Rocky Mountains. 431 



We remarked in the narrative of our expedition* that at 

 several places in the valley of the Ohio, the water of brine 

 springs discovered by boring through the strata to the depth 

 of two or three hundred feet, sometimes flows up and rises 

 considerably above the surface of the earth. We also ob- 

 served that there appears reason to suspect that confined 

 subterraneous veins of water, exist under the arid tract 

 lying westward of the Ozark Mountains.! It is not impro- 

 bable that the strata of many parts of this secondary forma- 

 tion towards its exterior circumference may vary from an 

 horizontal, to an inclined position, in consequence of which 

 the water that falls in dews and rains in the hilly districts, 

 becoming insinuated between curved stratifications, may de- 

 scend towards the centre of the formation under such cir- 

 cumstances as would ensure its rising to the surface through 

 wells or bore-holes sunk sufficiently to penetrate the veins. 

 We would recommend this suggestion to the attention of the 

 inhabitants of those parts of the secondary basin of the Mis- 

 sissippi, where an abundant and unfailing supply of water is 

 unf )rtunately wanting. In many parts of England, as at 

 Adelphi, Addle-Hill, Thames Street, and New-Bond street, 

 London; at Kensington Gravel-Pits, at Tottenham High- 

 Cross, near Silsoe in Bedfordshii'e, at Cambridge, and Wim- 

 pole, in Cam.bridgeshire, at Alford, in Lincolnshire, at 

 Dunce-Hill, near Hull, at Oakthorpe, in Derbyshire, and at 

 many other places within the Chalk-Basin called the London 

 Vale, water rises in the manner above alluded to, from the 

 bottom of wells of one hundred and ten to one hundred and 

 forty feet deep, and is applied at and above the surface oi 

 the earth to various ornamental and useful purposes. ^ It is 

 of a better quality than that of the superficial wells which do 

 not penetrate the stratum of tenacious clay to the sands ot 

 what is called the plastic clay formation, or to the substra- 

 tum of chalk, and sometimes rises with such rapidity as to 

 overtake the well-digger and flow over his head before he 

 can escape. § 



*The opinion there (p. 16. vol. i.) advanced that this effect is produced 

 exclusively by the elasticity of subterranean gases, is probably erroneous, 

 as the rising of the water is to be attributed to the agency of hydrostatic 

 pressure, modified in many instances by the cause there alluded to. 



t Vol. ii. p. 282. I Lond. Month. Mag. vol. liv. p. 34. 



^ Conybeare and Phillipps' Outline of the Geology of England and 

 Wales, part. 1. p. 35, and 88. 



