The weekly democratic statesman. [volume] (Austin, Tex.) 1871-1883, 1877-07-19
FIooding the Great Desert.

Flooding the Great Desert.
In an article treating on some re-
results OF evaporation and |
rainfall in our issue of April, we de-
scribei one of the instances Of the |
gtesl excesses Of evaporation over rsio
ftN aHmAv, ths Caspi an Sea. Of which |
TIE sg,fsce " az much below the ocean
Level - Gus Lax ChaHpialn IL above |
the same, namely, more than eighty |
feet. There are, however, two still |
moro remarkable cases ofthe same orf, |
the Dead Sea IN Palestine and the Great !
Desert OF Sahara in Africa. TIE for
mer IL remarkable for the great amount |
Of the depression, and the later for
the immense surface depressed, being
ia fact the bottom OF an extensive in
land lake, totally dried up by the heat
OF a tropical climate, aided by the al =
seAce OF feeding streams, and by Il c
rainless area which covers ITS greatest
portion. II IL, on an average, eighty
feet below the ocean, about rs much as
the Caspian Sea; but it is remarkable
for ITS extent, being nearly 1000 miles
square, or nearly 1000 900 square
miles.
The French government, having an
eye 10 the colonization Of Northern
Africa, with Algiers as a starting point,
has for some time favored project for
restoring this sandy waste to its prime
val condition by cutting commune
cation with the ocean, and SO trans
forming il into a salt alter inland lake.
The effect OF this on the climate of the
surrounding country, and especially
on the colony of Algiers, would I'M
doubtedlY be most beneficial, because
the south wind, instead of blowing, a.
II now does, over a sandy desert, would
become sea breeze; this would in
crease the rainfall and change rainless
district into fruitful region. In u
commercial point OF view, moreover,
the benefits of such a change could not
be overestimated. The introduction
Of water transportation is especially
advisable in this tropical region, where
the miserable and utterly inefficient
caravan is now the only mode Of carry
ing goods; and without doubt COM
meTeial cities would soon spring up
around the shores of the proposed in
land sea, which would become the
scene of mighty travel and traffic, as
the lake would give easy access to the
surrounding countries and develop this
part OF Africa to an extent thus far ut
terly undreamed of.
But it is well to look at the disad-
vantages of this gigf ntic scheme. In
the first place, it will rob the ocean OF
such an enormous amount of water
that its general sur ace will be lowered
TO an appreciable ,xtent. In order to
realize how much this lowering will
amount to, let US consider that the to
tai terrestrial surface IS, in round num-
bars, 200, 900, 900 square miles, OF
which the ocean occupies three-quar-
tiers, or $50. 900, coo. III the estimate
given Of the Desert OF Sahara, 4, 200,
coo square miles, is correct, it occupi6
onc-thirty. eighth part of the oceans
surface, and therefore every foot OF
depth of water distracted for the DIES.
ert wilI diminish the ocean one-thirty
eighth part of foot; and the with
drawal of water for lake eighty feet
deep would leave the ocean leve
eighty by one-thirty,eight, or moro
than two feet lower, which would bC
plainly perceptible in the many har'
bors where careful tidal observations
are made, and in some cases changes
may inference the shipping, robbing
as it would do, all parts of the worlC
of over two feet depth Of water, which
would be very bad in those localitie!
where the harbors are shallow.
This much as to an immediate re
suit; but the ultimate consequence
would be much more serious.
should be considered that this large
inland lake, If once established, woult
have no fresh water supply by rivers
but the sea water would certainly rusl
in through the channel to make up 70
the large evaporation, which we ma.
safely set down at 1900 pounds of waite
per year for every square foot. Thu
would lower the level twenty feet pc
year, which is one quarter of the who'll
quantity of the lake. This, for sur
face of 1000, 900 square miles, or 100,
900, 900, 900, 900 square feet, give
1900, 900, 000, 000.0 900 cubic feet o
water to be replaced annually from til,
ocean, or nearly 5000, 600, 900, 900 GU
bic feet per day, or $50, 900, 900, 00t
cubic feet per hour, or 4,1GG, GG6,
666 cubic feet per minute, or so.
444, 444 cubic feet, or 525, 900, 00C
gallons per second. AS the German
Rhine carries only 200, 900 gallons O
water per second, on an average, tn
channel bringing the supply to tn
Desert of Sahara from the ocean woul,
have to carry as much water "a is Cal
ried by 525 rivers like the Rhine; AM
from the salt water only pure waite
Would be evaporated, leaving the sal
behind. AS this amounts to four pc
cent, or one-twenty- of the SCI
water, and as nearly twenty feet deep
or ono-fourth of the water in this new
lake, would annually evaporate, i
would only take four times twenty-five
or one hundred years, one single cen
fury, for all the water to disappear
and deposit Of salt takes its place
Then the now sandy desert would b.
changed into desert of salt; which
salt would fill the whole basin anC
would certainly be more serious
ailiiction to Algeria than the presen
sand plain can possibly be-.