1-155-324 - Ann Ronan Picture Library/Heritage-Images

Gold mining, California, USA, c1868. Miners using a hydraulic method invented in California, washing down gold-bearing ore with a jet of water. The discovery of gold in 1848 led to mass immigration into California, with over half a million people from all over the world pouring into the state in search of riches. From Mines and Miners by L Simonin. (London, c1868).