The Portland daily press., 1898-09-16

tion THAT deserts consist of unbroken
tracts of sand. It is true that such tracts
in certain districts may extend on every
side as far rs the eye can reach, ana even
much further, but, sooner or later, rloges
and bands of pebbles. or OF solid rocK'
will be met with cropping up among tne
sand, while frequently, as in the Llbyan
desert, there are mountain ranges rising
to height of several thousand 1eet ABOVE
the level of the plain. And it Is these
exposed rocks which form the source
whence the sand was, and still Is, oe.
rived. Such mountains naturally ATTRACT
what moisture may remain in the air,
and in their valleys are found a more or
less luxuriant vegetation. Cases, too,
where the soil is more or less olayey, CO.
cur in most deserts; and it 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 Libyan des-
ert the sand is blown into large dunes,
which are frequently fat topped, and
show horizontal bands of partly consoli-
dated rock; and between these are open
valleys, partly covered with sand, and
partly strewn with blocks or rock pol
such sand wastes the traveller may journey
for days without seeing signs of vegeta-
tion or hearing the call of q bird or the
hum of an insects wing. But even in
many of such districts it is mistake to
suppose that vegetables and animal life is
entirely absent throughout the year; in
this western Sahara, for instance, showers
generally moisten the ground two or
three times year, and after each of these
short-liyed vegetation springs suddenly
up. and, If no other form of animal life
is observable. at least few passing birds
may be noticed.
Among the most important and exten-
sive deserts of the world we have first the
Great Sahara, with an approximate area
of I6, 600 square miles, nearly connected,
with which is the great desert tract ex-
tama and Persia. By means of the NJ ore
or less desert tracts of Baluchistan, Sind
and Kuch, this area leads on to the great
Rajputana desert Of India. More import
ant is the vast Cobb Desert Of Mongolia,
and other parts of Central Asia. In
southern Africa there is the great kala-
hari desert of which more anon. In
| NOrun AIu6ElCh bu0F6 40 % Acl 80 SAooSA y
tract lying east of the Rocky Mountains,
and including great part of Sonora !;
while in the southern half of the New
World there is the desert Atacama on
the borders of Peru ann Chile, Lastly,
the whole of the interior of Australia is
desert of 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, exten-
sively developed in the Sahara. as they
ore in the Cobb and the Australian des-
erts. Between such and the plains Of the
African weld there is an almost complete
transition, so that it Is sometimes hard to
say whether given tract rightly comes
under the designation OF desert at all.
A case in point Ia afforded by the South
African Kalahari. Although there are
endless rolling dunes of traokless land,
and rivers are unknown, yet in many
places there is extensive forest, and after
a rain large tracts could scarcely be called
desert at all. 81. A. Dryden, for in
stance, when describing the Kalahari,
writes as follows: "And yet, during the
brief weeks of rainfall no land can assume
a fairer or more tempting aspect. The
long grasses shoot up green, succulent
and elbow-deep; flowers spangle the weld
in every direction; the giraffe acacia for
ests robed in fresh dark green remind
one of nothing SO much as an English
deer park; the bushes blossom and flour
ishs; the air Is full Of fragrance, and
pans of water lie on every side. Another
month, and all is drouth; the pans are
dry again, and travel is full of difficult
ty." During the grassy season herds of
springbok used to migrate in the old days
to Kalahari. in the northern part of
which giraffes live the whole year, al
though, thy must exist without tasting
water for months.