Salisbury’s, Dr., theory concerning malarious fever, 214 Salt marshes, catch water drains, 201 Salt marshes, construction of embankment, 196 Salt marshes, dyke and ditch, (illustration), 197 Salt marshes, exclusion of the sea, 195 Salt marshes, how formed, 194 Salt marshes, inundations from upland , 201 Salt marshes, location and size of embankment, 195 Salt marshes, management of creeks, 198-200 Salt marshes, management of rivers, 201 Salt marshes, muskrats, 199 Salt marshes, outlet for under drainage, 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