CHAPTER VIII 

 OTHER CONDITIONS AND PROBLEMS 



VARIOUS questions arise in the course of the installing 

 of a tile system. In many cases the problem will suggest 

 its own solution. In other cases, solutions can be offered 

 only by those who have theoretical knowledge of condi- 

 tions or who have had a large practical experience. The 

 science and art of drainage have been matters of growth, 

 and of rather slow growth. There are many questions 

 yet to solve. A few of the more common questions will 

 be discussed in this chapter. 



202. Underground outlets. It sometimes happens 

 that a low area requires draining but has no outlet through 

 which the water can be taken off, or is surrounded by 

 ground so uniformly high as to make it expensive, or 

 even impossible, to secure a proper outlet. Not infre- 

 quently it will be found that the soil of this low area is 

 underlaid by a heavy clay, and that the clay in turn is 

 underlaid by 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 is dug through the clay into the gravel, all 

 the water from this low area may be drained into the 

 well, and from this well the water will disappear down 

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

 of at least one foot below the clay, and should be filled with 

 field stone to above the point where the outlet of the drain 



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