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Semaphore

Semaphore

Overview
A semaphore telegraph, optical telegraph, shutter telegraph chain, Chappe telegraph, or Napoleonic
Napoleon I of France
Napoleon Bonaparte later known as Napoleon I, and previously Napoleone di Buonaparte, was a military and political leader of France whose actions shaped European politics in the early 19th century.Born in Corsica and trained as an artillery officer in mainland France, Bonaparte rose to prominence...

 semaphore
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. These systems were popular in the late 18th - early 19th century.
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Encyclopedia
A semaphore telegraph, optical telegraph, shutter telegraph chain, Chappe telegraph, or Napoleonic
Napoleon I of France
Napoleon Bonaparte later known as Napoleon I, and previously Napoleone di Buonaparte, was a military and political leader of France whose actions shaped European politics in the early 19th century.Born in Corsica and trained as an artillery officer in mainland France, Bonaparte rose to prominence...

 semaphore
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. These systems were popular in the late 18th - early 19th century. In modern usage, "semaphore line" and "optical telegraph" may refer to a relay system using flag semaphore
Flag semaphore
Flag semaphore is a system for conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands. Information is encoded by the position of the flags; it is read when the flag is in a fixed position...

.

Semaphore lines were a precursor of the electrical telegraph
Electrical telegraph
The electrical telegraph is a telegraph that uses electric signals. The electromagnetic telegraph is a device for human-to-human transmission of coded text messages over wire...

. They were far faster than post riders for bringing a message over long distances, but far more expensive and less private than the electrical telegraph
Electrical telegraph
The electrical telegraph is a telegraph that uses electric signals. The electromagnetic telegraph is a device for human-to-human transmission of coded text messages over wire...

 lines which would replace them. The distance that an optical telegraph can bridge is limited by geography and weather, thus in practical use, most optical telegraphs used lines of relay stations to bridge longer distances.

History


Optical telegraphy dates from ancient times, in the form of hydraulic telegraph
Hydraulic telegraph
A hydraulic telegraph was a hydraulic-telegraphic telecommunication system of either 4th century BC Greek, or 19th century AD British design. The former Greek system was deployed in combination with semaphoric fires, while the latter British system was purely hydraulic.Although both systems...

s, torches (as used by ancient Greeks) and smoke signals.

Modern design of semaphores was first foreseen by the English scientist Robert Hooke
Robert Hooke
Robert Hooke, FRS was an English natural philosopher, architect and polymath who played an important role in the scientific revolution, through both experimental and theoretical work....

, who first gave a vivid and comprehensive outline of visual telegraphy to the Royal Society
Royal Society
The Royal Society of London for the Improvement of Natural Knowledge, known simply as the Royal Society, or even the Royal, is a learned society for science that was founded in 1660 and is considered by most to be the oldest such society still in existence...

 in a submission dated 1684 in which he outlined many practical details. The system (motivated by military concerns, following the recent Battle of Vienna
Battle of Vienna
The Battle of Vienna took place on 11 and 12 September 1683 after Vienna had been besieged by the Ottoman Empire for two months...

 in 1683) was never put into practice.

The first achieved optical telegraph arrived only in 1792 from the French engineer Claude Chappe
Claude Chappe
Claude Chappe was a French inventor who in 1792 demonstrated a practical semaphore system that eventually spanned all of France...

 and his brothers, who succeeded in covering France
France
France , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...

 with a network of 556 stations stretching a total distance of 4,800 kilometres. It was used for military and national communications until the 1850s.

Many national services adopted signaling systems different from the Chappe system. For example, Britain and Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...

 adopted systems of shuttered panels (in contradiction to the Chappe brothers' contention that angled rods are more visible). In Spain
Spain
Spain , officially the Kingdom of Spain , is a country located in southwestern Europe on the Iberian Peninsula.The Spanish constitution does not establish any official denomination of the country, even though España , Estado español and Nación española are used interchangeably...

, the engineer Agustín de Betancourt
Agustín de Betancourt
Agustín de Betancourt y Molina was a prominent engineer, who worked in Spain, France and Russia. His work ranged from steam engines and balloons to structural engineering and urban planning...

 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.

France


There was a desperate need for swift and reliable communications in France during the period of 1790-1795. It was the height of the French revolution
French Revolution
The French Revolution was a period of political and social upheaval and radical change in the history of France, during which the French governmental structure, previously an absolute monarchy with feudal privileges for the aristocracy and Catholic clergy, underwent radical change to forms based...

, and France was surrounded by the enemy forces of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...

, The Netherlands, Prussia
Prussia
Prussia was a historic state originating out of the Duchy of Prussia and the Margraviate of Brandenburg. For centuries this state had substantial influence on German and European history...

, Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.3 million people in Central Europe. It borders both Germany and the Czech Republic to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west...

, and Spain
Spain
Spain , officially the Kingdom of Spain , is a country located in southwestern Europe on the Iberian Peninsula.The Spanish constitution does not establish any official denomination of the country, even though España , Estado español and Nación española are used interchangeably...

. The cities of Marseilles and Lyon
Lyon
||-||}Lyon , often Anglicized as Lyons, is a city in east-central France in the region Rhône-Alpes, situated between Paris and Marseille. Its name is pronounced in French and Arpitan, and or in English...

 were in revolt, and the English Fleet held Toulon
Toulon
Toulon is a city in southern France and a large military harbour on the Mediterranean coast, with a major French naval base...

. In this situation the only advantage France held was the lack of cooperation between the allied forces due to their inadequate lines of communications.

The Chappe brothers in the summer of 1790 set about to devise a system of communication that would allow the central government to receive intelligence and to transmit orders in the shortest possible time. On March 2, 1791 at 11 A.M., Chappe and his brother 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 ten miles (16 km). 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
Place de l'Étoile
The Place de l'Étoile is a large road junction in Paris, France, the meeting point of twelve straight avenues including the Champs-Élysées which continues to the east...

, Paris
Paris
Paris is the capital of France and the country's most populous city. It is situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 was destroyed by mobs who thought they were communicating with royalist
Chouannerie
The Chouannerie was a royalist uprising in twelve of the western departements of France against the French Revolution, the First French Republic, and even for a time under the Empire...

 forces. However in the summer of 1792 Claude was appointed Ingénieur-Télégraphiste and charged with establishing a line of stations between Paris and Lille
Lille
Lille is a city in northern France. It is the principal city of the Lille Métropole, the fourth-largest metropolitan area in the country behind those of Paris, Lyon and Marseille. Lille is situated on the Deûle River, near France's border with Belgium...

, 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
Condé-sur-l'Escaut is a commune of the Nord department in northern France.It lies on the border with Belgium. The population in 1999 was 10,527. Residents of the area are known as Condéens or Condéennes. The Mayor of Condé-sur-l'Escaut is Daniel Bois .-Geography:Condé-sur-l'Escaut is northeast of...

 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.

Paris to Strasbourg
Strasbourg
Strasbourg is the capital and principal city of the Alsace region in north-eastern France. With 702,412 inhabitants in 2007, its metropolitan area is the ninth largest in France...

 with 50 stations was the next line and others followed soon after. 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 the system was funded by the proceeds of its own lottery did costs come under control.

In 1821 Norwich Duff, a young British Naval officer, visiting Clermont-en-Argonne
Clermont-en-Argonne
Clermont-en-Argonne is a commune in the Meuse department in Lorraine in north-eastern France.-Geography:The town is located along the old road from Paris to Verdun , which at this point is closely tracked by the A4 autoroute, on the edge of the Forest of 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 in six minutes it is here in four.

Description


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 black movable wooden arms, the position of which indicated alphabetic letters. With counterweights (named forks) on the arms, the Chappe system was controlled by only two handles and was mechanically simple and reasonably rugged. Each of the two 2m-long arms showed seven positions, and the 4.6m-long cross bar connecting the two arms had four different angles, for a total of 196 symbols (7x7x4). Night operation with lamps on the arms was unsuccessful.

To speed up transmission and to provide some semblance of security a code
Code
In communications, a code is a rule for converting a piece of information into another form or representation , not necessarily of the same type. In communications and information processing, encoding is the process by which information from a source is converted into symbols to be communicated...

 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.

Sweden


At the same time as Chappe, the Swedish inventor Abraham Niclas Edelcrantz
Abraham Niclas Edelcrantz
Abraham Niclas Edelcrantz was a Finnish born Swedish poet and inventor. He was a member of the Swedish Academy, chair 2, from 1786 to 1821....

 experimented with the optical telegraph in Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...

. 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
' is the capital and largest city of Sweden. It is the site of the national Swedish government, the Riksdag , and the official residence of the Swedish Monarch as well as the prime minister. The Monarch resides at Drottningholm Palace outside of Stockholm since 1980 and uses the Royal Palace of...

 to the King at Drottningholm
Drottningholm
Drottningholm, literally "Queen's Islet", is a locality situated in Ekerö Municipality, Stockholm County, Sweden, with 410 inhabitants in 2005....

.

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 from one another.

Soon telegraph circuits linking castles and fortresses in the neighbourhood of 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 and its fortresses. 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
Stockholm
' is the capital and largest city of Sweden. It is the site of the national Swedish government, the Riksdag , and the official residence of the Swedish Monarch as well as the prime minister. The Monarch resides at Drottningholm Palace outside of Stockholm since 1980 and uses the Royal Palace of...

, Gothenburg
Gothenburg
Gothenburg is the second-largest city in Sweden and the fifth-largest amongst the Nordic countries. Situated on the south-west coast of Sweden, the city proper has a population of 502,833 with 622,287 in the urban area and total of 911,406 inhabitants in the metropolitan area.The City of...

 and Karlskrona
Karlskrona
Karlskrona is a locality and the seat of Karlskrona Municipality, Blekinge County, Sweden with 32,606 inhabitants in 2005. It is also the capital of Blekinge County. Karlskrona is known as Sweden's only baroque city and is host to Sweden's only remaining naval base and the HQ of the Swedish Coast...

. Like its French counterpart, it was mainly used for military purposes.

U.K.


Lord George Murray
Lord George Murray (bishop)
Lord George Murray was an Anglican cleric best remembered for his work developing Britain's first optical telegraph, which began relaying messages from London to Deal in 1796, a few years after Claude Chappe's system began operation in France...

, stimulated by reports of the Chappe semaphore, proposed a system of visual telegraphy to the British Admiralty. He employed large wooden boards on his towers with six large holes which could be closed by shutters. Starting in 1795, chains of shutter telegraph stations were built along these routes:

Liverpool - Holyhead
Liverpool
Liverpool
Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...

, Bidston
Bidston
Bidston is a suburb of Birkenhead, on the Wirral Peninsula, Merseyside, England. Administratively, it is also a ward of the Metropolitan Borough of Wirral. Before local government reorganisation on 1 April 1974, it was part of the County Borough of Birkenhead, within the geographical county of...

, Hilbre Island
Hilbre Island
Hilbre Island is the largest of a group of three islands at the mouth of the estuary of the River Dee, which is a part of the estuary Site of Special Scientific Interest....

, Voel Nant, Foryd, Llysfaen
Llysfaen
Llysfaen is a village in Conwy county borough on the coast of north Wales. For local government purposes, it is also a community and Conwy County Borough Council ward.- Introduction :...

, Puffin Island
Puffin Island, Anglesey
Puffin Island is an uninhabited island off the eastern tip of Anglesey, Wales. It was formerly known as Priestholm in English and Ynys Lannog in Welsh.-Geography:...

, Point Lynas
Point Lynas Lighthouse
Point Lynas Lighthouse is located on the north coast of Anglesey in North Wales .-Construction:...

, Carreglwyd, Cefn Du, Holyhead
Holyhead
Holyhead is the largest town in the county of Anglesey in the north west of Wales.Although it is the largest town in the county, with a population of 11,237 , it is neither the county town nor actually on the island of Anglesey...

 

London - Deal and Sheerness
Admiralty (London
London
[]London is the capital of England and the United Kingdom. It has been a major settlement for two millennia, and the history of London goes back to its founding by the Romans, when it was named Londinium. London's core, the ancient City of London, the 'square mile', retains its medieval boundaries...

), West Square Southwark
Southwark
Southwark, or the Borough, is an area of south-east London in the London Borough of Southwark, situated 1.5 miles east of Charing Cross.-Naming:Southwark is the area of London immediately south of London Bridge...

, New Cross
Telegraph Hill, Lewisham
Telegraph Hill is a place and electoral ward just south of New Cross in the London Borough of Lewisham in southeast London, England. It was formerly known as Plowed Garlic Hill...

, Shooter's Hill
Shooter's Hill
Shooter's Hill is a place, and an electoral ward in the London Borough of Greenwich in south-east London. It lies east of Blackheath and west of Welling, south of Woolwich and north of Eltham...

, Swanscombe, Gad's Hill
Higham, Kent
Higham is a small village bordering the Hoo Peninsula, in Kent, between Gravesend and Rochester. The civil parish of Higham is in Gravesham district and as at the 2001 UK Census, had a population of 3,938.-History:...

, Callum Hill, Beacon Hill (Faversham, branch point), Shottenden, Barham Downs, Betteshanger, Deal
Deal, Kent
Deal is a town in Kent, England. It lies on the English Channel eight miles north-east of Dover. It is a small fishing community situated between Dover and Ramsgate...

.

(branch) Beacon Hill (Faversham), Tonge, Barrow Hill, Sheerness
Sheerness
Sheerness is a town located beside the mouth of the River Medway on the northwest corner of the Isle of Sheppey in north Kent, England. With a population of 12,000 it is the largest town on the island....

.

London - Great Yarmouth

Admiralty (London), Hampstead Heath
Hampstead Heath
Hampstead Heath is London's largest ancient parkland, covering . This grassy public space sits astride a sandy ridge, one of the highest points in London, running from Hampstead to Highgate, which rests on a band of London clay The Heath is rambling and hilly, embracing ponds, recent and ancient...

 (Telegraph Hill), Woodcock Hill, St Albans
St Albans
St Albans is a city in southern Hertfordshire, England, around north of central London, which forms the main urban area of the City and District of St Albans. It was a settlement of pre-Roman origin named Verlamion by the Ancient British, Catuvellauni tribe...

, Dunstable Downs
Dunstable Downs
Dunstable Downs are part of the Chiltern Hills, in southern Bedfordshire in England. They are a chalk escarpment forming the north-eastern reaches of the Chilterns...

, Lilley Hoo, Baldock
Baldock
Baldock is a town in the local government district of North Hertfordshire in the ceremonial county of Hertfordshire, England where the River Ivel rises. It lies north of London, southwest of Bedford, and north northwest of the county town of Hertford...

, Royston
Royston, Hertfordshire
Royston is a town and civil parish in the district of North Hertfordshire, Hertfordshire, England. It is situated slightly west of the Greenwich Meridian, and at the northernmost apex of the county on the same latitude of towns such as Milton Keynes and Felixstowe. It is located some 43 miles ...

, Gog Magog Hills, Newmarket (Side Hill), Icklingham, Barnham
Barnham, Suffolk
Barnham is a village and civil parish in the St Edmundsbury district of Suffolk, England. It is about south of Thetford. According to Eilert Ekwall the meaning of the village name is "Beorn's homestead"...

, East Harling
East Harling
East Harling is a village in the English county of Norfolk. The village forms the principal settlement in the civil parish of Harling, and is located some 8 miles east of the town of Thetford and 25 miles south-west of the city of Norwich.The village is served by Harling Road railway...

, Carleton Rode
Carleton Rode
Carleton Rode is a village in Norfolk, England, situated approximately five miles south-east of Attleborough. The village is extremely rural and is spread out over ....

, Wreningham
Wreningham
Wreningham is a village and civil parish in the English county of Norfolk. It is situated some south east of Wymondham and south west of Norwich.The civil parish has an area of 6.24 square kilometres and in 2001 had a population of 493 in 199 households...

, Norwich
Norwich
Norwich is a city in Norfolk, East Anglia which is in Eastern England. It is the regional administrative centre and county city of Norfolk...

, Strumpshaw
Strumpshaw
Strumpshaw is a village and civil parish in the English county of Norfolk, on the River Yare in Norfolk, England, within The Broads National Park.It covers an area of and had a population of 602 in 245 households as of the 2001 census....

, Great Yarmouth
Great Yarmouth
Great Yarmouth, often known to locals as Yarmouth, is a coastal town in Norfolk, England. It is at the mouth of the River Yare, 20 miles east of Norwich....

.

London - Portsmouth and Plymouth
Admiralty (London), Chelsea Royal Hospital, Putney Heath, Cabbage Hill, Netley Heath, Hascombe
Hascombe
The village of Hascombe contains a cluster of cottages and country estates, St Peter's church, the village green and The White Horse pub, all nestling between wooded hillsides in Surrey, England...

, Blackdown
Blackdown, Sussex
Blackdown, or Black Down, is the highest hill in the historic county of Sussex, at 280 metres , and is second only to Leith Hill in south-east England. It is also the highest point in the South Downs National Park. The pine and heather-covered slopes are owned by the National Trust, and are a...

, Beacon Hill
Harting
Harting is a civil parish in the Chichester District of West Sussex, England, situated on northern flank of the South Downs. It comprises four settlements namely Nyewood plus South, East and West Harting....

 (branch point), Portsdown Hill
Portsdown Hill
Portsdown Hill is a long chalk hill in Hampshire, England, offering good views over Portsmouth, The Solent, Hayling Island and Gosport, with the Isle of Wight beyond. The hill is on the mainland, just to the north of Ports Creek, which separates the mainland from Portsea Island, on which lies the...

, Portsmouth
Portsmouth
Portsmouth is a city located in the county of Hampshire on the south coast of England. Portsmouth is the United Kingdom's only island city and is located on Portsea Island. The City of Portsmouth and Portsmouth Football Club are both nicknamed Pompey...

 (Southsea Common).

(branch) Beacon Hill
Harting
Harting is a civil parish in the Chichester District of West Sussex, England, situated on northern flank of the South Downs. It comprises four settlements namely Nyewood plus South, East and West Harting....

, Chalton
Chalton, Hampshire
Chalton is a small village and civil parish in the East Hampshire district of Hampshire, England. It is 2.3 miles northeast of Horndean, just east of the A3 road....

, Wickham
Wickham
Wickham, formerly spelled Wykeham, is a civil parish and small market town in Hampshire, southern England, about three miles north of Fareham, and part of the City of Winchester local government district, in spite of it being notably closer to Fareham than to Winchester...

, Town Hill, Toot Hill, Bramshaw
Bramshaw
Bramshaw is a small village in Hampshire, England. It lies just inside the New Forest. The name Bramshaw means Bramble Wood.Bramshaw was once split in two, one half in Wiltshire and the other in Hampshire, by a boundary line that ran through the churchyard. When the 'County of Southampton Act...

, Pistle Down, Chalbury
Chalbury
Chalbury is a village in east Dorset, England, four miles north of Wimborne Minster and four miles west of Verwood. The village has a population of 140 .-Fiction:...

, Blandford racecourse
Blandford Camp
Blandford Camp is a military base comprising some 390 hectares of downland lying 2 miles north-east of Blandford Forum in the county of Dorset in southern England....

, Belchalwell
Belchalwell
Belchalwell is a village in the civil parish of Okeford Fitzpaine in the Blackmore Vale, North Dorset, and lies two and a half miles south of Sturminster Newton and six miles north-west of Blandford....

, Nettlecombe Tout, High Stoy, Toller Down, Lamberts Castle, Dalwood Common, St Cyrus, Rockbeare, Gt Halden, South Knighton, Marley, Lee, Saltram, Plymouth
Plymouth
Plymouth is a city and unitary authority area on the coast of Devon, England, about south west of London. It is built between the mouths of the rivers Plym to the east and Tamar to the west, where they join Plymouth Sound...

.

The London to Portsmouth shutter telegraph chain was replaced by a chain of semaphore stations which was operational from 1822 to 1847. It did not use the same locations as the shutter chain, but followed almost the same route with 15 stations -

Admiralty (London), Chelsea, Putney Heath, Coombe Warren (Kingston upon Thames
Kingston upon Thames
Kingston upon Thames is the principal settlement of the Royal Borough of Kingston upon Thames in south-west London.It was the ancient market town where Saxon kings were crowned and is now a suburb situated south west of Charing Cross...

), Coopers Hill
Claygate
Claygate is a large village in the English county of Surrey, approximately south west of London on the edge of the Green Belt.It is primarily a residential area but with offices, farms and two shopping areas with a supermarket, five pubs and numerous restaurants...

, Chatley Heath, Pewley Hill (Guildford
Guildford
Guildford is the county town of Surrey, England, as well as the seat for the borough of Guildford and the administrative headquarters of the South East England region...

), Bannicle Hill (Godalming
Godalming
Godalming is a town and civil parish in the Waverley district of the county of Surrey, England, south of Guildford. It is built on the banks of the River Wey and is a prosperous part of the London commuter belt. Godalming shares a three-way twinning arrangement with the towns of Joigny in France...

), Haste Hill (Haslemere
Haslemere
Haslemere is a town in Surrey, England, close to the border with both Hampshire and West Sussex. The major road between London and Portsmouth, the A3, lies to the west, and a branch of the River Wey to the south...

), Holder Hill (Midhurst
Midhurst
Midhurst is a market town and civil parish in the Chichester district of West Sussex, England, with a population of 4,889 in 2001. The town is situated on the River Rother and is home to the ruin of the Tudor Cowdray House and the stately Victorian Cowdray Park...

), Beacon Hill (Harting), Compton Down (Compton), Camp Down (Portsdown Hill), Lumps Fort (Southsea) and Portsmouth Dockyard. The semaphore tower at Chatley Heath, which replaced the Netley Heath station of the shutter telegraph, has been restored by Surrey County Council and is open to the public.

A semaphore based successor for the London to Plymouth shutter telegraph chain, branching much closer to London, at Chatley Heath in Surrey
Surrey
Surrey is a county in the South East of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire, and Berkshire. The historic county town is Guildford...

, was started but abandoned before completion.

Many of the prominences on which the towers were built are known as 'Telegraph Hill' to this day. As in France the network required lavish amounts of money and manpower to operate and could only be justified as a defence need.

Other countries



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
Post office
A post office is a facility authorised by a postal system for the posting, receipt, sorting, handling, transmission or delivery of mail. Post offices offer mail-related services such as post office boxes, postage and packaging supplies...

 operated the semaphore lines.

The Kingdom of Prussia
Kingdom of Prussia
The Kingdom of Prussia was a German kingdom from 1701 to 1918, until the defeat of Germany in World War I, was the leading state of the German Empire, comprising almost two-thirds of the area of the empire...

 began with a line
Prussian semaphore system
The Prussian Semaphore System was a telegraphic communications system used between Berlin and the Rhine Province from 1832 to 1849. It could transmit administrative and military messages by optical signal over a distance of nearly . The telegraph line comprised 62 stations each furnished with a...

 750 kilometres long between Berlin
Berlin
Berlin is the capital city and one of sixteen states of Germany. With a population of 3.4 million within its city limits, Berlin is Germany's largest city. It is the second most populous city and the eighth most populous urban area in the European Union...

 and Coblenz in 1833, and in Russia
Russia
Russia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...

, Tsar Nicolas I
Nicholas I of Russia
Nicholas I , , was the Emperor of Russia from 1825 until 1855, known as one of the most reactionary of the Russian monarchs. On the eve of his death, the Russian Empire reached its historical zenith spanning over 20 million square kilometres.Nicholas I was born in Gatchina to Emperor Paul I and...

 inaugurated the line between Moscow
Moscow
Moscow is the capital and the largest city of Russia. It is also the largest metropolitan area in Europe, and ranks among the largest urban areas in the world. Moscow is a major political, economic, cultural, religious, financial, educational, and transportation centre of Russia and the world, a...

 and Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River roughly from both the Baltic Sea coast and the Carpathian Mountains. Its population as of 2009 was estimated at 1,709,781, and the Warsaw metropolitan area at approximately 2,785,000...

 (1200 km) in 1833; this needed 220 stations manned by 1320 operators.

In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 the first optical telegraph was built by Jonathan Grout
Jonathan Grout
Jonathan Grout was a member of the United States House of Representatives from Massachusetts. He served in the First United States Congress, representing the area around Bristol County, Massachusetts....

. It was a 104 kilometre line connecting Martha's Vineyard
Martha's Vineyard
Martha's Vineyard is an island off the south of Cape Cod in New England. The islands both forming a part of the Outer Lands region....

 with Boston
Boston
Boston is the capital and largest city of the Commonwealth of Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is considered the economic and cultural center of the region and is sometimes regarded as the unofficial "Capital of New England"...

, and its purpose was to transmit news about shipping. One of the principal hills in San Francisco, California
San Francisco, California
San Francisco is the fourth most populous city in California and the 12th most populous city in the United States, with a 2008 estimated population of 808,976. It is the eighth most densely populated city in the U.S. and is the financial, cultural, and transportation center of the larger San...

 is also named "Telegraph Hill
Telegraph Hill, San Francisco
Telegraph Hill refers to a small hilly district in San Francisco, California. Its main feature is Coit Tower, which stands atop the hill.-Location:...

", after the semaphore telegraph which was established there in 1849 to signal the arrival of ships into San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...

.

The semaphores were successful enough that Samuel Morse failed to sell the electrical telegraph to the French government. However, France finally committed to replace semaphores with electric telegraphs in 1846. Note that electric telegraphs are both more private and almost completely unaffected by weather. Many contemporaries predicted the failure of electric telegraphs because "they are so easy to cut." 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 Ireland
Ireland
Ireland is the third-largest island in Europe and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain...

, Richard Lovell Edgeworth
Richard Lovell Edgeworth
Richard Lovell Edgeworth was an Anglo-Irish, politician writer and inventor.-Biography:Edgeworth was born in Pierrepont Street, Bath, England, grandson of Sir Salathiel Lovell through his daughter, Jane Lovell....

 (1744-1817) proposed a telegraph there when a French invasion was anticipated in 1794, and again in 1796, however the proposal was not implemented. Soon, the British forces fighting Napoleon in Portugal
Peninsular War
The Peninsular War was a contest between France and the allied powers of Spain, the United Kingdom, and Portugal for control of the Iberian Peninsula during the Napoleonic Wars...

 found that the Portuguese army had a very capable semaphore system giving the Duke of Wellington
Duke of Wellington
The Dukedom of Wellington, derived from Wellington in Somerset, is a hereditary title in the senior rank of the Peerage of the United Kingdom. The first holder of the title was Arthur Wellesley, 1st Duke of Wellington , the noted Irish-born British career officer and statesman, and unqualified...

 a decisive advantage in intelligence.

See also

  • Aldis lamp
  • Flag semaphore
    Flag semaphore
    Flag semaphore is a system for conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands. Information is encoded by the position of the flags; it is read when the flag is in a fixed position...

  • Heliograph
    Heliograph
    A Heliograph is a wireless solar telegraph that signals using Morse code flashes of sunlight reflected by a mirror. The flashes are produced by momentarily pivoting the mirror, or by interrupting the beam with a shutter...

  • Railway signalling
    Railway signalling
    Railway signalling is a system used to control railway traffic safely, essentially to prevent trains from colliding. Being guided by fixed rails, trains are uniquely susceptible to collision; furthermore, trains cannot stop quickly, and frequently operate at speeds that do not enable them to stop...

  • Signal lamp
    Signal lamp
    Signal lamp, also called Aldis lamp, is a visual signaling device for optical communication – essentially a focused lamp which can produce a pulse of light. It is named after its inventor Authur C W Aldis...

  • Telegraph Hill
    Telegraph Hill
    Telegraph Hill may be:* Telegraph Hill, San Francisco, California, USA* Telegraph Hill, Childs Hill, Barnet, London, England* Telegraph Hill, Claygate, Surrey, England* Telegraph Hill, Lewisham, London, England* Telegraph Hill , USA...

    , for a list of telegraph hill
    Telegraph hill
    A telegraph hill is a hill or other natural elevation, chosen as part of an optical telegraph system because of the relatively great distance between it and at least one other point, which it may observe or be observed from...

    s
  • Semaphore Flag Signaling System
    Semaphore Flag Signaling System
    In computer networking, Semaphore Flag Signaling System is a humorous proposal to carry Internet Protocol traffic by semaphores. Semaphore Flag Signaling System was initially described in RFC 4824, an April 1 RFC issued by the Internet Engineering Task Force edited by J. Hofmueller, et al. and...


Further reading

  • The Old Telegraphs, Geoffrey Wilson, Phillimore & Co Ltd 1976 ISBN 0900592796
  • Faster Than The Wind, The Liverpool to Holyhead Telegraph, Frank Large, an avid publication ISBN 0952102099
  • The early history of data networks, Gerard Holzmann and Bjorn Pehrson, Wiley Publ., 2003, ISBN 0-8186-6782-6

Semaphore in Fiction

  • Pavane
    Pavane
    The pavane, pavan, paven, pavin, pavian, pavine, or pavyn is a slow processional dance common in Europe during the 16th century .- Origin of term :The origin of this term is not known...

    , an alternate history novel by Keith Roberts
    Keith Roberts
    Keith John Kingston Roberts , was a British science fiction author. He began publishing with two stories in the September 1964 issue of Science Fantasy magazine, "Anita" and "Escapism.Several of his early stories were written using the...

    . This features a society where long distance communication is by a sophisticated network of mechanical semaphores operated by the powerful and semi-mystical Guild of Signallers.

External links