26 THE POPULAR SCIENCE MONTHLY. 



Trenton limestone ; and, No. 5, the Utica or black slate ; the fault, or 

 break-off, is indicated by the heavy black vertical line, in immediate 

 proximity to which the village of Saratoga Springs is situated. For 

 the reason that the black slate has been entirely eroded from that por- 

 tion of the village immediately west of the fault, and the Trenton 

 limestone nearlv so, none of the former and but a thin stratum of the 

 latter formation is represented on the accompanying chart. You will 

 observe that both the dislocation and upheaval of these various strata 

 are strongly marked at the fault, for, while that portion lying to the 

 east remains i)i situ, that to the west is tilted up to such an extent 

 that the dip of some of the strata is as great as twenty degrees. You 

 will also notice that the Laurentian rock on the west side of the fault, 

 occupying the position designated as No. 1 on the cut, as well as the 

 superimposed strata, viz., Nos. 2, 3, and 4, are not in perfect opposition 

 with formations of like character on the east side, the Potsdam sand- 

 stone lying opposite to the Trenton limestone, the calciferous sand-rock 

 lying in conjunction with the black slate, while the Trenton limestone 

 on the west occuj^ies a position above the black^slate on the east. The 

 consideration of this phenomenon naturally suggests an explanation, 

 but so far as is known there is but one theory relative to the subject, 

 it being universally conceded that the force that produced this disrup- 

 tion was due to volcanic agency. 



At distances varying from two to twelve miles in a westerly direc- 

 tion ranges of hills and mountains are encountered, presenting alti- 

 tudes several hundred feet above this village. In addition to the 

 enormous area of water-shed that these elevated regions afford, they 

 possess many ponds and lakes, some of which are of no insignificant 

 size. The surface-streams that drain this section flow toward the east, 

 and, as the various strata dip in the same direction, the tendency of 

 the subterranean drainage must be tOAvard the same point of the com- 

 pass. 



The advocates of the first of the theories regarding the origin of 

 the mineral springs of Saratoga, recognizing the disintegrating and 

 solvent action of the water under its various forms of rain, snow, and 

 ice, claim that they are produced by the process of displacement or 

 percolation, holding that, when water falls upon the elevated re- 

 gions just described, a portion of it gradually permeates the soil and 

 the various strata of tlie underlying rocks, dissolving and carrying 

 with it in its downward flow the various constituents of Avhich the 

 rocks are composed, and that these are decomposed by their reaction 

 on each other, and new compounds are formed with the evolution of 

 carbonic-acid gas, that this is dissoh^ed by the water, which becomes 

 highly impregnated with it, increasing its solvent properties to a great 

 extent, enabling it to accumulate basic matter in its flow, which con- 

 tinues downward and eastward, until the fault is reached, where an 

 opportunity is afforded for it to escape from the rocks and rise to the 



