Claude Chappe

Claude Chappe (25 December 1763 – 23 January 1805) was a French inventor who in 1792 demonstrated a practical semaphore system that eventually spanned all of France. His system consisted of a series of towers, each within line of sight of others, each supporting a wooden mast with two crossarms on pivots that could be placed in various positions. The operator in a tower moved the arms to a sequence of positions, spelling out text messages in semaphore code. The operator in the next tower read the message through a telescope, then passed it on to the next tower. This was the first practical telecommunications system of the industrial age, and was used until the 1850s when electric telegraph systems replaced it.

Claude Chappe
AduC 175 Chappe (Claude, 1765-1828)
Claude Chappe
Born25 December 1763
Died23 January 1805 (aged 41)
NationalityFrance
OccupationEngineer
Engineering career
Projectssemaphore system
Significant advancetelecommunications

Life

Télégraphe Chappe - tour Jonquières 7
One example of Chappe telegraph tower, in Narbonne, in the south of France.

Claude Chappe was born in Brûlon, Sarthe, France, the grandson of a French baron. He was raised for church service, but lost his sinecure during the French Revolution. He was educated at the Lycée Pierre Corneille in Rouen.[1]

His uncle was the astronomer Jean-Baptiste Chappe d'Auteroche famed for his observations of the Transit of Venus in 1761 and again in 1769. The first book Claude read in his youth was his uncle's journal of the 1761 trip, "Voyage en Siberie". His brother, Abraham, wrote "Reading this book greatly inspired him, and gave him a taste for the physical sciences. From this point on, all his studies, and even his pastimes, were focused on that subject." Because of his astronomer uncle, Claude may also have become familiar with the properties of telescopes.[2]

He and his four unemployed brothers decided to develop a practical system of semaphore relay stations, a task proposed in antiquity, yet never realized.

Claude's brother, Ignace Chappe (1760–1829) was a member of the Legislative Assembly during the French Revolution. With his help, the Assembly supported a proposal to build a relay line from Paris to Lille (fifteen stations, about 120 miles), to carry dispatches from the war.

Télégraphe Chappe 1
Chappe's telegraph

The Chappe brothers determined by experiment that the angles of a rod were easier to see than the presence or absence of panels. Their final design had two arms connected by a cross-arm. Each arm had seven positions, and the cross-arm had four more permitting a 196-combination code. The arms were from three to thirty feet long, black, and counterweighted, moved by only two handles. Lamps mounted on the arms proved unsatisfactory for night use. The relay towers were placed from 12 to 25 km (10 to 20 miles) apart. Each tower had a telescope pointing both up and down the relay line.

Chappe first called his invention the tachygraph, meaning "fast writer"[3]. However, the Army preferred to use the word telegraph, meaning "far writer", which was coined by French statesman André François Miot de Mélito.[4] Today, in order to distinguish it from subsequent telegraph systems, the French name for Chappe's semaphore telegraph system is named after him, and thus is known as a télégraphe Chappe[5]. Alternatively, Chappe coined the phrase semaphore[6], from the Greek elements σῆμα (sêma, "sign"); and from φορός (phorós, "carrying"),[7] or φορά (phorá, "a carrying") from φέρειν (phérein, "to bear").[8]

In 1792, the first messages were successfully sent between Paris and Lille.[5] In 1794 the semaphore line informed Parisians of the capture of Condé-sur-l'Escaut from the Austrians less than an hour after it occurred. Other lines were built, including a line from Paris to Toulon. The system was widely copied by other European states, and was used by Napoleon to coordinate his empire and army.[5]

In 1805, Claude Chappe killed himself.[9] He was said to be depressed by illness, and claims by rivals that he had plagiarized from military semaphore systems.

Chappe semaphore
Demonstration of the semaphore

In 1824 Ignace Chappe attempted to increase interest in using the semaphore line for commercial messages, such as commodity prices; however, the business community resisted.

In 1846, the government of France committed to a new system of electric telegraph lines. Many contemporaries warned of the ease of sabotage and interruption of service by cutting a wire. With the emergence of the electric telegraph, slowly the Chappe telegraph ended in 1852.[5]

Popular culture

The Chappe semaphore figures prominently in Alexandre Dumas' The Count of Monte Cristo. The Count bribes an underpaid operator to transmit a false message.

A bronze sculpture of Claude Chappe was erected at the crossing of Rue du Bac and Boulevard Raspail, in Paris. It was removed and melted down during the Nazi occupation of Paris, in 1941 or 1942.[10]

See also

  • Chappe code

References

  1. ^ "Lycée Pierre Corneille de Rouen - The Lycée Corneille of Rouen". lgcorneille-lyc.spip.ac-rouen.fr. Retrieved 1 May 2018.
  2. ^ "The Early History of Data Networks". people.seas.harvard.edu. Archived from the original on 1 April 2017. Retrieved 1 May 2018.
  3. ^ Beyer, p. 60
  4. ^ Le Robert historique de la langue française, 1992, 1998
  5. ^ a b c d French source: Tour du télégraphe Chappe Archived 2011-09-28 at the Wayback Machine
  6. ^ Groundbreaking Scientific Experiments, Inventions & Discoveries of the 18th Century, Jonathan Shectman, p. 172
  7. ^ Oxford English Dictionary.
  8. ^ Webster's Unabridged Dictionary.
  9. ^ "Claude Chappe (French engineer)". Encyclopædia Britannica. Archived from the original on June 25, 2009. Retrieved August 7, 2009.
  10. ^ "Where the Statues of Paris were sent to Die". messynessychic.com. 7 January 2016. Archived from the original on 19 March 2018. Retrieved 1 May 2018.

Bibliography

  • Beyer, Rick, The Greatest Stories Never Told, A&E Television Networks / The History Channel, ISBN 0-06-001401-6

External links

1763 in science

The year 1763 in science and technology involved some significant events.

1792 in science

The year 1792 in science and technology involved some significant events.

1805 in France

Events from the year 1805 in France.

1805 in science

Significant events in 1805 in science and technology are listed.

Chappe

Chappe may refer to:

Claude Chappe (1763 – 1805), French inventor

David Chappe (1947 - 2002), American screenwriter

Georges Chappe (b. 1944), French cyclist

Jean-Baptiste Chappe d'Auteroche (1722-1769), French astronomer

Chappe (crater), lunar crater

16238 Chappe, main belt asteroid

a flap of leather attached to a sword's crossguard, also known as a rain-guard

Château de Montlhéry

The Château de Montlhéry is a castle in the commune of Montlhéry in the Essonne département of France. Ruins date from various periods, most notably the 10th, 11th, 13th and 14th centuries.The present 13th-century castle, with its prominent keep, succeeded a castle built in the 11th century, and an earlier foundation, built from 991 to 1015. The castle is a rectilinear pentagonal plan, with five surviving towers, one of which is much larger than the rest and serves as the keep, forming the point of the pentagon, at the end of the ridge. A gate tower protected the entrance on the opposite site. Recent evidence suggests that there may have a second court or bailey extending in front of the present gate, as well as a substantial chapel inside the presumed lower court.

Thanks to its position, the keep was notably connected with the scientific experiments of Pierre Gassendi (measurement of the speed of sound), Claude Chappe (experiments with optical telegraphy in 1794) and Alfred Cornu (measurement of the speed of light in 1874).

Visitors today can see the keep, the well, the moat and the remains of the curtain wall. The castle is state property. It has been listed since 1840 as a monument historique by the French Ministry of Culture.

Communications receiver

A communications receiver is a type of radio receiver used as a component of a radio communication link. This is in contrast to a broadcast receiver which is used to receive radio broadcasts. A communication receiver receives parts of the radio spectrum not used for broadcasting, that includes amateur, military, aircraft, marine, and other bands. They are often used with a radio transmitter as part of a two way radio link for shortwave radio or amateur radio communication, although they are also used for shortwave listening.

Foy-Breguet telegraph

The Foy-Breguet telegraph was an electrical telegraph of the needle telegraph type invented by Louis-François-Clement Breguet and Alphonse Foy in 1842. The system used two-needle instruments that presented a display using the same code as that on the optical telegraph of Claude Chappe. The Chappe telegraph was extensively used in France by the government, so this arrangement was appealing to them as it meant there was no need to retrain operators.

Lycée Albert Camus (Bois-Colombes)

Lycée Albert Camus is a French senior high school in Bois-Colombes, Hauts-de-Seine, France, in the Paris metropolitan area.

The school has German, Spanish, Italian, and English international sections.

Lycée Charles Petiet

Lycée polyvalent Charles Petiet is a senior high school/sixth-form college in Villeneuve-la-Garenne, Hauts-de-Seine, France, in the Paris metropolitan area.

Lycée Paul Lapie

Lycée Paul Lapie is a French senior high school/sixth-form college in Courbevoie, Hauts-de-Seine, France, in the Paris metropolitan area.

The school building, designed by Florent Nanquette, opened in the fall of 1933. The school's design plans had been made in 1930.

Musée de Radio France

The Musée de Radio France was a museum operated by Radio France and located in the Maison de Radio-France, near the Pont de Grenelle in the XVIe arrondissement at 116, avenue du Président Kennedy, Paris, France. The museum was established in 1966, and contained a remarkable collection of radios and televisions from their origins to the present day, including the 1793 telegraph by Claude Chappe and early crystal radios. The museum's 2000 objects include prototypes and commercial devices, archival documents, photographs, and manuscripts, replicas of early radio laboratories and studios, and exhibits featuring research by Edouard Branly, Lee de Forest, Heinrich Hertz, Guglielmo Marconi, James Clerk Maxwell, and Alexander Stepanovich Popov. In 2007, the museum was closed to the public due to the renovation of the Maison de Radio France.

Nanterre

Nanterre (French pronunciation: ​[nɑ̃.tɛʁ]) is a commune in the Hauts-de-Seine department, the western suburbs of Paris. It is located some 11 km (6.8 mi) north-west of the centre of Paris.

Nanterre serves as both the capital of the Hauts-de-Seine department and seat of the eponymous arrondissement.

The eastern part of Nanterre, bordering the communes of Courbevoie and Puteaux, contains a small part of the La Défense business district of Paris and some of the tallest buildings in the Paris region. Because the headquarters of many major corporations are located in La Défense, the court of Nanterre is well known in the media for the number of high-profile lawsuits and trials that take place in it. The city of Nanterre also includes the Paris West University Nanterre La Défense, one of the largest universities in the Paris region.

Optical communication

Optical communication, also known as optical telecommunication, is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. The earliest basic forms of optical communication date back several millennia, while the earliest electrical device created to do so was the photophone, invented in 1880.

An optical communication system uses a transmitter, which encodes a message into an optical signal, a channel, which carries the signal to its destination, and a receiver, which reproduces the message from the received optical signal. When electronic equipment is not employed the 'receiver' is a person visually observing and interpreting a signal, which may be either simple (such as the presence of a beacon fire) or complex (such as lights using color codes or flashed in a Morse code sequence).

Free-space optical communication has been deployed in space, while terrestrial forms are naturally limited by geography, weather and the availability of light. This article provides a basic introduction to different forms of optical communication.

Outline of telecommunication

The following outline is provided as an overview of and topical guide to telecommunication:

Telecommunication – the transmission of signals over a distance for the purpose of communication. In modern times, this process almost always involves the use of electromagnetic waves by transmitters and receivers, but in earlier years it also involved the use of drums and visual signals such as smoke, fire, beacons, semaphore lines and other optical communications.

Parcé-sur-Sarthe

Parcé-sur-Sarthe is a commune in the Sarthe department in the region of Pays-de-la-Loire in north-western France.

Semaphore telegraph

A semaphore telegraph is an early system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the mechanical elements; it is read when the shutter is in a fixed position. The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries. Lines of relay towers with a semaphore rig at the top were built within line-of-sight of each other, at separations of 5–20 miles (8.0–32.2 km). Operators at each tower would watch the neighboring tower through a spyglass, and when the semaphore arms began to move spelling out a message, they would pass the message on to the next tower. This system was much faster than post riders for conveying a message over long distances, and also had cheaper long-term operating costs, once constructed. Semaphore lines were a precursor of the electrical telegraph, which would replace them half a century later, and would also be cheaper, faster, and more private. The line-of-sight distance between relay stations was limited by geography and weather, and prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. Modern derivatives of the semaphore system include flag semaphore (a flag relay system) and the heliograph (optical telegraphy using mirror-directed sunlight reflections).

Telegraphy

Telegraphy is the long-distance transmission of textual messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensive and sophisticated as in China, were generally not capable of transmitting arbitrary text messages. Possible messages were fixed and predetermined and such systems are thus not true telegraphs.

The earliest true telegraph put into widespread use was the optical telegraph of Claude Chappe, invented in the late eighteenth century. The system was extensively used in France, and European countries controlled by France, during the Napoleonic era. The electric telegraph started to replace the optical telegraph in the mid-nineteenth century. It was first taken up in Britain in the form of the Cooke and Wheatstone telegraph, initally used mostly as an aid to railway signalling. This was quickly followed by a different system developed in the United States by Samuel Morse. The electric telegraph was slower to develop in France due to the established optical telegraph system, but an electrical telegraph was put into use with a code compatible with the Chappe optical telegraph. The Morse system was adopted as the international standard in 1865, using a modified Morse code developed in Germany.

The heliograph is a telegraph system using reflected sunlight for signalling. It was mainly used in areas where the electrical telegraph had not been established and generally uses the same code. The most extensive heliograph network established was in Arizona and New Mexico during the Apache Wars. The heliograph was standard military equipment as late as World War II. Wireless telegraphy developed in the early twentieth century. Wireless telegraphy became important for maritime use, and was a competitor to electrical telegraphy using submarine telegraph cables in international communications.

Telegrams became a popular means of sending messages once telegraph prices had fallen sufficiently. Traffic was became high enough to spur the development of automated systems – teleprinters and punched tape transmission. These systems led to new telegraph codes, starting with the Baudot code. However, telegrams were never able to compete with the letter post on price, and competition from the telephone, which removed their speed advantage, drove the telegraph into decline from 1920 onwards. The few remaining telegraph applications were largely taken over by alternatives on the internet towards the end of the twentieth century.

Télégraphe (Paris Métro)

Télégraphe is a station on line 11 of the Paris Métro in the 19th and 20th arrondissements. The station's tracks are separated by a supporting wall, because it is built in soft ground.

The station opened as part of the original section of the line from Châtelet to Porte des Lilas on 28 April 1935. It is named after the Rue de Télégraphe, which was once a chemin de ronde (a raised protected walkway behind a battlement) of the park of the Château de Ménilmontant. Its name comes from the optical telegraph invented by Claude Chappe (1763–1805) in 1792. This was the first practical telecommunications system, but was eventually replaced by the electric telegraph. Chappe installed the relay station, containing the telegraph's apparatus which he called a tachygraphe, on this peak of 128 meters altitude.

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