Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Parallelmotion enlightened me on the history of Hour Balls and their function before the industrial age:

"They were used in ports and dropped at specific times so that mariners could set their ship's chronometers accordingly. Now we only drop one in Times Square at New Years."

He also recommended a book by Dava Sobel entitled "Longitude" about John Harrison, an 18th-century clockmaker who created the first clock (chronometer) sufficiently accurate to be used to determine longitude at sea—an important development in navigation.

https://en.wikipedia.org/wiki/Longitude_(book)