Moat
Construction
The observatory was over-constructed to reduce external vibrations. The basement and sub-basement area is surrounded by a ‘moat’ which separates the building from the surrounding physicality. The moat can still be accessed, and provides drainage for the building to this day.
The initial construction of Bidston Observatory was completed in 1866. It was built from, and in, the bedrock of Bidston Hill - Triassic windblown Sandstone [1].
- Details of moat size, span etc.
Functionality
Historically, this function facilitated the calibration of chronometers which was dependent on temperature and seismic vibration. The accurate readings could be adversely impacted by localised vibrations from people, animals, and even extreme weather.
Conversely, the seismic vibrations could also affect accurate telescope readings as the telescopes were supported from the building structure. Any seismic vibrations, whilst rare, would be unavoidable. By isolating the building structure from the surrounding physicality, immediate vibrations could also be reduced.
The moat still requires ongoing maintenance, notably regular clearing of fallen leaves which can cause rainfall build-up.
