CHAPTER XIX. 

 CISTERNS AND HOUSE TANKS. 



When Cisterns are Desirable. --The ordinary cistern is an 

 excavation in the ground, usually circular but sometimes rec- 

 tangular, curbed with cement or with bricks, stone or other mate- 

 rial (with a supposedly impervious lining of cement) and used 

 for the storage of rain water. Wood-curbed cisterns are also 

 occasionally encountered in frontier districts when other materials 

 are not at hand. 



Cisterns are desirable (i) wherever the rock, clay or other 

 material is a poor water bearer; (2) wherever the ground water is 

 too hard for washing, too alkaline for cooking or too brackish for 

 drinking; (3) wherever waters from other sources are inherently 

 unsafe; (4) whenever the ground waters are at depths prohibiting 

 their common use; and (5) whenever the rainfall is too irregular 

 to maintain a constant supply, or when wells, for one reason or 

 another, are impracticable. They are especially desirable in the 

 larger towns where the houses are crowded and the wells often 

 polluted, and where no public supply is available. Again, on 

 farms, where wells are not infrequently located near barns or 

 other sources of pollution, cisterns often constitute the only safe 

 source of water. 



Advantages of Cisterns. Perhaps the chief use of cisterns is 

 to furnish supplementary supplies in regions where the available 

 ground water is limited. In many of the best farming regions of 

 the country, as in the Blue Grass region of Kentucky and else- 

 where, the rocks either carry so little water or carry it so irregularly 

 that many wells fail to obtain a sufficient supply to meet domestic 

 needs and the demands of stock. In shaly regions the water sup- 

 plies are even more uncertain and it is often impossible to procure 



