Optical Telegraph (Semaphore System)
The Semaphore Optical Telegraph was invented by the Chappe brothers in France in 1792. Claude Chappe, the primary inventor, first called this device a tachygraph, ‘that which writes fast.’ It was eventually renamed the telegraph, ‘that which writes at a distance’ by the French army, who used the Semaphore Telegraph system for coordination in battle. The etymological history of this technology suggests that it enabled major breakthroughs in both speed and geographical reach for short-form, long distance, text-based messaging.
The Semaphore Telegraph system was comprised of towers that each had two arms that were connected by a cross-arm and controlled by pulleys and wheels. The operator of the semaphore telegraph would relay messages by physically adjusting the positions of the arms. Arm positions were decoded and transcribed into text by the operator in the next tower who used a telescope and a Semaphore System Code Book. The operator would then repeat this process to relay the message to the next tower. Messages could be relayed from tower-to-tower until they reached their final destination. Since this was an inherently visual technology, the towers were roughly 25km apart from one another in order to maintain line of sight.
The Semaphore Telegraph was the first mechanical system for long distance communication to be invented. It was in widespread use through the mid-19th century in France, and in its peak “comprised 534 stations covering more than 5,000 km” (Schofield, 2013). This system reduced the time it took to send a message from Paris to the borders of the country from three to four days to three to four hours (Schofield, 2013). Other countries like Sweden, the UK and Spain developed extensive networks, sometimes using alternative signaling mechanisms and codes but following the same principle (Villar-Ribera, 2011).
The Semaphore System’s prominence was short-lived. In 1846, France began to replace the Semaphore Telegraph system with the Electrical Telegraph. By 1852, the Semaphore Telegraph was no longer in use. It was expensive to maintain, required strenuous manual labor, and relied on too many factors that could not be controlled. These include daylight and good weather. (n addition, messages were neither secure nor private, as they were on public display in necessarily highly visible locations. In spite of its relatively quick disappearance, the Semaphore Telegraph’s impact can still be seen today. Physical and therefore permanent networks were established connecting major cities as well as rural areas, which, through fast transmission of urgent messages, enabled collective national experiences. Historical messages like the French military victory at Quesnoy in 1794 and the news of Napoleon’s success in seizing power in 1799 were relayed through the Semaphore Telegraph networks (Flichy, 1993).
BBC, June 17, 2013. https://www.bbc.com/news/magazine-22909590.
Stamp, Jimmy. “How the Telegraph Went From Semaphore to Communication Game Changer.”
Smithsonian.com. Smithsonian Institution, October 11, 2013.
https://www.smithsonianmag.com/arts-culture/how-the-telegraph-went-from-semaphore-
to-communication-game-changer-1403433/.
“Telegraph (n.).” Index. Accessed December 8, 2019.
https://www.etymonline.com/word/telegraph.
Villar-Ribera, Ricardo, Francisco Hernández-Abad, José Ignacio Rojas-Sola, and David Hernández-Díaz. "Agustin de Betancourt's telegraph: Study and virtual reconstruction." Mechanism and machine theory 46, no. 6 (2011): 820-830.
Flichy, Patrice. "The Birth of Long Distance Communication. Semaphore Telegraphs in Europe (1790-1840)." Réseaux. Communication-Technologie-Société 1, no. 1 (1993): 81-101.
