King Henry VIII commissioned Nicolas Kratzer (a Bavarian and friend of court painter Hans Holbein) to design an astronomical clock for his palace at Hampton Court, which was installed around 1540. The astronomer and ‘Devisor of the King’s Horologes’, working with French clockmaker Nicholas Oursian, created not only a marvel of Tudor engineering with complex mechanics, but also an enviable work of art. It also had great practical use showing the time, month, day of the month, position of the sun in the zodiac, the phase and age of the moon. It also determined the time at which the moon would cross the meridian and therefore the time of high water at London Bridge, useful if you, like King Henry, travelled to London by Royal Barge.

Originally there were two clock faces, one on either side of the gatehouse, both powered by the complex mechanical and gearing system created by Oursian (whose initials, N.O., and the date 1540 can still be seen on the mechanism). The smaller dial which faced Base Court was for guests, however, this was replaced in 1835 by a slate clock face from St James’s Palace bearing the monogram of William IV. The larger dial, measuring over 2.5 metres wide, overlooked the royal courtyard and survives today with a still striking, although probably less intricate, paint scheme. A description of works by George Gower, ‘Serjannte Painter’ to Elizabeth I, gives us insight into how spectacular the original Tudor dial looked with seas, ships and continents depicted:

’for cleansing of the two dialls the great diall with the howres of the day and the night, the course of the Sunne and Mone, xii Signes with the Carectors of the Planetts …, the Sea, shipps and Territories …all wrought in oyle coullors as Vermilion, Bise, White leade etc and gilded with fine golde…’