19th-century gold mining, California. Artwork of miners using a high-pressure water hose to break up a hillside containing gold ore, in California, USA. This will weaken the ground and cause the hillside to collapse. The workers will then break up the fragments and extract the small amounts of gold. This cheap method is used for areas that only contain a small amout of gold. Artwork from Mines and Miners (L. Simonin, 1868).