ainage, 204-205
Salt marshes, pumping, 206
Salt marshes, rain-fall and filtration, 204
Salt marshes, valve-gates and sluices, 204
Scraper for filling ditches, (illustration), 140
Seeds, germination of, 13
Sewage, use of in agriculture, 226
Sewers, defects of large, 228-238
Sewers, description of the London outfall, 225
Sewers, efficacy of glazed earthern pipes, 229-230-238
Sewers, experiments of Hale on pipe sewers, 230
Sewers, imperfect, 224
Sewers, of brick, defective, 228-235-238
Sewerage, conclusions of General Board of Health, 237
Sewerage, of New York, 227
Shrinkage of clay soils, 28
Sides of ditches in soft land, how braced, (illustration), 124
Silt, 90
Silt, basins, (illustrations), 121-135-136
Silt, basins, how made, 120
Silt, basins, 91-96-134
Silt, in tiles, 144
Sources of the water in the soil, 10
Springs, how to collect the water of, 59-60-141
Staking out the lines, 102
Staten Island, 209
Steam pumps, 206
Stone and tile drains, 142
Sub-mains, 59

Teams used in opening ditches, 122
Temperature, 35-66
Temperature, affected by draining, 36
Tile laying, 127
Tile-pick, (illustration), 131
Tiles, and tile laying, cost of, 157
Tiles, capacity for discharging water, 84-86
Tiles, double-style, 80
Tiles, drain--essential characteristics, 22
Tiles, how made, 174
Tiles, horse-shoe, 78
Tiles, kinds and sizes, 77
Tiles, ordering, 82-101
Tiles, objections to large sizes, 147
Tiles, pipes and collars, 81
Tiles, rapidity with which they receive water, 78
Tiles, sizes of, 81
Tiles, sizes required for different areas, 88
Tiles, should be well formed, 83
Tiles, sole, 80
Tiles, trimming and perforating, 131
Tile making, material for, 174
Tile preparation of earths, 176
Tile rolling and drying, 182
Tile washing the clay, 177
Tobacco, 169
Tools required, 113
Town drainage, conclusions of General Board of Health, 237

Undrained land not reliable for cultivation, 18

Vermin as a cause of obstruction, 93

Water, depth of, 66-70
Water, in the sub-soil, injurious effects of, 15
Water, movement of in the ground, 32-64-65
Water, objections to