THE ANALYST. 
SKETCH OF THE GEOLOGY OF DERBYSHIRE. 
SECOND PART. 
By J. B. Juxes, B.A. F.G.S. 
Havrne, in the last number of Zhe Analyst, given a slight sketch 
of each of the geological formations found within the county of 
Derby, I come now to the positions which they occupy, both abso- 
lutely and relatively to each other. This department of geological 
investigation has been correctly termed Physical Geology, and is that 
portion of the science which has the greatest practical importance in 
all mining or other operations in which a knowledge of the structure 
of any part of the earth’s crust is desirable. Nor is its theoretical 
importance to the scientific geologist less than its utility to the prac- 
tical man, since it is only by accurately cultivating this branch of the 
science that we can hope to arrive at the solution of those great dy- 
namical problems which the disturbing forces that act upon the crust 
of the globe propose to our investigation. 
In speaking of the geological structure of the Derbyshire district, 
it is necessary that we should reverse the order used in the preceding 
part of this paper, and begin with the lowest of the formations there 
mentioned, and, having thus got a base for our operations, proceed 
regularly in the structure of our edifice. 
The reader, then, must please to imagine a substratum of mountain 
limestone, of the thickness and with the characters previously de- 
scribed, to exist over the whole of Derbyshire and the adjoining 
counties to the east, north, and west, for an indefinite and unknown 
extent, sometimes forming the surface of the country, at others buried 
to a great depth under other materials.* The greatest extent of 
* That this is not a vain imagination will be shown presently. 
VOL. 1X., NO. XXV. 
