668 Physiography. [ October, 
ruins beneath me. But though the action of the weather was 
thus clear, the sea-waves, which alone permitted that action to 
continue, were not idle. The brown color of the sea for some 
distance from the shore gave evidence of this, and while I stood 
upon the beach, I saw several projecting blocks of clay wasted by 
more than half. 
In Scotland and Wéstern England, where the rocks are hard, 
the advance of the sea upon the land is quite imperceptible. All 
the beauties of our coast scenery, our bold headlands and sweep- 
ing bays, result from this unequal action of the sea upon the 
harder and softer rocks of which our island is built up. But little 
observation is necessary to make it clear that, along any coast-line, 
the promontories are composed of hard rock, the bays of a softer 
material. Sea-side scenery is, therefore, a joint preduct of wave ac- 
tion and the geological structure of the coast. We must not forget, 
however, that it is only along its margin, where it beats upon 
the shore-line, that the sea is an agent of denudation. Through- 
out its great extent the ocean is the area of deposit and construc- 
tion, just as the land is the area of destruction and waste. Be- 
neath the sea the products of that waste come to rest. Strange 
as it sounds, the sea is the cradle of the land. Beneath the 
waters of the ocean are formed those layers of sediment which 
will some day be raised above the waters to form the framework 
of new continents. 
From the answer to our first question, then, we learn that the 
waves are advancing upon the land, and thus producing our coast 
scenery, and that they are caused by the winds. 
Let us next consider the streamlet at our feet. What is it do- 
ing, and how comes it here? That little streamlet, if we will but 
listen to it, can tell us much about what the great rivers of the 
earth are doing. Let us learn from it. In the first place, then, 
we see that this miniature river! is gradually changing its course. 
The main current strikes against one bank more than the other. 
The result is that this bank is forced to recede. Its tiny cliffs are 
undermined by the action of the stream, and the upper portions, 
now and again, topple over with a little splash into the water. 
Here we have in miniature that which may be seen on an enor- 
mous: scale on the Mississippi and the Amazons. Large vessels 
may there be made to rock by the waves created by the fall of 
7 Miniature Physical Geology, Nature, March 8, 1877. 
