The immensely complicated astronomicalclock built by Richard of Wallingford, abbot of St Albans, was so complex it took eight years to run through its full cycle of calculations and was the most intricate machine ever built up to that point.
Seen in motion, this is at once a powerful skeleton clock and a curious astronomical one, a gift to anyone for whom a modern clock can do so much more than just tell the time.
His realization was that the solution wouldn't come from improved astronomical readings, as many thinkers believed, but from an extremely accurate clock that could tell the time of the home port while at sea.