d increases, its
carrying power increases. It is able to carry bits that are larger and
heavier. The following table is exact and interesting:

_Velocity_ _Pressure_
_in Miles_ _in Pounds_
_per Hour_ _per Sq. Ft._

Light breeze 14 1
Strong breeze 42 9
Strong gale 70 25
Hurricane 84 36

The terrible paths of hurricanes are seen in forest countries. The trees
are uprooted, as if a great roller had crushed them, throwing the tops
all in one direction, and leaving the roots uncovered, and a sunken
pocket where each tree stood. On a steep, rocky slope, the uprooting of
scattered trees often loosens tons of rock, and sends the mass
thundering down the mountain-side. Much more destruction may be
accomplished by one brief tornado than by years of wear by ordinary
breezes.

The wind does much to help the waves in their patient beating on rocky
shores. If the wind blows from the ocean and the tide is landward, the
two forces combine, and the loose rocks are thrown against the solid
beach with astonishing force. Even the gravel and the sharp sand are
tools of great usefulness to the waves in grinding down the resisting
shore. Up and back they are swept by the water, and going and coming
they have their chance to scratch or strike a blow. Boulders on the
beach become pockmarked by the constant sand-blast that plays upon them.
The lower windows of exposed seaside houses are dimmed by the sand that
picks away the smooth surface outside, making it ground glass by the
same process used in the factory. Lighthouses have this difficulty in
keeping their windows clear. The "lantern" itself is sometimes reached
by the sand grains. That is the cupola in which burns the great light
that warns vessels away from the rocks and tells the captain where he
is.

In the Far Western States the telegraph poles and fence posts are soon
cut off at the ground by the flinty knives the wind carries. These are
the grains of sand that are blown along just above the ground. The trees
are killed by having their bark girdled in this way. The sand-storms
which in the orange and lemon region of California are called "Santa
Anas" sometimes last two or three days, and damage the trees by piercing
the tender bark with the needle-pointed sand.

Wind-