THE DRAINAGE OF FARM SOILS 225 



spade, which has a narrow, curved blade about 18 

 inches long, is preferable. 



The soil snould oe placed on the edge of the ditch, 

 not thrown away from it. Both surface and subsoil 

 are placed upon the same side of the ditch, and usu- 

 ally it is not necessary to keep them separate. In 

 some cases it may be cheaper to have the ditch dug 

 by contract, except grading the bottom to receive the 

 tiles, which should be done by an experienced and 

 careful hand. If quicksand is encountered the sides 

 of the ditch will need to be supported with boards, 

 braced by sticks between them. Besides the spade, 

 a tile hoe is a convenient but not indispensable 

 tool. It is used for cleaning out and grading the 

 bottom of the ditch. It comes in various sizes, 

 according to the size of the tiles laid, and makes a 

 half-round groove into which the tiles fit snugly. 



Ditching should be begun at the outlet ana the 

 main should be laid back to the first lateral. This 

 junction is then made and two or three tiles of the 

 lateral are laid before the main is laid further. 



LAYING TILES 



It is well to begin laying the tiles as soon as a 

 strip of ditch is graded, for if a storm arises 

 enough water may run into the bottom of the 

 ditch to spoil the grade. Usually it is best to begin 

 laying the tiles at the lower end of the system. 

 They are first placed in a line along the edge of 

 the ditch. The man who lays the tiles may stand 

 in the ditch or he may stand on the edge of it and 

 handle the tiles with tile hooks, with which they 

 may be turned and twisted until the joints are 

 satisfactory. Professional tile layers often do 

 very rapid, and satisfactory work without getting 



