Sympiezometer, by Watkins and Hill, London, c. 1850

Simple wooden body with full length glazed panel to the front. Originally silvered copper alloy interior with a glass thermometer tube to the left and glass barometer tube to the right. Sliding scale to the right operated by a an exterior screw, and a rotating disk at the base operated at the outside; possibly for fine tuning. Total enclosed in the wood case with no opening doors to enable access.