DRAINAGE. 25 







A 6 inch tile with a fall of 2 inches to the 1.00 feet will 

 drain 19 acres. 



A 5 inch tile with a fall of 2 inches to the 100 feet will 

 drain 10 acres. 



A 4 inch tile with a fall of 2 inches to the 100 feet will 

 drain 6 acres. 



On the level soils of the South Atlantic and Gulf States 

 where there is a heavier rainfall, the same tile as recommended 

 above will drain about 75 per cent as much land as in Illinois 

 and Iowa. 



The less the fall the less will be the capacity of the tile to 

 remove the water, and therefore the larger must be the tile used. 



Systems of Drainage. 



The distance apart at which tile drains should be placed 

 will depend upon the character of the soil and the depth at which 

 they are to be placed. 



A depth of less than three feet is too shallow for the growth 

 'of many of our farm crops, and the distance between tile drains 

 will 'vary from 40 feet in very heavy clays to 100 feet in loose 

 open soils. 



The following plans seem to be generally in use : 



In 'heavy clay soils the distance apart for drains is 30 to 50 ft. 

 In ordinary loams the distance apart for drains is 40 to 60 ft. 

 In muck soils the distance apart for drains is 60 to 80 ft. 

 In sand or loam with clay subsoil near the surface the distance 

 should be about on the average, 50 feet. 



( ,'n the following page figure (2) represents a common ar- 

 rangement and is shown here to make the student acquainted 

 with the different terms and features of the work : 



The rectangle abed represents an area that is double 

 drained. 



NOTE TO TEACHERS Have pupils in the class in agriculture 

 draw a diagram of the drainage of the home farm or some farm 

 adjacent to the school house. Have them draw plans for a com- 

 plete system of tiling, giving size of tile required, also depth and 

 fall required. 



