Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1898-10-22
SECRET TOLD ATLAST
n. LYDEKKER, II. A., r. X. q, DIS
COVERS THE ORIGIN OF SAND.
ACCUMULATING FOR UNKNOWN AGES
Dig Down In the Arid Wastes of
Sahara and Arizona and the Mys-
terry Is ExpInined-Evolut or the
Desert Animal.
written for tho plspatch.)
Desert Animal.

being severed boldly in these latter days
knowledge must march on. and no one
can say: ''Thus far shalt thou CO. and
no farther" In the quietness of the
desert there has reposed during all the
years Of the worlds history a mystery
that takes this spoken shape: How
comes the sand there and why the almost
boundless expanse Of arid country over
which man must travel quickly and with
escape the ever-clutching hand Of death?
No adequate answer TO the question mas
been given. Bleaching bones bear silent
witness to the danger of tarrying 100
Icing In the domain Of the desert king, and
science has sought other and less risky
fields Of research rather than centre its
powers on this dry and unacceptable sub
ject. 1t must be grappled with however,
or Nature will be victor In the everlast-
ing fight to keep its secrets from the
human race The sealed book OF the
desert has been opened now, and its pages
can be read by all.
AS a matter OF fact, the opinions with
regard to tho origin and nature OF deserts
are scarcely, II at all, less erroneous,
than the deeply ingrained popular super
stiutiOn as TO the growth of fints and
pudding stones. And a little reflection
will show the idea of the loose sands
OF the desert being a marine deposit must
necessarily be erroneous. Apart from the
difficulty Of accounting for the accumu-
lation of such vast tracts of sand on the
marine hypothesis, it will be noticed, in
tho first place, that desert sands are not
IN bn nLor 10
OF aqueous formations, and. secondly
even supposing that they had been so de-
posted, they would almost certainly have
been washed 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 not the subjacent strata
have ever been beneath the ocean, it is
absolutely certain that 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 land, which drain them more or
less completely Of their lead Of moisture
Hence I'm 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
below.
In other words, as has been well said,
desert sands correspond In all respects
so far as their mode OF origin is concern
ed. TO the dust and sand which accumu-
late on high roads during dry summer
On highways, indeed, the summers dust
and sand are removed by the rains Of
autumn and winter, only to be renewed
the following season. but I'm a desert no
such removal takes place, and the amount
OF sand Increases year by year, owing to
the disintegration OF the solid rock ex-
posed here and there.
Only one degree less incorrect than the
idea Of their submarine origin is the no
ton that deserts consist OF unbroken
tracts of sand. IL 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
sert there are mountain ranges rising TO
a heights OF several thousand feet above
the level of the plain. And II is these
exposed rocks which form the source
whence the sand was, and still is. de-
rived. Such mountains naturally attract
what moisture may remain in the air,
and in their valleys are found a more or
less luxuriant vegetation. Gases, too.
where the soil IS more or less clayey
occur in most deserts, and II is in such
spots that animal and vegetable life at
tains the maximum development possible
in the heart Of the desert
In the most arid and typical part Of the
Lybian desert the sand is blown into
large dunes, which are frequently fiat
topped and show horizontal bands Of
partly consolidated rock, and between
these are open valleys, partly covered
with sand and partly strewn with blocks
OF rock polished and secured by the sand
blast. In such sand wastes the traveller
may Journey for days without seeing signs
of vegetation, or hearing the call of a
bird or the hum Of an insects wing But
even in many Of such districts IL is mis-
take TO suppose that vegetable and ami
NAL life is entirely absent throughout the
year; in the western Sahara, for instance
two or three times year, and after each
Of these a short-lived vegetation springs
suddenly up, and If no other form Of ami
NAL life is observable, at least few
passing birds may be noticed.
Among the most important and extern
sive deserts Of the world we have nrst
the great Sahara, with an approximate
area Of sixteen thousand 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 desert 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, Of which
more anon. In the United States there is
a large desert tract lying east OF the
Rocky Mountains, and including great
part OF Sonora; while In South America
there Is the desert OF Atacama, on the
borders of Peru and Chilli. Lastly, the
the whole OF the interior OF Australia is
desert os the most arid and typical de-
scription.
But among these there are deserts and
deserts. Tracts OF the typical barren
sandy type are, as already said, extern
sively developed in the Sahara. as they
are in tho Cobb and Australian deserts.
Between such and the plains OF the Afri-
can weld there Is an almost complete tran
sition. so that IL Is sometimes hard TO say
whether a given tract comes under the
DESIGNATION OF a desert at all. A case
i'm point is afforded by the South African
Kalahari Although there are endless