The Supply and Uses of Water 



213 



FIG. 63. A water trap to 

 block sewer gas. 



and connected pipes and unless removed will cause trouble. 

 The regular use of concentrated lye and boiling water will keep 

 the pipes free from all such materials. 



When waste pipes are not in use for a long period, the water 

 in the traps is evaporated. This gives free passage to sewer 

 gas. To prevent this it is necessary 

 to pour a small quantity of kerosene 

 or a similar oil upon the trapped 

 water and to close securely the waste 

 openings. This is especially neces- 

 sary if the pipes are to be left unused 

 for several weeks. 



A large supply of water is needed 

 to carry away all the house waste. 

 In the larger pipes materials tend to 

 accumulate and unless removed by a 

 strong flow of water will stop up the 

 passageway. To aid in the removal 

 of waste matter the rainfall is often turned into the house sewer. 

 If this is not done, it will be necessary to provide at frequent 

 intervals extra water for the purpose. 



85. Rural sanitary sewage disposal. Modern sanitary 

 methods and devices are becoming more and more common in 

 many rural sections of our country. The old imperfect ways 

 of disposing of sewage are being replaced by those which com- 

 pletely purify or convert it into safe and valuable fertilizing 

 compounds. Such methods and devices are much less expen- 

 sive and more effective than laying conduits to a more or less 

 distant stream or body of water. They are the result of sound 

 sense and scientific knowledge of the conditions, agents, and 

 process of sewage putrefaction and purification. The wonder- 

 ful discoveries of Pasteur proved that the process of decay or 

 putrefaction as well as fermentation is due to the activities of 

 certain kinds of exceedingly small, microscopic plants, called 

 bacteria. These bacteria flourish in certain conditions which 



