IRRIGATION TOOLS AND DEVICES 



433 



MEAN VELOCITY AND DISCHARGE OF DITCHES WITH DIFFERENT 

 GRADES, Continued 



Farm Ditch No. 2 



Farm Ditch No 4 



When the natural grade of the land is so steep as to 

 make it dangerous to employ ditches of the same grade, 

 suitable drops must be installed at various points. (Figs. 

 135, 136.) To carry water from the laterals to furrows, in 



