SHAPE OF THE LAND. 585 



rocks ; and the midland, eastern, and south-eastern portions of the 

 country, comprising broad vales of clay-land, alternating with long 

 ranges of hills or escarpments (formed chiefly of limestones), of 

 which the Oolites of the Cotteswold Hills and the Chalk Downs are 

 conspicuous examples.' Turning to the features of the coast, we 

 find that the harder rocks stand out in headlands, while the softer 

 strata have been worn away in bays : so that our first impressions 

 are that hill and dale, like promontory and bay, are mainly due to 

 the relative positions of harder and softer strata. When we seek 

 an explanation of the shaping of the ground, our attention is 

 naturally directed to the destruction or denudation now in progress, 

 on the one hand by the sea encroaching upon our coast-line, and 

 on the other by the rivers carrying away in solution and in sus- 

 pension solid matter derived from the land ; and we may conclude 

 that the features are due to the relative resistance of the harder and 

 softer strata to the forces of denudation. No doubt rain, rivers, sea, 

 and glaciers also, have been at work in various geological epochs 

 on the land that has appeared over what is now the area of England 

 and Wales ; and individuals who are of a prophetic turn of mind 

 may calculate how long it would take under present circumstances 

 for the whole of our land to be washed away into the sea." In 

 studying our scenery, however, we are concerned rather with the 

 origin of the present features, than with their future modifications, 

 and we soon learn that the forces which have helped to mould 

 them are manifold ; indeed, adequately to explain the subject, it is 

 necessary to consider the history and physical changes of the 

 country since the earliest geological times. 



In the first place the rocks, most of which were deposited under 

 water, have been upraised ; many of them indeed have been 

 uplifted and depressed again and again at successive periods ; 

 consequently they have been exposed to wear and tear at different 

 times. The texture, more especially of the older rocks, has been 

 hardened by the pressure of overlying deposits, or altered by 

 the intrusion of eruptive rocks. Hence, when ultimately exposed 

 at the surface by upheaval and by the denudation of superin- 

 cumbent strata, these old rocks are better able to withstand the 

 denuding agents, than newer strata that are less indurated. But 

 the texture and composition of rocks have an important influence 

 on scenery apart from their age, for different strata may be locally 

 hardened by chemical and other agencies, and in any case clays, 

 sandstones, and limestones are differently acted upon by the agents 

 of destruction. The shapes of our hills and valleys, moreover, 

 are due in part to the way in which the strata have been uptilted, 



^ On the subject of English Scenery and Geology, see Pop. Science Review, 

 Jany. 1875 ; A. C. Ramsay, Physical Geology and Geography of Great Britain, 

 ed. 5, 1878 ; D. Mackintosh, Scenery of England and Wales, 1869 ; Col. G. 

 Greenwood, Rain and Rivers, ed. 2, 1866 ; A. Geikie, Lectures on Scenery of 

 British Isles, Nature, 1884. 



* See A. Geikie, G. Mag. 186S, p. 249 ; Geographical Evolution, in "Geological 

 Sketches at Home and Abroad," p. 336; Trans. G. S. Glasgow, iii. 153; and 

 T. M. Reade, Chemical Denudation, 1879. 



