Semaphore - AbsoluteAstronomy.com

For the now closed railway in Adelaide
Adelaide
Adelaide is the capital city of South Australia and the fifth-largest city in Australia. Adelaide has an estimated population of more than 1.2 million...

, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, see Semaphore railway line, Adelaide
Semaphore railway line, Adelaide
Map of the Line Route|300px|right|thumbSemaphore railway line was a railway in the north-west of Adelaide servicing the suburb of Semaphore and Exeter. It serviced two stations: Semaphore and Exeter...

.

A semaphore telegraph, optical telegraph, shutter telegraph chain, Chappe telegraph, or Napoleonic
Napoleon I of France
Napoleon Bonaparte was a French military and political leader during the latter stages of the French Revolution.As Napoleon I, he was Emperor of the French from 1804 to 1815...

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 to early 19th century. In modern usage, "semaphore line" and "optical telegraph" may refer to a relay system using flag semaphore

Flag semaphore

Semaphore Flags is the 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...

, and "optical telegraph" may refer to a heliograph

Heliograph

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

(optical telegraphy using mirror-directed sunlight reflections).

Semaphore lines were a precursor of the electrical telegraph

Electrical telegraph

An electrical telegraph is a telegraph that uses electrical signals, usually conveyed via telecommunication lines or radio. The electromagnetic telegraph is a device for human-to-human transmission of coded text messages....

. 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

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 one of two hydraulic-telegraphic telecommunication systems, one developed in 4th century BCE Greece, and the other in 19th century AD Britain...

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.His adult life comprised three distinct periods: as a scientific inquirer lacking money; achieving great wealth and standing through his reputation for hard work and scrupulous honesty following the great fire of 1666, but...

, who first gave a vivid and comprehensive outline of visual telegraphy to the Royal Society

Royal Society

The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...

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 and his brothers, who succeeded in covering France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

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. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

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 languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

, the engineer Agustín de Betancourt

Agustín de Betancourt

Agustín de Betancourt y Molina was a prominent Spanish-Canarian 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 , sometimes distinguished as the 'Great French Revolution' , was a period of radical social and political upheaval in France and Europe. The absolute monarchy that had ruled France for centuries collapsed in three years...

, and France was surrounded by the enemy forces of Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

, the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

, Prussia

Prussia

Prussia was a German kingdom and historic state originating out of the Duchy of Prussia and the Margraviate of Brandenburg. For centuries, the House of Hohenzollern ruled Prussia, successfully expanding its size by way of an unusually well-organized and effective army. Prussia shaped the history...

, Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

, and Spain

Spain

. The cities of Marseilles and Lyon

Lyon

Lyon , is a city in east-central France in the Rhône-Alpes region, situated between Paris and Marseille. Lyon is located at from Paris, from Marseille, from Geneva, from Turin, and from Barcelona. The residents of the city are called Lyonnais....

were in revolt, and the British Fleet held Toulon

Toulon

Toulon is a town in southern France and a large military harbor on the Mediterranean coast, with a major French naval base. Located in the Provence-Alpes-Côte-d'Azur region, Toulon is the capital of the Var department in the former province of Provence....

. 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 devising 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 Charles de Gaulle, , historically known as 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. It was renamed in 1970 following the death of General and President Charles...

, Paris

Paris

Paris is the capital and largest city in France, 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, particularly in the provinces of Brittany and Maine, against the French Revolution, the First French Republic, and even, with its headquarters in London rather than France, 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

-Administration:Condé-sur-l'Escaut is the eastern member of the agglomerated Valenciennes metropolitan area, which together administers 35 communes.-References:...

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 eastern France and is the official seat of the European Parliament. Located close to the border with Germany, it is the capital of the Bas-Rhin département. The city and the region of Alsace are historically German-speaking,...

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.The former towns of Auzéville-en-Argonne, Jubécourt, and Parois were joined to Clermont-en-Argonne in 1973.-Geography:...

, 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 2-metre-long arms showed seven positions, and the 4.6-metre-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

A code is a rule for converting a piece of information into another form or representation , not necessarily of the same type....

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.

From 1803 on, the French also used the 3-arm Depillon semaphore at coastal locations to provide warning of British incursions.

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

. 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

Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...

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

, Gothenburg

Gothenburg

Gothenburg is the second-largest city in Sweden and the fifth-largest in the Nordic countries. Situated on the west coast of Sweden, the city proper has a population of 519,399, with 549,839 in the urban area and total of 937,015 inhabitants in the metropolitan area...

and Karlskrona

Karlskrona

Karlskrona is a locality and the seat of Karlskrona Municipality, Blekinge County, Sweden with 35,212 inhabitants in 2010. 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 headquarters of the...

. 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 in 1795. He employed rectangular framework towers with six large octagonal shutters on horizontal axes that flipped between horizontal and vertical positions to signal

. 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. Messages passed from London to Deal in about sixty seconds, and sixty-five sites were in use by 1808. Each shutter was five feet high. In 1816, Murray's shutter telegraphs were replaced by simpler semaphores invented by Sir Home Popham. 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 semaphore. Popham's 2-arm semaphore was modeled after the 3-arm Depillon French semaphore.

Chains of Murray's 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, 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 Cheshire...

, 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. The island is currently uninhabited....

, Voel Nant, Foryd, Llysfaen

Llysfaen

Llysfaen is a village in Conwy County Borough near the coast of north Wales and is located high above the coast. 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:This unusual and distinctive lighthouse was designed by Jesse Hartley, engineer to the Mersey Docks and Harbour Board from 1824 to 1860, but with additions by G Lyster some twenty years later.It is a...

, Carreglwyd, Cefn Du, Holyhead

Holyhead

Holyhead is the largest town in the county of Anglesey in the North Wales. It is also a major port adjacent to the Irish Sea serving Ireland....

London - Deal and Sheerness
Admiralty (London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

), West Square Southwark

Southwark

Southwark is a district of south London, England, and the administrative headquarters of the London Borough of Southwark. Situated east of Charing Cross, it forms one of the oldest parts of London and fronts the River Thames to the north...

, New Cross

Telegraph Hill, Lewisham

' is a place and electoral ward just south of New Cross in the London Borough of Lewisham in southeast London, England.The hill rises to around 30 metres. It was formerly known as Plowed Garlic Hill. It gained its current name from a semaphore telegraph station which was constructed on the summit...

, Shooter's Hill

Shooter's Hill

Shooter's Hill is a district and electoral ward in south London, England, located in the London Borough of Greenwich. 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 and eight miles south of Ramsgate. It is a former fishing, mining and garrison town...

.

(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 a large, ancient London park, 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...

(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 is a historic market town, and is now a sought-after dormitory town within the London commuter belt...

, 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 historic market 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, southeast 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 and county of Hertfordshire in England.It is situated on the Greenwich Meridian, which brushes the towns western boundary, and at the northernmost apex of the county on the same latitude of towns such as Milton Keynes and...

, 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 England. It is the regional administrative centre and county town of Norfolk. During the 11th century, Norwich was the largest city in England after London, and one of the most important places in the kingdom...

, 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, east of Norwich.It has been a seaside resort since 1760, and is the gateway from the Norfolk Broads to the sea...

.

London - Portsmouth and Plymouth
Admiralty (London), Chelsea Royal Hospital, Putney Heath, Cabbage Hill

Malden Rushett

Malden Rushett is a small settlement in the Royal Borough of Kingston upon Thames, London at the southernmost tip of the Royal Borough.-Facilities:...

, Netley Heath

Netley Heath

Netley Heath is an area of woods and heathland near Gomshall in Surrey, England. It has a significant geological stratum which gives rise to the name of "Netley Heath Beds"....

, Hascombe

Hascombe

Hascombe is a village in Surrey, England. It 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 southeastern England....

, 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 the second largest city in the ceremonial county of Hampshire on the south coast of England. Portsmouth is notable for being the United Kingdom's only island city; it is located mainly on Portsea Island...

(Southsea Common).

(branch) Beacon Hill

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 small historic village and civil parish in Hampshire, southern England, located about three miles north of Fareham. It is within the City of Winchester local government district, although it is considerably closer to Fareham than to Winchester...

, Town Hill, Toot Hill, Bramshaw

Bramshaw

Bramshaw is a small village and civil parish in Hampshire, England. It lies just inside the New Forest. The name Bramshaw means Bramble Wood. Until 1895, Bramshaw was divided into two parts, one half in Wiltshire, and one half in Hampshire...

, 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 Haldon, 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 shutter stations were temporary wooden huts, and at the conclusion of the Napoleonic wars they were no longer necessary. In 1816 they were replaced by a simpler semaphore system. However the Admiralty decided to establish a permanent link to Portsmouth and built a chain of semaphore stations. These were operational from 1822 until 1847, when the railway and electric telegraph provided a better means of communication. The semaphore did not use the same locations as the shutter chain, but followed almost the same route with 15 stations -

Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill

Claygate

Claygate is a village in the English county of Surrey, approximately south west of London and within the Metropolitan 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

Chatley Heath

Chatley Heath is part of 336 hectare reserve including Wisley Common and Ockham with a mixed habitats including heathland, ancient woodland and conifer woodland. On Chatley heath is a tower built as part of the Royal Navy Semaphore line....

, Pewley Hill

Pewley Hill

Pewley Hill is a hill 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 centuries much of the land was built upon....

, Bannicle Hill

Witley

Witley, in Surrey, England is a village south west of Godalming. The village lies just east of the A3 that runs from Guildford to Petersfield. Witley together with the neighbouring area of Hambledon have a population of about 4,000. Neighbouring villages include Milford, Chiddingfold and...

, Haste Hill

Haste Hill

Haste Hill is a hill near Haslemere, Surrey in England which was probably the original settlement of the town of Haslemere. It was used as the site of a semaphore station in the nineteenth century....

(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. Haslemere is approximately south-west of Guildford.Haslemere is surrounded by hills,...

), Holder Hill, (Midhurst), Beacon Hill

Harting

, Compton Down

Compton Down, Compton

Compton Down is an extent of high ground near Compton, West Sussex where there was an Admiralty semaphore station.The semaphore station was built at Compton Down in 1821 and it operated on the semaphore line from London to Portsmouth between 1822 and 1847. The hill to the east of Compton on...

, Camp Down

Camp Down, Portsdown Hill

Camp Down is a location at Portsdown Hill, Hampshire, which was used as an Admiralty semaphore station and later as a redoubt on the line of Palmerston Forts, Portsmouth....

, Lumps Fort

Lumps Fort

Lumps Fort is a disused fortification built on Portsea Island as part of the defences for the naval base at Portsmouth.Lumps Fort dates from the 18th century. The earliest reference is in the records of the Board of Ordnance in 1805 which mention "Lumps Fort-three 32-pounder guns".By 1822 the fort...

(Southsea) and Portsmouth Dockyard

HMNB Portsmouth

Her Majesty's Naval Base Portsmouth is one of three operating bases in the United Kingdom for the British Royal Navy...

. The semaphore tower at Chatley Heath, which replaced the Netley Heath station of the shutter telegraph, has been restored by Surrey County Council

Surrey County Council

Surrey County Council is the county council that governs the non-metropolitan county of Surrey in England. The council is composed of 80 elected councillors.The council is controlled by the Conservative party.The leader of the council is David Hodge....

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. Surrey County Council sits at Kingston upon Thames, although this has been part of...

, 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 forming part of 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.

In Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, Prince Edward, Duke of Kent established the first semaphore line in North America. In operation by 1800, it ran between the city of Halifax

City of Halifax

Halifax is a city in Canada, which was the capital of the province of Nova Scotia and shire town of Halifax County. It was the largest city in Atlantic Canada until it was amalgamated into Halifax Regional Municipality in 1996...

and the town of Annapolis

Annapolis Royal, Nova Scotia

Annapolis Royal is a town located in the western part of Annapolis County, Nova Scotia. Known as Port Royal until the Conquest of Acadia in 1710 by Britain, the town is the oldest continuous European settlement in North America, north of St...

in Nova Scotia

Nova Scotia

Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...

, and across the Bay of Fundy

Bay of Fundy

The Bay of Fundy is a bay on the Atlantic coast of North America, on the northeast end of the Gulf of Maine between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state of Maine...

to Saint John

Saint John, New Brunswick

City of Saint John , or commonly Saint John, is the largest city in the province of New Brunswick, and the first incorporated city in Canada. The city is situated along the north shore of the Bay of Fundy at the mouth of the Saint John River. In 2006 the city proper had a population of 74,043...

and Fredericton in New Brunswick

New Brunswick

New Brunswick is one of Canada's three Maritime provinces and is the only province in the federation that is constitutionally bilingual . The provincial capital is Fredericton and Saint John is the most populous city. Greater Moncton is the largest Census Metropolitan Area...

. 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

Quebec , also Québec, Quebec City or Québec City is the capital of the Canadian province of Quebec and is located within the Capitale-Nationale region. It is the second most populous city in Quebec after Montreal, which is about to the southwest...

. However, the many hills and coastal fog meant the towers needed to be placed relatively close together to ensure visibility. The required labour to build and continually man so many stations taxed the already stretched-thin British military and there is doubt the New Brunswick 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.

In 1801, the Danish post office installed a semaphore line across the Great Belt

Great Belt

The Great Belt is a strait between the main Danish islands of Zealand and Funen . Effectively dividing Denmark in two, the Belt was served by the Great Belt ferries from the late 19th century until the islands were connected by the Great Belt Fixed Link in 1997–98.-Geography:The Great Belt is the...

strait, Storebæltstelegrafen, between islands Funen

Funen

Funen , with a size of 2,984 km² , is the third-largest island of Denmark following Zealand and Vendsyssel-Thy, and the 163rd largest island of the world. Funen is located in the central part of the country and has a population of 454,358 inhabitants . The main city is Odense, connected to the...

and Zealand with stations at Nyborg

Nyborg

Nyborg is a city in central Denmark, located in Nyborg Municipality on the island of Funen and with a population of 16,492 . Nyborg is one of the 14 large municipalities created on 1 January 2007...

on Funen, on the small island Sprogø

Sprogø

Sprogø is a small, protected Danish island, which is located in the Great Belt, the strait that separates the main islands of Funen and Zealand...

in the middle of the strait, and at Korsør

Korsør

Korsør is a Danish town and port. It is out on the Great Belt, on the Zealand side, just south of where the Great Belt Bridge lands. It was the site of the municipal council of Korsør municipality - today it is part of Slagelse municipality...

on Zealand. It was in use until 1865.

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, it comprised almost two-thirds of the area of the German 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 of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

and Coblenz in 1833, and in Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal 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 kilometers...

inaugurated the line between Moscow

Moscow

Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

and Warsaw

Warsaw

Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...

(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 located south of Cape Cod in Massachusetts, known for being an affluent summer colony....

with Boston

Boston

Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...

, and its purpose was to transmit news about shipping. One of the principal hills in San Francisco, California

San Francisco, California

San Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...

is also named "Telegraph Hill

Telegraph Hill, San Francisco

Telegraph Hill refers to a neighborhood in San Francisco, California. It is one of San Francisco's 44 hills, and one of its original "Seven Hills."-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 an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

, 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 war between France and the allied powers of Spain, the United Kingdom, and Portugal for control of the Iberian Peninsula during the Napoleonic Wars. The war began when French and Spanish armies crossed Spain and invaded Portugal in 1807. Then, in 1808, France turned on its...

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 career British Army officer and statesman, and...

a decisive advantage in intelligence.

Semaphore in fiction

Pavane
Pavane (novel)
Pavane by Keith Roberts is an alternate history science fiction fix-up novel first published by Rupert Hart-Davis Ltd in 1968. Most of the original stories were published in Science Fantasy...

, an alternate history novel by Keith Roberts
Keith Roberts
Keith John Kingston Roberts , was an English 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 pseudonym...

, features a society where long distance communication is by a network of semaphores operated by the powerful Guild of Signallers.

Terry Pratchett's Discworld
Discworld
Discworld is a comic fantasy book series by English author Sir Terry Pratchett, set on the Discworld, a flat world balanced on the backs of four elephants which, in turn, stand on the back of a giant turtle, Great A'Tuin. The books frequently parody, or at least take inspiration from, J. R. R....

novels describe a system of 8-shutter semaphore towers, known as Clacks.

In Chapter 60 ("The Telegraph") of Alexandre Dumas' The Count of Monte Cristo
The Count of Monte Cristo
The Count of Monte Cristo is an adventure novel by Alexandre Dumas. It is often considered to be, along with The Three Musketeers, Dumas's most popular work. He completed the work in 1844...

, the title character describes with fascination the semaphore line's moving arms. "I had often seen one placed at the end of a road on a hillock, and in the light of the sun its black arms, bending in every direction, always reminded me of the claws of an immense beetle..." He later bribes a semaphore operator to relay a false message in order to manipulate the French financial market.

In chapter 10 of C. S. Forester's Hornblower and the Hotspur, the destruction of a French semaphore tower and a shore battery is a key plot point. A similar event is also the focus of the seventh episode of the A&E Horatio Hornblower series,

In David Weber's
David Weber
David Mark Weber is an American science fiction and fantasy author. He was born in Cleveland, Ohio. Weber and his wife Sharon live in Greenville, South Carolina with their three children and "a passel of dogs"....

Safehold
Safehold
Safehold is a science fiction book series by David Weber. , the series consists of five titles. The series is mostly set around the 31st century, on a distant world dubbed "Safehold" where a group of humans has hidden themselves from an alien race known as the Gbaba...

series, a world-wide Semaphore system is used by the Church to help them maintain their dominion over the world.

In Alastair Reynolds
Alastair Reynolds
Alastair Preston Reynolds is a British science fiction author. He specialises in dark hard science fiction and space opera. He spent his early years in Cornwall, moved back to Wales before going to Newcastle, where he read physics and astronomy. Afterwards, he earned a PhD from St Andrews, Scotland...

' Terminal World
Terminal World
Terminal World is a 2010 science fiction novel by Welsh author Alastair Reynolds . It is a standalone novel set in the distant future, and it chronicles the journey of Quillon, a pathologist forced into exile. The Gollancz hardcover edition of the book was published in March 2010 in the United...

, the distant-future terrain is criss-crossed with semaphore lines relaying information between the one remaining city, Spearpoint, outlying communities and the airborne community Swarm.

In the young adult fiction book Death Cloud
Death Cloud
Young Sherlock Holmes: Death Cloud is the first novel in the Young Sherlock Holmes series that depicts Arthur Conan Doyle's detective Sherlock Holmes as a teenager in the 1860s...

by Andy Lane
Andy Lane
Andrew Lane , who also writes as Andy Lane, is a British author and journalist. He has written a number of spin-off novels in the Virgin New Adventures range and audio dramas for Big Finish based on the BBC science fiction television series Doctor Who , as well as assorted non fiction books based...

, Mycroft Holmes
Mycroft Holmes
Mycroft Holmes is a fictional character in the stories written by Arthur Conan Doyle. He is the elder brother of the famous detective Sherlock Holmes.- Profile :...

tells 14-year-old Sherlock Holmes
Sherlock Holmes
Sherlock Holmes is a fictional detective created by Scottish author and physician Sir Arthur Conan Doyle. The fantastic London-based "consulting detective", Holmes is famous for his astute logical reasoning, his ability to take almost any disguise, and his use of forensic science skills to solve...

about semaphore stations, commenting about his school beforehand, saying "All the Latin a boy can cram into his skull, but nothing of practical use."

External links

Chappe's semaphore (an illustrated history of optical telegraphy)
Webpage including a map of England's telegraph chains
Diagrams and maps of Murray's U.K. semaphore stations
Photo and diagrams of Popham's U.K. semaphore stations
Map of visual telegraph (semaphore) and electrical telegraph lines in Italy, 1860 (in Italian)

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

History

France

Description

Sweden

U.K.

Other countries

Semaphore in fiction

See also

Further reading

External links