IRRIGATION TOOLS AND DEVICES 



427 



determined by the layout and contour of the farm. All 

 ditches, whether large or small, must follow, in general, 

 the ridges of the land. 



Farm ditches may be made by any machine that will 

 make a furrow in the ground. The first modern irrigation 

 ditch in America was made by an ordinary moldboard 

 plow, the furrow from which was cleaned out with shovels. 

 Thousands of small farm ditches have been made in that 

 way since that first day of irrigation. The lateral plow or 

 winged shovel plow is now more frequently used in ditch- 



FIG. 136. Drop in flume. 



