248 



INDEX 



Changing temperature, 208. 



Character of soils, 1. 



Cheaper devices, carpenter's level, 

 105 ; hose-level, 107 ; water 

 level, 106. 



Cheaper levels, 96 ; using, 104. 



Checking grade bars, 137, 184. 



Checking the hose-level, 169. 



Chemical changes, 56. 



Chemical composition of soils, 1. 



Chief causes resulting in lowering 

 of ground water, 201. 



City wells, effect on underground 

 water. 203. 



Classification of swamps, 58. 



Clay tile, 71. 



Cleavages in soil, 54. 



Climate, affected by drainage, 208 ; 

 changing, 208. 



Clogging of tile by roots, 142. 



Closing the upper end of the drain, 

 143. 



Common spade, 135. 



Common swamps, 58. 



Computations, 102, 122, 123. 



Connecting laterals to mains, 147 ; 

 angles, 148 ; making open- 

 ings for, 148 ; side, 147 ; 

 top, 147. 



Construction of district drains, 221. 



Construction of ditch, 134 ; econ- 

 omy in, 134. 



Construction of silt-basin, 93. 



Controversial evidence must be 

 heard in considering drain 

 petitions, 220. 



Convenient aids in using data, 118. 



Cornell reading course, 193. 



Correcting depth of ditch, 141. 



Correct plowing and later struc- 

 ture of the soil, 32. 



Cost of digging ditch, 162, 163; 

 cost per rod, 163. 



Cost of hauling tile, 162. 



Crop needs, water, 204. 



Crumbs, soil, theory of, 32. 



Cumulative effects of drainage, 57. 



Data concerning ground water- 

 table, 201. 



Data, using, 133. 



Datum plane, 99, 115; above 

 ground, 182 ; for hose- 

 level, 180. 



Davis, C. A., 61. 



Dayton floods, 209. 



Delta lands, 60, 62. 



Denitrification, 15. 



Denitrifiers, 16. 



Depth of cut, 131 ; to determine, 

 131. 



Depth of drain, 80; trial, 128, 

 131. 



Designating sub-mains and laterals, 

 151. 



Destruction of forests, 202. 



Diked farm in Michigan, 65 ; size 

 of, 65; system, 65. 



Dikes, 61, 62. 



Diminishing rainfall, 208 ; due to 

 drainage, 208. 



Direct draft on underground water, 

 203. 



Direct reading of leveling rod, 100. 



Dismal Swamp, 58. 



Distance apart of tile drains, 83 ; 

 of grade stakes, 110. 



Ditch cleaner, 134. 



Ditch, cost of digging, 162 ; cor- 

 recting depth of, 141 ; 

 construction of, 134 ; fill- 

 ing, 143 ; finishing, 140 ; 

 not too wide, 138 ; open- 

 ing, 138 ; order of steps in 

 installing a system, 163 ; 

 precautions, 143 ; remov- 

 ing the soil from, 139 ; us- 

 ing line for, 138. 



Ditching tools, 134 ; common 

 spade, 135; hook, 134; 

 pick, 135 ; scoop, 154 ; 

 spade, 134. 



Drain, 80; depth, 80; distance 

 apart of, 83 ; factors 

 governing, 83 ; modified 

 by subsoil, 83 ; limits of 

 depth, 80. 



Drainage by wells, 153 ; by wind- 

 mill, 198; by electric 

 motor, 198 ; general in- 



