CONTENTS ix 



CHAPTER III 



PAGES 



HUMID AREAS AND THEIR RECLAMATION .... 58-68 



Common swamps, 84 ; Alluvial plains, 85 ; Swamps 

 of the drift regions, 86 ; Marine marshes, 87 ; Reclama- 

 tion of common swamp lands, 88 ; Reclaiming delta 

 lands, 89 ; Size of the unit, 90 ; How the expense of 

 installing, operating, and upkeep is met, 91 ; Reclaim- 

 ing the swamp lands of the drift regions, 92 ; A diked 

 farm in Michigan, 93 ; Reclaiming marine marsh lands, 

 94 ; Economic oversights, 95 ; Areas of imperfect natu- 

 ral drainage, 96 ; Small wet areas, 97 ; Proportion of 

 waste land, 98. 



CHAPTER IV 

 GENERAL DRAINAGE INFORMATION . . . 69-93 



Lands requiring drainage, 99 ; Methods of drainage, 

 100 ; Open ditches, 101 ; Shallow open ditches, 102 ; Tile 

 drainage, 103. Tile : Kinds of tile, 104 ; Common clay 

 tile, 105 ; Glazed tile, 106 ; Cement tile, 107 ; Difficulties 

 with cement tile, 108 ; Precautions, 109 ; How water 

 enters the tile, 110; Tile systems, 111; Outlet, 112; 

 Depth of tile drain, 113 ; The distance apart of tile 

 drains, 114 ; How water approaches the tile drains, 115 ; 

 Size of tile to use, 116 ; Grade or fall, 117 ; Relation of 

 size of tile to the grade, 118 ; Uniformity of grade, 119 ; 

 Silt-basins, 120 ; How the silt-basin performs its work, 

 121 ; The construction of a silt-basin, 122 ; Finishing 

 the silt-basin, 123. 



CHAPTER V 

 LEVELING . . . . ...'... 94-107 



The level, 124 ; Cheaper levels, 125 ; Leveling rods, 

 126; Target, 127 ; Using the level, 128; Setting up the 

 level, 129; Cautions, 130; Determining the height of 

 the level, 131 ; Direct reading, 132 ; Target reading, 133 ; 



