Chicago : Engineering and Contracting Pub. Co. · leaf 416
oles meeting at a point is >ctober 18, 1911. ENGINEERING & CONTRACTING 401 ost as large as by live or six, so that it isually better to use only three or four holesr cutting-in; and, if the ground requiresem, to put the extra holes in as relief holeslere they will break more ground.After… … Fig. 4. les, will suffice; Fig. 5 shows two on eitherle and one above, helping the middle backle, which is important because upon itseaking depends the successful blasting of theher two back holes. In the sketch the cut-ig-in holes are placed low; they might haveen shifted higher and the upper…
Buildings
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