2 SKETCH OF THE GEOLOGY OF DERBYSHIRE. 
surface formed by the mountain limestone is in the north of Derby- 
shire and part of the adjoining county of Stafford. If the reader 
will take a map in his hand, and draw an undulating line through the 
following places, he will get a rough notion of the extent of this dis- 
trict. Beginning at Burton, the boundary of the limestone runs 
nearly north to the small village of Dove Hole, thence, leaving Cha- 
pel-en-le-Frith about two miles to the left, proceeds just under 
Rushup Edge till it reaches Castleton. From Castleton it goes 
towards Hope, and then turns to the S. to Abney. From Abney it 
goes round Eyam and Stoney Middleton, and proceeds thence, by 
Hassop, to Ashford. From Ashford it runs close to the N. and E. 
of Bakewell, and proceeds by Haddon Hall to the Lathkill. Here 
it deflects to the W. following the course of that river till it meets 
the Bradford. It keeps along the eastern bank of the Bradford to 
its source, and then turns again to the E. by Gratton and Elton, runs 
just to the north of Winster and Wensley, and crosses the Derwent 
in Darley Dale. Hence it runs just at the back of Matlock High 
Torr, and recrossing the river at Cromford, continues S. to Wirks- 
worth. From Wirksworth the boundary of the limestone turns due 
W. running by Carsington and Bradburn to Tissington, and thence, 
turning S. to Thorpe, crosses the Dove into Staffordshire. Here its 
boundary is irregular, but it includes the villages of Blore, Caldon, 
Waterfall, Grindon, Mixon, Butterton, and Ecton, and recrosses the 
Dove at Hartington. From Hartington, it runs up the E. bank of 
the Dove to Crowdygate and Glutton, then passes through Dowel to 
Thirkalow, and including Harper Hill and Burbage, arrives at Burton. 
The space enclosed in this irregular outline is occupied entirely by 
mountain limestone and its associated toadstone. The other places 
where this formation is visible at the surface would be marked on the 
map by an oval inclosing the village of Ashover, of about 15m. long 
and im. broad, having its longer axis running about 20° N. of W. 
and the village in the northern part of the space; by a similar oval 
running nearly in the same direction, but of twice the length, with 
Crich about in its centre; by a small circle at Birchwood Park, 5m. 
S. of Ashbourne ; and by the larger district about Calke and Ticknal 
connected with the mountain limestone patches of Leicestershire, and 
mentioned in a former paper. 
The condition of the first and principal district above mentioned 
will be best understood by imagining the rocks to have been originally 
horizontal at a lower level, and then to have been elevated by an ex- 
pansive force acting from below, until they were swollen up, as 
