Optical telegraph

semaphore linesemaphoreshutter telegraph chainsemaphore telegraphsemaphore towersemaphore systemsemaphore stationoptical telegraphysignal stationChappe Telegraph
An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals.wikipedia
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Claude Chappe

ChappeChappe brothersChappe Telegraph
The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries.
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.

Electrical telegraph

electric telegraphtelegraphtelegraph line
Semaphore lines were a precursor of the electrical telegraph, which would replace them half a century later, and would also be cheaper, faster, and more private.
In the 1840s the electrical telegraph superseded optical telegraph systems (except in France), becoming the standard way to send urgent messages.

Flag semaphore

semaphoresemaphore flagsflags
A modern derivative of the semaphore system is flag semaphore, the signalling with hand-held flags.
Semaphores were adopted and widely used (with hand-held flags replacing the mechanical arms of shutter semaphores) in the maritime world in the 19th century.

Code

encodingencodedencode
To speed up transmission and to provide some semblance of security, a code book was developed for use with semaphore lines.
For example, semaphore, where the configuration of flags held by a signaler or the arms of a semaphore tower encodes parts of the message, typically individual letters and numbers.

Richard Lovell Edgeworth

Richard EdgeworthRichard LovellEdgeworth
One of the first experiments of optical signalling was carried out by the Anglo-Irish landowner and inventor, Sir Richard Lovell Edgeworth in 1767.
The two men installed a semaphore line for Ireland.

Foy-Breguet telegraph

Foy-Breguet electrical telegraph
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.
The system used two-needle instruments that presented a display using the same code as that on the optical telegraph of Claude Chappe.

Parcé-sur-Sarthe

Parcé
Chappe settled on using an optical system and the first public demonstration occurred on 2 March 1791 between Brûlon and Parcé, a distance of 16 km.

Lord George Murray (bishop)

Lord George MurrayGeorge Murray
Lord George Murray, stimulated by reports of the Chappe semaphore, proposed a system of visual telegraphy to the British Admiralty in 1795.
Lord George Murray (30 January 1761 – 3 June 1803) 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.

Great Yarmouth

YarmouthGreat Yarmouth, NorfolkGt. Yarmouth
Chains of Murray's shutter telegraph stations were built along the following routes: London–Deal and Sheerness, London–Great Yarmouth, and London–Portsmouth and Plymouth.
From 1808 to 1814 the Admiralty in London could communicate with its ships in Yarmouth by a shutter telegraph chain.

HMNB Portsmouth

Portsmouth DockyardPortsmouthHM Dockyard, Portsmouth
The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations: Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort (Southsea), and Portsmouth Dockyard.
QHM Harbour Control is based in the Semaphore Tower building.

Lumps Fort

The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations: Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort (Southsea), and Portsmouth Dockyard.
By 1822 the fort was the site of a semaphore station on the semaphore line from London to Portsmouth.

Deal, Kent

DealDeal PierDeal, England
Chains of Murray's shutter telegraph stations were built along the following routes: London–Deal and Sheerness, London–Great Yarmouth, and London–Portsmouth and Plymouth. The British Admiralty accepted Murray's system in September 1795, and the first system was the 15 site chain from London to Deal.
Just outside the gates of the yard there is now a building originally used as a semaphore tower planned to be used as a communication link to the Admiralty in London but converted to a timeball tower, in 1855 which remains today as a museum.

Għargħur Semaphore Tower

Għargħur
Due to this, in 1848 new semaphore towers were constructed at Għargħur and Għaxaq on the main island, and another was built at Ta' Kenuna on Gozo.
The Għargħur Semaphore Tower (It-Torri tas-Semaforu tal-Għargħur) is a semaphore tower in the town of Għargħur, Malta.

Ta' Kenuna Tower

Ta' KenunaTa' Kenuna GardenTa’ Kenuna
Due to this, in 1848 new semaphore towers were constructed at Għargħur and Għaxaq on the main island, and another was built at Ta' Kenuna on Gozo.
Ta' Kenuna Tower (Torri ta' Kenuna) is a semaphore tower on the cliffs near Nadur on the island of Gozo, Malta.

Għaxaq Semaphore Tower

Għaxaq
Due to this, in 1848 new semaphore towers were constructed at Għargħur and Għaxaq on the main island, and another was built at Ta' Kenuna on Gozo.
The Għaxaq Semaphore Tower (It-Torri tas-Semaforu ta' Ħal Għaxaq), known locally as it-Turretta (the turret), is a semaphore tower in the town of Għaxaq, Malta.

Signilskär

Signilsskär
By 1797 there were also lines from Stockholm to Fredriksborg, and Grisslehamn via Signilsskär to Eckerö in Åland.
A thirty meter tall optical telegraph was constructed in 1796 which connected Åland to the Swedish telegraph network.

Telegraph hill

Many of the prominences on which the towers were built ('telegraph hills') are known as Telegraph Hill to this day.
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.

Heliograph

helioheliographic stationoptical signal
In some places, the heliograph replaced the optical telegraph rather than the electrical telegraph.
This is the first reliably documented heliographic device, despite much speculation about possible ancient incidents of sun-flash signalling, and the documented existence of other forms of ancient optical telegraphy.

Coombe, Kingston upon Thames

CoombeCoombe HillCoombe Warren
The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations: Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort (Southsea), and Portsmouth Dockyard.
In 1822 the Admiralty opened a semaphore station in the Warren, which was part of the semaphore line from London to Portsmouth.

Chatley Heath

The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations: Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort (Southsea), and Portsmouth Dockyard.
On the top of Chatley heath (formerly known as Breach Hill) is a tower built as part of the Royal Navy Semaphore line.

Abraham Niclas Edelcrantz

Abraham Niclas Clewberg-EdelcrantzAbraham EdelcrantzAbraham Niclas Clewberg
Inspired by news of the Chappe telegraph, the Swedish inventor Abraham Niclas Edelcrantz experimented with the optical telegraph in Sweden.
He is known for his experiment with the optical telegraph.

Claygate

Claygate, SurreyCoopers Hill
The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations: Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort (Southsea), and Portsmouth Dockyard.
On the other side on Telegraph Hill is a semaphore station built in 1822 to transmit messages between the Admiralty and Portsmouth.

Clermont-en-Argonne

ClermontAuzeville-en-ArgonneCount of Clermont
In 1819 Norwich Duff, a young British Naval officer, visiting Clermont-en-Argonne, walked up to the telegraph station there and engaged the signalman in conversation.
The telegraph station was one in line of a semaphore line constructed in the Napoleonic period for the rapid transmission of messages between Paris and Landau; but by 1819 France's eastern frontiers had been much reduced, and the final point of this telegraph line was first Landau and after 1819 Strasbourg.

Wimbledon Common

Putney HeathWimbledon and Putney CommonsWimbledon
The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations: Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort (Southsea), and Portsmouth Dockyard.
Because of its elevation, from 1796 to 1816 Putney Heath hosted a station in the shutter telegraph chain, which connected the Admiralty in London to its naval ships in Portsmouth.

Pewley Hill

The semaphore line did not use the same locations as the shutter chain, but followed almost the same route with 15 stations: Admiralty (London), Chelsea Royal Hospital, Putney Heath, Coombe Warren, Coopers Hill, Chatley Heath, Pewley Hill, Bannicle Hill, Haste Hill (Haslemere), Holder Hill, (Midhurst), Beacon Hill, Compton Down, Camp Down, Lumps Fort (Southsea), and Portsmouth Dockyard.
An Admiralty semaphore station was built at Pewley Hill in 1822 forming part of the London-Portsmouth semaphore line.