DRAINAGE 



229 



or by other power, may be the practical means of moving 

 the earth. The immense dikes, in part built generations 

 ago, reclaiming large portions of Holland, have thor- 

 oughly demon- 

 strated that if 

 the area is 

 large very ex- 

 pensive drains 

 may be eco- 

 nomical. Along 

 the Mississippi 

 river immense 

 areas have been 

 reclaimed from 

 flooding 



1 -11' 1 Figure 133. 



or "levees," confining the 

 waters to the natural chan- 

 nel. Along many of our 

 streams, beside lakes and 

 along the ocean coast lines, 

 there are large areas which 

 are occasionally flooded or 

 are daily affected by high 

 tide, and as great damage 

 often results to the growing 

 crops, their use for farms is 

 not practicable without con- 

 trol of the water. In Figures 

 135, 143 and 144, with the 

 subjoined notes, is shown 

 how drainage and irrigation 

 may be combined. By dik- 

 ing and draining with open 



Figure 134. anc { t {J e ditcheS tO Si pit from 

 Figures 133 and 134. Longitudinal and . 



cross-sections of pole drain in peaty land, which the Water IS DUmped 

 X, poles; Y, heather or other small shrubs 



of trees; C, peat^ soil j nto t ] ie l a k e , Fields H and I, 



