250 



INDEX 



development, 56 ; on ven- 

 tilation, 56. 



Elevation of bottom of ditch, 129 ; 

 of stakes, 102, 122 ; to de- 

 termine, 129. 



Elliott, C. G., 73, 76, 80, 86. 



Encircling ditch, 63. 



England, leads in acre-yields of 

 crops, 204 ; rainfall and 

 wheat growing, 204 ; tile 

 drainage in, 192, began 

 in 1684, 192. 



Estimates, of tile, 114. 



Expense apportioned, 64. 



Expense of drainage system and 

 pumping plant, 64 ; of 

 constructing district 



drains, how met, 221. 



Experience of other countries with 

 falling ground water, 207. 



Factors determining size of tile to 

 use, 85. 



Fall of tile, 88 ; computations of, 

 with hose-level, 183 ; de- 

 termining, 129 ; to de- 

 termine with hose-level, 

 183 ; uniform, 89. 



Farm operations delayed, 189. 



Filling the ditch, 143 ; by plow or 

 scraper, 143. 



Finders, 109, 110; sometimes not 

 needed with hose-level, 

 186. 



Finishing ditch by hand, 143. 



Finishing silt-basin, 93. 



Finishing the outlet, 144. 



Fippin, E. O., 74, 88, 135, 142, 

 193. 



Fitting the joints, 142. 



Floods, Dayton floods, 209; Mis- 

 souri floods, 209 ; Paris 

 floods, 209; relation to 

 drainage, 210; to erratic 

 rpinfall, 209; to forests, 

 210; to rainfall, 209. 



Fore-sight, 101 ; its use, 101 ; 

 limitations with cheaper 

 levels, 116; reading, 101. 



French Acadians, 60. 



Fresno region, 160. 



Frost dates, changes in, 213. 



Frosts and wooded areas, 214. 



General precautions, concerning 

 cement tile, 74. 



Geneva, 12, 13. 



Germination of seeds, 6 ; affected 

 by temperature, 6 ; af- 

 fected by ventilation, 16 ; 

 desirable temperature con- 

 ditions, 8 ; occurs at very 

 low temperatures, 8 ; oc- 

 curs on ice, 8 ; prevented 

 by exclusion of oxygen, 

 16. 



Glazed tile, 7 ; qualities of, 72. 



Good soil management will improve 

 ground water conditions, 

 206. 



Grade bars, 131 ; checking, 137, 

 184 ; height of, 131 ; nail- 

 ing in place, 137 ; setting 

 up, 136 ; to determine 

 height, 133 ; with hose- 

 level, 184. 



Grade or fall, changing, 89 ; of 

 mains, 88 ; preliminaries 

 to establishing grade, 125 ; 

 profile, 125; range of, 88; 

 relation to size of tile, 88 ; 

 to establish, 126; uni- 

 formity of, 89. 



Grade stakes, 108 ; distance apart, 

 110; may not be needed 

 with hose-level, 186. 



Ground water-table, falling, 200; 

 rising, 200. 



Haberland, G., 7. 



Hall, A. D., 11. 



Hard-pan, 188, 192. 



Harlem lake, 64. 



Hauling and distributing tile, 114. 



Heat losses, extent of, by evapora- 

 tion, 39. 



Heat, of soils, 33 ; of vaporization, 

 36 ; temperature effects 

 of, 37, 38; theoretical 

 influence on soil, 51. 



