Mining and Metallurgy Volume 91-96 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1914 edition. Excerpt: ...and Scientific Press, Dec. 4,1909) Ore breaking including superintendence and general charges was 41c. Machine drilling with 2%-in. drill was at the rate of 31 ft. per man-day at a cost of 2.0250. a foot. Hand drilling was done at the rate of 13.8 ft. per man-day at a cost of 8.20. Cost of Development Bunker Hill and Sullivan, Coeur d'Alene. (Engineering and Mining Journal, June 14, 1913) 11,050 ft. of vertical and horizontal development: Foremen, blacksmiths, etc................ Miners................................. Shovelers............................... Explosives.............................. Timber and lagging...................... Power, labor and supplies................ Not specified........................... Total.............................. Per Foot Per Cent................. $0.312 4.4............... 2.500 35.0................ 1.650 23.1................ 0.990 13.8................ 0.400 5.6................ 0.524 7.33................ 0.774 10.8................ $7.15 100.0 Portland Gold Mining Co., Cripple Creek, Col. Cost of drifts or levels, $6.12; crosscuts, $6.23; winzes and raises, $8.60. In the Cost of Mining by Finlay, p. 380, the cost of 896 ft. of 5 by 7 ft. drifts is given as follows: _ ' Per Foot Tramming............................................ $1.00 Pipe and trackmen.................................... 0.14 Machine men......................................... 1.88 Total labor....................., .................. $3.02 Other costs: Use of machines, air, etc............................... $0.97 Repairs, cars, etc...................................... 0.08 Explosives............................................ 1.43 Hoisting............................................. 0.46 General expense, ...