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History

The telegraph was invented by Claude Chappe (1763 - 1805). The Chappe brothers carried out on March 3, 1791 a first public experiment of air telegraph of Brûlon with Parcé on a distance of 14 km. The air telegraphs were adopted on July 26, 1793 by national Convention. July 16, 1794 the first official line Paris-Lille was brought into service.


In a few years, 5000 km of network and nearly 533 stations were set up, covering a significant part of the French territory.

The success of the optical telegraph grew blurred and Bonaparte reduced into 1800 the appropriations aloués to their construction and maintenance. Claude Chappe did not support this disavowal and desperate threw itself in a well in 1805 at the 42 years age. The brothers continued the development of the optical telegraph until 1830, date on which it was definitively stopped.

The defect of the telegraph of Cap is that it does not function during the night and by time of fog. This defect had a considerable importance in the French history: At the time of the return of Napoleon during the hundred days, this one unloaded on March 1, 1815 with 1200 men with the Gulf Juan, but Paris, then under the reign of Louis XVIII, learned it by the telegraph from Cap only on March 5, 1815, due to fog. So Napoleon was not intercepted (without success) only with the lake of LAFFREY right before Grenoble, March 7, 1815.

 

The telegraph of Cap was replaced then by the electric telegraph.


Principle of operation
the telegraph of the Chappe brothers is a 5 height m mechanical device made up:

- of two wings or indicators 2 meters length and 30 cm broad.
- counterweight to ensure the balance of the unit.
- of a manipulator to put moving the wings.


Detail of a manipulator of the Chappe's telegraph exposed to the Museum

 

The Chappe telegraph was placed on a natural height (hill, mountain) or artificial (turn).

 

The Chappe's telegraph at the Museum
Animated gif by Philippe Morin

The manipulator modified the position of the wings to transmit a message according to an established code. This visible message by far was observed using glasses.

 

 

 

 

Telescop for Chappes' telescop at the Museum

 

 

 

 

The codes used were not the same ones according to countries' but the objectives remained identical: speed of transmission and confidentiality of the message.


 

 

 

 

An original apparatus: The electric telegraph with signals Cap In 1850, i.e. approximately 17 years after the realization of the first electric needle telegraphs, an apparatus was developed by associating the modern techniques of the electric telegraph and that of the Chappe telegraph.

 

The electric telegraph with Chappe's signals at the Museum

This telegraph was then replaced by the recording telegraphs (Morse, Wheastone) which made it possible to keep a trace of the message sent

To discover the evolution of the telegraphs, click on one of the images of the electric telegraphs with wire.

Principe des télégraphes électriques et historique télégraphe de Bréguettélégraphe de Morsetélégraphe de Hugues pantélégraphe de Caselli

The pictures are placed by chronological apparition time of telegraph

 
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