A Treatise on Metalliferous Minerals and MiningC. Lockwood and Company, 1881 - 438 páginas |
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Términos y frases comunes
acid alluvial average beds blende calcareous Cambrian Cambro-Silurian Carboniferous limestone cavities cent chloritic clay slate coal Coal-measures colour Comstock lode containing copper pyrites Cornwall course cracks crystals deposits depth described Devonian drill dwts dykes earthy east engine fathoms feet thick felspar felspathic filled fissure flat Flintshire galena geological gneiss gold gossan grains granite greenstone grey hæmatite hornblendic inches iron pyrites ironstone lead mines Llandeilo lode lower machine mass matter mercury metallic metalliferous metamorphic rocks mica micaceous miles mineral mineralised mining district Mining Journal mountains North Wales occurs ounces of silver oxide pass porphyritic portion production proportion protoxide pumping quantity quartz quartz veins range river sandstones seams shaft shale shown in fig side silica Silurian slaty rocks sluice spar stamps stone stopes strata sulphide sulphur surface tons traversed upper usually washed Wheal yards yield zinc
Pasajes populares
Página 308 - ... and shall be inclined at the most convenient angle which the space in which the ladder is fixed allows, and every such ladder shall have substantial platforms at intervals of not more than twenty yards.
Página 172 - ... made in the laws and regulations of the Stannaries. A warden was appointed to do justice in law and equity, from whom there was an appeal to the Duke of Cornwall in council, or, for want of a Duke of Cornwall, to the Crown. Henry VII.
Página 2 - ... The specific heat of water is taken as the standard and equal to one. Specific Gravity. — By specific gravity is meant the relation existing between the weight of any substance and the weight of an equal volume or bulk of water. Thus the specific gravity of cast iron is about 7, which means that a cubic foot of iron is seven times heavier than a cubic foot of water. In Table 2 are given the specific heats and specific gravities of common substances.
Página 426 - Saltpeter or nitrate of potassium. 2. (Chile) Sodium nitrate. (Halse) Sailer (Corn.). 1. A chamber in a mine. 2. A stage to work on. 3. A boarded channel for water to run in along the bottom of an adit. 4. The floor or stage on which the ladders rest in a shaft (Davies).
Página 413 - The паше ought properly to be only applied to effusive or volcanic rocks, but it is often used as a synonym for Igneous. (Kemp) Eruptive vein. A vein filled by eruption of igneous matter from below. (Standard) ïrythrite; Cobalt bloom.
Página 341 - duty" of an engine is meant the amount of work done in relation to the amount of fuel consumed.