Davies, Charles, 1798-1876 · New York, Cincinnati [etc.] American book company · leaf 375
368 ELEMENTS OF SURYETING. [book X. In opening mines it is considered good practice to follow thevein for a considerable distance in depth, to be fully satisfied ofits continuity, before sinking a vertical shaft for deep working. Should the vein be vertical, however, the prospecting shaftmay be… … Fig 19c. charge and upon the characteristics of the vein. A carefulengineer will not incur the expense of sinking a deep working shaftto intersect an inclined vein, until he has followed the vein forsuch a distance that the possibility of its terminating, or pinch-ing out, is quite remote. Should…
Surveying
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