The Hydraulic Telegraph

There's one from, not the oldest of greek history, but like maybe fourth century b c, greece, that is called a a hydraulic telegraph. Picture two people within line of sight, but a long ways across and you want to communicate across this bay. You use a torch, with both buckets with identical messages on opposite sides of the hill full, you use a torch to signal open the spigot. Then you just read that message. So it's kind of like, that's genius text, auto reject. Oh, i love it. Isn't that cool? That's amazing.