EFFECTS OF WATER ON THE LANDSCAPE 127 



that fresh sand or gravel will have to be thrown down on either 

 side. The same effect on a large scale in nature causes ridges of 

 hard rock to stand up as hills or " escarpments " over plains consist- 

 ing of materials more easily washed away. The Chiltern and 

 Cotswold Hills are good instances of this action. Then again, look 

 at a stream during and after a flood. The water rushes along bear- 

 ing a much greater quantity of soil, so that it appears dirty. As it 

 overflows its banks it deposits a good deal of it on either side, thus 

 forming a plain, through which it deepens its channel as it goes 

 along. Many of the great plains of the world have been formed in 

 this way, while the remains of former plains at higher levels may be 

 seen in the ridges and terraces which so often strike the eye of the 

 observer as he walks along a river valley. 



A storm at sea is perhaps one of the grandest sights of nature. 

 The thundering of the breakers on the shore will stir the dullest 

 imagination. Walk along a cliff after a great storm, and you will 

 almost certainly notice that its appearance has altered somewhat since 

 you last saw it. Often you will notice that great pieces of rock have 

 been broken off, and lie half buried in the water. It is not difficult 

 to realise that the sea acts as a great destroyer of the dry land, 

 continually sawing round and round, and depositing the materials it 

 has broken off, so as to form an ever increasing shelf round the 

 coast. We know that the whole of our British Islands are resting 

 on such a shelf, and were once far more extensive than they are now. 



Nothing, perhaps, appeals more to our sense of the marvels of 

 nature, when we realise that the whole surface of our globe has been 

 gradually brought to its existing shape, not by great catastrophes and 

 sudden eruptions, as was previously supposed, but by the accumulated 

 effect of processes which are going on every day and all day around us. 



The above cases are three out of any number of instances that 



