1664 



Report of Farmers' Institutes 



the surface or the underground water is concentrated, the drain 

 should be located only after careful study to determine the way 

 in which the water moves. Much land that is undulating is par- 

 ticularly wet only in the low places and a line or two of tile through 

 these will suffice. Sometimes surface water from hill sides accum- 

 ulates at the foot of the slope and spreads out over the low land. 



Fig. 111. Surveying for a Line of Drain Tile With a Home-made 



Level 



In that case there should be a drain near the foot of the slope. If 

 there is seepage from the hillside the drain should be cut near the 

 upper edge of the wet soil and should be deep enough if possible to 

 let the tile be laid on the impervious substratum and thereby inter- 

 cept the flow. Whether the drains shall be laid across the slope or 

 down the slope depends much on the local conditions. In many 

 cases an arrangement diagonally across the slope at a hi<>h angle is 

 best as it combines many of the advantages of both the other ar- 

 rangements. 



Clearly defined springs should l)e topped by the most direct 

 route. If the water seeps out of a considerable area around the 

 spring, Y-shaped spur drains may be helpful. 



DEPTH OF DRiS.INS 



The depth of drains will range from about twenty inches up to 

 three and a half or four feet. The most common depth is from 



