Description of a fiew Levelling- Staff. 33 



and in the quarry S.S.W. of it, on the W. of the road, 

 and thence across the pastures to the Lalhkil river; the 

 sudden elevation of the limestone knowlsS.W. of Yolgrave, 

 near the shale; and by this same lift, it happens, that the 

 vale of the Bradford suddenly cuts through the first lime 

 rock, as soon as it has crossed this fault, and shows the 

 first loadstone to a considerable height up each side of the 

 valley, but which declines wjth the dip of the measures in this 

 tract', until the Bradford again gets upon the first loadstone, 

 and then on the first limestone. In like manner, the greater 

 rise of the measures al this fault, on the S.W. of Over-Had- 

 don village occasions the valley of the Lathkil river, which 

 till then had been excavated in the first lime rock, to enter 

 abruptly so deep into the first loadstone, as to lay bare a 

 patch of the second limestone under it in ihe river, both of 

 which however descend again below the bed of the river, 

 Ijefore we get down to the crossing of the Ashburne turn- 

 pike road. 



This fault also occasions the sudden appearance of shale- 

 limestone on the surface N.W. of it, opposite to first lime- 

 stone on the other side in Bakewell Fields, and of the first 

 loadstone on the N.W. of Bakewell Cotton-Mill, almost 

 excavated through by the vale of the Wye river, where it 

 abuts against shale or shale-limestone at the northern end 

 of this noted patch of loadstone, the situation and circum- 

 stances of which, when compared with those of the other 

 two patches, at the edge of this same raised tract, as above, 

 will be divested of much of that singularity which has been 

 ascribed to it ; for we see, that each of the three rivers, 

 which pass on to this fourth inner raised tract, have their 

 excavations cut through the first limestone, so as to expose 

 the first loadstone for some distance, until the more rapid 

 descents of the measures than of the vales, occasion them 

 again to dip and disappear in the bottoms of each of these 

 vales. I am, sir, ^ 



Your obliged and very humble servant, 



Upper Crown Street, Westminster, J- rAREY, ben. 



January 31, 1811. Mineral Surveyor. 



III. Description of a new Levelling- Staff. 



To Mr. Tilloch. 



Sir, riAViNG frequently experienced much inconveniency 

 in the use of the levelling-stafF on the common construc- 

 tion, on account of the narrow opening in the vane pre- 



C 2 venting 



