7G8 



SUCCESSFUL FARMING 



are driven so that the tops are a uniform distance above the bottom of 

 the ditch as it is to be excavated. This may be 4^ feet or any convenient 

 height. A cord or wire is next stretched tightly over the top of the grade 

 stakes. By means of a gauge, the ditcher can control the depth of the 

 ditch. Care should be exercised not to get it too deep, or to make the 

 bottom wider than necessary. 



The sketch on page 766 shows the method of gauging the depth, 

 the character of excavation and the position of the tile. 



Small Ditching Machines. — These majr be used to facilitate the work 



The Ditcher in Operation. 



Can be operated by one man and six horses. It will excavate 100 rods of dirt 

 to a depth of 3 feet daily. 



of excavation. They do it more rapidly than can be done by hand and 

 at less cost. They are adapted only to fairly long courses. It will gen- 

 erally be necessary to grade the bottom of the ditch by hand. 



Size of Tile. — In any system the major portion of the tiles will be 

 three inches in diameter. All lines not exceeding 500 feet in length and 

 having no branches entering may be of this size. When such lines exceed 

 500 feet the lower portion should be 4-inch tile. The capacity of pipes 

 is in proportion to the square of their respective diameters, plus some- 

 thing for the relatively lesser amount of friction in the large diameters. 

 In practice, one 4-inch line will accommodate two 3-inch lines. One 

 8-inch line will accommodate five 4-inch lines, etc. 



