This clock was used by mariners to set their Chronometers to the correct time. It stood at a window in the small Transit House. The outer facing clock-face could be seen by mariners without the need to enter into the Transit House and disturb the Astronomer. Meanwhile, the Astronomer could use the inner facing clock-face when he required to access the time.
The clock dates from about 1812. It is commonly referred to as a “Politician’s Clock”. It continued to be used in the Transit House even after the process of measuring accurate time passed to the main observatory building.
The case is almost certainly original, but the mechanical workings were replaced by electrical ones at some time in its history.
Dr Bruce Vickery