Mining System. 235 



There are some shafts, thirty or forty feet in diameter, and they 

 were made so large, on account of the clumsiness and multiplicity of 

 the machines used in extracting the ore and water. A better choice 

 of machinery, would enable them to diminish the diameter of the 

 shafts, and consequently the expense of new excavations. 



4th. The lining of the shafts, when of wood, is little attended to, 

 but those of stone, are in general well executed. 



5th. In blasting, more powder is used than is necessary, and they 

 do not lay bare that part of the rock which is to yield to the ex- 

 plosion. 



6th. The interior transportation is upon men's backs, but, in some 

 mines, mules are employed. Rail-ways were not known, and on ac- 

 count of the bad arrangement of the internal communications, it 

 would be difficult to introduce them. The porters or tenateros carry 

 for a load, from two hundred and twenty-five to three hundred 

 and fifty pounds, and in some mines, they have to ascend thousands 

 of steps, at an angle of 45°. The labor is so severe, that it injures 

 their health, but the appetite for gain retains them. They can earn 

 $1,25 in six hours. In the mine of Valenciana, there are three por- 

 ters to each miner, and their wages, alone, amount to $10,000 per 

 pionth. Two thirds of this expense might be saved, by having well 

 arranged internal communications, rail- ways and machines for rai- 

 sing the ore and water. 



7th. The method of draining the mines, is very defective. The 

 water is either drawn up in leathern sacks, which are expensive, and 

 from their constant friction against the sides of the shaft, last but a few 

 days, or, it is carried up on men's shoulders. In some mines, the 

 water which comes in far above the bottom, instead of being stopped 

 out, or conducted off, is allowed to collect in the lower parts of the 

 mine, whence it must be removed with great labor and expense. 



8th. The mechanical preparation of the ores, consists in picking, 

 stamping, and pulverizing, under the stone rollers, which were men- 

 tioned in the Mexican method of amalgamation. The different wash- 

 ing tables, do not appear to be known. Mier, in his travels, mentions, 

 that the roasting of silver ores is common, for the purpose merely of 

 rendering them capable of being more easily pulverized * 



The methods of mining, and working the ores, have undergone 

 little variation, since Humboldt's visit to the mining districts. It has 



* Mier's Travels, Vol. ii, p. 401. 



