The times., 1898-09-06
NOT ALL sAND.
The Popular Idea of Deserts Is a
Mistake.
(From knowledge. }

Mistake.
From Knowledge.)
Only one degree less incorrect than the
Idea of their submarine origin Is the no.
ton that deserts consist 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 Libyan
Desert, there are mountain ranges rising
to a height of several thousand feet above
the level of the plain. And 1t Is these ex-
posed rocks which form the source whence
the sand was, and still Is, derived. Such
mountains naturally attract what moist
ure may remain In the air, and in their
valleys are found a more or less luxuri-
ant vegetation. Oases too. where the
soil is more or less clayey, occur in most
deserts; and II is ip such spots that ant
NAL and vegetable life attains the maxi
mum development possible in the heart
of the desert. In the most arid and typi-
cal part of the Libyan Desert the sand is
blown into large dunes, which are fire.
quently hat-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 scored by the
sand blast. In such sand wastes the trav-
eler may journey for days without seeing
signs of vegetation or hearing the call of
bird or the hum of an insects wing.
But even in many of such districts IL is a
mistake TO suppose that vegetable and ami
mai life is entirely absent throughout the
year; in the western Sahara. for instance
showers generally moisten the ground two
or three times 4 year, and after each of
these a short-lived vegetation springs
suddenly up. and, If no other form of
animal life is observable. at least a few
passing birds may be noticed.
Among the most important and extern
sive deserts in the world We have, first
the Great Sahara, with an approximate
area of $1,000 square miles. nearly con-
nected with which is the great deser.
tract extending through trabia. Syria,
Mesopotamia and Persia. By means of
the more or less desert tracts of Balu-
ch3stan. Sind and Kuch rhis area leads
on 10 the great RajpWana Desert OF In
dia. 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 large desert tract
lying east of the Rocky Mountains. and
including great part OF Sonora; while
III the southern half of the new world
there is the Desert of Atacama. on the
borders of Peru and Chile. Lastly, the
whole of the interior Of Australia is des-
ert Of the most ard and typical descrip-
ton.
But among these there are deserts and
deserts Tracts of the typical barren
sandy type are. as already said. eXten-
sively developed in the Sahara, as they
are in the GoZi and the Australian des-
erts Between such and the plains of
the African weld there IS an almost com
plete transition, so that IL Is sometimes
hard TO say watcher given tract rightly
comes under the designation of desert
al all.
A case in point is afforded by the
South African Kalaharl. Although there
are endless rolling dunes of trackless
sand and rivers are unknown, yet In
many places there is extensive forest
and after a rain large tracts could
scarcely be called a desert at all. II. A
Dryden for instance. when describing
the Kalahari. writes as follows: And
yet, during the brief weeks of rainfall
no land can assume a faire- or more
tempting aspect. The long grasses shoot
up green. siucculent and elbow deep
flowers spangle the veid in every direc-
ton: the giraffe acacia forests robed In
a fresh dark green remind one of moth
ing so much an English deer park
he bushes blossom and flourish; the all
| is full of fragrance, and pans of water
lie on every side. Another month. ano
all is drought; the pans are dry again
and travel is full of difficulty" Dur
ing the grassy season herds of spring
box used to migrate in the old days tC
kalahari. in the northern part OF which
| giraffes live the whole year, althoues
they must exist without tasting water
for months.