But clacks are optical telegraphs [1]; they communicate by semaphores, not wires. [1] https://en.wikipedia.org/wiki/Optical_telegraph https://en.wikipedia.org/

But clacks are optical telegraphs [1]; they communicate by semaphores, not wires. [1] https://en.wikipedia.org/wiki/Optical_telegraph https://en.wikipedia.org/wiki/Optical_telegraph