——, sliding forward of, 207, 208, 213 ——, well system of, 223 Drainage, ballasting, 82 ——, catchwater drains and ditches, 76, 77 ——, chalk, 29 ——, clay, 73–75 ——, controlling discharge, 74 ——, counterforts and trench drains, 77–80 ——, culverts, 83–85 ——, equable, necessary, 150 ——, field drains, interception of, 77 ——, filling of trench drains, 78, 79 ——, formation, 81, 82 ——, mixed soils, 72 ——, number and depth of drains, 75 ——, object of, 65, 72, 73, 81 ——, overflowing earthworks, 74, 75 ——, peat, 77, 149, 150 ——, sand, 77, 80, 81 ——, seat of an embankment, 82, 83, 85, 86 ——, slope drains, 77–80, 111, 112 ——, soft soils, 73, 149, 150 ——, spoil banks, 80 ——, springs, 75, 76, 80, 81 ——, systems required, 72–77, 80, 81 ——, well system, 81 Drifts of snow, protection against, 131–134 Drift soil, treacherous, 13, 18 ——, —— upon sidelong ground, 143–145 E. Earths, preservation when loaded, 88 ——, maximum safe load upon, 87–91 ——, table of weights of, 92 ——, treacherous, 13 ——, universality of slips in, 2 Effect of a slip, cuttings, 50 ——, embankments, 50 ——, influence of depth of cutting and height of embankment, 50, 51 Embankments, ballast upon, 151 ——, causes of slips and subsidences, 2, 5–8 ——, condition of earth, 97 ——, consolidation of soft soil, 148–151, 153–155 ——, consolidation by time, 17 ——, deposition of, 156–159, 161–9 ——, deposition, from side cutting, 157, 158 ——, depositing upon soft soil, 154, 155, 168, 169 ——, deterioration of excavated earth, 93, 94 ——, drainage of the seat of, 160, 161 ——, failure of, 167 ——, fascine mattress bed, 155 ——, forming, 158 ——, height, safe, 91, 92 ——, —— of tip, 164–167 ——, high, 95 ——, homogeneousness, 158 ——, junction of, precautions, 164, 165 ——, long lead, 163 ——, precautions in deposition, 157–159, 161–163 ——, preparation of ground, 159–161 ——, safe maximum heights of, 94–96 ——, safe load upon, 88, 93, 94 ——, sidelong ground, 142, 143, 145 ——, side tipping, 167, 168 Embankments. ——, soft soil, 147–149 ——, specifications, impracticable, 156, 157 ——, steam navvy, influence of, 169, 170 ——, systems of deposition, 159, 161–169 Embankments, tip head, form of, 168 ——, vibration, effects of, 136–141 ——, weather influence during deposition, 167 Estuary or shore embankments. ——, closure of, 177 ——, deposition of, 176–177 ——, design, 171–173 ——, effect of erection, 173, 179, 180 ——, excavation for, 176, 177, 187 ——, height, 179 ——, material, 187 ——, pressures, calculations showing changes of 182–187 ——, protection of slope, 174–180 ——, shore deposit protection, 176, 177 ——, site, 171 ——, slope, form of, 174, 180 ——, trestle work, and on sea-shore, 180 ——, viaducts and, 172, 173, 180 F. Fascine covering of slopes, 128, 129, 178, 179