Others followed in the major ports of the United Kingdom (including Liverpool) and around the maritime world. The first time ball was erected at Portsmouth, England, in 1829 by its inventor Robert Wauchope, a captain in the Royal Navy. Following the introduction of the electric telegraph around 1850, time balls could be located at a distance from their source of mean time and operated remotely. Originally they either had to be stationed at the observatory, or had to keep a very accurate clock at the station which was set manually to observatory time. Time ball stations set their clocks according to transit observations of the positions of the sun and stars. Ancient Greek clocks had this system in the main square of a city, as in the city of Gaza in the post-Alexander era, and as described by Procopius in his book on Edifices. The fall of a little ball was in antiquity a way to show to people the time. Accurate timekeeping is essential to the determination of longitude at sea.Īlthough time balls have since been replaced by electronic time signals, some time balls have remained operational as historical tourist attractions. It consists of a large, painted wooden or metal ball that is dropped at a predetermined time, principally to enable navigators aboard ships offshore to verify the setting of their marine chronometers. Installed in 1833, a time ball sits atop the Octagon RoomĪ time ball or timeball is a time-signalling device.
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