... between Paris and Lille, a distance of 230 kilometres (about 143 miles) ... The first symbol of a message to Lille would pass through 15 stations in only ni

... between Paris and Lille, a distance of 230 kilometres (about 143 miles) ... The first symbol of a message to Lille would pass through 15 stations in only nine minutes. The speed of the line varied with the weather, but the line to Lille typically transferred 36 symbols, a complete message, in about 32 minutes ... [1] So a short message could be sent at around 450km/h, like two orders of magnitude faster than the postal service it partially replaced, or, I guess that more likely for that kind of communication, still more than on order of magnitude faster than messenger pigeons. Then again, snail mail obviously still had vastly greater throughput. [1] https://en.wikipedia.org/wiki/Semaphore_line https://en.wikipedia.org/wiki/Semaphore_line