The Rise and Fall of the Visual Telegraph (2017)

Summary

Sometimes we go looking for blog ideas, and sometimes they come along and tap us persistently on the shoulder. This one did – three times. First, I spotted an “advertorial” in a 1912 issue of a small American magazine called The Philistine. It was a two-page item on “Napoleon’s Visual Telegraph: The First Long-Distance System” and it was sponsored by American Telephone and Telegraph. The illustration looked vaguely familiar. A few days later, I was hunting for a postcard in our collection and I ran across this one of “La Tour du Télégraphe” in Montmartre, sitting on top of what appear to be the ruins of a church. But I still wasn’t sure what I was looking at. What was that thing on the tower? Finally, out of the blue, my stepson Alex sent us a link to an article from The Economist about “the world’s first cyber-attack” featuring this same telegraph system. When I mentioned this to Norman, he looked thoughtful and went to find a history of telegraphy called The Victorian Internet by Tom Standage as well as Volume IV of the Oxford History of Technology. And so I came to read about Claude Chappe (1763–1805) and the world’s first telegraph system. Claude Chappe, whose intended career as a member of the clergy was derailed by the French Revolution, became obsessed with finding a way to communicate at a distance. His first effort, with his brother René, used sounds that corresponded to numbers that could be decoded into messages. But he soon realized that visual methods would allow for communications over even longer distances. So he experimented with a large disc painted black on one side and white on the other that could be used to transmit numerical information; if the receiver used a telescope, the information could be detected 16 km away. The brothers demonstrated their invention in 1791, and a friend of theirs suggested the name “télégraphe” – meaning “far writing.” Still, the process of transmitting numbers with a simple black/white, on/off system and then decoding...