Battery, tracing the, 47 Belfort, siege of, 71-2, 86, 104 Besieging force, bringing up and posting, 67 Besieging force, strength and composition, 70-2 Blasts, 178 Blasting and demolitions, 178-84 Blindage-frames or blinds, 156 Blinded descents or galleries, 38, 156, 170 Blinded sap, 38 Blinded sap, traverse by, 35 Blinds or screens, 45 Blockade, 1 Bombardment, 8 Bombardment, defence against, 10 Bombardment, defence during, 105 Bomb-proofs and traverses, 25, 170 Branches, 170-72 Breach, capture and crowning of, 89 Breaching batteries, 83 Breaching by mines, 176-7 Breaching galleries, 177 Breaching the scarp and counter-scarp, 88 Breaking out a full sap from a parallel, 30 Breaking out a double sap from a parallel, 33 Bridge, demolition of, 182 Bridge, floating--passage of ditch, 40 Brigade or detachment of sappers, 28 Bringing up and posting the besieging force, 67 C Camps, fortifying, 68 Camouflet, 120, 167, 171, 172 Canal locks, demolition of, 183 Capitulation, the, 109 Capture and crowning of breach, 89 Capture and crowning of covered way, 87 Cases, mining, 139-41 Chamber, definition, 119 Chamber, form and location, 160 Changing direction of double sap, 33 Changing direction of galleries, 148, 150, 154 Changing slope of galleries, 149, 155 Charge, definition, 119