1-158-475 - Oxford Science Archive/Heritage Images

Washing ore to extract gold, 1683. Water is fed into a sieve containing crushed ore. The solution containing ore in suspension is fed along collecting pans, often lined with dark woollen cloth. Gold, being the heaviest ingredient, is separated out on the way. From a 1683 English edition of Beschreibung allerfurnemisten mineralischen Ertzt by Lazarus Ercker. (Prague, 1574).