The Hawaiian gazette., 1876-04-05
HAWAIIANGAZETTE
AN INDEPENDENT JOURNAL,
DEVOTED TO HAWAIIAN PROGRESS.
Progress Ofthe Great betty Works
at the Mouth of the Mississippi.


On January 10, 1876, the jetty works con.
structed under the United States grant, made to
MIR. James B. Eads on March 3 last, had been SO
far extended into the sea that the almost com
peie control Of the river discharge had been ac-
complished through distance of = miles from
the lands end and within 2 500 feet OF the crest
Of the bar.
Through the extent Of this mile and bali, the
river current had swept out 263 ,222 cubic yards
OF the bar on December %. 1870 and the removal
BIZ the river is progressing at the rate OF about
10000 cubic yards per day; 100000 yards more
will have to be secured away before 20 feet depth
OF water Is secured across the bar.
The works of each line Of jetty are partially
constructed out beyond the crest Of the bar to
the fnl distance they are intended TO be built,
and the work on this portion OF the jeties Is being
pushed with the utmost yigor, over 10000 cubic
yards Of willow mattress work having been con-
structed and securely placed in position, and
balasted with stone, within the last 30 doys-the
total amount laid thus far being about l25,000
cubic yards. The construction Of 10000 addi-
tional yards is all that is now required TO build
the ietties up above mean low tide, aud out 10
the crest Of the bar, 10000 feet from the lands
end at the mouth OF the Mississippi.
1t is confidently believed that sufficient
amount Of material is now in place, If no more
work we're done, to insure depth Of 20 feet of
water across the bar, within three or four months
One remarkable feature, thus far developed, Is
the deepening Of the water between the incom-
plete ietties on the outer slope OF the bar, which
is doubtless caused by the tidal action that is now
partially controlled by the jetty works beyond
the crest. This deepening clearly shows how
groundless are the fears that the effect of the
jetties would simply be to pile out the eXcayated
Il In mt ctnun of tho blr Tho fart
that the crest of the bar has not deepened. not
wilhslanding the immense amount OF material ex-
cavated from above IT, between the lines of the
iettes, is in exact accordance with the theory
upon which Mr.. Erds has based his application of
Of the jetty system to the improvement OF The
mouth of the Mississippi.
Those predicting the failure OF the system have
constantly asserted that the chief part OF the sedi
mentary matter Of the river was pushed out to
sea, on the bottom by the action Of lbe current:
while Mr.. Eads has persistently declared that this
was grave error, aud that these matters were
almost wholly borne to The sea suspended in the
water Of the river and that, the more rapid the
current, the greater would be the amount Of ma
terial held By it in suspensions and hence an in
crease of current above the normal 10 any part of
the river, flowing over strictly aluvlal bed.
would cause the water to take up an additional
Ddu Ol Llll6 ludlltIs WHICH IL Nuulu lGldu III ruo-
pension so long as the velocity of current was
maintained and when thus charged, it would be
simply impossible for it TO take up any load or
produce any additional securing The current re-
ceiyes its first acceleraton ct the upper end of
lhe ietty works aud here it first becomes charged
with the surplus load. 1t receives no further ac-
celerauon in its passagd the crest OF the bar
lowing to the incompleteness of the work there,)
over which it escapes ateraly. The enlargement
produced by the excavation gradually reduces the
current, where it occurs, by the enlargement OF
the channel, aud the acceleration aud extra load
ing of the water then takes place lower down and
nearer the crest of the bar. The effect of this is
TO shorten up the base of the bar and to deepen
the channel above it, before the crest ia reduced
The original crest Of the bar was plateau g.
500 feet wide, over which an average depth OF
~ feet of water could be found, between the
parallel lines Of the jettes which placed 1000
feet asunder This plateau is now reduced to
width of less than GOO feet, aud will be gradually
reduced to nothing before the deepening OF the
bar crest will begin to take place. As the cur
rent is quite as rapid nov across the crest OF the
bar as it is between The completed parts OF the
jetties, it is evident that If the sedimentary mat
tiers Of the river were pushed along the bottom
by the current, the deposits which are most eie-
vated like the summit of the bar, would be the
fret to be pushed off and piled up beyond the
bar crest, in the sea water beneath the river dis
charge, or in what has been termed the dead
angle" The base Of the bar on the 20 feet line
of depth was nearly 10000 feet long when the jet
ties were commenced This base has been short
ened still more than the plateau forming the bar
summit and is now only about GOO feet long,
measured in the direction of the jetties.-Sciel-
1,,,ss.;cto