THE DRAINAGE OF FARM SOILS 



KINDS OF TILES 



At least eight styles of tile have been used since 

 the beginning of tile drainage, but at the present 

 time practically all farm under-drainage is done 

 with round tiles. Sole and double-sole tiles, which 

 are flat on one, two, or four sides, are heavier and 

 can be joined together only in two ways; whereas a 

 round tile can be joined to its neighbour at any point. 

 Six or eight-sided tiles with a round bore are quite 

 popular in the West and have all the merits of 

 round tiles, except that collars cannot be used with 

 them, which is unnecessary in most cases. How- 

 ever, they have no advantage over ordinary round 

 tile and it is doubtful if they can be laid as rapidly. 



There are a number of special forms of tiles for 

 certain uses. "Elbows" or L's are made in all 

 sizes, either with a slight curve or a curve of 45 

 degrees. They are used principally for the mains. 

 At the point wnere a lateral empties into the main, 

 or a sub-main into the main, "junction pieces," 

 or branch tiles, are necessary. These may be Y's 

 or T's, the Y's usually being preferred. The use of a 

 Y is almost indispensable at junctions, in order to 

 prevent an accumulation of soil and displacement 

 of the tiles at that point. "Collars" are tile rings 

 two or three inches long, which are slipped over the 

 outside of the tiles to cover the joint. They pre- 

 vent soil from washing in and hold the tiles in place ; 

 but they cost so much and the incovenience of 

 applying them is so great that they are impracticable 

 except where there is great danger of tiles being 

 displaced, as where the fall is sharp and the 

 soil rather light. "Enlarging tiles," wnich taper, 

 are useful at the point where the drain changes 

 from one size to a larger size, as from a 3-inch 



