ANCIENT SILVER MINES.
The locality of the ancient silver mines is buried in obscurity; but it is known that silver was obtained, together with gold, from various parts of Africa, and also from Asia. The Spanish silver mines were developed at a very early period, and were the basis of the extensive commerce which Spain conducted for a long time with other countries. Hannibal is said to have opened a mine which furnished three hundred pounds of silver daily, and was worked by horizontal tunnels extending a mile and a half into a mountain. During the middle ages the production of silver fell off very greatly, and until the fifteenth century comparatively little silver mining was carried on. The production of Spanish mines was greatly decreased, and the wealth of Spain fell off in a proportionate degree.
GREAT MINES OF MEXICO.
Rich mines of silver existed in the new world, particularly in Mexico and Peru. The conquest of Mexico by Cortes in 1519 was speedily followed by the development of the rich silver mines of that country. From a very early period the Aztecs had been familiar with silver, and wrought it into many ornamental and useful articles. The mines were opened and extensively worked by the Peruvians in Guanajuato, Zacatecas, and other districts, and their production was greatly increased by the abundance of quicksilver, and its employment in the reduction of ores. Quicksilver is used for this purpose to a greater extent in Mexico and Peru than in other countries.
At the time of the visit of Humboldt in the early part of this century, it was estimated that three thousand distinct mines were in operation. The greatest of all the mines of Mexico are those of Guanajuato and Zacatecas. They were opened in 1558, upon the great vein known as Veta Madra. The great vein is chiefly in clay slate. It is of wonderful thickness, sometimes more than one hundred and fifty feet across, and is said to have been traced for about twelve miles.
The vein is made up of half a dozen substances, the most important of which are native silver, sulphuret of silver, and red silver. Near the surface they are partly decomposed, but in their unchanged condition, farther down, they are known as “black ores.” The vein has been penetrated downward more than two thousand feet, and is found to be very rich at that depth. The mine of Valenciana, upon a rich portion of this vein, has averaged at times a product of two million dollars, or about one fifteenth part of the total product of all the mines of Mexico. At the present time no work is carried on in these mines. Operations were suspended some years ago by floods of water, and the unsettled state of the country, added to other disadvantages, prevented a renewal of work. Before any productive operations could be prosecuted, it would be necessary to erect powerful machinery; and to set it up and put it in operation would cost enormously; so great, in fact, would be the cost, as to deter any body of men, or any association of capitalists, from entering upon the enterprise.
Until the present century the ores of the silver mines of Mexico have been worked by rude processes, very little in advance of those of the native Indians. Little or no mining machinery was used. The ores had to be transported out of the mines upon the backs of Indians, climbing up a series of long steps over slippery rocks, and working in a nude state. When the mines were troubled with water, rude pumps were set up, and in many cases there were no pumps, but the water was carried out on the backs of men.
HOW TO SECURE A PIG SKIN.
A traveller who visited one of these mines, where operations on a small scale were going on, says the sight of the men carrying their burdens, some laden with ore, and some with water, formed a curious picture. The ore was carried in sacks or baskets slung across the shoulders of the men, while the water was carried in pig-skins. These skins were in the natural shape of the animal, and were supposed to have been removed without cutting. When slung over the shoulders of the men in the dim light of the mine, the man and the pig clinging to his back appeared to form a single animal. An unsophisticated traveller, who accompanied the narrator, was curious to ascertain how the skins were obtained in that condition, as the ordinary mode of skinning pigs, oxen, or any other beasts requires a liberal use of the knife. He was informed that the animal was starved for several days, so that his skin became quite loose. Then a stout cord was tied to his tail, and by this mode he was securely fastened to a tree. A potato or an ear of corn was then held a few feet in front of his nose, and the pig was finally coaxed out of his skin, and induced to walk away from it. The man seemed to have his doubts as to the truth of the statement, but finally concluded to accept it as correct.