Becoming operational in 1855, this ball was raised up and then dropped at 1 o'clock so that the ships waiting in the channel could set their timepieces to Grenwich Mean Time The time signal was sent down telegraph wires from Grenwich alongside the South Eastern Railway line. It operated until reliable radio time signals were established in 1927. It now runs as a museum and the ball is dropped on the hour from 9am to 5pm. I've never seen it drop as Tetters hasn't got the patience to wait there
