a town in England * Deal, a ...
.F.B. Wrixon (2005), Codes, Ciphers, Secrets and Cryptic Communication pp. 444-445 cover Murray's shutter telegraph in the U.K., with codes. Messages passed from London to Deal in about sixty seconds, and sixty-five sites were in use by 1808. Chains of Murray's shutter telegraph stations were built along the following routes:
London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
Deal A deal, or deals may refer to: Places United States * Deal, New Jersey, a borough * Deal, Pennsylvania, an unincorporated community * Deal Lake, New Jersey Elsewhere * Deal Island (Tasmania), Australia * Deal, Kent, a town in England * Deal, a ...
and
Sheerness Sheerness () is a town and civil parish beside the mouth of the River Medway on the north-west corner of the Isle of Sheppey in north Kent, England. With a population of 11,938, it is the second largest town on the island after the nearby tow ...
, London– Great Yarmouth, and London–
Portsmouth Portsmouth ( ) is a port and city in the ceremonial county of Hampshire in southern England. The city of Portsmouth has been a unitary authority since 1 April 1997 and is administered by Portsmouth City Council. Portsmouth is the most d ...
and
Plymouth Plymouth () is a port city status in the United Kingdom, city and unitary authority in South West England. It is located on the south coast of Devon, approximately south-west of Exeter and south-west of London. It is bordered by Cornwall to ...
. The line to Plymouth was not completed until 4 July 1806, and so could not be used to relay the news of Trafalgar. 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.Military Signals from the South Coast, John Goodwin, 2000 Following the Battle of Trafalgar, the news was transmitted to London by frigate to Falmouth, from where the captain took the dispatches to London by coach along what became known as the
Trafalgar Way The Trafalgar Way is the name given to the historic route used to carry dispatches with the news of the Battle of Trafalgar overland from Falmouth to the Admiralty in London. The first messenger in November 1805 was Lieutenant John Richards Lapeno ...
; the journey took 38 hours. This delay prompted the Admiralty to investigate further. A replacement semaphore system was sought, and of the many ideas and devices put forward the Admiralty chose the simpler semaphore system invented by
Sir Home Popham Rear Admiral Sir Home Riggs Popham, KCB, KCH (12 October 1762 – 20 September 1820), was a Royal Navy commander who saw service against the French during the Revolutionary and Napoleonic Wars. He is remembered for his scientific accomplishme ...
. 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. The signals of the Popham semaphore were found to be much more visible than those of the Murray shutter telegraph. Popham's 2-arm semaphore was modelled after the 3-arm Depillon French semaphore. An experimental semaphore line between the Admiralty and Chatham was installed in July 1816, and its success helped to confirm the choice. Subsequently, the Admiralty decided to establish a permanent link to Portsmouth and built a chain of semaphore stations. Work started in December 1820 with Popham's equipment replaced with another two-arm system invented by Charles Pasley. Each of the arms of Pasley's system could take on one of eight positions and it thus had more
codepoint In character encoding terminology, a code point, codepoint or code position is a numerical value that maps to a specific character. Code points usually represent a single grapheme—usually a letter, digit, punctuation mark, or whitespace—but ...
s than Popham's. In good conditions messages were sent from London to Portsmouth in less than eight minutes. 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 The Royal Hospital Chelsea is a retirement home and nursing home for some 300 veterans of the British Army. Founded as an almshouse, the ancient sense of the word "hospital", it is a site located on Royal Hospital Road in Chelsea. It is an in ...
,
Putney Heath Wimbledon Common is a large open space in Wimbledon, southwest London. There are three named areas: Wimbledon Common, Putney Heath, and Putney Lower Common, which together are managed under the name Wimbledon and Putney Commons totalling 4 ...
, Coombe Warren, Coopers Hill, Chatley Heath,
Pewley Hill Pewley Hill is a hill, and a street so named, near Guildford in England. It links to the open space at Pewley Down and was used as the site of a semaphore station and a defensive fort in the nineteenth century. In the late 19th and early 20th ce ...
, Bannicle Hill, Haste Hill ( Haslemere), Holder Hill, (Midhurst),
Beacon Hill Beacon Hill may refer to: Places Canada * Beacon Hill, Ottawa, Ontario, a neighbourhood * Beacon Hill Park, a park in Victoria, British Columbia * Beacon Hill, Saskatchewan * Beacon Hill, Montreal, a neighbourhood in Beaconsfield, Quebec United ...
, Compton Down,
Camp Down Camp Down () is a biological Site of Special Scientific Interest in Wiltshire in South West England. It was designated as such in 1965. Location The area overlooks the valley of the River Avon, and is about northwest of Salisbury. It lies e ...
, Lumps Fort (Southsea), and
Portsmouth Dockyard His Majesty's Naval Base, Portsmouth (HMNB Portsmouth) is one of three operating bases in the United Kingdom for the Royal Navy (the others being HMNB Clyde and HMNB Devonport). Portsmouth Naval Base is part of the city of Portsmouth; it is ...
. The semaphore tower at Chatley Heath, which replaced the Netley Heath station of the shutter telegraph, is currently being restored by the
Landmark Trust The Landmark Trust is a British building conservation charity, founded in 1965 by Sir John and Lady Smith, that rescues buildings of historic interest or architectural merit and then makes them available for holiday rental. The Trust's headqua ...
as self-catering holiday accommodation. There will be public access on certain days when the restoration is complete. The Board of the
Port of Liverpool The Port of Liverpool is the enclosed dock system that runs from Brunswick Dock in Liverpool to Seaforth Dock, Seaforth, on the east side of the River Mersey and the Birkenhead Docks between Birkenhead and Wallasey on the west side of t ...
obtained a
Private Act of Parliament Proposed bills are often categorized into public bills and private bills. A public bill is a proposed law which would apply to everyone within its jurisdiction. This is unlike a private bill which is a proposal for a law affecting only a single p ...
to construct a chain of Popham optical semaphore stations from
Liverpool Liverpool is a City status in the United Kingdom, city and metropolitan borough in Merseyside, England. With a population of in 2019, it is the List of English districts by population, 10th largest English district by population and its E ...
to
Holyhead Holyhead (,; cy, Caergybi , "Cybi's fort") is the largest town and a community in the county of Isle of Anglesey, Wales, with a population of 13,659 at the 2011 census. Holyhead is on Holy Island, bounded by the Irish Sea to the north, and i ...
in 1825. The system was designed and part-owned by Barnard L. Watson, a reserve marine officer, and came into service in 1827. The line is possibly the only example of an optical telegraph built entirely for commercial purposes. It was used so that observers at
Holyhead Holyhead (,; cy, Caergybi , "Cybi's fort") is the largest town and a community in the county of Isle of Anglesey, Wales, with a population of 13,659 at the 2011 census. Holyhead is on Holy Island, bounded by the Irish Sea to the north, and i ...
could report incoming ships to the
Port of Liverpool The Port of Liverpool is the enclosed dock system that runs from Brunswick Dock in Liverpool to Seaforth Dock, Seaforth, on the east side of the River Mersey and the Birkenhead Docks between Birkenhead and Wallasey on the west side of t ...
and trading could begin in the cargo being carried before the ship docked. The line was kept in operation until 1860 when a railway line and associated electrical telegraph made it redundant. Many of the prominences on which the towers were built (' telegraph hills') are known as Telegraph Hill to this day.


British empire


=Ireland

= In Ireland R.L. Edgeworth was to develop an optical telegraph based on a triangle pointer, measuring up to 16 feet in height. Following several years promoting his system, he was to get admiralty approval and engaged in its construction during 1803–1804. The completed system ran from Dublin to Galway and was to act as a rapid warning system in case of French invasion of the west coast of Ireland. Despite its success in operation, the receding threat of French invasion was to see the system disestablished in 1804.


=Canada

= 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 Annapolis ( ) is the capital city of the U.S. state of Maryland and the county seat of, and only incorporated city in, Anne Arundel County. Situated on the Chesapeake Bay at the mouth of the Severn River, south of Baltimore and about east ...
in
Nova Scotia Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland". Most of the population are native Eng ...
, and across the Bay of Fundy to Saint John and
Fredericton Fredericton (; ) is the capital city of the Canadian province of New Brunswick. The city is situated in the west-central portion of the province along the Saint John River, which flows west to east as it bisects the city. The river is the do ...
in
New Brunswick New Brunswick (french: Nouveau-Brunswick, , locally ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. It is the only province with both English and ...
. 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 Quebec City ( or ; french: Ville de Québec), officially Québec (), is the capital city of the Canadian province of Quebec. As of July 2021, the city had a population of 549,459, and the metropolitan area had a population of 839,311. It is t ...
, but the many hills and coastal fog meant the towers needed to be placed relatively close together to ensure visibility. The labour needed to build and continually man so many stations taxed the already stretched-thin British military and there is doubt the 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.


=Malta

= The British military authorities began to consider installing a semaphore line in
Malta Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
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 Għargħur ( mt, Ħal Għargħur) is a village in the Northern Region of Malta. It is situated on a hilltop between two valleys, and it has a population of 2,768 as of March 2014. Għargħur Festa In Malta, each village celebrates a different ...
and Għaxaq on the main island, and another was built at
Ta' Kenuna Taw, tav, or taf is the twenty-second and last Letter (alphabet), letter of the Semitic abjads, including Phoenician alphabet, Phoenician Tāw , Hebrew alphabet, Hebrew Tav , Aramaic alphabet, Aramaic Taw , Syriac alphabet, Syriac Taw ܬ, and A ...
on Gozo. Further stations were established at the Governor's Palace, Selmun Palace and the
Giordan Lighthouse __NOTOC__ The Giordan, Ġordan or Ta' Ġurdan Lighthouse is an active lighthouse on the Maltese island of Gozo. It is located on a hill above the village of Għasri on the northern coast of the island. History An earlier lighthouse was known to ...
. Each station was staffed by the
Royal Engineers The Corps of Royal Engineers, usually called the Royal Engineers (RE), and commonly known as the ''Sappers'', is a corps of the British Army. It provides military engineering and other technical support to the British Armed Forces and is head ...
.


=India

= In India, semaphore towers were introduced in 1810. A series of towers were built between Fort William,
Kolkata Kolkata (, or , ; also known as Calcutta , the official name until 2001) is the capital of the Indian state of West Bengal, on the eastern bank of the Hooghly River west of the border with Bangladesh. It is the primary business, comme ...
to
Chunar Fort The Chunar Fort (also known as Chandrakanta Chunargarh and Charanadri) is located in Mirzapur district of Uttar Pradesh, in India. Along with Chunar town, near Mirzapur city, situated below the fort, the two are historic places with common hi ...
near
Varanasi Varanasi (; ; also Banaras or Benares (; ), and Kashi.) is a city on the Ganges river in northern India that has a central place in the traditions of pilgrimage, death, and mourning in the Hindu world. * * * * The city has a syncretic t ...
.The towers in the plains were tall and those in the hills were tall, and were built at an interval of about .


=Van Diemen's Land

= In southern Van Diemens Land (
Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...
) a signalling system to announce the arrival of ships was suggested by Governor-In-Chief Lachlan Macquarie when he made his first visit in 1811 Initially a simple flag system in 1818 between Mt.Nelson and
Hobart Hobart ( ; Nuennonne/ Palawa kani: ''nipaluna'') is the capital and most populous city of the Australian island state of Tasmania. Home to almost half of all Tasmanians, it is the least-populated Australian state capital city, and second-small ...
, it developed into a system with two revolving arms by 1829, the system was quite crude and the arms were difficult to operate. In 1833
Charles O'Hara Booth Charles O'Hara Booth (31 August 1800 – 11 August 1851), was an English-born army officer who served in India, the West Indies and England for a total of 18 years before being posted to Van Diemen's Land, Australia (later to be named Tasma ...
took over command of the Port Arthur penal settlement, as an "enthusiast in the art of signalling" he saw the value of better communications with the headquarters in Hobart. During his command the semaphore system was extended to include 19 stations on the various mountains and islands between Port Arthur and Hobart. Until 1837 three single rotating arm semaphores were used. Subsequently the network was upgraded to use signal posts with six arms - a pair top, middle and bottom. This enabled the semaphore to send 999 signal codes. Captain George King of the Port Office and Booth together contributed to the code book for the system. King drew up shipping related codes and Booth added Government, Military and penal station matters. In 1877 Port Arthur was closed and the semaphore was operated for shipping signals only, it was finally replaced with a simple flagstaff after the introduction of the telephone in 1880. In the north of the state there was a requirement to report on shipping arrivals as they entered the Tamar Estuary, some 55 kilometers from the main port at this time in Launceston. The Tamar Valley Semaphore System was based on a design by Peter Archer Mulgrave. This design used two arms, one with a cross piece at the end. The arms were rotated by ropes, and later chains. The barred arm positions indicated numbers 1 to 6 clockwise from the bottom left and the unbarred arm 7,8,9, STOP and REPEAT. A message was sent by sending numbers sequentially to make up a code. As with other systems the code was decoded via a code book. On 1 October 1835 it was announced in the Launceston Advertiser - "...that the signal stations are now complete from Launceston to George Town, and communication may he made, as well as received,from the Windmill Hill to George Town, in a very few minutes, on a clear day". The system comprised six stations - Launceston Port Office, Windmill Hill, Mt. Direction, Mt.George, George Town Port Office, Low Head lighthouse. The Tamar Valley semaphore telegraph operated for twenty-two and a half years closing on 31 March 1858 after the introduction of the electric telegraph. In the 1990s the Tamar Valley Signal Station Committee Inc. was formed to restore the system. The works were carried out over several years and the semaphore telegraph was declared complete once more on Sunday 30 September 2001.


Iberia


Spain

In Spain, the engineer
Agustín de Betancourt Agustín de Betancourt y Molina ( rus, Августин Августинович де Бетанкур, r=Avgustin Avgustinovich de Betankur; french: Augustin Bétancourt; 1 February 1758 – 24 July 1824) was a prominent Spanish engineer, who wo ...
developed his own system which was adopted by that state; in 1798 he received a Royal Appointment, and the first stretch of line connecting
Madrid Madrid ( , ) is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a metropolitan area population of approximately 6.7 million. It is the second-largest city in the European Union (EU), and ...
and
Aranjuez Aranjuez () is a city and municipality of Spain, part of the Community of Madrid. Located in the southern end of the region, the main urban nucleus lies on the left bank of Tagus, a bit upstream the discharge of the Jarama. , the municipality h ...
was in operation as of August 1800. Spain was spanned by an extensive semaphore telegraph network in the 1840s and 1850s. The three main semaphore lines radiated from
Madrid Madrid ( , ) is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a metropolitan area population of approximately 6.7 million. It is the second-largest city in the European Union (EU), and ...
. The first ran north to Irun on the Atlantic coast at the French border. The second ran east to the Mediterranean, then north along the coast through
Barcelona Barcelona ( , , ) is a city on the coast of northeastern Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within c ...
to the French border. The third ran south to Cadiz on the Atlantic coast. These lines served many other Spanish cities, including:
Aranjuez Aranjuez () is a city and municipality of Spain, part of the Community of Madrid. Located in the southern end of the region, the main urban nucleus lies on the left bank of Tagus, a bit upstream the discharge of the Jarama. , the municipality h ...
,
Badajoz Badajoz (; formerly written ''Badajos'' in English) is the capital of the Province of Badajoz in the autonomous community of Extremadura, Spain. It is situated close to the Portuguese border, on the left bank of the river Guadiana. The populati ...
,
Burgos Burgos () is a city in Spain located in the autonomous community of Castile and León. It is the capital and most populated municipality of the province of Burgos. Burgos is situated in the north of the Iberian Peninsula, on the confluence o ...
, Castellon,
Ciudad Real Ciudad Real (, ; en, "Royal City") is a municipality of Spain located in the autonomous community of Castile–La Mancha, capital of the province of Ciudad Real. It is the 5th most populated municipality in the region. History It was founded ...
, Córdoba, Cuenca, Gerona,
Pamplona Pamplona (; eu, Iruña or ), historically also known as Pampeluna in English, is the capital city of the Chartered Community of Navarre, in Spain. It is also the third-largest city in the greater Basque cultural region. Lying at near above ...
, San Sebastian,
Seville Seville (; es, Sevilla, ) is the capital and largest city of the Spanish autonomous community of Andalusia and the province of Seville. It is situated on the lower reaches of the River Guadalquivir, in the southwest of the Iberian Penins ...
, Tarancon, Taragona, Toledo, Valladolid,
Valencia Valencia ( va, València) is the capital of the autonomous community of Valencia and the third-most populated municipality in Spain, with 791,413 inhabitants. It is also the capital of the province of the same name. The wider urban area al ...
, Vitoria and
Zaragoza Zaragoza, also known in English as Saragossa,''Encyclopædia Britannica'"Zaragoza (conventional Saragossa)" is the capital city of the Province of Zaragoza, Zaragoza Province and of the autonomous communities of Spain, autonomous community of Ara ...
. The rugged topography of the Iberian peninsula that facilitated the design of semaphore lines conveying information from hilltop to hilltop, made it difficult to implement wire telegraph lines when that technology was introduced in the mid 19th century. The Madrid-Cadiz line was the first to be dismantled in 1855, but other segments of the optical system continued to function until the end of the Carlist Wars in 1876.


Portugal

In Portugal, the British forces fighting Napoleon in Portugal soon found that the Portuguese Army had already a very capable semaphore terrestrial system working since 1808, giving the
Duke of Wellington Arthur Wellesley, 1st Duke of Wellington, (1 May 1769 – 14 September 1852) was an Anglo-Irish soldier and Tory statesman who was one of the leading military and political figures of 19th-century Britain, serving twice as prime minister ...
a decisive advantage in intelligence. The innovative Portuguese telegraphs, designed by , a mathematician, were of 3 types: 3 shutters, 3 balls and 1 pointer/moveable arm. He also wrote the code book "Táboas Telegráphicas", the same for the 3 telegraph types. Since early 1810 the network was operated by "Corpo Telegráfico", the first Portuguese military Signal Corps.


Other regions

Once it had proved its success in France, 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. Many national services adopted signalling systems different from the Chappe system. For example, the UK and Sweden adopted systems of shuttered panels (in contradiction to the Chappe brothers' contention that angled rods are more visible). In some cases, new systems were adopted because they were thought to be improvements. But many countries pursued their own, often inferior, designs for reasons of national pride or not wanting to copy from rivals and enemies. In 1801, the Danish post office installed a semaphore line across the Great Belt strait, ''Storebæltstelegrafen'', between islands
Funen Funen ( da, Fyn, ), with an area of , is the third-largest island of Denmark, after Zealand and Vendsyssel-Thy. It is the 165th-largest island in the world. It is located in the central part of the country and has a population of 469,947 as o ...
and Zealand with stations at Nyborg on Funen, on the small island Sprogø in the middle of the strait, and at Korsør on Zealand. It was in use until 1865. In the
Kingdom of Prussia The Kingdom of Prussia (german: Königreich Preußen, ) was a German kingdom that constituted the state of Prussia between 1701 and 1918.Marriott, J. A. R., and Charles Grant Robertson. ''The Evolution of Prussia, the Making of an Empire''. ...
, Frederick William III ordered the construction of an experimental line in 1819, but due to the procrastination of defence minister Karl von Hake, nothing happened until 1830 when a short three-station line between Berlin and
Potsdam Potsdam () is the capital and, with around 183,000 inhabitants, largest city of the German state of Brandenburg. It is part of the Berlin/Brandenburg Metropolitan Region. Potsdam sits on the River Havel, a tributary of the Elbe, downstream of ...
was built. The design was based on the Swedish telegraph with the number of shutters increased to twelve. '' Postrat'' Carl Pistor proposed instead a semaphore system based on Watson's design in England. An operational line of this design running Berlin-
Magdeburg Magdeburg (; nds, label=Low Saxon, Meideborg ) is the capital and second-largest city of the German state Saxony-Anhalt. The city is situated at the Elbe river. Otto I, the first Holy Roman Emperor and founder of the Archdiocese of Magdebu ...
-
Dortmund Dortmund (; Westphalian nds, Düörpm ; la, Tremonia) is the third-largest city in North Rhine-Westphalia after Cologne and Düsseldorf, and the eighth-largest city of Germany, with a population of 588,250 inhabitants as of 2021. It is the la ...
- Köln-
Bonn The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ru ...
-
Koblenz Koblenz (; Moselle Franconian: ''Kowelenz''), spelled Coblenz before 1926, is a German city on the banks of the Rhine and the Moselle, a multi-nation tributary. Koblenz was established as a Roman military post by Drusus around 8 B.C. Its nam ...
was completed in 1833. The line employed about 200 people, comparable to Sweden, but no network ever developed and no more official lines were built. The line was decommissioned in 1849 in favour of an electrical line. Although there were no more government sponsored official lines, there was some private enterprise. Johann Ludwig Schmidt opened a commercial line from
Hamburg Hamburg (, ; nds, label=Hamburg German, Low Saxon, Hamborg ), officially the Free and Hanseatic City of Hamburg (german: Freie und Hansestadt Hamburg; nds, label=Low Saxon, Friee un Hansestadt Hamborg),. is the List of cities in Germany by popul ...
to
Cuxhaven Cuxhaven (; ) is an independent town and seat of the Cuxhaven district, in Lower Saxony, Germany. The town includes the northernmost point of Lower Saxony. It is situated on the shore of the North Sea at the mouth of the Elbe River. Cuxhaven ...
in 1837. In 1847, Schmidt opened a second line from
Bremen Bremen ( Low German also: ''Breem'' or ''Bräm''), officially the City Municipality of Bremen (german: Stadtgemeinde Bremen, ), is the capital of the German state Free Hanseatic City of Bremen (''Freie Hansestadt Bremen''), a two-city-state cons ...
to Bremerhaven. These lines were used for reporting the arrival of commercial ships. The two lines were later linked with three additional stations to create possibly the only private telegraph network in the optical telegraph era. The telegraph inspector for this network was Friedrich Clemens Gerke, who would later move to the Hamburg-Cuxhaven electrical telegraph line and develop what became the International Morse Code. The Hamburg line went out of use in 1850, and the Bremen line in 1852. In
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...
, Tsar Nicolas I inaugurated a line between
Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...
and
Warsaw Warsaw ( pl, Warszawa, ), officially the Capital City of Warsaw,, abbreviation: ''m.st. Warszawa'' is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland, and its population is officiall ...
of length in 1833; it needed 220 stations staffed by 1,320 operators. The stations were noted to be unused and decaying in 1859, so the line was probably abandoned long before this. In the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
, the first optical telegraph was built by Jonathan Grout in 1804 but ceased operation in 1807. This line between Martha's Vineyard with
Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- mo ...
transmitted shipping news. An optical telegraph system linking
Philadelphia Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Since ...
and the mouth of the Delaware Bay was in place by 1809 and had a similar purpose; a second line to
New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...
was operational by 1834, when its Philadelphia terminus was moved to the tower of the Merchants Exchange. One of the principal hills in
San Francisco San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17t ...
,
California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
is also named " Telegraph Hill", after the semaphore telegraph which was established there in 1849 to signal the arrival of ships into
San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water f ...
.


As first data networks

The optical telegraphs put in place at the turn of the 18th/19th centuries were the first examples of data networks. Chappe and Edelcrantz independently invented many features that are now commonplace in modern networks, but were then revolutionary and essential to the smooth running of the systems. These features included control characters, routing,
error control In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communic ...
, flow control, message priority and symbol rate control. Edelcrantz documented the meaning and usage of all his control codes from the start in 1794. The details of the early Chappe system are not known precisely; the first operating instructions to survive date to 1809 and the French system is not as fully explained as the Swedish. Some of the features of these systems are considered advanced in modern practice and have been recently reinvented. An example of this is the error control codepoint 707 in the Edelcrantz code. This was used to request the repeat of a specified recent symbol. The 707 was followed by two symbols identifying the row and column in the current page of the logbook that it was required to repeat. This is an example of a selective repeat and is more efficient than the simple go back n strategy used on many modern networks.Holzmann & Pehrson, p. 216 This was a later addition; both Edelcrantz (codepoint 272), and Chappe (codepoint 2H6)The notation here follows that given in Holzmann & Pehrson (p. 211). The two digits represent, respectively the angle of the left and right indicators. Vertical pointing up is "1" and each successive 45° from this position increments this number. "H" means the regulator is in the horizontal position and "V" the vertical. initially used only a simple "erase last character" for error control, taken directly from Hooke's 1684 proposal. Routing in the French system was almost permanently fixed; only Paris and the station at the remote end of a line were allowed to initiate a message. The early Swedish system was more flexible, having the ability to set up message connections between arbitrary stations. Similar to modern networks, the initialisation request contained the identification of the requesting and target station. The request was acknowledged by the target station by sending the complement of the code received. This protocol is unique with no modern equivalent. This facility was removed from the codebook in the revision of 1808. After this, only Stockholm would normally initiate messages with other stations waiting to be polled. The Prussian system required the Coblenz station (at the end of the line) to send a "no news" message (or a real message if there was one pending) back to Berlin on the hour, every hour. Intermediate stations could only pass messages by replacing the "no news" message with their traffic. On arrival in Berlin, the "no news" message was returned to Coblenz with the same procedure. This can be considered an early example of a
token passing On a local area network, token passing is a channel access method where a packet called a ''token'' is passed between nodes to authorize that node to communicate. In contrast to polling access methods, there is no pre-defined "master" node. The mos ...
system. This arrangement required accurate clock synchronisation at all the stations. A synchronisation signal was sent out from Berlin for this purpose every three days. Another feature that would be considered advanced in a modern electronic system is the dynamic changing of transmission rates. Edelcrantz had codepoints for faster (770) and slower (077). Chappe also had this feature.


In popular culture

By the mid-19th century, the optical telegraph was well known enough to be referenced in popular works without special explanation. 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 get it down—provoke an international crisis by inadvertently transmitting disturbing messages. In "
Lucien Leuwen ''Lucien Leuwen'' is the second major novel written by French author Stendhal in 1834, following ''The Red and the Black'' (1830). It remained unfinished due to the political culture of the July Monarchy in the 1830s and Stendhal's fears of losing ...
" (1834), Stendhal pictures a power struggle between 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'' (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." He later bribes a semaphore operator to relay a false message in order to manipulate the French financial market. Dumas also describes in detail 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 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. was told laterthat this was Saint-Eustache church and that these large black arms were a telegraph."See second paragraph in
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See also

* History of telecommunication *
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 w ...
, for more information on many of the codes used * Optical communication *
Railway signalling Railway signalling (), also called railroad signaling (), is a system used to control the movement of railway traffic. Trains move on fixed rails, making them uniquely susceptible to collision. This susceptibility is exacerbated by the enormo ...
* San Jose Semaphore * Semaphore Flag Signaling System * Signal lamp * Telegraph Hill, for a list of telegraph hills


Notes


References

; Citations ; 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 pp. 123–125 * Edelcrantz, Abraham Niclas, ''Afhandling om Telegrapher'' ("A Treatise on Telegraphs"), 1796, as translated in ch. 4 of Holzmann & Pehrson. * Holzmann, Gerard J.; Pehrson, Bjorn, ''The Early History of Data Networks'', John Wiley & Sons, 1995 . * Huurdeman, Anton A., ''The Worldwide History of Telecommunications'', John Wiley & Sons, 2003 .


Further reading

* ''The Victorian Internet'', Tom Standage, Walker & Company, 1998, * ''The Old Telegraphs'', Geoffrey Wilson, Phillimore & Co Ltd 1976 * ''Faster Than The Wind, The Liverpool to Holyhead Telegraph'', Frank Large, an avid publication * ''The early history of data networks'', Gerard Holzmann and Bjorn Pehrson, Wiley Publ., 2003, *


External links


Chappe's semaphore
(an illustrated history of optical telegraphy)
Webpage including a map of England's telegraph chains



Chart of Murray's shutter-semaphore code




* ttps://www.inc.com/magazine/19990915/13554.html Details on the history of the Blanc brothers fraudulant use of the Semophore line
Live recreation of the Spanish optical telegraph code (in Spanish)
{{DEFAULTSORT:Semaphore Line History of telecommunications Latin-script representations Napoleonic beacons in England Optical communications Telegraphy Semaphore