San Marcos free press. [volume] (San Marcos, Tex.) 1877-1892, 1882-03-02

the forests, and the consequent IN
creased denudation OF the Alps. Freneh
engineers estimate that the delta OF tho
Rhone has advanced Mt a rate inr
greater than il did previous TO the eui-
ovation of its valley. In the eastern
nart of the United States, wherever II
mountain slope has been stripped III
cipient ravines quickly form ana en-,
lrae with such rapidity as 20 excite the
attention OF geologists, This Is espee,,
irlly the case with the sandy SOILS %
MARYLAND, Georgia and Alabama pre-
yiously covered with Pine forests Inc
black earth OF Russia, one OF the chieI
sources of the agricultural wealth OF
the empire, is quickly cut up into huge
rayines. and the finest soil in Europe Is
being rapidly carried away to increase
the deltas of the Volga aud the Don'
and to slit up the Sea OF AZof. during
the great floods OF 1866 and 1870 III
France and Switzerland, the wooded
soils alone escaped being washed away.
The immunity OF the provinces OF
Brescia and Bergamo from damage by
the great floods of 1872 was chiefly due
10 forestal improvements. During ten
years the department OF the Lower
Alps lost 81 900 acres OF cultivated sou
from the effects of torrents; and the
clearing of the forest Of the Ardeche
has resulted in the covering up OF 10
600 acres of good land with barren sand
and gravel. .. ...
It is thought by many that vegetation
eleyates the surface as much as water
depresses it. This, however, can only
be the case when natural vegetation is
suffered to decay on the ground in
which it grew. In the case Of cultivated
crops, which only partly return to the
soil, this elevation of the surface cam
not take place; and, its compensating
effect being lost, denudation is rela-
lively greater from this cause alone.
Hence it appears that one result OF
mans influence by laying bare large
tracts of land for cultivation has been
greatly to increase the erosion OF the
surface. In some instances, however,
the action of man has been to check
the natural transport of sediment. This
especially has been done in the case OF
shifting sand-dunes and encroachments
of the sea. Along that part OF the
French coast which extends from the
Gironde to the Adour, the sea throws
up annually one million two hundred
and forty five thousand cubic metres OF
sand, which the wind heaps up into
hills and carries inland, overwhelming
villages and converting streams into
marshy pools. The annual progress OF
the sand-hills was so great that i'll many
parts of Bretagne the tops of chimneys
above sea of sand alone marked the
sight of buried villages. The amount
of duneland in Western Europe alone
has been estimated to cover more than
a million acres; and still larger depos-
it's exist in parts of Africa, Asia and
America. The destruction caused by
these shifting sands has, from an early
date, attracted the attention of govern
ments, and the result has been to check
their ravages by careful planting. Thus
has mans ingenuity been successfully
opposed to the action of the agencies
which have caused those endless wastes
of drifting sands in Poland, Peru, and
the United States; and to the devasta-
ton which has resulted in the formation
of the la1ades of Gascony, Sologne and
Bremen, and the CAMPING sands OF
Belgium.-Chambers' Journal.