36 JOURNAL OF THE 



to the smaller towns and manufacturing- communities. 

 This system is based upon the existence of fairly well 

 defined under«-round "currents" of water in regions 

 where the topog*raphy is favorable and where the rocks 

 have decayed to a considerable depth, and where near 

 the lower limit of this decay there is more or less por- 

 ous material throug^h which this water may readily 

 percolate. Of course it has been well known in the 

 past that more or less well defined underg^round move- 

 ments of water existed, and that at favorable locations 

 the small currents come to the surface as springs, and 

 that frequently, on both elevated reg^ions and about 

 lowlands, when wells are sunk sufficiently deep into the 

 soil, — usually near the surface of the hard rocks, — a 

 sufficient amount of water is found either to empty in- 

 to the well as a small stream or to ooze into it from the 

 surrounding* soil and thus furnish a limited supply. 

 But it is only recently that the location and extent of 

 these underg-round sources of water have been investi- 

 gated in some regions with considerable care and have 

 been found to yield under proper treatment much 

 larg-er quantities of water than have been reckoned upon 

 in the past. This investig-ation has been prosecuted in 

 this reg-ion mainly by Mr. Henry E. Knox, Jr., a hy- 

 draulic eng-ineer, of Charlotte, N. C, and he has in 

 this way located considerable sujjplies of underg-round 

 water in reg-ions where these were sorely needed. 



I g-ive below, in tabulated form, the results obtained 

 by Mr. Knox in Piedmont North and South Carolina. 

 His method of investig-ation is to examine carefully the 

 topography and geolog-y of the region where the water 

 supply is needed. The topographic conditions favor- 

 able to success arc, as might be expected, where there 

 is more or less of the basin, shallow ravine, or valley, 



