Copper-mines have long been known in England, but they were wrought with very little skill or effect until towards the year 1700. Even at that time the an nual produce, after smelting the metal from the ore, was only a few hundred tons of copper; and it hardly exceeded 1000 tons annually down to the middle of last century. From that time forward the increase became considerable, as well in Cornwall as in De von, North Wales, and Derbyshire; in all of which copper mines were discovered and wrought. In North Wales there were two mines (Parys and Mo na), which, for some time after the year 1780, yielded annually a large quantity of ore, but they are no longer productive: the mines of Devon and Derby shire continue to be wrought, but the great product is from Cornwall, the mines of which yield 80,000 tons of ore annually: the metal obtained varying from 5 to 15 in the 100 parts, may be stated at 8000 tons of copper. It is the Welsh collieries that afford to Cornwall, as to Devonshire, the great means of smelting ; and as the ore is less heavy than the cued required for this operation (one ton of ore re quiring from two to two and a half tons of coal), the practice is to convey the ore in vast quantities to Wales, particularly to Swansea. The total quantity of coal consumed for this purpose at Swansea is nearly 200,000 tons a-year ; exclusive of a farther consumption of coal at the copper-mines of Cornwall, in working the ponderous steam-engines used in out the water from the pits. In this, as in other minerals, France is greatly behind England. She has various copper mines, but her coal mines, at least hitherto wrought, are at too great a distance to make such undertakings profitable; she consequent ly requires an annual import from England. For the destination of our exported copper, we refer to the following table : The produce of the mines does not materially dif fer from the last of these averages. From abroad we receive tin from one quarter only, viz. the East Indies, in particular from the Island of Banes. Of this we imported, in 1815 and 1816, nearly 600 tons, the chief part of which was re-exported to the Con tinent of Europe. Of our own tin, about the half is used at home, and the other half finds its way to the following countries : The lead mines of England are principally in Cum berland, Northumberland, and Derbyshire ; the whole calculated to produce from 12,000 to 15,000 tons annually. Black lead is found in abundance in Cum berland, in the romantic district of Borrodale; but the mine is opened only 'periodically, that the mar ket may not be overstocked.
Salt is already a very important product in Eng land, and is likely to become much more so from the measures urged of late years on the Legislature, part of which have been adopted, while a farther part seem only to wait a season of less financial pres. sure. (Report of Committee on the Salt Duties, June 1818.) Salt is obtained in several ways; partly from brine springs, partly from the rock, partly from sea The price of copper in 1746, and the succeeding years, was generally about Is. 3d. per lb. ; in 1765, it,fell to I s. ld., in 1778 to 10d.; since 1781 it has not been under I I d. In 1805, it reached the un exampled price of ls. ltd. per lb.; and large importa tions took place during 1806, 1807, 1808, 1809, and 1810; but the average price of the last 60 years may be called 1 s. 2d. In using copper for coin, it has been proposed to take 16d. per lb. as the rate of value, which would leave a profit to government on • the mint operation, without affording a temptation to individuals to melt the pieces. (Grenfell on Cop per Coinage, 1814.)
Cornwall is also the great seat of the tin-mines England. A century ago the average produce of our tin-mines hardly exceeded . 1500 tons. From 1720 to 1740, the average produce was 2100 From 1740 to 1760 . 2570 From 1760 to 1780, . 2740 From 1780 to 1800, . . 3100 water. In the last manner it is manufactured in va rious salt-pans along the coast, viz. in Hampshire, Kent, and Essex; also in the northern counties of Durham and Northumberland, where the abundance of coal cheapens materially the expence of the pro.. cess. But the great supply is from the rock salt and brine springs of Cheshire, situated in the south ern part of the county, near Northwicb. From these springs it is obtained (see the article CHESHIRE) at the rate of one gallon of solid salt from four gallons of liquid, while common sea water does not yield above one in twenty-eight. The price of rock-salt at the rocks is only 12s. per ton; it is there mixed with the brine from the saline springs, and refined in large iron pans, after which it is called white salt, and is sold, the inferior at 23s. the best from 35s. to 40s. the ton.. On salt for home consumption there has been, since 1805, the enormous duty of 15s. per bushel, nearly fifteen times the prime cost. The sale price was thus raised to L.80 the ton. This duty has rendered to government, since 1805, no less than L1,400,000 nett ; it is, besides] of easy col lection, from the mines and manufactories of salt being confined to particular districts, and smuggling readily prevented.
This concentration will, it is hoped, be the means of facilitating materially the expected changes in the law, since it will render practicable the use of rock salt duty free to certain manufactures (as sal-ammo niac, magnesia, and Glauber's salt) without any great risk of fraud on the revenue. An act of great im portance was lately passed (27th June 1817), per mitting the free use of rock salt, not only in curing fish, but in making mineral alkali, an ingredient of great use as a substitute for built, in the manufac ture of soap. This alkali is subjected to a duty, . which, it is believed, may soon be raised to 10s. per cwt., producing about L.400,000 to the revenue. Were the whole salt duty taken off, the mines and springs of Cheshire might produce annually 24,000,000 bushels of salt, each bushel of 56 lbs. ; but the actual quantity extracted, as appears by evidence before a Committee of the House of Com mons, in May. 1817, is only about 10,000,000 bushels.
The capital vested in the works is about L.700,000 ; and the persons employed, including women and children, about 2400.
Our agriculture has already felt the good effects of the recent relaxation of the salt regulations. The high duty of 1805 had necessitated the absolute loss of a quantity of refuse, thrown out from the salt pans, and eagerly bought up in former years by far riers. This precious manure is now restored, and affords the means of giving fertility to 100,000 acres annually. On salt used for feeding cattle, this duty is reduced to 55. a-bushel. For bleaching or refin ing, 'salt is delivered duty free; in the latter, the quantity used considerably exceeds 1,000,000 bush els a-year. (Return to House of Commons, 2d April 1818.) A season of peace is always favourable to the extension of our fisheries ; and, if we may judge from the progress lately made, this branch of our national industry is likely to be carried much far ther than at any former period of our history. Of this we shall treat more fully under the article FISHERY. At present our space allows no more than a brief notice of the principal branches of °Ur fisheries.