Claude Chappe

Semaphore

Semaphore is a visual signalling system invented by a Frenchman, Claude Chappe, in 1793. Different letters are represented by holding flags or lights outstretched in different positions around a circle. Prior to 1793, Chappe had experimented with a number of telegraph designs along with his brother, but these proved less than successful. The semaphore telegraph that Chappe designed consisted of a large pivoted horizontal beam, with two smaller bars attached at the ends, looking rather like a person with outstreched hands holding signal flags. The position of the horizontal beam could be altered, as well as the angle of the indicator bars at the ends. Chappe had developed the semaphore system to be used in the French revolution, to transmit messages between Paris and Lille, which was near the war front. In August 1794, Chappe's semaphore system delivered a message to Paris of the capture of Conde-sur-l'Escaut from the Austrians, in less than an hour. This success led to more semaphore telegraph lines being built, radiating in a star pattern from Paris. The semaphore network that was built in France represented the first telecommunications network in Europe. The semaphore system became widely copied and spread to Italy, Germany, and Russia. However, the invention of the electric telegraph was to signal the demise of semaphore, replacing it beginning in 1846.

[ Source of article ] [ semaphore.pdf ]