Smoke signals, drum telegraphs, and the marathon runner are all examples of man’s effort to conquer the tyranny of distance. However, the first truly successful solution to the problem of rapidly transmitting language across space was the Frenchman Claude Chappe’s optical telegraph.
Chappe's chain of stone towers, topped by 10-ft. poles and 14-ft. pivoting cross members, and spaced as far apart as the eye could see, was first demonstrated to the public in March of 1791 on the Champs Elysees.
Chappe created a language of 9,999 words, each represented by a different position of the swinging arms. When operated by well-trained optical telegraphers, the system was extraordinarily quick. Messages could be transmitted up to 150 miles in two minutes.
Eventually the French military saw the value of Chappe’s invention, and lines of his towers were built out from Paris to Dunkirk and Strasbourg. Within a decade, a network of optical telegraph lines crisscrossed the nation. When Napoleon seized power in 1799, he used the optical telegraph to dispatch the message, “Paris is quiet and the good citizens are content.”
Renovated in 1998, the optical telegraph next to the Rohan Castle in Saverne functioned as part of the Strasbourg line from 1798 until 1852. It is one of several remaining relay points in the system that can still be visited today.