The structural and industrial materials of California (1906)
Aubury, Lewis E., b. 1862 · Sacramento, W.W. Shannon, Superintendent State printing · leaf 137
CATE. 9-BUL. 38 (^-^> 130 STRUCTURAL AND INDUSTRIAL MATKHLM.S OF CALIFORNIA. The blocks thiit form the San Pedro breakwater are broken down bychurn-drilling (three men to the drill) rows of holes, having an averagedepth of 25 feet, with 20 feet face, and blasting with black powder, tamp-ing… … ILL. No. 00. cn.VTSWOUTII I.^RK SAN DSTON K (jrAKHV, LOS .\N(;KLES COlNTY. pounds; 20 per cent is lilocks from 1000 to 1000 pounds; and 45 percent large blocks over 4000 pounds. (See sketch of front elevation ofquarry.) The quarry is equipped with four steam derricks, using oil as fuel.
Building stones · Portland cement · Clay · Mines and mineral resources
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