CHAPTER II.
Description of, and descent into, a Silver Mine.—The Miner's Chapel.
When a mine is first begun, it is always left open to the sky, and the mineral is extracted by following the vein that contains it; but, as the mine gets deeper, two obstacles present themselves: the extraction of the ore becomes more costly, and the workmen are not long in meeting with hidden springs, the waters of which, unless removed, would drown the mine and stop the works. To provide against this danger, shafts are sunk, at the bottom of which a working gallery runs, that follows the vein of metal. The depth of the shaft depends upon the lode, which sometimes stretches so far down into the ground that two or three working galleries, one above the other, are obliged to be constructed. In the richest mines little paths of communication are added to these principal arteries, besides other works to assist in its exploration.
The ore and water are raised out of the mines by means of machines called Malacates, placed at the mouth of the shaft. Large bags, some made of the stringy bark of the aloe, others of ox-hide, are fixed to the ends of ropes wound round an enormous drum, the former for raising the ore, the latter for the water, and these are constantly passing up and down the shaft. The motive power is given by horses, which are kept constantly at the gallop.
Besides the grand shaft (tiro general), the mine of
