Cables, 53 Cellulose dynamite, 105 Charging and firing, 150 ---- the shot-holes, 132 Chemical compounds, 81 Claying iron, 20 Conditions of disruption, 110 Connecting wires, 52 Cotton powder, 103
Darlington drill, 26 Detonation, 95 Detonators, 54 Dislodged rock, removal of, 154 Disruption, conditions of, 110 ---- force required to cause, 107 Division of labour, 155 Drills, dimension of, 6 ---- form of, 4 ---- hand, 1 ---- hardening and tempering, 10 ---- making and sharpening, 7 ---- sets of, 13 Drivings, examples of, 157 Dubois-François carriage, 39 Dynamite, 100 ---- composition of, 87
Electrical firing, advantage of, 153 Electric fuses, 47 ---- tension fuse, 50 Example of a heading, 115 Examples of drivings, 157 Explosion, force developed by, 72 ---- heat liberated by, 67 ---- gases generated by, 69 ---- nature of, 64 Explosive agents, nature of, 76
Firing batteries, 62 ---- blasting charges, appliances for, 42 ---- by electricity, 138 ---- machines, 55 ---- machine, Bornhardt’s, 57 ---- ---- induction coil, 61 ---- ---- Mowbray’s, 59 ---- ---- Siemens’, 60 ---- ---- Smith’s, 58 ---- points of the common explosive agents, 102 ---- table for frictional electric machine, 140 ---- the charges, 137 Force developed by an explosion, 72 ---- developed by gunpowder, 88 ---- required to cause disruption, 107 Fuse, safety, 45 Fuses, electric, 47
Gases generated by an explosion, 69 Gun-cotton, 99 ---- constitution of, 81 Gunpowder, 97 ---- composition of, 80 ---- force developed by, 88
Hammers, 14 ---- patterns of, 15 Hand boring, 128 Heading, example of, 115 Heat, action of, in firing, 92 ---- liberated by an explosion, 67 ---- measure of, 66 ---- specific, 66 Hoosac Tunnel, 158
Labour, division of, 155 Line of least resistance, 106 Lithofracteur, 104
Machine boring, 142 ---- rock-drills, 23 Machines, firing, 55 Means of firing the common explosive agents, 92 Measure of heat, 66 Mechanical mixture, 76 Mowbray’s firing machine, 59 Musconetcong Tunnel, 159
Nature of an explosion, 64 Nitrated gun-cotton, 103 Nitro-glycerine, constitution of, 86
Obstructions in water-courses, 178 Operations of rock blasting, 128
Preparation of subaqueous charges, 164 Principles of blasting, 106
Rammer, 20 Relative strength of gunpowder, gun-cotton, and dynamite, 91 ---- ---- of the common explosive agents, 88 Removing dislodged rock, 154 Rock-drill supports, 34