EXPERIMENT STATION BULLETINS. 



507 



charges, or such that the bottom of the tile shall rest properly upou 

 the tile to which it discharges according to which of the methods of 

 connection is used. 



MISCELLANEOUS SUGGESTIONS. — UNDERGROUND OUTLETS. 



It sometimes happens that a low area requires draining but has no 

 outlet through which the water can be drained. Not infrequently it 

 will be found that the soil of this low area is underlaid with a heavy 

 clay and that the clay in turn is underlaid with an open gravel or an open 

 gravelly sand, in which the water table stands at a considerable distance 

 below the clay. Under such conditions, if a well three feet in diameter 

 be dug through the clay into the gravel, all of the water from this low 

 area may be drained into this well and the water will disappear down 

 through the gravel. The well should be dug to a depth of a few feet be 

 low the clay and should be filled with field stone to above the point 

 where the outlet of the drain is turned into it. The top stones should 

 be small and upon these should be placed gravel, then sand, then the 

 regular soil of the field. The writer has in mind one such arrange- 

 ment in which a tile system covering something like 160 acres discharges 

 its water and has been in successful operation for many years. 



In small depressions such a well at the lowest point is frequently suffi- 

 ent to carry away the excess of water without the aid of a tile system. 



QUICK-SAND. 



It sometimes happens that quick-sand is encountered at or near the 

 bottom of the ditch in laying the tile. In such case it will usually be 



Fig. 29. Steel shield used to hold back quicksand. Should be 28 inches 

 long and 12 inches or more high. 



necessary to use some kind of guard to hold back the quick-sand while 

 the bottom of the ditch is being completed, to receive the tile. Fig. 29 

 shows a shield of iron used for this purpose. In the use of the shield 

 the ditch is dug to the quick-sand. The shield is then placed so as to 

 include that portion of the ditch in which the next section or sections 

 of tile are to be laid. The workman can press it down into the quick- 

 sand by his own weight sufficiently to bring it even with or a little below 

 the bottom of the ditch when it is complete, or if his weight is not suffi- 

 cient for that, he may remove a portion of the sand inside the shield and 



