We dropped stones into the abyss, and when they struck the water the report and echoes which followed, lasted fifteen seconds, and were perfectly deafening. We then fired a pistol down the tiro, and the report which came back to us was like that of a twenty-four pounder cannon, causing our ears to ring for hours thereafter.
The enclosure around the great tiro is circular and of immense extent. Radiating from the tiro to the outer wall, like the sections of an opened fan, are eight subenclosures corresponding to the eight sides of the tiro: in each of these enclosures stood, formerly, a great upright drum wheel, or winze, called a malacate, on which were the cables which hauled up and let down the buckets filled with water and ore, or men and supplies. The rope was always winding up on one end and down on the other end of the malacate when it was in motion. These eight great malacates were all worked by mule power for centuries, but the English company introduced an immense hoisting engine to do the work. The engine was found to require more feed than the mules, and so was put out of use and the mules substituted again. There is another, but smaller tiro lower down the hill. Humboldt estimated that it would require a tunnel seven or eight miles in length to drain this immense mine; but it seems to me that a much shorter one would do the work effectually; and the chance of striking "feeders" or "blind veins" of ore in the course of the work sufficient to pay the whole or a considerable portion of the cost of its construction, would, apparently, justify the adoption of the plan, by a company having an adequate capital. As the mine now stands, it is estimated, that it would require two
