From 1852 to 1893, this master clock was the heart of Britain's time system. Its time was sent by telegraph wires to London, Edinburgh, Glasgow, Dublin, Belfast and many other cities. By 1866, time signals were sent from this clock to Harvard University in Cambridge, Massachusetts via the new transatlantic submarine cable. In terms of the distribution of accurate time into everyday life, this is one of the most important clocks ever made. A slave dial connected to this clock, at the gates of the Royal Observatory, was the first clock ever to show Greenwich Mean Time (GMT) directly to the public.Shepherd
