In the 19th century Cornish mining reached its zenith, before foreign competition depressed the price of copper, and later tin, to a level that made the extraction of Cornish ore unprofitable.
The areas of Cornwall around Gwennap and St Day and on the coast around Porthtowan were among the richest mining areas in the world.
At its height the Cornish tin mining industry had around 600 steam engines working to pump out the mines (many mines reached under the sea and some went down to great depths).
Adventurers put up the capital, hoping that the mine would return them a profit, but the outcomes were very uncertain.

Caradon Hill had the most productive mine in east Cornwall.
The South Caradon Copper Mine, 1 km to the southwest of the Caradon Hill transmitting station, was the largest copper mine in the UK in its heyday in the second half of the 19th century.
Other disused copper and tin mines are scattered around the base of the hill.
By the mid-19th century Looe had become a major port, one of Cornwall's largest, exporting local tin, arsenic, and granite, as well as hosting thriving fishing and boatbuilding industries.
At Callington arsenic was found with copper ores and was processed by crushing and condensing; the poisonous nature of dust containing arsenic made the work very hazardous.
Numerous precautions were taken but the workers tended to die in middleage.
Menheniot was a centre of lead mining and is now surrounded by disused shafts and engine houses.
Lead seams were discovered in the 1840s and Menheniot became the centre of a mining boom which lasted until the 1870s.
During this period the population doubled.
Kit Hill Country Park is steeped in mining history.
Metals extracted included, tin, silver, copper, and tungsten.
The main mines were Kit Hill Summit Mines (which included a windmill near the present stack) (started about 1826; Kit Hill United closed in 1864); East Kit Hill Mine, worked from 1855 to 1909; Hingston Down mine (which worked westwards towards Kit Hill, may have started in the 17th century, it closed in 1885; and South Kit Hill Mine, worked from 1856 to 1884.

The last Cornish Stannary Parliament was held at Hingston Down in 1753, and the Devon Stannary Parliament last met in 1748.
The Stannary Courts of Devon and Cornwall were combined in 1855 and their powers transferred to local authorities in 1896.

By the middle and late 19th century, Cornish mining was in decline, and many Cornish miners emigrated to developing mining districts overseas, where their skills were in demand: these included South Africa, Australia and North America.
Cornish miners became dominant in the 1850s in the iron and copper districts of northern Michigan in the United States, as well as in many other mining districts.
In the first six months of 1875, over 10,000 miners left Cornwall to find work overseas.
In the 19th century Cornish mining reached its zenith, before foreign competition depressed the price of copper, and later tin, to a level that made the extraction of Cornish ore unprofitable. The areas of Cornwall around Gwennap and St Day and on the coast around Porthtowan were among the richest mining areas in the world. At its height the Cornish tin mining industry had around 600 steam engines working to pump out the mines (many mines reached under the sea and some went down to great depths). Adventurers put up the capital, hoping that the mine would return them a profit, but the outcomes were very uncertain.
Caradon Hill had the most productive mine in east Cornwall. The South Caradon Copper Mine, 1 km to the southwest of the Caradon Hill transmitting station, was the largest copper mine in the UK in its heyday in the second half of the 19th century. Other disused copper and tin mines are scattered around the base of the hill. By the mid-19th century Looe had become a major port, one of Cornwall's largest, exporting local tin, arsenic, and granite, as well as hosting thriving fishing and boatbuilding industries. At Callington arsenic was found with copper ores and was processed by crushing and condensing; the poisonous nature of dust containing arsenic made the work very hazardous. Numerous precautions were taken but the workers tended to die in middleage. Menheniot was a centre of lead mining and is now surrounded by disused shafts and engine houses. Lead seams were discovered in the 1840s and Menheniot became the centre of a mining boom which lasted until the 1870s. During this period the population doubled. Kit Hill Country Park is steeped in mining history. Metals extracted included, tin, silver, copper, and tungsten. The main mines were Kit Hill Summit Mines (which included a windmill near the present stack) (started about 1826; Kit Hill United closed in 1864); East Kit Hill Mine, worked from 1855 to 1909; Hingston Down mine (which worked westwards towards Kit Hill, may have started in the 17th century, it closed in 1885; and South Kit Hill Mine, worked from 1856 to 1884.
The last Cornish Stannary Parliament was held at Hingston Down in 1753, and the Devon Stannary Parliament last met in 1748. The Stannary Courts of Devon and Cornwall were combined in 1855 and their powers transferred to local authorities in 1896.
By the middle and late 19th century, Cornish mining was in decline, and many Cornish miners emigrated to developing mining districts overseas, where their skills were in demand: these included South Africa, Australia and North America. Cornish miners became dominant in the 1850s in the iron and copper districts of northern Michigan in the United States, as well as in many other mining districts. In the first six months of 1875, over 10,000 miners left Cornwall to find work overseas.
Mining in Cornwall and Devon