Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1882-08-23
The Mississippi River Problem,

Ihe mississippi River Problem.
The whole valley is filled with silt at
least thousand feet deep. In order Ia
have deposited this sih thus all over the
valley the river must have flowed in differ.
ent ages in all parts Of the valley. doipo
for countless centuries Just what il is doino
to-day building up sand-bars gand mud
banks, breaking and cutting them again,
and tossing the atoms from place to place
dropping them at low water, and shifting
them in foods. but always bringing down
more, and building the valley A. higher
and higher, and carrying the delta out
farther and farther to sea. If the supply
OF materi Il holds out, the Gulf of Mexico
must inevitably become dry land, rs the
arm of the sea above it has done.
The character of the silt which forms
this made ground" is an important factor
] in the problem. 1t is chiefly mineral in
Its formation, and is Of great specific gray
lty; hut there is considerable admixture
OF vegetable matter, which doubtless is
the cause OF its exceeding fertility. 3 ing
formed by heterogeneous atoms brought
in solution by the water, and not having
amalSamated thoroughly at least on the
'5urhfcc, or where the water can resah it,
pit remtins soft soluble mud, which is ca.
pable OF resisting the action OF water only
by means of gravity. 1t has almost no
cohesion, AMI offers no proper foundation
for any work that is Of greater specific
gravity than itself 1t is used as material
for the mud banks called levees, which
have been until lately the only engineer
ing works on which reliance has been
placed, for there is no other material there
to use, but from the fact that it is soluble
1t is poor material for such works
These facts. thoughtfully considered,
present difficulties enough in the way of
engineering works, but the main difficulty
is yet untouched. This lies first In the
magnitude of the river itself, secondly in
the variations in its volume. and thirdly
in its variations in altitude and speed.
This may seem like variety ofdif1icultes
instead Of one. but that one all lies in the
effort to control vast stream which con-
stantlv varies in volume, altitude, lateral
position, and speed. 1t is evident enough
that it would be comparatively simple
thing to control a smaller stream of as OBJ
stinate nature, or one equally as large
that should not change from month to
month in its conditions. One can manage
puddle, or protect himself from tho sea,
but against thing that Is alternately pud
die and sea it is difficult to act.
The stretch of bottom land over which
river rolls from St. Louis to the sea is from
twenty to two hundred miles wide, and
seven hundred miles long. Over this flat
surfaceQor it is almost fiat, sloping gently
to the sea, the river meanders, cuttinga
shifting groove in the soft mud, that is
1900 miles long. Why 1t does not cut for
i self straight line, thus securing fall
of $4,000 of foot per mile, instead of
3l-l00 of a foot, which it now has, seems
strange until we stop to consider that it
carries its own distractions with it until
they become too heavy to carry. Then
dropping thwn in its own path, it has to
run around them. 1t thus forever corrects
its own tendency to cut away the ground
it has made. for if 1t were Strengthened
and kept straight, as has been proposed
by Captain Eads, it wonld have a direct
tendency to do this, which tendency would
have to be counteracted by other means.
BY the increased slope it would acquire
increased rapidity, and would carry TO the
sea rs great burden as it has at ST.. Louis, |
if not greater
As to the variations in the river between
high and low water, they are almost in
conceivable to one who has not witnessed |
them. They are as If the Hudson river
should once II year flood tho second floor |
Of the city hall in New York city, and
occasionally in "hood year" flow over
the third floor; and the problem before |
the Mississippi engineers is to be compared |
with the question bow, with such foods, |
scrviceab!e piers could be constructed on |
ourriver front if there were norock founda. |
tio1 less than one thousand feet deep. |
One is no more difliculta question than |
the other, except on the Mississippi there
are thirteen hundred miles to LOOK after. |
Durin the foods of last spring the Miss
issippi river from Cairo to the sea-1100 |
mies-had an average width of not less
than twenty miles, an average depth from |
shore to shore of not less than ten feet. |
Ut conrse much of this was slack water,
or the btckset caused by the overflow. |
An this volume of water was not flowing |
to the sea- with the full force that comes |
ot II fall of $500 OF foot. If it had been, |
there would have been little use in asking |
to d,v what is to be done for the valley, |
for there would have been very little |
valley left, But the volume of water was |
there. and if it could have escaped into
the set as rapidly as it flowed into the
valley from above, it would still have been
too large to lie in its bed.
The problem in BRIEF then, is to decide /
how to keep within bounds stream that
flows in varying volume over bed of mud,
without banks that can be called banks. |
-Darid A. Curtis, in Harper'S Magazine
for September.