AMERICA'S UNDERGROUND WORKERS 27 



Three hundred and fifty million dollars worth of ])ul]ion wjus 

 taken from the lode. The develoj)m('nt of niiniii*!: in tliis lode 

 made necessary the invention and adoption of {\\v best min- 

 ing machinery in the world and trained a magnificent body 

 of American miners who set a pace that spnrred up pros- 

 pecting and mine development all throngh the United States 

 and Canada and even in the old woi'ld. 



One of the methods introduced in the Comstock mines 

 had much to do with the rapid development of other mines 

 of different ores. That method was the square set timber- 

 ing scheme that made easy the opening of the great copper 

 lodes of Butte. Soft and shifting vein formations that warped 

 massive timbering and crushed shafts lost their terror for 

 miners when the men saw the ease with which the Comstock 

 miners contended with such and still greater difficulties. 

 In the mines of Colorado when they were first opened the 

 inrush of water was so great that often it was necessary to 

 pump forty tons of water out of the mine for every ton of 

 ore extracted. In the Ontario and Friedensville mines the 

 flood was greater but the massive pumps of the Comstock 

 mines were able to cope, partly, and with some degree of suc- 

 cess, with the worst floods that the lode ever saw. The 

 sinking of shafts to great depths became comparatively a 

 simple problem after the engineers and workers in the Com- 

 stock mines had shown the way. In Bohemia it took gener- 

 ations of miners to sink a shaft to the depth of thirty-two 

 hundred feet. The two Tamarack shafts in the Michigan 

 copper field were driven to the lowest depths entered by man 

 — 4,218 and 4,143 feet beneath the surface. 



It was not until the South African diamond mines were 

 developed by an American manager, Gardner Williams, that 

 the progress of American mines was equalled outside of this 

 continent. 



Of course work may not be done so rapidly in some mines 

 as in others, sometimes on account of the difference in the 

 kind of ore and again because of a diflerence in the formation 

 of the veins in the two mines. 



Coal, salt and stratified deposits are found in layei-s, 

 sometimes perfectly horizontal, as originally deposited, again 



