The New Orleans bulletin. [volume] (New Orleans [La.]) 1874-1876, 1876-03-02
CAPT. EADs's PLAN.

CAPT. EADS'S PLAN.
The plan which Capt. Eads has proposed
for improving the channel Of the Mississippi
River and securing the protection of its allu
vial lands from overflow, is the same as that
which has been SO successfully applied to the
Rhine in Holland, and is based upon identi-
cally 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 order to reach the
Gulf, pursues winding course Of nearly 1870
miles, in some places through q deep and
narrow channel, 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 short cut of half mile or less
several miles in the length of the river can be
saved.
The principles upon which the improve
ments suggested are based are as follows:
l. That stream requires more fall for a
wide and shallow than for narrow and deep
channel. The accelerating force acting upon
the current is gravity, or the fall of the
river. The retarding forces are, first, friction
on the bed of the river; second. resistance
due to curvature.
The nearer any geometric figure approaches
the circular form, the less is the ratio of its
perimeter to its area. Now, q narrow and
deep river channel generally resembles seq
ment of circle, and the frictional surface Is
requires less fall for the same velocity of cur
rent or.same capacity of channel.
This indicates the first step in the i'm
provement, viz: The narrowing Of the water
way over the shoals to q calculated sufficient
average width. This improvement alone,
when systematically applied to the Mississippi
River, will overcome mo It of the difficulties
of navigation and of prote' ton. Beginning
at the lower part Of the river, every gain by
this plan is carried up the river, and all gains
are cumulative, the depression of water sur
face at any point being eventually the sum of
eli the gains below, the greatest gain being in
the upper part of the basin. where the auclu-
atoms of level are now greatest.
2. That every bend in the river requires an
additional height to overcome both the re-
sistance due to curvature and the excess of
its length over straight line joining its ends.
the elevation Of high water at st. Louis |
above the Gulf is 4o8 feet. Making no allow.
ance for the resistance due to curvature the |
height, were the channel |
straight, would be only 2l3 feet.
The most unscientifc reader can see how
title Of the work possible is necessary for
he complete relief of the navigation and the
protection of the agriculture of this valley, +
when 10 feet reduction of food line will
ecure it.
Briefly stated. the plan is to make a. COM
uniform width Of channel, by
lykes controlling the current over the bars,
md to make cut offs where the conditions re-
Luire them.
As regards the method Of construction, the
uccess in the use of willow mattresses, as
made at South Pass for the jetties, suggests
he use of these as being the most econoni-
al, as well as the most efficient plan. The
AGILITY with which willows or other similar
Material can be procured at most any point on
be river, and the quarries Of stone which are
valuable by convenient water navigation,
make the proposed improvement exceedingly
easible if undertaken.