Show drilling through granite in deep gogebic shaft new york dynamite by the carload drill steel by the ton air by tho the cubic mile were used by miners in the gogebic range of michigan during the 14 months battlo battle with granite while they sank a now shaft halt a mile deep 13 feet wide and 21 feet long to reach a new ore body details ol of this grim battle with the billion year yea rold r old rocks were described to the american institute of mining and metallurgical engineers here by W A knoll and J C sullivan michigan mining engineers drilling 68 holes hola including a 4 inch center hole 12 feet into the resistant rock charging these holes with 1084 1064 sticks of 0 dynamite firing this charge without damaging expensive steelwork only BO 50 feet above were only parts of this stupendous task alter after the blasts sweating muckers duckers tolled for 23 hours with power machinery including air driven to pavement bi breakers enkers to clear the bottom of the hole for the next blast repeating this laborious cycle times during the 14 months of work the shaft was completed recently |