sive; but even close to the water's edge there was nothing like foul air. The operation of retimbering, and, in many parts, of digging out the communications anew, was proceeding rapidly, and from some levels ores were raised which produced at times silver enough very nearly to cover the weekly expences of the mine. These amounted to six thousand dollars, including both the mining operations and the malacate horses employed for the drainage, which were upwards of three hundred in number; each malacate requiring thirty horses in the twenty-four hours.
On re-ascending from the lower levels, we visited the Tiro General, which is both a wonderful and an imposing sight. Its dimensions are unnecessarily large, but it is sunk with a magnificence unparalleled in the annals of European mining, the diameter being eleven Varas. The whole of the Tiro is sunk in solid masonry, and the sixteen cueros, or leather buckets, by which the water is raised, though composed each of two bullock's hides, are lost in the immense dimensions of the shaft.
The greatest praise is due to Mr. Williamson, the principal commissioner of the Anglo-Mexican Association, for the constancy that he has displayed in carrying on the drainage of the Valenciana with the means within his reach. Public opinion was unfavourable to the undertaking, until he demonstrated its practicability; and although in the deeper levels the application of steam may be necessary,
