Opening fire, defence, 104 Opening fire from second artillery position, 83 Opening the first parallel, 80 Organization and duties of brigade of sappers, 28 Organization and tactics of mines, 169-76 Ovens and kitchens, 114 Overcharged and undercharged mines, 120, 125, 171-2 Overground approaches, 31 P Parallels, 15 Parallels, demi-, 86 Parallels, execution of, 20-3 Parallel, first, 78 Parallel, first, opening, 80 Parallel, first, advance from, 84 Parallel, second, 85 Parallel, third, etc., 86 Parallel, tracing a, 17 Parks, camps, etc., fortifying, 68 Parks and depots, 111 Partly-lined galleries, 148 Paris, siege of, 71-2 Passage, central, of battery, 48 Passage of the ditch, 37 Period, first, of siege, 65, 103 Period, second, of siege, 75, 106 Period, third, of siege, 86, 107 Pick and shovel, miner’s, 136 Pick, miner’s, distance heard, 170 Placing fuzes in charge, 164 Placing the charge, 165, 176 Plan of attack, 78 Plevna, siege of, 71, 72 Point of attack, 73 Posting besieging force, 67 Posting working parties, 18 Powder-boxes, 58 Powder for siege batteries, 44, 57 Precautions against dampness, 63 Precautions in blasting, 180 Preliminary considerations of defence, 98 Preparations for defence, 101