IRRIGATION 



235 



will make many thousands of irrigated farms available 

 for farmers. Care is being used that these lands may be 

 divided into family farms and thus made to serve well 

 the largest possible number of people and to increase 

 the number of America's farm homes. This constitutes 

 the most extensive irrigation scheme ever undertaken, 

 and is one of the most ambitious engineering feats ever 

 entered upon. It is a public enterprise which will again 

 prove the ability of a republican form of government to 



Figure 136. Showing ditch from stream, lake or reservoir through excavation, on an 

 embankment, across a low area, and through land at grade. 



carry out large national movements which benefit the 

 whole people. Through this work the United States 

 government is extending its policy, inaugurated through 

 the national homestead law, of dividing the land into 

 family farms. 



Not only is irrigation profitable in arid and semi-arid 

 countries, but also in countries where the rainfall is not 

 evenly distributed throughout those months in which 

 crops make their greatest growth. Irrigation on a large 

 scale is practicable only where streams, lakes, rivers, 



Figure 137. Showing ditch extended across a low place through an iron conduit sup- 

 ported on trestle work. 



