Up to the mid-16th century, Devon produced approximately 25-40% of the amount of
tin that Cornwall did but the total amount of
tin production from both Cornwall and Devon during this period was relatively small. After the 1540s, Cornwall's production took off and Devon's production was only about between a ninth to a tenth of that of Cornwall. From the mid-16th century onwards, the Devon Stannaries were worth very little in income to the King and were sidelined as such following the Supremacy of Parliament Act 1512 (this does not apply to the
Stannaries of Cornwall). The landscapes of Cornwall and West Devon were radically reshaped during the 18th and 19th centuries by deep-lode mining for
copper and tin. The underground mines, engine houses,
foundries, new towns,
smallholdings, ports, harbours, and ancillary industries together reflect prolific innovation which, in the early 19th century, enabled the region to produce two-thirds of the world's supply of copper. During the late 19th century,
arsenic production came into ascendancy with mines in the east of Cornwall and West Devon supplying half the world's demand. near St Just, Cornwall The early 19th century also saw a revolution in
steam engine technology which was to radically transform hard-rock mining fortunes. The high-pressure expansively operated pumping engines developed by the engineers
Richard Trevithick and
Arthur Woolf enabled mining at much greater depths than had been possible hitherto. Cornish-design beam engines and other mining machinery was to be exported from major engineering foundries in
Hayle,
Perranarworthal,
Tavistock and elsewhere to mining fields around the world throughout the century. Commencing in the early 19th century, significant numbers of mine workers migrated to live and work in mining communities based on Cornish traditions, this flow reaching its zenith at the end of the 19th century. Today numerous migrant-descended Cornish communities flourish around the world and distinctive Cornish-design engine houses can be seen in Australia, New Zealand, South Africa, Mexico, the
British Virgin Islands, Spain, and in the mining fields of other parts of England, Wales, Scotland, Ireland, the
Channel Islands, and the
Isle of Man. A much reduced mining industry continued in Cornwall after the copper crash of the 1860s with production mainly focused on tin. Metalliferous mining finally ceased in Cornwall in 1998 with the closure of
South Crofty Mine,
Pool, the last tin mine to operate in Europe. South Crofty has substantial tin reserves, and in January 2025 the British government announced a £28.6m investment to support its reopening. ==Areas==