in which the breakwater is situated. On the other hand, the height, and,
consequently, the destructive force of waves, is increased on running up
a funnel-shaped bay, by the increasing concentration of the waves in the
narrowing width, just as the tidal range of a moderate tidal current is
much augmented by its passage up the Bay of Fundy, or up the Bristol
Channel into the Severn estuary, or by filling the shallow enclosed bay
of St Malo. This effect is intensified when the bay faces the direction
of the strongest winds. Thus at Wick a mass of masonry weighing 1350
tons, placed at the head of the breakwater projecting half-way across
the bay and facing the entrance, was moved by the waves during a violent
storm; and a portion of Peterhead breakwater, weighing 3300 tons, was
shifted 2 in. in 1898, indicating a wave-stroke of 2 tons per sq. ft.
Southwesterly gales, blowing up the Gulf of Genoa, cause large waves to
roll into the bay, reaching a height of about 21 ft. in the worst
storms.

Where outlying sandbanks stretch in front of a coast, as for instance
the Stroombank in front of Ostend and the adjacent shore, and the
sandbanks opposite Yarmouth sheltering Yarmouth Roads, large waves
cannot approach the land, for they break on the sandbanks outside.
Waves, indeed, always break when, on running up a shoaling beach, they
reach a depth approximately equal to their height; and the largest waves
which can reach a shore protected by intervening sandbanks, are those
which are low enough to pass over the banks without breaking.

The force of the wind, as transmitted by degrees to the sea, is
manifested as a series of progressing undulations without any material
displacement of the body of water, each undulation transmitting its
accumulated force to the next in the direction the wind is blowing, till
at last, on encountering an obstacle to its onward course, each wave, no
longer finding any water to which to communicate its energy, deals a
blow against the obstacle proportionate to its size and rate of
transmission; or on reaching shoal water near the shore, the undulation
is finally transformed into a breaking wave rushing up the sloping
beach. till, on its energy being spent, it recoils back to the sea down
the beach. A breaking wave concentrates its transmitted force on a
portion of the water forming the undulation, which, consequently,
strikes a more powerful blow over a limited area against any structure
than the more