DRAINAGE 



293 



inspection by the engineer to determine whether the tile is 

 laid to the required grade. This can be determined by the 

 landowner when there is a small quantity of water run- 

 ning. A measurement at the hubs will determine the 

 depth, and the flow of water through the pipe will indicate 

 the grade. 



TOP 



BOTTOM 

 nt£ W TRENCH 



FACTORY JUMCT/CW 



After the University of Minnesota 



Fig. 240. 



Details of tile construction showing the position of the tile in 

 the trench, junctions, curves, and branches 



