Description:Drawing 'No. 3.' of the inside view of the Poldory Engine seen from the Lower Wall. Also shows longitudinal section of the boiler and seating and external view of the chimney.
This engine was a typical Cornish pumping engine made by Boulton & Watt. It was single-acting, with a 48 inch cylinder and an 8 foot stroke. Poldory Mine was part of a group or 'set' of mines known as United Mines. The engine worked until 1794 when it was stopped due to the cylinder being completely worn out. It was replaced with a larger second-hand engine that United Mines bought from Pool Mine. This is a rare almost complete coloured set of drawings for a Cornish engine, with the explanatory key still surviving. The drawings are numbered 2 to 6 – what drawing No. 1 was is not recorded. [Scale: 3 feet to the inch]
This drawing is part of the Archives of Soho collection, which is held by Birmingham City Archives [Ref. MS3147/Portfolio/5/1289]