INDEX 



Accuracy of readings with hose- 

 level, 165. 



Adjusting size of mains to needs, 86. 



Agencies active in soil ventilation, 

 40. 



Ammonia in the soil, 5. 



Angle of approach of laterals, 113. 



Angles, for connections, 114; may 

 be purchased, 149, 150. 



Animal forms enter soil, 56. 



Animal needs for water, 204 ; in 

 acre-inches of rainfall, 205. 



Areas of imperfect natural drainage, 

 66. 



Artesian wells, effect on under- 

 ground water, 203. 



Back-sight, 100 ; illustrated, 101 ; 



limitations with cheaper 



levels, 116; reading, 100, 



116; to use, 100. 

 Bacteria and molds, 57. 

 Bad soil management, effect on 



evaporation, 202 ; effect 



on run-off, 202. 

 Bayou La Fourche, 60. 

 Biological activities, 5, 57. 

 Blackwelder and Barrows, 4. 

 Blinding, 142. 

 Boggy places, 156. 

 Boning line, 131 ; position, 131 ; 



stretching, 140 ; using, 



140. 



Boning rod, 131. 

 Bottom of ditch, elevation of, 129 ; 



to determine, 129. 

 Bouyoucos, George J., 14, 33. 

 Breaking grade with hose-level, 185. 

 Breaking up of prairies, 202. 

 Briggs, L. J., 10. 

 By-products of plants, 18. 



Calling meeting to consider drain 

 petition, 219. 



Cameron, F. K., 202. 



Capillary movements of water, 26 ; 

 cause, 26 ; direction of, 28. 



Capillary water, 25 ; a factor in 

 soil structure, 52 ; affects 

 soil structure, 29, 40; 

 affects other physical 

 conditions, 40 ; affects 

 ventilation, .40, 52 ; and 

 use of plow, 29, 31 ; as- 

 sists in food preparation, 

 52 ; effect of, on soil tem- 

 perature, 34, 52 ; effects 

 on soil structure illus- 

 trated, 45; functions of, 

 52 ; importance of, in 

 plowing, 31 ; proper soil 

 content, 34, 40 ; relation 

 of drainage to, 207 ; sol- 

 vent of foods, 52. 



Cautions, in using level, 99. 



Caving, 143. 



Cement tile, 72 ; general precau- 

 tions, 74 ; mix, 73 ; opin- 

 ions concerning, 73 ; pre- 

 cautions suggested, 73 ; 

 proportions, 73 ; should 

 be made with care, 72. 



Changes, in flow of springs, 208 ; 

 in frost dates, 213 ; in 

 ground water-table, 201, 

 202, 209; in rainfall, 

 208 ; in temperature, 208. 



Changes may be made in plans and 

 boundaries of a drainage 

 district, 220. 



Changing climate, 208. 



Changing grade or fall, 89. 



Changing rainfall, 208. 



247 



