New Orleans Republican. [volume] (New Orleans, La) 1867-1878, 1874-04-26
VOLUME VIII-NO. Il
Correspondence Of the Republican,
DYNAMICS OF THE MISSISSIPPI.
ST. LOUIS April l6, 1874.

EDITOR REPUBLICANS:
In response to your reqgest that woul'
| give you my views on the principles dis
cusssed in the letter Of Nr. James B. Fad
to Hon. William Window. United State
Senator and chairman o. the Committee OF
Transportation Routes to the Seaboard
published in the ST. Louis daily Times o
| April Is, herewith comply.
| Upon O careful reading Of the letter per
cieve the object to be to demonstrate tn,
practicability Of jettying the mouth Of ont
OF the passes Of the Mississippi, and thereby
| securing q confined volume Of water will
an increased current sufficient to keep oper
| a channel over the bar of some fifty OF
| sixty feet.
The principles laid down by the author
from which he argues to arrive at this result
] shall reduce to four.
As preliminary proposition he truly
says: ''The Mississippi is simply trans
porter of solid matter to the sea- This
solid matter we will call sediment, whether
1t be mud or other matter.
The propositions involved in the first prin.
clpies are as follows:
First-'The amount of this matter, and
the size and weight of the particles which
the stream is enabled to hold and carry for
ward depends wholly upon the rapidity OF
the stream, modified by it's depth"
the ability Of holding in suspense proper
tionate quantity OF solid matter; and when
it is thus charged it can sustain no more,
and therefore can not then wear away it's
banks, no matter how directly the current
may impinge against them"
1.-The water once loaded it can carry no
more, and hence may sweep around half a
score of bends below with equal velocity,
without injury to them"
fo hot uiu bon
in suspension corresponding quantity of
solid material" etc.
The propositions embodied in No. all
tend to establish the assumed principle that
the amount of mud or sediment that water
can hold in suspension "depends wholly on
the rapidity-velocity Of the current; and
that it becomes saturated at q certain point,
and can hold no more"
This is fallacy. Were he speaking of
gentle current Of water flowing over bed
Of salt or sugar it would be true, tor water
will hold in solution only given quantity of
either of these substances; but even then if
the water be stirred from the bottom, the
undissOlved portions may be made to rise
and mingle with the water and carried and
deposited in different parts of the bottom.
Ii the water of the Mississippi and the
mud were of the same specific gravity, they
would intermingle with equal facility, and
tatiOn of the mud. But the mud being the
heavier it continu ally tends to settle to the
bottom, and is only prevented by mechan-
lcal causes, one of which is current-or
velocity of the stream; but this is the least
OF the causes, though it may be the first
The principal causes are other agitati0ns
and cOmmOtiOns Of the water, such as ebul-
lition. BY rapidity alone the sand, pebbles,
boulders, etc, resting on the bottom would
hn vn6 fpn 4 Il
little sediment would be raised and mingled
with the super strata of water. The simple
current motion is from the surface to the
bottom, as it we're, direct pushing or
dragging motion. The upper part of the
surface is elevated, causing an inclination
of surface. The surface fret moves down
ward according to the declination, land
drags as it wele at an inclination from q
the water beneath to the
bottom.
In body of water like the Mississippi,
Of great volumn and depth, the pressure,
From the surface to the bottom, drives the
waters laterally along the bottom, up the
banks to the surface again, thence toward
he surface channel, like concentric circles,
md hence the bOilings and ebullitiOns we
always see in great rivers, and hence the |
'edimeut from the bottom and banks are |
made to pervade every portion of the body |
# the water. So it is clear that if there |
vas only velocity and not lateral motion |
md ebuilitions there would be but little |
ediment held suspended, and it is equally |
manifest that lateral motion and ebullitiOn |
8 the chief cause Of the amount of sedi- |
nent held in suspension and not rapiGity |
# current. There is no such thing as |
point beyond which the water will not |
Old sediment in suspension. No such thing
9 surcharging it to point beyond which it
Vill not carry. The ability of the water to
old in suspension, is only limited by it's
ut one item.
This is probably sufficient to satisfy you,
hat the amount of matter and the size and
eight of the particles which the stream is
nabled to hold and carry forward, do not
epend ,chOlly upon the rapidity of the
,ream. Ii not, as l can devote no more
pace now, l will enlarge upon it ON some
her occasion.
Now, as to the next proposition of Mr.
raulics OF Great Rivers, and which fear
, has misinterpreted, and hence led into
rOng conclusions. 1t is this:
"Revy. in his recent valuable treatise on |
7draulics of great rivers, declares that
10 current is doubled by doubling the
spth, and trebled when it is three times as |
'ep, the inclination of surface being the
me. The cause Of this is owing to the re-
iced amount of frictiOnal surface of the
'ttOm and sides of the channel" This he
terward reaffirms in the sixth paragraph
the second column, when he says: "As
ub)ing the depth doubles the current, $
th the same inclination of surface, it
lst be evident that the great reduction of
ction accomplished by narrowing the
annel from 10000 feet to 1900 will enable | g
momentum OF tho stream to be kept up O
greatly increased distance beyond the =
r, etc."
never read that passage in Revy, and t
q not say whether the exact sense of q
1t assertion without qualification, i would y
deem it advisable to spend time read
, his work. Why, that is saying that if "
ter is deep it will necessarily run fast, e
the deeper it is the faster it will run. q,
other words, that depth of water is the n
~ essential to the velocity of current. T
that were trne, why stays the ocean in b
bedf Why does he not pour out his fo
lit currents over the land and wash away
everlasting hillsi If depth alone gives
Ocity OF current, you could not contain
ter in your cisterns if the velocity of the
rent could not break through the sides OF
the clstern is round, it would take a CIR | tb
ar motion in continual pursuit of an out r
But you always find your cisterns ~
% and orderly. at
this were SO, the ponds and lakes would NJ
ever be in turmoil, and, as the current n,
Id not mount over the banks in a -
light line, it would vent it's rage around TO
area like race horse around the ca
,airie track. The poet could no longer as
. of the placid bosom of the silver lake an
ven tide. ~
" reason teaches me but one cause for ro
ion in water-that is current. And that on
Sc is difference Of surface; in other words on
inatfon of surface. As we always see
hen We see water moving with cur
!, the water behind is q little higher ,
, fha u, q tor hoforo ouH tho uroo for fho |