David Allan painted a fascinating set of pictures when the Industrial Revolution was taking hold in Scotland. The setting is the famous lead mines at Leadhills in South Lanarkshire, owned by the 3rd Earl of Hopetoun, who commissioned these paintings. They show the four key stages in lead processing, of which this is the second. The broken ore needed to be washed several times to sift out impurities. The waste water, often contaminated with arsenic, sulphur and zinc, compounded the pollution from toxic fumes emanating from the smelters.