There has been a clock in Trinity Great Court since 1610. A new clock and dial-plate were put in place under the Mastership of Richard Bentley, in 1726–27. The original "1610" clock mechanism was given to the village of Orwell. It still runs today in the tower of the village church. Meanwhile in Trinity two new bells were provided for the chimes before the striking and the wooden bell-tower on top of the gate was modified from the original one constructed in 1610. This wooden tower was replaced by a replica in 1856–57. The new clock with its new bells was notable for striking the hour twice, first on a low note and then on a much higher one.
In 1910 the old clock was replaced yet again by the mechanism which is still now in place. It was built by Smith of Derby to a design by Lord Grimthorpe very much along the lines of the mechanism used for the clock in the Palace of Westminster ("Big Ben"). The clock is governed by a temperature-compensated pendulum 2 metres in length driven by a three-legged gravity escapement. It is a remarkable instrument, capable of keeping time to better that one second in a month without any intervention. It is possible to monitor the present state of "going" of the clock by visiting the website here
For info on the Great Court Run go here
Dr Hugh Hunt
(For other gyroscopic things: go to Gyro and boomerang page
and for all sorts of video clips on spinning things go to: Dynamics movies page
and for other stuff: go to Hugh Hunt's Cambridge University home page )