Existing comment:
Blasting:
Stone was dislodged from the quarry wall by exploding black powder in holes drilled by the quarrymen.
Drilling: Holes for powder charges were formed by steel drills which ground the stone into dust. Several holes were required ranging from 16 to 35 inches deep. The drill was struck by either a sledge hammer or a one-hand hammer (A). A sledge hammer weighed about eight pounds and was swung in both hands while another person held the drill and struck it with a hammer of about three pounds.
Shooting: Blasting powder, a large-grained, mild explosive was used to dislodge stone intended for building purposes since its explosive force did not shelter the stone (B). The powder was poured into the hole. After a safety fuse was set into the powder, rags and dried clay were tamped in firmly with a wooden stick, then the fuse was lit. |