Grasshopper Escapement - John Taylor's Corpus Clock

John Taylor's Corpus Clock

A unique public clock built as a tribute to John Harrison's grasshopper escapement, the Corpus Clock, was unveiled at Corpus Christi College, Cambridge University, in Cambridge, England on 19 September, 2008. Industrialist John Taylor spent £1 million building the mechanical clock. Feeling that Harrison's escapement was not well enough known, the clock's grasshopper escapement is exposed on the top of the clock, built in the form of a demonic grasshopper called the "Chronophage" or "time eater", which rhythmically opens and closes its jaws, representing time being devoured.

The clock, 1.5 metres in diameter, has many other notable features. It has no hands, but rather uses three concentric pairs of stacked annular disks—one pair each for hours, minutes and seconds—slotted and lensed to allow the selective escape of light from an enclosed, continuously lit set of light emitting diodes. The arrangement of slots in each disk, along with the rotation of the foremost disk of each pair, creates a Vernier effect, producing the illusion of lights rotating at various speeds about three concentric circumferences on the clock's face.

The pendulum speeds up, slows down, and sometimes stops, but returns to the correct time every five minutes. Taylor designed the clock to remind himself of his own mortality.