Identifier: cassiersmagaz401911newy (find matches)
Title: Cassier's magazine
Year: 1891 (1890s)
Authors:
Subjects: Engineering
Publisher: New York Cassier Magazine Co.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

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GIANT STRING OF OXEN HAULING MARBLE IN CARRARA., ITALY will be so shattered by the explosionthat the waste marble is much morethan the block which is loosened. Theheight of the quarries, however, al-lows the block to slide down theslopes of the mountains by gravity,and in this way a mass weighing somuch that it could not be lifted bythe power available can be lowered bymeans of block and tackle to the foot of the mountain to be shaped into aform so that it can be sent away. While some of the miners havedrills operated by steam and electricpower, much of the work is donewith the hand-power mill. Apparatusfor grooving the marble has not asyet been employed, except in a fewworks, the bulk of the product beingobtained by blowing it out. The METHODS OF STONE QUARRYING 147
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148 CASSIERS MAGAZINE holes are drilled where, in the judg-ment of the quarry director, the ex-plosive will be most effective, but be-fore being charged they are usuallyenlarged by pouring nitric acid intothem, which eats away the interior.The explosive is then inserted. Inrecent years the electric current hasbeen used to ignite it, but in many ofthe larger operations the fuse is stillemployed. The charges are not always sodistributed that the block desired isloosened, so a second blast is fre-quently necessary to completely de-tach the mass, when some of theneedless surface is cut off on thespot with chisel and mallet. Thenthe material is ready to be trans-ported to the marble mills in the val-ley or to Avenza for shipment bywater. As the quarry may be severalmiles from the railroad advantage istaken of its height. If the marble isa very large piece an inclined planemay be made, down which the blockslides upon a wooden sledge, con-trolled by ropes fastened about it,which are run thro

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