. The Vermilion iron-bearing district of Minnesota : with an atlas . A. VIEW SHOWING METHOD OF LOADING B. VIEW OF MAIN DRIFT WHICH HAS BEGUN TO CAVE. CHANDLER MINEFrom photographs belonging to the Minnesota School of Mines. SOUDAN FORMATION. 239 falls prevented by breaking- down tbe rock as soon as it is observed tobe loose. From the top of the fill the roof can readily be reached and aslice of ore about 10 feet in thickness is blasted down from it, brokenup, and tluown into the chutes (mills). These chutes are 25 feet they were much more widely separated, but experience
. The Vermilion iron-bearing district of Minnesota : with an atlas . A. VIEW SHOWING METHOD OF LOADING B. VIEW OF MAIN DRIFT WHICH HAS BEGUN TO CAVE. CHANDLER MINEFrom photographs belonging to the Minnesota School of Mines. SOUDAN FORMATION. 239 falls prevented by breaking- down tbe rock as soon as it is observed tobe loose. From the top of the fill the roof can readily be reached and aslice of ore about 10 feet in thickness is blasted down from it, brokenup, and tluown into the chutes (mills). These chutes are 25 feet they were much more widely separated, but experience hasshown that the distance now maintained is the best. The men han-dling the ore which falls between can work both ways from the chutesand can throw the ore into the chutes without tramming or secondhandling. These chutes lead down to the drift below, and from themtlie ore is let out into the tram cars. PI. X, A shows the method ofloading these cars in the main drift at the bottom of one of the filled the cars are hauled by mules to the shaft and thence hoistedto the surface. As the stope is
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectgeology, bookyear1903
