pended to the cage of a whim with eight horses, (malacate doble) weighs 1250 pounds: it is made of two hides sewed together. The bags used for the whims called simple, those with four horses (malacates sencillos) are only half the size, and are made of one hide. In general the construction of the whims is extremely imperfect; the bad custom also prevails of forcing the horses, by which they are made to go at far too great a speed. I found this speed at the shafts of San Ramon at Real del Monte no less than ten feet and a half per second; at Guanaxuato in the mine of Valenciana from thirteen to fourteen feet; and every where else I found it more than eight feet. Don Salvado Sein, Professor of Natural Philosophy at Mexico, has proved in a very excellent paper on the rotatory motion of machines, that, notwithstanding the extreme lightness of the Mexican horses, they produce only the maximum of effect on the whims, when exerting a force of 175 pounds they walk at a pace of from five to six feet in the second.

It is to be hoped that pumps, moved either by horse-engines of a better construction, or by water wheels, or by pressure engines, will at last be introduced in the mines of New Spain If wood and coal, which has only yet been discovered in New Mexico, should be found sufficiently abundant for employing the steam-engine, the use of it would be of great advantage in the inundated mines of Bolaños, as well as in those of Rayas and Mellado.

It is in the draining the mines of water that we particularly feel the indispensable necessity of having plans drawn up by subterraneous surveyors (geometres). Instead of stopping the course of the water, and bringing it by the shortest road to the shaft where the machines are placed, they frequently direct it to the bottom of the mine, to be afterwards drawn off at a great expense. In the district of mines of Guanaxuato nearly two hundred and fifty workmen perished in the space of a few minutes on the 14th of June 1780; because, not having measured the distance between the works of San Ramon and the old works of Santo Christo de Burgos, they had imprudently approached this last mine while carrying on a drift in that direction. The water of which the works of Santo Christo were full, flowed with impetuosity through this new gallery of San Ramon into the mine of Valenciana. Many of the workmen perished from the sudden compression of the air, which, in taking vent, threw to great distances pieces of timber, and large masses of rock. This accident would not have happened, if, in regulating the operations, they could have consulted a plan of the mines.

After the picture which we have just drawn of the actual state of the mining operations, and of the bad management which prevails in the mines of New Spain, we cannot be astonished at seeing works which for a long time have been most productive, abandoned whenever they reach a considerable depth,

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or whenever the veins appear less abundant in metals. We have already observed, that in the famous mine of Valenciana, the annual expenses rose in the space of fifteen years from 90,000l. to 180,000. sterling. Indeed, if there be much water in this mine, and if it require a number of whims to draw it off, the profit must, to the proprietors, be little or nothing. The greater part of the defects in the management which I have pointed out, have been long known to a respectable and enlightened body, the Tribunal de Mineria of Mexico, to the professors of the School of Mines, and even to several of the native miners, who, without having quitted their country, know the imperfection of the old methods: but we must repeat here, that changes can only take place very slowly among a people who are not fond of innovations. It is a prejudice to imagine, that the wealth of the mines of New Spain renders unnecessary the intelligence and the economy which are requisite in other mines. We must not confound the abundance of ores with their intrinsic value. The most part of the ores of Mexico being low in produce, as all those who do not allow themselves to be dazzled by false calculations well know, an enormous quantity of stuff impregnated with metals must be extracted, in order to produce 1,540,000lbs. troy of silver. Now it is easy to conceive that in mines of which the different works are badly disposed,

and without any communication with one another, the expense of extraction must be increased in an alarming manner, in proportion as the shafts (pozos) increase in depth, and the levels (cañones) become more extended.

The working of the mines has long been regarded as one of the principal causes of the depopulation of America. It would be difficult to deny, that at the first epoch of the conquest, and even in the seventeenth century, many Indians perished from the excessive labour to which they were compelled in the mines. They perished without posterity, as thousands of African slaves annually perish in the West Indian plantations from fatigue, want of nourishment and of sleep. In Peru, at least in the most southern part, the country is depopulated by the mines, because the barbarous law of the mita is yet in existence, which compels the Indians to remove from their homes into distant provinces, where hands are wanted for extracting the subterraneous wealth.

In the kingdom of New Spain, at least within the last thirty or forty years, the labour of the mines is free; and there remains no trace of the mita, though a justly celebrated author* has advanced the contrary. No where do the people enjoy in greater security the fruit of their labours

* Robertson, History of America, vol. ii. p. 373.

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than in the mines of Mexico; no law forces the Indian to choose this species of labour, or to prefer one mine to another; and when he is displeased with the proprietor of the mine, he may offer his services to another master who may pay perhaps more regularly. These unquestionable facts are very little known in Europe. The number of persons employed in subterraneous operations, who are divided into several classes (Barenadores, Faeneros, Tenateros, Bureteros), does not exceed in the whole kingdom of New Spain 28 or 30,000. Hence there is not more than of the whole population immediately employed in the mines.

The mortality among the miners of Mexico is not greater than what is observed among the other classes. We may easily be convinced of this by examining the bills of mortality in the different parishes of Guanaxuato and Zacatecas. This is a phenomenon, so much the more remarkable, as the miner in several of these mines is exposed to a temperature 11° above the mean temperatures of Jamaica and Pondicherry. I found Fahrenheit's thermometer at 93° at the bottom of the mine of Valenciana (en los planes), a perpendicular depth of 1681 feet, while at the mouth of the pit in the open air, the same thermometer sinks in winter to 39° or 40°. The Mexican miner is, consequently, exposed to a change of temperature of more than 54°. This enormous heat of the Valenciana mine is not the effect of a great number of men and