The Lady Isabella water wheel at Laxey is 22m in diameter, and is reputedly the largest in the world. It was designed by Robert Casement, began work on 27 September 1854, and operated pumps in nearby lead and zinc mines, although its estimated power output of 200 hp was much more than was required for that purpose. The pump rods were carried on a 34-arch stone viaduct, and there are extensive remains of the ore-dressing floors. The wheel was always intended to be a spectacular feature of the Manx landscape, and was depicted on postcards and tourist souvenirs from the time it was built. Laxey is situated on the Manx Electric Railway, and is the terminus of an electric rack railway that climbs to the summit of Snaefell.