h large stones, he
may perceive that the waves come in against the cliffs which plunge
into deep water without taking on the breaker form. In this case the
undulation strikes but a moderate blow; the wave is not greatly
broken. The part next the rock may shoot up as a thin sheet to a
considerable height; it is evident that while the ongoing wave applies
a good deal of pressure to the steep, it does not deliver its energy
in the effective form of a blow as when the wave overturns, or in the
consequent rush of the water up a beach slope. It is easy to perceive
that firm-set rock cliffs, with no beaches at their bases, can almost
indefinitely withstand the assaults. On the steep and stony beach,
because of its relatively great declivity, the breaker or surf forms
far in, and even in its first plunge often attains the base of the
precipice. The blow of the overfalling as well as that of the inrush
moves about stones of great size; those three feet or more in diameter
are often hurled by the action against the base of the steep, striking
blows, the sharp note of which can often be heard above the general
roar which the commotion produces. The needlelike crags forming isles
standing at a distance from the shore, such as are often found along
hard rock coasts, are singularly protected from the action of
effective waves. The surges which strike against them are unarmed with
stones, and the water at their bases is so deep that it does not sway
with the motion with sufficient energy to move them on the bottom.
Where a cliff is in this condition, it may endure until an elevation
of the coast line brings its base near the level of the sea, or until
the process of decay has detached a sufficient quantity of stone to
form a talus or inclined plane reaching near to the water level.

As before noted, it is the presence of a sloping beach reaching to
about the base of the cliff which makes it possible for the waves to
strike at with a hammer instead of with a soft hand. Battering at the
base of the cliff, the surges cut a crease along the strip on which
they strike, which gradually enters so far that the overhanging rock
falls of its own weight. The fragments thus delivered to the sea are
in turn broken up and used as battering instruments until they are
worn to pieces. We may note that in a few months of heavy weather the
stones of such a fall have all been reduced to rudely spherical forms.
Observations made on the eastern face of Cap