ARTESIAN WELLS. 425 



ratus of Hydraulic Machinery, co-operating incessantly with 

 the Sea and with the Atmosphere, to dispense unfaihng sup- 

 plies of fresh Water over the habitable surface of the Land.* 



Among the incidental advantages arising to Man from 

 the introduction of Faults and Dislocations of the strata, into 

 the system of curious arrangements that pervade the sub- 

 terranean economy of the Globe, we may farther include 

 the circumstance that these fractures are the most frequent 

 channels of issue to mineral and thermal waters, whose 

 medicinal virtues alleviate many of the diseases of the 

 Human Frame.f 



" Thus in the whole machinery of springs and Rivers, 

 and the apparatus that is kept in action for their duration,, 

 through the instrumentality of a system of curiously con- 

 structed hills and valleys, receiving their supply occasionally 

 from the rains of heaven, and treasuring it up in their ever- 

 lasting storehouses to be dispeiised •perpetually by thousa^nds 

 of never-failing fountains, we see a provision not less striking, 

 than it is important. So also in the adjustment of the re- 

 lative quantities of Sea and Land, in such due proportions 

 as to supply the earth by constant evaporation, without 

 diminishing the waters of the ocean; and in the appoint- 

 ment of the Atmosphere to be the vehicle of this wonderful 

 and unceasing circulation,; in thus separating these waters 

 from their native salt, (which though of the highest utility 

 to preserve the purity of the sea, renders them unfit for the 



* The causes of intermitting Springs, and ebbing-, and flowing- wells, 

 and many minor irregularities in the Hydraulic Action of natural vents of 

 water, depend on local Accidents, such as tlie interposition of Siphons, 

 Cavities, Sec, which are scarcely of sufficient importance to be noticed, in 

 the general view we are here taking of the Causes of the Origin of Springs. 



f Dr. Daubeny has shown that a large proportion of the tiiermal springs 

 witli which we are acquainted, arise tlirough fractures situated on the great 

 lines of dislocation of the strata. See Daubeny on Thermal Springs, Edin. 

 Phil. Jour. April, 1832, p. 49. 



Professor Hoffman has given examples of tliese fractures in the axis of 

 vMeys of elevation, through which chalybeate waters rise at Pyrmont, and. 

 va other valleys of Westphalia. See PI. 67, frg. 2. 



36* 



