A post-medieval lead mine in Laxey. The Great Laxey Mine was worked for lead, zinc, silver and copper from around 1782 until closure in 1929 (with residual working of spoil continuing to about 1934), and consisted primarily of three main shafts - the Welsh Shaft, Dumbell's Shaft and the Engine Shaft - linked by a series of levels reaching a depth of over 2,200 ft (670 m). By 1833 it employed more than 200 men and was, for a time, extremely profitable, with its ore including a galena specimen that holds the world record for the largest sulphide crystal by both volume and mass, now on display at the Natural History Museum, London. The mine's pumping was powered by the Laxey Wheel (the "Lady Isabella"), built during the mine's period of greatest prosperity. A fire in the Welsh Shaft in March 1904 was safely contained, but an accident in December 1904 killed four miners who fell into a flooded sump; they were buried at Lonan Churchyard.