Semaphore Line - History

History

Optical telegraphy dates from ancient times, in the form of hydraulic telegraphs, torches (as used by ancient cultures since the discovery of fire) and smoke signals.

Modern design of semaphores was first foreseen by the English scientist Robert Hooke, who first gave a vivid and comprehensive outline of visual telegraphy to the Royal Society in a submission dated 1684 in which he outlined many practical details. The system (motivated by military concerns, following the recent Battle of Vienna in 1683) was never put into practice.

The first achieved optical telegraph arrived in 1792 from the French engineer Claude Chappe and his brothers, who succeeded in covering France with a network of 556 stations stretching a total distance of 4,800 kilometres. It was used for military and national communications until the 1850s.

Many national services adopted signaling systems different from the Chappe system. For example, Britain and Sweden adopted systems of shuttered panels (in contradiction to the Chappe brothers' contention that angled rods are more visible). In Spain, the engineer Agustín de Betancourt developed his own system which was adopted by that state. This system was considered by many experts in Europe better than Chappe's, even in France.