Designed by Danny Hillis, this nine foot tall prototype clock was built by the Long Now Foundation to explore the mechanism needed for a clock intended to keep time for 10,000 years. The final version of the clock would be an enormous version of an architectural scale, big enough for visitors to walk through. To reduce wear, the clock uses a torsional pendulum which rotates slowly and the clock ticks only once every 30 seconds. It is controlled by a binary mechanical computer that counts the hours, the calendar and solar years, the centuries, and phases of the Moon and the Zodiac. The prototype is shown on display in the 'Making the Modern World' gallery at the Science Museum, London.
© Science Museum / Science & Society Picture Library