Gold and Silver: Comprising an Economic History of Mining in the United States, the Geographical and Geological Occurrence of the Precious Metals, with Their Mineralogical Associations, History and Description of Methods of Mining and Extraction of Values, and a Detailed Discussion of the Production of Gold and Silver in the World and the United StatesJ. Wiley & Sons, 1908 - 727 strani |
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Zadetki 1–5 od 88
Stran 10
... varying somewhat with the country and occupation . This condition of affairs is well illustrated by labor in mining camps , where the usual number of non - producers , two or three , is often increased to four and five . After the first ...
... varying somewhat with the country and occupation . This condition of affairs is well illustrated by labor in mining camps , where the usual number of non - producers , two or three , is often increased to four and five . After the first ...
Stran 18
... varying somewhat with each locality and material produced . The principal causes of failure are probably : lack , of proper foresight in the develop- ment and equipment of the property ; extreme positions taken by the management , i.e. ...
... varying somewhat with each locality and material produced . The principal causes of failure are probably : lack , of proper foresight in the develop- ment and equipment of the property ; extreme positions taken by the management , i.e. ...
Stran 22
... varying in depth from ninety to one hundred feet . Six miles southeast of this locality are five other shafts similar in age and construction . The presence of iron and the marks of sharp metallic tools prove that these ancient mining ...
... varying in depth from ninety to one hundred feet . Six miles southeast of this locality are five other shafts similar in age and construction . The presence of iron and the marks of sharp metallic tools prove that these ancient mining ...
Stran 152
... varying resistance of the different rocks present , there would be both fracture and flowage . " These conceptions are fundamental and far - reaching . At once , so far as the consideration of the circulation of underground waters . is ...
... varying resistance of the different rocks present , there would be both fracture and flowage . " These conceptions are fundamental and far - reaching . At once , so far as the consideration of the circulation of underground waters . is ...
Stran 164
... varies largely with both kind and character of formations present . Therefore the zone of fracture will be within ... varying quantities . Often the rock is cemented into a solid mass of ore . At Gold Mountain , San Bernardino County ...
... varies largely with both kind and character of formations present . Therefore the zone of fracture will be within ... varying quantities . Often the rock is cemented into a solid mass of ore . At Gold Mountain , San Bernardino County ...
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Alaska amalgamation andesite argentiferous assay auriferous average bed-rock blende bornite calcite California Carolina cent chalcopyrite chloride chlorination Colorado Comstock lode concentration considerable copper country-rock County Cripple Creek cyanide cyanide process Deep Mines deposits depth diorite discovered discovery district dollars drift employed extraction feet free-gold furnace galena gangue gneiss gold and silver gold production Gold-bearing granite gravel gray copper Gulch Hill hydraulic Ibid Idaho inches iron Jour lead limestone located mercury method Mexico mill Mineral Industry Mineral Resources Mines and Minerals Montana Mountain Nevada North occur operations ore-bodies ounces output oxide placer mines placers porphyry precious metals Press probably production of gold pyrite pyrrhotite quantities quartz quartz-veins quartzites Rept rhyolite River rocks schists shaft siliceous silver production Silver-bearing slate sluices smelting solution South stamps stope sulphides sulphurets surface TABLE tellurides tellurium tetrahedrite timber tion tons Total tunnel Utah yield zinc