This wonderful item is not usually visible to visitors as it is hidden in the tower. The plaque says that it was "thoroughly repaired and altered to eight day" by Charles Porter of Southwark in 1841, but its original date of manufacture is unclear.
It still drives the two clock faces on the north and
south of the tower, and keeps good time. It is able, if set, to chime the hours (but it disturbs the
neighbours!)
This page updated 23 September 2010