GRADING THE DITCHES FOR TILE. Ill 



the bore of the drain. Attach a rope securely to this 

 and pass the rope through the drain from one open- 

 ing to the other. This can be done by means of a 

 light flexible pole. By means of this rope pull the 

 swab through the drain and as the material is forced to 

 the opposite end let it be dipped or shovelled out. It 

 is well to have two ropes attached to the swab so that 

 having passed it through once it can be drawn back 

 and the operation reversed. All this should be done 

 when there is but little water flowing through the drain. 

 After the stretch of drain which is obstructed is cleaned 

 out return the tiles which were removed to their orig- 

 inal position. A little mud or sand will always remain 

 in the drain after it has been scoured in this way, but 

 it will be readily washed out when the drain is flushed, 

 provided the drain is otherwise in perfect condition. 



Submerged Outlet. — Where a submerged outlet is 

 necessary the drain must be laid when the ground is 

 dry or nearly so. A submerged outlet in itself is not 

 objectionable, but it should be understood that the fall 

 or effective head of the drain is diminished by the depth 

 at which the water must rise above the outlet before 

 flowing away, and the line of soil saturation will ex- 

 tend back on a level until it intersects the line of the 

 drain. With a proper head no injury will be done to 

 the drain at the outlet, and the rate of discharge will 

 be nearly as great, taking into account the diminished 

 head, as though the discharge were into the open air. 

 Submerged outlets are frequently a necessity in the 

 drainage of level tracts into artificial outlets, for the 

 reason that the drains must be placed so low with refer- 

 ence to the outlet channel that the tile outlets are 



