Mr. H. Holland on the Cheshire Rock-salt District, 4Y 



another pit further to the south on the same Hne of boundary, but 

 as the mine was destroyed many years ago by the ingress of fresh 

 water, this statement is considerably more doubtful than the former. 

 It may be remarked too, that in sinking for brine a little beyond, or 

 out of the area, on this side, the brine met with is of a very weak 

 and inferior kind, and at a short distance altogether disappears. 

 Appearances leading to the same conclusion of the sudden termi- 

 nation of the body of rock-salt occur on the opposite side of the 

 area marking its extent. In a mine at the northern extremity of the 

 western line of boundary, a shaft situated nearer to this line is fifteen 

 yards deeper than another shaft immediately contiguous, apparently 

 in consequence of the rapid sinking of the rock-salt at this point. In 

 most of the pits on this side, the upper bed of rock is met with at 

 a depth of from thirty to forty yards ; yet at Barnton, a mile further 

 to the west, and on the same or a lower level, none was met with 

 in a sinking of one hundred and fifteen yards. 



Corresponding appearances have been observed in the body of 

 rock-salt which occurs at Moulton, between Winsford and North- 

 wich, where in two sinkings on the same level, and at the distance 

 of one hundred yards from each other, the difference in the depth at 

 which the rock was found, was nearly twenty yards, a circumstance 

 from which the limitation or going off of the bed at this particular 

 point may reasonably be inferred. As nothing further, however, 

 is ascertained with respect to the extent and direction of this parti- 

 cular body of rock-salt, I merely mention the fact to corroborate the 

 statement given of the limitation of the great beds at Northwich. 



Another important observation with respect to the Northwich 

 rock-salt, is, that there seems to be a progressive thinning of the 

 upper bed of salt from NW to SE, or in a direction nearly at right 

 angles to the longitudinal extent of the stratum. Though much 



