Gunnislake: grid reference SX426733

Notable minerals: Chalcopyrite, Copper & Mispickel .

As its name implies, this was an amalgamation or consolidation of several smaller mines. Devon Great Consols includes the mines of Wheal Maria, Wheal Fanny, Wheal Anna Maria, Wheal Josiah, Wheal Emma, which lie from west to east along the main lode and were the principal sources of firstly copper then arsenic in the latter days. Wheal Frementor, Watson's Mine and Bedford United Mine all lie south of the main lode. Situated one mile north of Gunnislake, the mine worked from Main Lode. Its component mines are found below. Despite earlier attempts the mine did not become a going concern until Josiah Hitchins took up a lease in 1844. The lode was struck just 4 fathoms below the bottom of the previous working in Gard's Shaft at the western end of the sett. Within 6 months and at only 28 fathoms in depth this shaft was 'cutting yellow ore from corner to corner' and in March alone 810 tons of ore was sold. For the year of 1845 £72,704 profit was divided. When Wheal Fanny was started in 1845 the lode was cut only 3 fathoms below the surface. In March of 1856 with the lode being worked on its full length from Wheal Maria to Wheal Emma 3,389 tons of ore were sampled, an all time record. Output in 1856 was 28,836 tons. The only limiting factor on output was transport and storage to the quays at Morwellham. By 1860 the lode at Anna Maria was up to 45 feet wide and yielding up to 80 tons per fathom. By 1870 refined arsenic was also being produced from arsenopyrite deposits up to 6 feet thick which lined the copper lode and had previously been left in place as having no value. The mine produced over half the British output and only limited output to avoid depressing the world market price. By 1880 the copper boom was over. Arsenic production sustained the mine for another 20 years until the original company folded in 1901. The overall output from 1844 to 1902 had been 736,229 tons copper ore sold for £3,473,046 and 72,279 tons refined arsenic for £625,062. From 'The Mines of East Cornwall and West Devon', D.B. Barton, 1964

The 1856 Post Office Directory states that 'Devon Great Consols Mine is in the township, parish, union, and hundred of Tavistock, Devon, within the bounds of the manor or lordship of the Duke of Bedford, and mining district of Tavistock; it is situated 4 miles from the town of Tavistock. The nearest shipping place for ores and machinery is at Morwellham, 4 miles from the mine, and the nearest railway station at Plymouth, 18 miles from the mine, and 246 from London. The mine is held under a lease for 21 years, from 1844, at a royalty of 1-12th, granted by the Duke of Bedford, of Woburn Abbey, Milton Abbot, etc. The country is killas, and the dip south. The nearest granite is at Frementor (in the sett). The known lodes on the sett are three. There are several known crosscourses. There have been 18 shafts sunk. The mines are worked by steam-engines and by water-power, two steam-engines of 50 h.p. each for pumping; four steam-engines of 20 h.p. each, for hauling and crushing; two water-wheels, 40 feet by 12 feet, for pumping; and several smaller wheels for hauling and crushing. The mines are drained by all the engines. The minerals found in this sett include copper only. The mines were first opened in 1844, and are worked by a London company, under the name of the Devonshire Great Consolidated Copper Mining Company. These mines are now worked for copper. The produce in 1851 was 18,946 tons 8 cwt. of ore, or £118,478 16s. 2d.; in 1852, 20,886 tons 14 cwt. 3 qrs. of ore, or £147,657 5s. 1d.; in 1853, 24,009 tons 18 cwt. of ore, or £158,076 153. ld.; in 1854, 24,076 tons 10 cwt. 1 qr. of ore, or £152,709 2s. 8d.; in 1853, to the end of November, 20,416 tons 13 cwt. 2 qrs. of ore, or £126,349 2s. 11d. The company is on the joint-stock system, and consists of 1,024 shares, with £1 paid, representing a capital of £1,024. The dividends in 1851 were £40,960, or £40 per share; 1852, £46,080, or £45 per share; in 1853, £65,024, or £63 10s. per share; in 1854, £57,344, or £36 per share. The captain is James Richards; the London offices are 77 Gresham house, Old Broad street; the secretary is Alexander Allen, Esq. The company is managed by a board of directors, composed as follows:- W. A. Thomas, Esq., chairman, John Thomas, Esq., and Francis Morris, Esq.; Thomas Morris, Esq., of Tavistock, being the resident director; J. H. Hitchins, Esq., of Tavistock, consulting engineer'.