31. THE MINING INDUSTRY. When it is considered that mining enterprise in Great Britain .and Ireland accounts, at the present time, for the employment of no less than 1,236,210 persons directly engaged in the produc tion of 354,890.867 tons of minerals estimated to be worth, at the mines and quarries from which they are drawn, the sum of i160,112,607, the vastness of the industry, and its effect on the economic life of the country will perhaps be more fully realized than by the recital of detailed descriptions of the various branches of mining. Indeed it may be said that the wealth of Britain is mainly due to the unique position, mineralogically, that it occupies rela tively to other nations; for no country contains proportionately to its area, so great or so varied a store of mineral wealth.
Mines in the United Kingdom are usually treated as coming within one of two categories. viz.," metalliferous mines, and' those which are governed by the Coal Mines Act, the latter comprising chiefly coal and stratified iron stone mines, and being by far the most exten sive and important section, though a develop ment of later growth, having expanded through seven centuries to what, as judged by some, is believed to be the zenith of their development.
Of the metalliferous de posits' mined in the United Kingdom, the most important are, and have always been, the ores of tin, copper, lead and iron. Native silver has never been worked, and it is doubtful whether it occurs in Britain or Ireland, although Strabo writing about 19 A.D. mentions silver as well as gold as being among its products.* Tacitus also makes reference to it indirectly.' Gold is very sparsely dis seminated, occurring in min eral veins, found chiefly in Menionethshire (North Wales), Lanarkshire (Lead hills, Scotland) and Corn wall; and in some alluvial deposits in Sutherlandshire (Scotland) and Wicklow (Ireland).
Probably the earliest min ing on commercial lines in Britain was that of tin. The 'icassiterides," whence the Phoenicians obtained their British tin, were, in all prob ability, what are now known as Scilly, the Channel Islands, and, more particularly, Corn walL The industry is and always has been restricted to Cornwall and, to a very small extent, to the contiguous part of Devon, and as early as 60 B.c. we find Diodorus Sicu
lus describing the tin trade of these parts. In the early years of the 19th century (1817) Cornwall was the chief source of production of the world's supply of tin, now it •stands fifth on the list of tin producing countries, contributing only 4.25 per cent of the total production.
What has been written of tin is also largely true of copper. Carew' said, writing about 1600, that he could not find that it was being profitably worked in the west of England, yet nearly two centuries later, the (dur ing the dicennial period 1766-75) was abnor mally large, and as late as 1888 we find no less an authority than the late Mr. D. C. Davies" stating that for their size the British Islands constitute the greatest copper producing country of the world, but the production has greatly dwindled since the time he wrote. Cornwall and Anglesea are the chief copper bearing dis tricts in the kingdom, and very remarkable profits have, in times past, been derived from some of the mines." The production of lead far exceeds that of tin and copper," and as in the case of tin and copper, signs of a revival are not wanting, still, it is very doubtful whether this branch of min ing in the United Kingdom will in the near future attain to a similar state of prosperity as that experienced about the year 1877. Lead mining in these islands is of considerable an tiquity; we know that lead ore was mined in Shropshire in the days of the Emperor Hadrian from the fact that °pigs° of lead were some years ago discovered in the refuse heaps of the Roman Gravel Mine in that county, one of which is preserved in the Geological Museum in Jermyn street. It may be mentioned of this district that, though possibly the smallest mineralized area in Europe, it was believed by so great an authority as the late Sir Roderick Murchison" to be probably unequaled for its size, in point of wealth in lead ore.