. The sampling and estimation of ore in a mine . ^4«36* V^ SdjTvple D e^oX eio- ) \ V lAixi»N^ C-VolK S^(\p^e sajcK FIG. I.—18 — SAMPLING AND ESTIMATION OF ORE IN A MINE them with an explosive, is too tough for a moil struck by adouble-hand hammer, when swung by a good man. Theuse of an explosive introduces an element of danger fromsalting, as it is easy to charge the cartridges withpowdery gold, which the dynamite will distribute veryprettily amid the ore. Of course, one can avoid suchtricks by using ones own dynamite, but engineers, as arule, do not find it convenient to travel ab
. The sampling and estimation of ore in a mine . ^4«36* V^ SdjTvple D e^oX eio- ) \ V lAixi»N^ C-VolK S^(\p^e sajcK FIG. I.—18 — SAMPLING AND ESTIMATION OF ORE IN A MINE them with an explosive, is too tough for a moil struck by adouble-hand hammer, when swung by a good man. Theuse of an explosive introduces an element of danger fromsalting, as it is easy to charge the cartridges withpowdery gold, which the dynamite will distribute veryprettily amid the ore. Of course, one can avoid suchtricks by using ones own dynamite, but engineers, as arule, do not find it convenient to travel about with high-grade explosives. Apart from this, there is a commonerdanger. Dynamite tends to break a conical cavity, withthe drill-hole as the axis of a cone which tapers product of the drill-hole would not be a fair sampleeven if it could all be secured without loss or the explosion of the hole breaks a mass of rock,the cross-section of which tapers from the width of severalfeet to almost a point, so that
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Keywords: ., bo, bookcentury1900, bookdecade1900, booksubjectores, bookyear1907
