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

Jan Oosterhof, on September 25, 2007, said:

Claude 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.

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.

In 1792, the first messages were successfully sent between Paris and Lille