The optical telegraph or semaphore (a composition of the Greek words 'sign' and 'carry') was the first usable optical telecommunication apparatus. Although the principle was already described in antiquity is not sure whether it was really used at that time. At the end of the 18th century Frenchman Claude Chappe designed a semaphore, also known as the Chapptelegraph, and in the following years a chain of semaphores connected Paris to Lille. Napolean understood the importance of this communucatiesystem and had built a 5,000 km network across France. The Chappetelegrafh played a big role for 50 years, until being replaced by the electric telegraph.
The semaphore inspired artist Philippe Druez (ON1PHD) in a mixed / multi-media project.