The Portland daily press., 1874-04-20
The Mississippi Passes.

hC AhpiONSAChu vi thC COuu'blOH VI Vic
mouths Of the Mississippi, now choking with
mud, presents a problem which urgently
calls for speedy solution. The great river
Is simply transporter of solid NATTER as
sand and alluvium, to the sea. In the passeS'
and in the river for several hundred mites
above, the slower shore currents nave
dropped their excess fload for years unti
all further deposits tend to increase the
steepness of the banks hence the additional
deposit slides down towards the middle OF
the channel-bed as fast as it is dropped.
The narrowness of the banks tends to in
crease the velocity of the stream, and the
mud is hurried to the mouth. There the
natural slope is lost, the velocity diminishes,
and the stream widens out and grows shall
low. The shore currents are continU ally
dropping the surplus load which their di-
minished velocity is unable to hold up, and
the shores of the passes are built up and mar
rowed in aud brought to the surface Of the
water where, with reed grass, marine plants,
&C., they are gradually converted into dry
land.
The strong central current, however, is
maintained intact by the reduced depth over
which the stream passes as it expands, like
fish's tail, out to the bar. The velocity OF
the stream being m maintained by shoaling in
depth as it expands in width it is able to
transport its load out beyond the bar, except
what is dropped on the submerged and in
cipient shores of the passes. Although the
;e tha bor is
soon checked because of its immense width
and shallow depth, by which great friction in
proportion to volume is induced. Hence the
load is deposited just outside the bar, and its
constant growth is assured. This yearly in
creasing bar is a matter of grave import 10,
the commerce and transportation facilities of
the great central basin drained by the Mis-.
sissipi and its tributaries. Upon the
proper and unrestricted development of the
industries of that vast region depends in a
great measure the future growth and pros
perity of the whole country. So the problem
Of the removal Of the bar or of check to its
increase is subject of vital interest to us all
at the East as well as at the West.
Mr.. James B. Eads of st. Louis, in a me-
moriai addresss to the congressional COM
mittee on transportation, advances a solution
dependent on the principle that swift cur
rent holds the alluvum in solution and car
ries it far out to sea beyond the mouths of the
passes and the attraction of the encroaching
bar. The preservation of the velocity of the
current he proposes to accomplish by sys-
of ioftio uo hat kba
point where the banks Of pass be 200 feet
assunder and the depth sixty, we should arti-
ficially prolong them to the crest of the bar
still keeping them but 1900 feet asunder, we
would inevitably have sixty feet depth at the
mouth of the jetties. As doubling the depth
doubles the current with the same inclina-
tion of surface it must be evident that the
great reduction Of friction accomplished by
narrowing the channel from 10000 feet to
1,2O0 will enable the momentum of the stream
to be kept up to greatly increased distance
beyond the bar, and hence the yer will be
gulf currents, that load which 1t is now only
able 10 deposit just outside of the bar. That
stream will preserve its individuality from
great distance while flowing through the sea
or through another body of water, can be
proven by every river which enters the ocean
with strong and consequently deep volume.
Mr.. Eads does not apprehend that the feeble
tides at the mouth will retard the velocity of
the current, or that there is danger of pro.
gressive advancement of the bar beyond the
jetties.
This project is certainly the most reason
able and feasible solution of the problem of
improving the navigation between the river
and the gulf yet presented, That some bet
ter plan may be suggested is very possible but
the presentation OF Mr.. Eads' project will be
productive of much good even if it only serves
to awaken public attention to matter which
affects the whole commercial interests of the
country, or to suggest and draw forth propo-
sitions of greater merit and simpler execution