CHAPTER XXXVII 

 PLUMBING AND WATER SUPPLY 



546. Relation of Plumbing to the Water Supply. In 

 large communities where people live close together, pipes 

 for conducting water and sewerage must be installed. To 

 make installations intelligently so as to have enough water 

 for household use, fire protection, and other purposes, it is 

 necessary to know something about the water supply. 



Water is usually obtained from rivers, lakes, springs, or 

 wells. 



546. Rivers and Lakes. A river usually begins with a 

 small stream in the hills and represents the drainage of the 

 rain, ice, or snow that falls there. If there is a growth of 

 trees on the hills, the roots of the trees tend to hold the water 

 in the ground and prevent it from trickling down the slope 

 rapidly. A lake usually has no outlet but is fed either by 

 springs or by the drainage of the hills. 



547. Wells. In small communities the householder 

 usually receives his supply of water from a well near the 

 house. To understand how a well obtains its water, it is 

 necessary to recall what has been said concerning the struc- 

 ture of the earth.* The earth is made of layers of sand, 



Pages 150-151. 



460 



