Galleries are passages running off horizontally from the shaft, either cut through the solid porphyry to intersect some vein, or else the space which a vein once occupied is fitted up for a gallery by receiving a wooden floor and a brick arch over head. They are the passages that lead to others, and to transverse galleries and veins, which, in so old a mine as this, are very numerous. When a vein sufficiently rich to warrant working is struck, it is followed through all its meanderings as long as it pays for digging. The opening made in following it is, of course, as irregular in form and shape as the vein itself. The loose earth and rubbish taken out in following it is thrown into some abandoned opening or gallery, so that nothing is lifted to the surface but the ore. Sometimes several gangs of hands will be working upon the same vein, a board and timber floor only separating one set from another. When I have added to this description that this business of digging out veins has continued here for near three hundred years, it can well be conceived that this mountain ridge has become a sort of honey-comb. THE MINERS. When our party had reached the limit of descent, we turned aside into a gallery, and made our way among gangs of workmen, silently pursuing their daily labor in galleries and chambers reeking with moisture, while the water trickled down on every side on its way to the common receptacle at the bottom. Here we saw English carpenters dressing timbers for flooring by the light of tallow candles that burned in soft mud candlesticks adhering to the rocky walls of the chamber. Men were industriously digging upon the vein, others disposing of the rubbish, while convicts were trudging along under heavy burdens of ore, which they supported on their backs by a broad strap across their foreheads. As we passed among these well-behaved gangs of men, I was a little startled by the foreman remarking that one of those carriers had been convicted of killing ten men, and was under sentence of hard labor for life. Far from there being any thing forbidding in the appearance of these murderers, now that they were beyond the reach of intoxicating drink, they bore the ordinary subdued expression of the Meztizo. According to custom, they lashed me to a stanchion as an intruder; but, upon the foreman informing them that I would pay the usual forfeit of cigaritos on arriving at the station-house, they good-naturedly relieved me. Then we journeyed on and on, until my powers of endurance could sustain no more. We sat down to rest, and to gather strength for a still longer journey. At length we set out again, sometimes climbing up, sometimes climbing down; now stopping to examine different specimens of ores that reflected back the glare of our lights with dazzling brilliancy, and to look at the endless varieties in the appearance of the rock that filled the spaces in the porphyry matrix. Then we walked for a long way on the top of the aqueduct of the adit,