of those poor wretches may be, whose sufferings, amidst the eternal snows of the Andes, (at Upsallata, and San Pedro Nostoli,) Captain Head so forcibly describes, there is no sort of analogy between their situation, and that of the mining population of New Spain. Compulsory labour has never been known there; and the temperature of Zăcătēcăs and Guănăjūātŏ, where the first mines were worked, differs but little from that of Tlăscălă, Chŏlūlă, and Tĕnōchtĭtlān, where the population was found to be most concentrated at the time of the Conquest.
So little, indeed, are the metalliferous ridges, which have been, hitherto, the seat of the great mining operations of the Spaniards, elevated above the level of the Table-land, that, with the exception of Jesus Maria, (North-west of Chihuahua,) I hardly know one mining district, in the vicinity of which the snow remains long on the ground. Real del Monte, and Tlalpujahua, are certainly not warm; and the first is liable to be occasionally enveloped in clouds, as is the district of El Oro, near Zĭmăpān, and many others on the Eastern branch of the Cordillera. But the difference between their level, and that of the Capital, does not exceed 1,500, or 2,000 feet, (as will be seen by a reference to the map of Routes and elevations annexed to this volume,) and the cold felt there by visitors from the warmer districts, is merely relative; the Thermometer seldom falling below 40° of Fahrenheit, except in the nights, which are sometimes severe. This temperature seems
