IRRIGATION TOOLS AND DEVICES 



421 



the farm. This should be done with extreme care, for 

 any mistakes made in the placing of irrigation ditches will 

 mean loss in tune and money when a new system is built. 



In general, water 

 should be delivered 

 from the supply lateral 

 at the highest point 

 of the farm. This 

 makes it possible to 

 distribute water over 

 the whole farm. In 

 earlier days, all the 

 farm ditches were 

 carried along ridges 

 or high lines of the 

 farm. This method 

 led to the formation of irregular and somewhat unsightly 

 fields, awkward to fit into a system of rotation. While it 

 is indispensable that the farm ditches follow, in a general 

 way, the contour lines of the farm, yet an irrigated farm 

 may be laid off into regular, rectangular fields by the 

 use of special devices to carry the water across depres- 

 sions of the land. 



The most common method of securing straight ditches 

 on the farm is the use of earthen levees, to carry the 



FIG. 126. Flume with lateral gate. 



FIG. 127. Buck scraper. 



