as they increase in depth, and it is to be apprehended that the district of El Oro will not form an exception to this rule. The mines, however, were worked to advantage as late as 1810, and it is upon record that, in 1805, a single Carga of Ore was sold at the mouth of the shaft for eleven thousand dollars. A very few montones of ore, of a quality much inferior to this, would repay the Company for all its advances; although these are likely to be increased by the construction of a Hacienda, which is indispensable, if the enterprise of working the mines is persevered in; every building connected with them having been destroyed in 1811, in order to furnish palisades for Rayon's camp upon the Cerro del Gallo.
The plans for this Hacienda were not completed when I was at El Oro; but I have been since informed, that it is to be situated in the valley of Tĕpĕtōngŏ, where a Presa, or dam, has been constructed, during the last year, of sufficient size to form a reservoir of water in the rainy season, for the supply of the machinery during the dry months. This Presa is built across a ravine, and is seventeen varas in thickness at the foundation, terminating, at the height of sixty feet, in a wall three varas thick, and 200 feet in length, from side to side. The whole is solid masonry; so that the cost, in addition to the other expences connected with the construction of a Hacienda, must be very considerable.
I took my former road, on my return to Mexico,
