37-39. Change of Direction of Galleries with Frames and Sheeting, 148 38. Change of Slope, of Galleries, 149 40, 41. Returns, 150 42, 43. Maps and Drawings, 151 44, 45. Sinking a Shaft with Cases, 152 46-48. Driving a Gallery with Cases, 153 49. Change of Direction of Galley Lined with Cases, 154 50, 51. Change of Slope, 7 Galleries Lined with Cases, 155 52. Shafts à la Boule, 156 53-55. Blinded Galleries, 156 56. Rate of Advance of Galleries, 157 VENTILATION OF MINES. 57. Sources of Deleterious Gases, 158 58. Ventilation by Forcing in Air, 159 59. " by Exhausting Air,159 60. " by Assisting Natural Ventilation, 160 61. " by Use of Masks, etc.,160 MINE-CHAMBERS. 62. Form, Size, and Location of Chambers, 160 LOADING AND FIRING MINES. 63. Preparing the Charge, 161 64. Distribution of Fuses in Charge, 161 65. Character and Construction of Fuses, 163 66-68. Electric Fuses, 163 69. Placing the Fuses in the Charge, 164 70. The Fuzes in Frozen Dynamite, 165 71. Placing the Charge, 165 72. Tamping Mines, 166 73. Firing Mines, 166 CAMOUFLETS BY BORING. 74. In Favorable Soil, 167 75. In Stony Soil, 168 CHAPTER III. ORGANIZATION AND TACTICS OF MINES. 76. Organization of Mines, 169 77. The Attack, 169 78. The Lodgment, Galleries, Transverses, Listening-galleries, etc., 170 79. Avoid Exposing a Flank, 171 80. Use Overcharged Mines, 171 81. The Defence, 171 82. Conditions to be Fulfilled, 171 83. System of Galleries Used, 172 84. Use Undercharged Mines, 172 85. Shaft Mines, 172 MINE TACTICS.