ISBN: 9780217010474

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustra… Mehr…

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1876. Excerpt: ... then started, one on the hanging wall, the other on the footwall side of the lode. See fig. 209.) (279 The crosscut method is also suitable when you have to deal with a more or less irregular mass, limited on all sides horizontally, instead of a regular lode. (Fig. 210, plan and section.) In this case the level which serves as a base to any story is a closed curve, instead of extending indefinitely along the strike, and is called a contour level. Its object is not only for opening out the deposit previous to its removal, but also for ascertaining the shape and size of its horizontal section. As soon as the contour level has been made, a drivage should be put through Ihe mass in the direction of its greatest length, or two drivages at right angles to it, and then crosscuts may be started in the manner described above, so as to remove the whole slice by degrees and replace it by deads. As already stated, the slices should be taken one after another in ascending order. One set of levels will do for all the slices, for passes can be built up as the deads rise, to effect a communication between the working places above and the level below. (JS80) THIRD CASE:.--Methods of working away wide lodes or masses not containing a sufficient quantity of deads for IHIing-up.--We have already stated (No. 267) that deposits of vein-like origin usually furnish a sufficient quantity of deads for filling up the excavations, because rocks occupy a very much larger space when broken up; we also remarked that it was useless to take these deads out of the mine, indeed that it was advantageous not to remove them, lirstly, in order to avoid to extra cost of conveyance underground, and secondly, in order to derive the benefits obtained by using them for filling up, the principal of ... Jules Pierre Callon, Books, History, Lectures On Mining Delivered At The School Of Mines, Paris (volume 1) Books>History This is an OCR edition without illustrations or index. It may have numerous typos or missing text. However, purchasers can download a free scanned copy of the original rare book from GeneralBooksClub.com. You can also preview excerpts from the book there. Purchasers are also entitled to a free trial membership in the General Books Club where they can select from more than a million books without charge. Volume: 1; Original Published by: Dunod in 1876 in 490 pages; Subjects: Mining engineering; Mineral industries; Mines and mineral resources; Science / Applied Sciences; Technology & Engineering / General; Technology & Engineering / Engineering (General); Technology & Engineering / Mining;<

ISBN: 0217010474

Lectures on Mining Delivered at the School of Mines Paris Vol. 1 Author :Edmond Boutan Jules Pierre Callon 9780217010474 0217010474

ISBN: 0217010474