Show rock that strikes 4 1 av I 1 t IN FIRE h va M drilled avi R 8 at the wasatch mines co alta utah two IR I R no rock drills have driven 3 ft of 7 1 tunnel at an upkeep cost of about fifteen cents per foot advance A STREAM OF FIRE COMES FROM THE DRILL HOLE UNTIL IT IS 18 INCHES DEEP illustrating THE CHARACTER OF THE ROCK DRILL the upkeep cost per foot of the ingersoll rand imp imperial rial compressor which furnishes the air has been NOTHING these facts were furnished by T W blake superintendent specify ingersoll rand equipment for service rand company par ii 11 broadway y new york Ino eroll rand |