34 Mr. A. B. Northcote on the Brine-springs of Worcestershire. 



the strata from which it is produced between the two places ; at 

 the same time, the possibility of the extension of the rock-salt 

 is, at least on one side, confined to that direction, since at Forest 

 Hill, near H anbury*, a place about two miles south of a line 

 joining Stoke and Droitwich, outcroppings of Lias are found, 

 which, as they indicate the termination of the New Red Sand- 

 stone, show also of necessity that of the rock-salt. Whether as 

 great a similarity exists between these two great English deposits 

 in their shape as in their direction, cannot so readily be inferred, 

 since it is of course doubtful whether at either of the explored 

 parts the lowest limit of the salt has hitherto been reached ; yet 

 since the level of the ground at Stoke is from 300 to 400 feet 

 higher than that at Droitwich, and the productive salt deposits 

 there do not appear to begin until the borings have been sunk to 

 about the level of the former place, it would seem that in the 

 Worcestershire salt beds no such thinning out in a south- 

 westerly direction takes place. 



These brines doubtless spring from large subterranean reser- 

 voirs, produced probably in the hist instance by the solvent 

 action exerted on the rock-salt by spring- or rain-water. That 

 this is so at Droitwich is clear from what Mr. Horner states as 

 having occurred on the first sinking of a shaft at that place ; he 

 says, that after penetrating for 150 feet, the borer suddenly de- 

 scended 22 inchesf > the roof of the brine chamber had evidently 

 been broken through, and the water instantly burst into the 

 tube and gushed from the aperture with great force. This 

 account is confirmed by observations of the same kind made at 

 Stoke Prior; but owing to the greater elevation of the land, the 

 brine when " tapped " rose only to within 90 feet of the surface, 

 but its ascension in this case also was very rapid. The idea of 

 extensive cavities filled with brine existing beneath these places, 

 also receives additional support from the distinct sinking of the 

 ground around the salt-works at Droitwich j at that place, i. e. at 

 which the subterranean reservoir would be nearer the surface, and 

 where consequently the intervening strata would present a lesser 

 obstacle to the filling up by a more solid material of the space 

 rendered vacuous by the removal of the brine. We can readily 

 conceive the incessant action of the pumps to gain in the course 

 of years upon the supply by which the chamber is replenished, 

 and an occurrence of this sort is exactly that which might have 

 been predicted. 



It is thought by persons on the spot, that a stream of brine 

 passes from Stoke to Droitwich, and is at once the source from 

 which the supply at both places is derived ; and although at first 



* Murchison's Silurian System, vol. i. p. 32. 

 t Geological Transactions, Old Series, vol. ii. 



