Pearl Engine House

Located in a prominent position on the extreme north-east side of Parys Mountain. Accessed via a minor road leading W off the A5025.

The Pearl Shaft Engine House was constructed in the early C19 for the Mona Mine, to house an 18" Cornish Beam Engine, which was used for pumping water up the 600'(182.9m) deep Pearl shaft. The design is based on a Cornish engine house. The engine was in operation by 1819, when it was visited and described by the physicist Michael Faraday. The water in the shaft sump was lifted a short distance to a cistern by lift pump, from where a force pump pushed it up the shaft to another cistern, where the process was repeated. The Engine House fell into disuse when the mine ceased operating in 1904, was stripped of machinery and steadily became derelict. In 1992 the Welsh Mines Preservation Trust was formed and one of its first objectives was to promote the importance of the engine house as an industrial building and to raise funds and support to save the building from further collapse. In 1993 permission to proceed was granted by the landowner, the Marquis of Anglesey and consolidation work was carried out in mid to late 1990s. Copper ore had been extracted from Parys Mountain from the Bronze Age onwards, although operations before the late C18 were small-scale and piecemeal. In 1768 a rich deposit of copper ore was discovered, and the two opencast mines of Parys and Mona became the largest producers of copper in the world, with over 3000 tons(3048 tonnes) of copper produced annually between 1773 and 1785. Production levels had peaked by 1800, after which time production fluctuated. The underground workings were expanded after 1811, under the direction of Cornish mine captains. There was a brief boom in the early 1830s, but by the end of the century less than 500 tons(508 tonnes) was being raised annually. By 1904 the mines had closed, due to the competition from cheaper copper imported from America and Africa. The total production of copper from the area during the period between 1768 and 1904 has been estimated at 3.5 million tons(3.6 million tonnes) of ore, from which 130,000 tons(132,080 tonnes) of copper metal was recovered.