> In Terry Pratchett's science-fantasy Discworld series, "The Clacks" is a network infrastructure of Semaphore Towers, that operate in a similar fashion to telegraph - named "Clacks" because of the clicking sound the system makes as signals send.
Surely named "Clacks" because of the clacking sound the system makes.
The Clacks is a copy of an optical telegraph system that was used in Sweden
https://en.m.wikipedia.org/wiki/Abraham_Niclas_Edelcrantz
Also UK used a system close to that. And a lot of countries along Europe developed their networks with different signaling devices.