344 CONNECTION OF THERMAL SPRINGS IN VIRGINIA 



natural slope of the gently dipping rocks on the southeast of the 

 anticlinal, or through the fissures of the shattered and steeply in- 

 clined or inverted strata on the northwest. Where but little of 

 this Assuring occurs on the northwest side, they would meet 

 with least obstruction by flowing in the opposite course, and 

 might, therefore, bo looked for on the southeast. Such would 

 seem to be the case with the thermals of the Mill Mountain and 

 Keyser's, (Sections I, and IV,) where the steeply inclined strata 

 are comparatively entire. But, as formerly remarked, the usual 

 position of thermals is on the other side of the anticlinal axes. 



It may here be added, that where such springs present a tem- 

 perature but little above the atmospheric mean, it is unnecessary, 

 in accounting for their heat, to suppose that the water has been 

 conveyed to any very considerable depth below the base of the 

 mountain, as the subterranean line of equal temperature (chthon- 

 isothermal line), deflected iqnvards by a massive and steep anti- 

 clinal range, would come nearer to the general surface. 



Such is a sketch of the views to which I have been led in 

 considering the positions occupied by our thermals, in connec- 

 tion Avith the probable mechanical agencies by which their waters 

 are accumulated and brought to the surface. Though in some 

 degree hypothetical, as must be all attempts at explaining the 

 unseen mechanism of nature, they are, I think, in harmony with 

 observation, and at all events possess the merit of agreeing in 

 general principles with doctrines sanctioned by the authority of 

 such names as Arago and Bischoff. 



As regards the evolved g-ases and the chemical ingredients of 

 these springs, my opinions, like those of others who have spec- 

 ulated on this subject, are, confessedly, far from satisfactory. 

 While I am inclined, in some respects, to agree with the views 

 which have been so ably advocated by Dr. Daubeny, in relation 

 to the origin of the gases and other matters associated ^^^th ther- 

 mal waters, I am by no means prepared to adopt the hypothesis, 

 that such impregnations are chiefly due to the chemical action 

 of the metallic bases of the alkalies and earths ; much less can I 

 accede to the opinion, that the heat of our thermals, as well as 



