The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-06-06
DESERTS AND THEIR HABIrANrs.
Some Popular misconceptions Cor
rected by Scientific Observer.


rected by a Scientific Observer.
Condensed from knowledge by Public
Opinion.
1t is not improbable that there are per-
sons possessing a more or less intimate
mountaineering with science who still
cherish the belief that deserts are uniuter-
rupted plains of smooth sand, originally
deposited at the bottom of the sea, from
which they have been raised at a compare
lively recent epoch. Apart from the diff
fculty of accounting for the accumulation
of such vast tracts of sand on the ma
rlne hypothesis, it will be noticed, in the
first place, that desert sands are not STRAIT
flied in the manner characteristic of hque-
Gus formations and, secondly, even sup
posing they mad been so deposited they
would almost certainly have been waehed
away as the land rose from beneath the
sea. Then, again, We do not meet with
marine shells in the desert sands, of which
at least some traces ought to have been
left had they been marine deposits of
comparatively modern age. Whether or no
the subjacent strata have ever been be-
meath the sands of all the great deserts Of
the world have been formed in stu by the
disintegration of the solid rocks on which
they rest, and have been blown about
and rearranged by the action of wind alone
All deserts. are situated in districts where
the winds blowing from the oceans surface
have to pass over mountains or extensive
tracts of 'Fand, which drain them more
or less completely of their load of moist
ure Hence, in the desert itself, when of
the typical kind, little or no rain falls, and
there is consequently no flow of water to
wash away the debris resulting from the
action of the atmosphere on the rocks be-
low.
nlyO one degree less incorrect than the
idea of their submarine origin is the no
ton that deserts consists of unbroken
tracts of sand. 1t is true that such tracts
in certain districts may extend on every
side as far as the eye can reach, and even
much farther; but, sooner or later, ridges
and bands of pebbles or Of solid rock will
be met with cropping up among the sand,
while frequently, as in the Lybian desert,
there are mountain ranges rising TO
hight of several thousand feet above the
level of the plain And it is these exposed
rocks which form the source whence the
sand was and still is, derived. Such
mountains naturally attract what moist
IRE NAV remain in the air, and in their
valleys are found a more or less luxuriant
vegetation. Gases, too where the SOL is
more or less clayey, occur in most deserts:
and il is in such spots that animal and
vegetable life attains the maximum devel-
ODment DOSSiDIc IN the nedIl Ol the desert.
Among the most important and extensive
deserts of the world we have first the great
Sahara, with an approximate area of 1900
square miles. nearly connected with which
is the great desert tract extending
through ARABIA, Syria, Mesopotamia and
Persia. BY means Of the more or less des-
ert tracts Of Baluchistan, Sind and Kuch
this area leads on to the great Rajputana
desert of India. More important is the
vast Cobb desert Of Mongolia, and other
parts of Central Asia. In Southern Africa
there is the great Kalahari desert. In
North America there is a large desert
tract lying east of the Rocky mountains,
and including a great part of Sonora;
while In the southern half of the New
World there Is the desert of Atacama, on
the borders of Peru and Chilli. Lastly. the
whole Of the interior Of Australia is desert
of the most arid and typical description.
For sand to accumulate to the depths in
which it occurs In many parts Of the Sa-
hara and the Cobb by the slow disintegra-
ton of solid rocks under the action of at
mospheric agencies, must require an enor-
nous amount or time. to be reckoned GER
tainiy by thousands. and. for all we know,
possibly by millions Of years. And we ac-
cordingly arrive at the conclusion that the
larger desert tracts must not only have