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 98
Stran 6
... deep and porous gravel bed will produce for a few seasons , yet without due fertilization annually thereafter it cannot remain a permanent agricultural proposition . The land therefore must be considered from a standpoint of its ...
... deep and porous gravel bed will produce for a few seasons , yet without due fertilization annually thereafter it cannot remain a permanent agricultural proposition . The land therefore must be considered from a standpoint of its ...
Stran 47
... deep pay gravels . The depths of the shafts sunk varied from 65 to 120 feet . Unfortunately the information thus obtained was entirely local in nature as the shafts were unsystematically arranged and far apart . The discovery in 1900-02 ...
... deep pay gravels . The depths of the shafts sunk varied from 65 to 120 feet . Unfortunately the information thus obtained was entirely local in nature as the shafts were unsystematically arranged and far apart . The discovery in 1900-02 ...
Stran 55
... deep he had hit upon the plan of cutting the excavation deeper by the action of running water , accomplished in this case by turning on a full head of water from the mill - pond by simply raising the gate . Examining the cut one morning ...
... deep he had hit upon the plan of cutting the excavation deeper by the action of running water , accomplished in this case by turning on a full head of water from the mill - pond by simply raising the gate . Examining the cut one morning ...
Stran 76
... deep ( 13th Annual Rept . , 1883 ) . According to the First Annual Report of the State Geologist issued in 1869 , gold was found in Franklin County on Sein Creek , but in such small quantities that it took a pailfull of sand and gravel ...
... deep ( 13th Annual Rept . , 1883 ) . According to the First Annual Report of the State Geologist issued in 1869 , gold was found in Franklin County on Sein Creek , but in such small quantities that it took a pailfull of sand and gravel ...
Stran 100
... deep , made in such alluvial deposits with the view of exploiting the auriferous strata . " It is known that the watershed of the rivers Corozal , Negros , Congos , Cibuco , Navilla , and Manatí contain auriferous sands . The idea which ...
... deep , made in such alluvial deposits with the view of exploiting the auriferous strata . " It is known that the watershed of the rivers Corozal , Negros , Congos , Cibuco , Navilla , and Manatí contain auriferous sands . The idea which ...
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Alaska amalgamation andesite argentiferous assay auriferous average bed-rock blende calcite California Carolina cent chalcopyrite chlorination Colorado Comstock lode 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 gold and silver gold production gold-bearing granite gravel gray copper Gulch Hill hydraulic Ibid Idaho igneous rocks inches iron Jour lead limestone located mercury method Mexico mill Mineral Industry Mineral Resources Mines and Minerals Montana Mountain Nevada North North Carolina occur operations ore-bodies ounces output oxide placer mines placers porphyry precious metals Press probably production of gold pyrite quantities quartz quartz-veins Rept River roasting rocks schists shaft silver production Silver-bearing slate sluices smelting solution South stamps stope sulphides sulphurets surface TABLE tellurides tellurium tetrahedrite timber tion tons Total tunnel usually Utah veins width yield zinc