So I was curious what this was called by contemporaries, because "optical telegraph" seems like an overly-specific construction. And sure enough, Wikipedia tel

So I was curious what this was called by contemporaries, because "optical telegraph" seems like an overly-specific construction. And sure enough, Wikipedia tells us that its inventor, Claude Chappe, coined the terms semaphore and tachygraph, while a French statesman preferred to apply the novel term telegraph. "Optical" was clearly applied in retrospect, after its electrical counterpart came on the scene. Fun semaphore fact: the Peace Symbol, popularized along with the smiley face by hippies, is a superposition of two semaphores: "N" and "D", meaning "Nuclear Disarmament".