Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress .. . he mine developmentis planned along lines almost unheard of ten years ago. In the first placethe gravel which overlies the ore is stripped off, even if it is fifty feet is done with steam shovels, which load the gravel upon cars. Theseare then pulled away by one locomotive while a seco
Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress .. . he mine developmentis planned along lines almost unheard of ten years ago. In the first placethe gravel which overlies the ore is stripped off, even if it is fifty feet is done with steam shovels, which load the gravel upon cars. Theseare then pulled away by one locomotive while a second places new empties in position to be filled. One shovel will load from 150 to 175 cars a day;that is, will take from 3500 to 4500 tons of dirt from the sides of the pit andput it upon the cars. This method obviates the use of timber for holding upthe surface. After the overlying gravel is removed, should the conditions be favorable,the ore is taken out with a shovel. If this cannot be done, some methoddepending on rock-filling is adopted. At the Auburn mine, after strippingand driving the levels, raises are made to the surface at intervals of aboutfifty feet, the ore broken down around them, starting at the surface, anddropped down through them. This leaves openings in the shape of inverted. 584 TRIUMPHS AND WONDERS OE. THE XIXth CENTURY cones, having their bases at the surface. Additional raises are then madehalfway between the others, and the remaining material extracted. At the Fayal mine they take out rooms twenty-four feet wide by threehundred feet long, with a twenty-four-foot pillar between them. Theserooms are carried up from the first level to the surface, and filled with gravelwhich is run in from above. Then the pillars are mined by slicing andcaving ; that is, by running drifts along the sides of the pillar and cavingthe ore down from the roof. After removing this ore another drift isrun, the roof caved, and another slice taken off. It is claimed the savingin tim
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Keywords: ., bookcentury1800, bookdecade1890, bookidtri, booksubjectinventions
