44 A CHAPTER IN THE PHYSICAL GEOGRAPHY OF THE PAST. 
periclinal as it is called, we notice that the north and south 
folding of the rocks gives place to great corrugations in a 
direction at right angles to this, that is east and west. 
The result of this has been to bring up lower beds from beneath 
the Coal Measures, these latter having been entirely swept off 
north of a line drawn due east and west a few miles to the north 
of Leeds, as far as the Tees. These east and west folds have 
impressed themselves on the physical conformation of the North 
of England, just as the great Pennine anticlinal has done further 
south ; for to them is due that system of east and west valleys, 
with high separating ridges, which run across the moorlands of 
Yorkshire. Here also, just as further south, the upper parts of 
the folds have been denuded right down to the Mountain 
Limestone. 
Having now briefly considered the structure of the Pennine 
Hills we must turn our attention for a short time to the Central 
Midland District immediately south of the termination of the 
range, and I must ask you to accompany me in imagination to 
the summit of the Weaver Hills near Ashbourne. Here, at a 
height of 1,200 feet above sea level, we find ourselves on the 
southern extremity of the Pennine Range. If we look upon the 
range as the “backbone” of England, we are now standing upon 
what an anatomist would call its ferminal caudal vertebra. To 
the north is all the rugged hill country of Derbyshire, but to the 
south, the country over which we look, stretched out like a map 
at our feet, is of an entirely different character, and consists of a 
gently undulating plain, which, elevated only 300 to 4oo feet above 
the sea, is in fact the western extension of the largest plain in 
the world. When standing on Weaver we look towards the 
rising sun, if it were possible to extend our powers of vision to an 
indefinite extent, and allow for the curvature of the earth, we 
should find no mountain or hill to obstruct our line of sight until 
our eyes rested upon the Ural Mountains, which divide Europe 
from Asia. Broken only by the inconsiderable ripple of these 
mountains, this mighty plain extends across the whole of Northern 
Asia. 
