NATURE FOR ITS OWN SAKE 
Cuff under- 
Mining. 
along, one over another, prove very effective 
weapons of destruction. They are swept in 
and out of pools and crevices, lodged in pot- 
holes, caverns, and scoops, and churned round 
and round by eddies and currents with a scrape 
and a grate at every turn. The cliff is thus 
gradually undermined, and needs only the 
heave of frost to topple it into the sea. It is 
protected in a way by its own ruins—the outer 
guard of fallen rock that breaks the force of the 
wayes—and besides this, the cliff bases, as well 
as the fallen bowlders, are sheathed with fringes 
of seaweed and barnacles; but still this grind 
of the surge and the ceaseless beat of the surf 
finally wear all of them away, and their parti- 
cles, like the sands from the beaches, are carried 
out to sea by the under-currents and deposited 
on the shoals. The diagonal thrust of the 
waves has something of the effect upon the 
shore that the running stream has upon its 
banks. It not only has cutting and wearing 
power, but it makes currents which carry off 
what is cut away. 
The greatest wear of the waves is, naturally, 
where the rock is the softest. A hard quality 
of rock—so hard that it has endured—usually 
appears as the armored prow of every project- 
