CHAPTER III. 

 SPRINGS, 



What a Spring Is. --The term " spring " is properly applied 

 to the water emerging from the ground at a single point or within 

 a restricted area. The distinction between springs and general 

 seepage, however, is not always very sharp, for there are all gra- 

 dations between the concentrated outflows characterizing true 

 springs and the diffused emergence of water over large areas or 

 beneath the level of the water in streams. 



In size springs vary from the little pools only a few inches 

 across and barely overflowing their tiny depressions to immense 

 basins like that of Silver Spring in Florida, which is navigable by 

 steamboats and gives rise to a river several rods in breadth. 



In manner of emergence there is likewise a wide divergence. 

 By far the greatest number of springs probably emerge in the 

 beds or banks of streams or ponds, but they are inconspicuous 

 and often almost unsuspected. The base of steep bluffs is also a 

 favorable point for the emergence of the ground water, and is 

 often dotted with a line of springs. Springs are by no means con- 

 fined to such situations, however. Many boil up through the 

 soils of perfectly flat plains, while others gush forth as cascades 

 from the rocks. (Fig. 4.) 



Allied to the springs, and often classed with them, are the un- 

 derground streams that sometimes flow forth in limestone regions 

 from the subterranean caverns. Some are almost rivers in size. 

 A good example of a subterranean stream of this sort is shown in 

 Figure 5. 



Source of Water. - - The water of all springs is of subterranean 

 origin, the supply coming from the great underground water body 

 fed by precipitation falling upon and absorbed by the soil and 

 rocks. The greater part of the water is naturally from shallow 



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