Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1879-08-09
THE MISSISSIPPI JETT1Es.
What lanes 3. Eads Has Accomplished.

Captain James B. Eads. the builder
of the jetties at the mouth of the Mis-
sisslppi river, has given to reporter
of the New York World the following
interesting particulars of the work:
: presume, ifyou have everroughed
1t in the West, that you know what a
shuck mattress is. Now, imagine your
shuck mattress enlarged until it is
100 feet long, 30 feet wide and % feet
thick, field bed capable of holding a
great many sleepers. Suppose. con-
tinued the captain, that instead Of
cornshucks your mattress was stuffed
with willow twigs, small branches of
the willow tree, and in the place of
the bed-tick were broad stats at the
top and bottom of these willow twigs.
binding them together, then you have
the lower course of a section of our
jetties. There are, as you know three
passes into the river-the Southwest
Pass, the South Pass and Pass Lou
ire or the Northeast Pass. Before |
began my work the first and last
named were the only passes used by
vessels, since in the South Pass there
was only seven feet Of water. 1t had
in former years been the principal
pass, but had been filled up and be-
come useless for commercial purposes.
| would rather have tried my plan at
the Southwest Pass or at Pass LOu-
ire, but the government would not
permit this There were few people
down there that had any confidence in
my success, and they feared that |
would injure and block up whatever
channel | operated in.
They preferred to keep the pas
sages they had and let you operate on
one that at all events you could not
spOil?"
Exactly. The South Pass being
good for nothing, | could not harm
even if did not improve it. If YOU
have ever been to the mouth of the
Mississippi you know that the trouble
from shoal water was not in the
passes; there was water enough there:
but the trouble was out at sea. but
clear from the land distance of over
two miles, where a bar had formed,
and it was here that | undertook to
make a greater depth, while at the
same time, by the refusal of the au-
thorities to permit me to use Pass
L'Outre or the Southwest Pass, [ was
obliged to deepen the South Pass for
its whole length" F"
And you have accomplished this?'
Completely. There is now more
water at low tide in the shoalest place
of entrance through that pass than
there is at low tide over the Sandy
Hook ban" ="
And this was accomplished by the
willow mattresses you have de-
scribed? "
Exactly. This mattress or float
of willow twigs having been built upon
the land at the head of the passes, it
was launched and foated down to the
lands end and there moOred. In a
short time it would become so loaded
with the mud deposited by the river
water as it flowed through 1.-THE
willow twigs acting like filter-that
it would sink, and we generally aided
this operation by loading it with stone,
although it would sink without this
ballast. And here was the foundation
for our jetty-a solid fat surface at
the bottom of the river 100 feet long
by 80 feet wide. The next mattress
we moored at the outer end of this,
and so continued them out for two
and half miles, until the outer edge
of the bar was reached. Beyond this
was deep water Our next course was
of mattresses exactly like those have
described, except that they were only
30 feet wide. These were sunk exactly
on top Of the first ones, being of the
same length and thickness. The third
course was exactly similar to the 9th
ers, bnt only 30 feet wide, and the
fourth or top tier of mattresses was
but 25 feet wide. The addition of this
brought the jetty above water. On top
of this top tier we puta course of rub
BILE stone, and on top Of this laid blocks
of concrete, each block about 20 feet
long and of varying widths, weighing
from 20 to 76 tons, according to posi-
ton, the heaviest blocks being at the
sea end of the work, the end blocks
being about l3 feet wide. These
blocks covered about 1000 feet in
length Of the jetties The blocks to
ward the land are only six feet wide.
This 5000 feet is all that is exposed to
the action of the sea. Above that the
sea has broken up the sand ON one
side, and the river deposits have
formed substantial bank of mud and
sand on the river side. Imagine two
jetties thus formed extended out to
the outer edge Of the bar, and with
but a narrow channel or canal between
them, and you have a picture of the
outside work the result being, as |
had contemplated, that the action of
the current thus confined would be to
scour or sweep out the mud to depth
level, or nearly so, with the lower part
of the jetties, which by their weight
had sunk deep into the mud and found
a firm foundation
And did this also deepen the
South Pass ?"
Certainly. But at the head of
the pass twelve miles above the Jet.
ties, there was shoal obstructing the
entrance into the pass. On this shoal
there was only IA feet of water when
began operations; to-day there is a
depth on this sh0al of q 2-1Q feet"
And what depth have you through
the jetties ?" Il
The least depth is 3Ol feet and
the pass itself is from 30 to 40 feet
deep consequently the least depth
between the Gulf Of Mexico and the
city of New Orleans is over this
shoal, and here it is as / have said q
0- 10 foot nt low rntnr mhiln thn lnnnt