The Milan exchange. (Milan, Gibson County, Tenn.) 1874-1978, 1876-03-23
Captain Eads'S Plan.

The plan which Capt. Eads has pro-
posed for improving the channel of the
Mississippi River and securing the pro-
lection of its alluvial lands from over
flow, is the same as that which has been
so successfully applied to the Rhine in
Holland, and is based upon identically
the same principles which have gov.
erned the construction of the South Pass
jetties.
The distance from st. Louis to the
mouth of South Pass, in direct line, is
about 664 miles.
The water which flows through the
channel of the river at st. Louis, in or.
der to reach the Gulf, pursues wind
ing course of nearly 1870 miles, in some
places through deep and narrow chan
mel, in others over wide sand-bars, with
but little water on them at low stage
and scarcely ever straight for any con.
siderable distance, but with curves and
bends whereby a short cut of half 6
mile or less, several miles in length Of
the river can be saved.
The principles upon which the i'm
provements suggested are based are as
follows:
l. That a stream requires more fall
for a wide and shallow than for a mar
row and deep channel. The accelerat.
ing force acting upon the current is
gravity or the fall of the river. The re
tarding forces are, first, friction on the
bed of the river; second, resistance due
to curvature.
The nearer any geometrical figure
approaches the circular form, the less
is the ratio of its perimeter to its area
Now, narrow and deep river channel
generally resembles a segment of cir
Gle, and the FRACTIONAL surface is less than
in wide and shallow one, hence it re-
quires less fall for the same velocity OF
current or same capacity of channel.
This indicates the first step in the i'm
provement, viz: The narrowing of the
waterway over the shoals to a calcu-
lated sufficient average width. This i'm
provement alone, when Systematically
applied to the Mississippi River, will
overcome most of the difficulties of nav
igation and of protection. Beginning
at the lower part of the river, every
gain by this plan is carried up the river,
and all gains are cumulative, the de-
preston of water surface at any point
being eventually the sum of all the gains
below, the greatest gain being in the
upper part of the basin, where the
fluctuations of level are now greatest.
2. That every bend in the river re-
quires an additional height to overcome
both the resistance due to curvature and
the excess of its length over a straight
line joining its ends. ....,... a. ..--
The elevation of high water at St
Louis above the Gulf is 40S feet. Max
ing no allowance for the resistance due
to curvature, the proportional height,
were the channel straight, would be on
ly 213 feet.
The most unscientifc reader can see
how little of the work possible is neces-
sary for the complete relief of the navi-
CATION and the protection of the agri-
culture of this valley, when ten feet re-
duction of flood line will secure it.
Briefly stated, the plan is to make a
comparatively uniform width of chan
mel by bikes, controlling the current
over the bars, and to make cut-offs
where the conditions require them.
As regards the method of construc-
ton, the success in the use of willow
mattresses, as made at South Pass for
the jetties, suggests the use of these as
being the most economical, as well as
the most efficient plan. The facility
with which willows, or other similar
material, can be procured at most any
point on the river, and the quarries of
stone which are available by convenient
water navigation, make the proposed
improvement exceedingly feasible if
undertaken,-Ne1o Orleans Bulletin.