On a hill near Liverpool, England, stands the Bidston Observatory. Built in 1867, it initially provided, by astronomical observation, the correct time for setting the chronometers of the ships that used the harbour and docks at the mouth of the River Mersey. With the advent of radio, the time-keeping function of the Observatory became redundant but, in keeping with tradition, it maintained responsibility for the timing of the ‘One O'Clock Gun’ that was a feature of Merseyside life until 1969. Earlier, however, in 1929, the building also took on an additional function when the University of Liverpool transferred into it ingenious facilities for the prediction of tides. Then renamed the Bidston Tidal Institute and Observatory, the facility became largely responsible for tidal predictions throughout the world in regions of British influence, helped on a smaller scale by a similar facility established under British jurisdiction in India. Even until late in the twentieth century there stood in the entrance hall of the Bidston building a mechanical tide predictor. It was an impressive museum piece after it ceased to be used in the 1950s, and was in the form of a large machine comprised of fixed and moving pulleys, gears and revolving drums. The pulleys were designed to mimic the changing interrelationships of the earth, moon and sun, in terms of their relative movements and distances from each other.