2o8 ISAAC A. HOURWICH 



to-day." The same is true of the silver mines of Peru and 

 Bohvia. ''Until a short time ago all ores and all the water 

 had to be carried from the mines on the backs of the work- 

 men in leather bags." 



It goes without saying that the absence of mechanical 

 apparatus for hoisting and pumping did not permit of vein 

 mining except at very shallow depths. 



In the United States the pioneer state in vein mining 

 was Georgia, where a few deep mines were operated in the 

 first half of the nineteenth century. The first miners natur- 

 ally followed the methods which were in vogue in the Latin- 

 American countries, whose experience extended over nearly 

 three centuries. As late as the close of the nineteenth century 

 a specimen of an open mine not very different from its Brazilian 

 prototype was in actual operation in Georgia. 



In the early days of quartz mining in the United States 

 the veins were worked to shallow depths only. In New 

 Mexico about forty years ago powder was practically un- 

 known in mining, and the veins could not be worked for more 

 than 50 feet in depth. Water was another source of trouble. 

 Mines were operated by men of small means, capital was 

 scarce, hand pumps only could be afforded, and when the 

 column of water in the pump became too heavy to be lifted 

 by hand, shafts with a good average grade of ore had to be 

 abandoned. A recent example of this character is cited in 

 the report of the geological survey of Georgia, where but a 

 few years ago a mine was abandoned upon reaching the depth 

 of 300 feet, 30 feet below water level, because the operators 

 had to lift with a hand pump an 80 foot column of water in 

 order to keep the shaft free. At the time work ceased the 

 ore was yielding $25 per ton. The progress in the course of 

 the last half century consiste'd of the introduction of more 

 powerful hoisting and pumping machinery, in the invention 

 of power drills and more effective explosives, in the con- 

 struction of extensive tunnels for draining the mines, and 

 lately in the application of electric power. 



The evolution of mining methods and machinery is 

 best exemplified by the history of the famous Comstock lode 

 in Nevada. The greatest depth reached after more than 



