Funny you should say that! We have a semaphore mast just 5 klm from where I am writing this. Way back in the 1830's, when a ship was spotted entering the Tamar estuary, they would send a semaphore signal down to Launceston 50 klm away telling all about it, who was on board, what she was carrying etc. The message would get there in about 30 minutes!. No electricity, no smartphones, just a telescope to read the message from the relay masts - of which there were three!
I bet they did not have the scope mounted on a HEQ5 though!
