Memphis daily appeal. [volume] (Memphis, Tenn.) 1847-1886, 1883-04-12

use the language OF the New Orleans Pica-
yuue, "hss been one continuous demonsira-
ton OF the necessity Of the jetty system Tor
the protection .of the riparian proprietor,
and this year in particular has furnished the
| most conclusive evidence to the same effect
| Forty years ago the Alchafalaya csrfled
| away from the main channel OF the
Mississippi 10000 10 10000 cubic feet
of water per second. At the present
time it carries of between 100000 and 300,-
900 cubic feet in that time. II the outlet
system-ss this way Of tapping the river by
allowing a portion of the water 10 pass out
Of the main cb annel into side stream, which
called-be a correct one, the water in the
main channel below the mouth Of the Atcha-
falaya should be safer from food oday
than it was forty years ago. The proof that
that system is wrong is clear, for the liability
TO food, Notwithstanding an outlet Of 100000
cubic feet second flowing away from the
lain stream, is az great as when that outlet
was only 40 900 cubic feet second. Those
who are ignorant Of the causes at work that
produce the peculiar phenomena Of the ME-
sissippi river, are staggered by such fact
az this, but attention 10 few facts will
make the matter clear. The Mississippi water
carries large amount OF material along
with it; when the stream runs swift II washes
up and carries off a very large quantity; when
the steam runs slower it carries q smaller
quantity and allows a portion of the larger
quantity it had gathered where the current
was rapid to sink TO the bottom where it is
less rapid because slow running water can
not carry as much sediment as swiftly run
ming water. Now, 10 apply this 10 the Atcha-
falaya and the whole outlet system-when
the whole mass Of water is pouring down
the maiu channel the water behind pushes
the water before it with certain force. On
reaching the Atchafslaya, in one single sec
ond $4,000 cubic feet of water, and the
pressure that came from that 275, 600 feet, is
diverted into the Atchafalaya. Tie conse-
quence is that below the Atchsfalaya the
pressure OF the reduced amount OF water be-
ing less the rapidity OF the current is less.
: The rapidly OF the current being lees it
cannot carry as much sediment as be-
fore, and a portion OF what it was carry
Jog falls to the bottom. This deposit
on the bottom raises the bottom, makes
the stream shallower. 10 other words, the
channel, having less water TO carry,
contracts in proportion. This being the
case, the next high water that comes is as
high as before, notwithstanding all the
Atchafalays has carried off. The bottom Of
the river having come nearer the top, the
water runs over, or floods, just as before.
We think any reader can understand this,
but 10 make sure we will carry the matter
little further. Suppose we stop the Atcha.
falaya and send the $4,000 cubic feet 2
second all down the main channel, in addi-
ton to what was there before, will the addi-
ton all run off at the surface? No. The
smount of water being increased increases
the weight or pressure, that increases the
speed of the current, that causes a washing
from the bottom of sediment, which is car
ried off BY the quick running waters. This
washing away deepens the bottom, and
in that way if there is more water
there is more room TO contain the water.
By making the channel deeper the water,
finding space for itself at the bottom of the
river, does not run over in foods a. the top.
This explanation shows the absurdity Of The
Cincinnati Commercial Gazette in conteudiBg
that water from the Mississippi should be
drawn of at the Atchafalsya, Bonnet Care
and other places, as that system would make
the main stresm slower and shallower, and,
especially in dry seasons, injure its nayiga-
BILE quality.