152

AMERICAN MINES.

CHAP. XXII.

to the end of the year 1699. From that periodthe progress during the first twenty or thirtyyears, though constant, was comparatively slow,but towards the latter end of the century becamemuch more rapid.

The great mine of Valenciana, which, duringforty years, yielded to its proprietors a clearprofit of from eighty-five thousand to one hun-dred and twenty-five thousand pounds sterlingyearly, had been neglected till the year I 76 O, andafter ten years’ labour and expenditure, when therich part of the vein had been reached, continuedfor upwards of forty years to yield more than halfa million sterling in gold and silver. The richdistrict of Guanaxuato, which in the years before1766 yielded only three hundred and eighty thou-sand ounces of silver yearly, produced in the latteryears of its prosperity more than one million fivehundred thousand. The mineral repository ofCatorce was only discovered in the year 1773, butit yielded a very large quantity both of gold andsilver till 1798, when the value of the mineralsdeclined. The vein of Biscaina, though it beganto be worked at the beginning of the sixteenthcentury, did not become enormously productivetill 1762 , though in twelve years from that periodthe owner of it had gained a profit of more thana million sterling, with part of which he presentedto the King of Spain two ships of war, one of themof one hundred and twenty guns, and, besides,