I 4 



DOMESTIC WATER SUPPLIES FOR THE FARM 



sources, much of it from the superficial soil, but considerable 

 quantities come from deeper sources, perhaps from hundreds of 

 feet down in the rocks. 



Kinds of Springs. Springs may be divided, according to 

 their mode of origin, into gravity and artesian springs, and, ac- 

 cording to the nature of the passages traversed by the water, into 

 seepage, tubular and fissure springs. 



Gravity Springs. A gravity spring is one whose water is not 

 confined between impervious beds but flows from loose materials 



FIG. 6. Spring of gravity type fed from unconfined waters in porous sands. 



or open passages under the action of gravity, just as a surface 

 stream flows down its channel. The conditions are shown in 

 Figure 6. 



Artesian Springs. An artesian spring is one whose waters 

 are confined in impervious channels or between impervious beds 

 and are under hydrostatic pressure because the water level at their 

 source is higher than the point where they emerge. The waters 

 of such a spring, if confined in a pipe instead of being allowed to 

 flow out upon the ground, may rise considerably above the spring 

 mouth. (Fig. 7.) 



Seepage Springs. Seepage springs are springs in which the 

 water seeps out of sand or gravel; they differ from general seepage 

 only in being restricted to a small area. Such springs are usually 

 marked by abundant vegetation at their points of emergence, and 

 their waters are often colored or carry an oily scum due to the 

 decomposition of vegetable matter or the presence of iron. The 

 scum is frequently mistaken for petroleum. The waters of the 

 seepage springs commonly come from no great distance beneath 

 the surface and are not usually very cold. 



