New Zealand - Cromwell - Hydraulic mining - circa 1885 - Photographer: Walter Burton Alfred Burton Hydraulic mining - A form of mining that uses high-pressure jets of water to dislodge rock material or move sediment - In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold. - It is also used in mining kaolin and coal. - Hydraulic mining developed from ancient Roman techniques that used water to excavate soft underground deposits. - Its modern form, using pressurized water jets produced by a nozzle called a "monitor", came about in the 1850s during the California Gold Rush in the United States. - Though successful in extracting gold-rich minerals, the widespread use of the process resulted in extensive environmental damage, such as increased flooding and erosion, and sediment blocking waterways and covering farm fields. - These problems led to its legal regulation. Hydraulic mining has been used in various forms around the world. (Reference: Wikipedia) Cromwell - A town in Central Otago - A prominent feature surrounding much of the town is the man-made Lake Dunstan - Cromwell also has the newly constructed Highlands Motorsport Park - Cromwell is also the home of the Cromwell Chafer Beetle - Cromwell was originally known as "The Junction", being at the confluence of the Clutha and Kawarau Rivers. (Reference: Wikipedia) Image source: Auckland Art Gallery Toi o Tāmaki, purchased 1976 https://www.aucklandartgallery.com/explore-art-and-ideas/artwork/4379