the great Derbyshire Denudation. 253 
■well as on its S. side), then the first toadstone, next the second 
limestone, then the second toadstone, and after its turning to 
pass through Middleton by Wirks worth, the third limestone 
also abuts against it, and continues so to do, till the third toad- 
stone appears against it at Hopton, and then the fourth lime- 
stone, or lowest known rock of the district, abuts against it 
all the way round, through Staffordshire to Castleton (with 
the exception of the hummocks of third limestone at Buxton 
and at Barmoor in Peak Forest, and a few sunk gulfs of 
shale) through a length of more than forty-five miles. At the 
SE. end of Castleton Town, the third toadstone abuts again 
on the right or S. side of this great limestone fault, and from 
thence to the SW. side of the Windmill-Houses, the third 
limestone abuts against it, then the second toadstone, the se- 
cond limestone, the first toadstone, and at length the first 
limestone, before the fault terminates or becomes too incon- 
siderable to be readily traced, owing to its no longer derang- 
ing the order of the strata on the surface, but has the first 
limestone on both its sides ; and thus it happens, that the third 
inner raised tract,, or mineral-field, consisting of the four 
limestone rocks and three interposed toadstones, and contain- 
ing about 105,000 acres, has about 51,500 acres of these on 
its eastern side, occupied by the three upper limestones and 
the toadstones, and the remaining 53,500 acres in Derbyshire 
and Staffordshire is occupied by the fourth, or lowest lime- 
stone rock, in which only a few mineral veins occur among 
its numerous open fissures and caverns. 
In the sketch map which accompanies this, I have shewn a 
smaller, or fourth inner raised tract, on which Bakewell is 
situated, in great part surrounded by a fault, which X have 
