and Pachuca, at extraordinary distances, without changing their direction, and almost without coming in contact with other veins which traverse or derange them.

The veta de la Biscaina not so extensive, but perhaps still richer than the vein of Guanaxuato, was successfully wrought from the sixteenth to the beginning of the eighteenth century. In 1726 and 1727, the two mines of Biscaina and Xacal, still produced together 542,700 marcs of silver*. The great quantity of water which filtrated through the crevices of the porphyritic rock, joined to the imperfection of the means of drawing it off, compelled the miners to abandon the works when they were yet only 120 metrest in depth. A very enterprising individual, Don Joseph Alexandro Bustamente, was courageous enough to undertake a level near Moran; but he died before completing this great work, which is 2352 metres in length from its mouth, to the point where it crosses the vein de la Biscaina,

The direction

of this vein is hor. 6; and its inclination is 85° to the south: its extent is from four to six metres§. The direction of the porphyry of this district is generally hor. 7-8, with an incli

* 356,182 lib. Troy. Trans.

† 393 feet. Trans.

7715 feet. Trans.

From 13 to 19 feet. Trans.

nation of 60° to the north east, particularly in the road from Pachuca to Real del Monte. the level is at first cut through the solid rock, (querschlagsweise) in a direction of hor. 7, towards the west; but farther on it takes its way over three different veins, hor. 11-12 of which one alone the veta de le Soledad*, has furnished a sufficiency of silver minerals to pay all the expences of the undertaking. The level was only finished in 1762, by Don Pedro Tereros, the partner of Bustamente. The former known by the title of Count de Regla, as one of the richest men of his age, had already drawn in 1774, a net profit of more than 25 millions of livres tournoist, from the mine of Biscaina. Besides the two ships of war which he presented to King Charles the Third, one of them of 120 guns, he lent five millions of francs to the Court of Madrid, which have never yet been repaid him. He erected the great amalgamation work of Regla, at an expence of 10 millions§; and he purchased estates of an immense

It is believed that this vein is the same with that which M. D'Elhuyar, began to work in the pit of Cambrera, at Moran. It appeared to me however that the octa de Cabrera, is rather the same with that of Santa Brigida, and that its principal wealth is to be found in following it towards the mine of Jesus.

† 1,041,750 Sterling. Trans.

208,350 Sterling. Trans.

$416,700 Sterling. Trans.

extent, and left a fortune to his children, which has only been equalled in Mexico, by that of the Count de la Valenciana.

The level of Moran traverses the vein of la Biscaina, in the pit of San Ramon, at a depth of 210 metres*, below the level of the surface, on which the baritels a chevaux are placed. The profit of the proprietor has been annually diminishing since 1774. In place of cutting galeries of investigation, to discover the vein on a great extent, they continued their sinking operations to a depth of 97 metres below the levelt. At that depth, the vein preserved its great wealth in sulfuretted silver, mixed with native silver, but the abundance of water increased to such a degree, that 28 baritels, each of which required more than 40 horses, were not sufficient to draw it off. In 1783, the weekly expence amounted to 45,000 francs. After the death of the old Count de Regla, the works were suspended till 1791, when they ventured to re-establish all the baritels. The expence of these machines which drew up the water, not by means of pumps, but by bags suspended to ropes, then amounted to more than 750,000 francs per annum§. At length they reached

the deepest point of the mine, which according to my measurements* is only 324 metres† above the level of the lake of Zumpango; but the minerals which they extracted did not compensate the expence of the process, and the mine was again abandoned in 1801.

It is surprizing that they never thought of substituting to this wretched plan of drawing off the water by bags, proper pump apparatus, put in motion by horse baritels, by hydraulical wheels, or by machines moved by a column of water (colonne d'eau). A level begun at Pachuca, or lower down towards Gazave in the valley of Mexico, would have exhausted the mine of Biscaina at the pit of San Ramon, for a depth of 370 metres. The same object could be attained at less expence, by following the project of M. D'El huyar, in placing the mouth of a new level near Omitlan, in the road which leads from Moran, to the place of amalgamation at Regla. This

* I found the absolute height of the lake of Zumpango, 2284 metres (7492 feet. Trans.); the pit of Ramon 2815 metres (9233 feet. Trans.); now the deepest point of the mine of Biscaina is 307 metres (1006 feet. Trans. below the upper mouth of the pit. I insert these results here, because in the country it is generally believed, that the works of the Real del Monte, have already reached the level of the salt lake of Tezeuco.

last level before reaching 3800 metres in length, would cut the vein of Biscaina.

The very wise plan which the Count de Regla at present follows is, to leave off the clearing of the old works, and to examine the mineral depository, in points where it has never yet been worked (in unverfahrenem felde). In studying at Real del Monte, the surface and undulations of the ground, we observe that the vein of Biscaina has furnished for three centuries its greatest riches on a single point, that is to say, in a natural deepening (enfoncement) contained between the pits of Dolores, Joya, San Cayetano, Santa Teresa, and Gaudalupe. The pit from which the greatest quantity of silver minerals has been extracted, is that of Santa Teresa. To the east and west of this central point, the vein is strangled for a distance of more than 400 metrest. It preserves its primitive direction, but being destitute of metals, it is reduced to an almost imperceptible vein. For a long time it was believed that the vein of Biscaina was insensibly lost in the rock; but they discovered in 1798 very rich metals, at a distance of more than 500 metres, to the east and west of the centre of the old works. They then