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Dolcoath mine was a copper and tin mine in Camborne, Cornwall, England, United Kingdom. Its name derives from the Cornish for 'Old Ground', and it was also affectionately known as ''The Queen of Cornish Mines''. The site is north-west of Carn Brea. Dolcoath Road runs between the A3047 road and Chapel Hill. The site is south of this road. ==History== The mineral rights were owned by the Basset family of Tehidy who are recorded on a deed in 1588 as leasing the ground to a family called Crane. By 1720 the mine was being worked for copper, and it was almost deep in 1746,〔 when William Borlase called it a "very considerable mine".〔 In 1778 it was nearly deep, according to William Price.〔 The mine closed in 1787 because the large amount of copper ore that was being cheaply mined from Parys Mountain on Anglesey had depressed the price. However the price of copper slowly recovered and the mine reopened in 1799.〔 Of around 470 copper-producing mines in Cornwall and Devon, Dolcoath became the fifth largest.〔Trounson & Bullen 1999, p.36〕 But as depth increased the copper died out, and by 1832 the mine was in danger of closing. However the mine captain, Charles Thomas, was convinced that tin ore would be found deeper down and after disagreements with the shareholders his faith was repaid and the first tin dividend was paid in 1853. By 1882 the mine had reached a depth of and had of tunnels passable by men and a further of old workings which had become unused and impassable. In 1893 there was a major accident at the 412-fathom level (see below). In 1895 it took men employed in the lower levels between 2–3 hours to go down and return to the surface, so they could not work more than 4–5 hours a day.〔Trounson & Bullen 1999, p.47〕 Dolcoath became the largest and deepest mine in Cornwall, with its principal shaft, known as New Sump Shaft, eventually reaching a depth of below the surface.〔 The pumping engine that worked this shaft dated from 1815; a piece of the cast iron bob from this engine is preserved in the collection of the Trevithick Society.〔(【引用サイトリンク】title=Perran foundry beam )〕 This engine originally had a cylinder, but this had to be replaced with an cylinder when it was not powerful enough to cope with the deepening shaft. The rebuilt engine was so large that there was not enough room in the engine house for the stairs, so a unique wooden extension was built on the back to house them.〔Trounson & Bullen 1999, p.38〕 In 1895 it was decided to reconstruct the company as a limited company, replacing the old cost book system under which most Cornish mines had traditionally been run. A new shaft, named the Williams Shaft after the first chairman of the new company, was started in October 1895, intended to be the first vertical shaft in Cornwall. It was completed in 1910 and came into use the next year.〔Morrison 1983, p.52〕 In 1920 when the mine had become virtually worked out and following the tin price collapse (new deposits were also being found elsewhere in the world) Dolcoath finally closed. The company was reconstructed in 1923 when fresh capital was raised and a new circular shaft was sited north of the old mine at Roskear.〔Trounson & Bullen 1999, p.52〕 The ''New Dolcoath Mine'' was actually an amalgamation of several smaller mines including Stray Park and Roskear. In 1936 Dolcoath's sett was purchased by South Crofty. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dolcoath mine」の詳細全文を読む スポンサード リンク
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