INDEX 



251 



Height of instrument, 99. 



Hilgard, E. W., 5. 



Horse and power machines, 135. 



Hose-level, 107, 165 ; accuracy of 

 reading, 165 ; availability 

 and cost, 166 ; breaking 

 the grade, 185 ; checking 

 instrument, 169 ; check- 

 ing up on depth of ditch, 

 184 ; computing eleva- 

 tions, 177 ; construction, 

 167 ; construction of rods, 

 170; datum plane, 180; 

 for more extensive work, 

 186 ; grade stakes not 

 needed, 186 ; how to read 

 height of column, 174 ; 

 introducing water into, 

 168; leveling, 181; limi- 

 tations, 166 ; long stakes, 

 180 ; materials needed for, 

 166 ; moving the level, 

 175 ; negative reading, 

 175 ; positive reading, 

 175 ; recording data, 176 ; 

 recording in feet and 

 inches, 178 ; removing 

 air bubbles from, 168 ; 

 rods for, 170 ; suggestions 

 concerning material, 167 ; 

 to determine fall, 183 ; to 

 determine height of grade 

 bar, 182 ; to use hose- 

 level, 173 ; using the 

 hose-level without rods, 

 180 ; zero reading, 175. 



How effects of drainage take place, 

 54. 



How plant-food exists in the soil, 4. 



How plants secure their foods, 3. 



How water approaches tile, 84. 



How water enters tile, 75. 



Humid areas, 58 ; alluvial plains, 

 58 ; classification, 58 ; Dis- 

 mal Swamp, 58 ; extent 

 of areas, 58 ; marine 

 marshes, 61 ; Mississippi 

 delta, 60 ; swamps of 

 drift areas, 60 ; value of, 

 58. 



Hutchinson, H. B., 5. 

 Hygroscopic water, 25. 



Impervious strata, 192. 



Increasing evaporation, 202. 



Increasing the run-off, 202. 



Intelligent handling of soil needed, 

 206 ; influence on ground 

 water, 206. 



Interesting facts concerning ground 

 water-table, 201. 



Irrigated lands, cost of tiling, 161 ; 

 observations concerning, 

 161 ; subject to accumu- 

 lation of gravitational 

 water, 159 ; injured by, 

 159 ; remedy, 160. 



Joining lateral to mains, 147 ; 



three methods, 147. 

 Jones, E. R., 199. 

 Jordan River region, 160. 



Keeping notes, 102, 117. 



Kinds of tile, 71. 



King F. H., 10, 11, 23, 47, 50. 



Lands of irrigated regions injured 

 by gravitational wate* , 

 159; remedy for, 160; 

 tiled, 160. 



Lands requiring drainage, 69. 



Laterals, 76 ; angle of approach, 

 113; depth of outlet of, 

 146 ; designating, 151 ; 

 joining to mains, 147 ; 

 leveling for, 146 ; making 

 provisions for, 147 ; 

 method of joining to main, 

 147 ; size of tile, 146. 



Laying out a drain, 108 ; a main, 

 109 ; a system, 108. 



Lenawee Co., Michigan, 163. 



Level, the, 94 ; carpenter's level, 

 105 ; cheap devices, 105 ; 

 cheaper levels, 96 ; cau- 

 tions, 102 ; direct reading, 

 100 ; hose-level, 107 ; 

 moving and re-setting, 

 103 ; purpose, 98 ; setting 



