New Orleans Republican. [volume] (New Orleans, La) 1867-1878, 1876-12-10

| with the views OF the commission OF l6I4 4,
which estimated the total length of the
| the entire distance from the deep water in
the river above to deep water in the gulf.
To the second paragraph of this query we
answer, yes; provided the depth so OBJ
tained has . bottom width required by the
fifth section of the act of Congress.
The obligation of the United States to
pay 100000 on obtaining . channel
twenty feet in depth, and of not less
than 200 feet in width, is expressed in that
section in terms which apply exclusively to
the ''wide and deep channel between the
South Pass of the Mississippi river and the
Gulf of Mexico" The obligations of Mr..
| Eads in reference to the shOal 1T the head
| of the pass are expressed in the second pro-
viso to section four of the act. the language
of which provides all necessary. guarantees,
and is the only language of the law defining
depths, etc., which does apply to this
| sh0al.
Query 2.-What depth and width of
channel is it desirable to secure perman-
emily through this shoall
The second pr0viso to section four of the
act demands . navigable depth Through
said pass" and of course through this
shOal, of twenty feat" within ehirty
months; and IAN additional depth Of not
less than two feet during each succeeding
year thereafter, until twenty-six feet shall
have been secured" We deem these
that an inland channel requires less depth
for equal facility of navigation than . sea-
exposed bar, that they are fairly equivalent
to the greater depths demanded by the act
in it's fifth section for the "wide and deep
channel connecting the pass with the Gulf
of Mexico"
With regard to the width of channel
through this shoal, it is probable that all
the necessities OF commerce would be salts.
fed, at least for time, by width sufficient
for tho passage of single vessel. One
hundred feet would suffice for this purpose.
We deem it desirable to provide ultimately
channel wide enough for two large ships
to pass each other when under full head
way without danger of collision. This
would require . bottom width of. say. 200
feet. Though this is somewhat greater
than is now to be found in reaches of con-
siderable length in the body of the South
Pass itself, below Grand Bayou, We recon-
mend it - Q desirable width to be secured.
Query 3.-"What is your Interpretation
of the words average flood tide,' a. used in
the second lfftb) section Of the acts"
The phrase average fo0d-tide" is used
in the section referred to only in reference
to the depths prescribed in that section,
which depths refer exclusively to the
South Pass Of the Mississippi river and the
Gulf of Mexico" i. g., to the channel
to be created by 'jetties and auxiliary
works" through the sea bar of the South
Pass. The expression does not apply to the
''navigable depth" to be secured "through
the pass" in the second provis0 of the
fourth section of the act; and hence not to
at the head of the pass" The matter is
left, as is the width, to be governed by the |
general prescription of providing 'navi- |
gable depth" This navigable depth ought |
to be found at the low a. we'll a. at the |
high stages of the river. We therefore con.
slider the principle governing the decision |
of the chief of engineers in his Endorsement |
Gated to us with your letter of instructions,
to be the correct one for the head of the
pass, viz: That the measure of depths pre- |
scribed by the second proviso to the fourth |
section of the act should be from the level !
average high tides occurring during the !
stage of the river when the volume is least"
that is, the mean of the high waters of the |
river at this place, taken for one or more
!unations when the river is at what is |
known as its low stage. Inasmuch. how.
ever, as Major Comstock found it necessary
to fix Professionally his zero on insufficient |
data, it is recommended that it be revised |
on the principle above stated.
In reference to the prescriptions of |
the second (6fth) section of the
act, the phrase average food-tide
mean average high water of the tide; and, |
with no qualifications in the language, we |
understs nd this to mean the average of all |
daily observed high waters throughout the |
full cycle of year. No complaint has been
made as to the zero mark fixed by the en-
eineer officer for the determination of the
depths Of water at the Gulf end of the pass
1t is possible that, having been established
on series OF only three lunations from Au-
gust ~ to November 9, it may vary slightly
from what would be given by such pro-
tracted series OF observations. 1t is, how
over, our opinion that this zero, as estab-
ished, is go nearly correct, that it need not
be altered, for alteration would involve con-
fusion in the comparison OF future sound
ngs with those heretofore made.
Query Al desire q full expression of |
your opinion as to "the materials used and
the character and permanency with which
The Jetties are being constructed" and as to
whether the work is being constructed &C
,ording to the spirit of the act, as mentioned
a the tenth section thereof.
The several reports of Major Comstock,
he United States engineer officer. give a
very precise description of the materials
lsed. Maps No. 9 OF his reports of June 9,
$40, (snce printed as Elk. Doc. No. II,
senate, fOrty-fOurth Congress, first session.
md OF his fourth report of September 90,
$50, represent to the eye 80 clearly the
lection prOfiles, the component parts, the
dimensions, and manner of construction of
ne two jetties, that we need add nothing
lescriptively. Our opinion thereon is ex-
PRESSED a. follows:
The commission of engineers of 1874 gave
he project for these works q protracted
tudy, and set forth plan and details with
founded thereon. While Mr.. Eads |
8, by the language of the act. "untram-
ae!ed in the exercise of his judgment and
kill in the location, design, and construc-
ion OF said jetties and auxiliary works."
'ot he is required by the law to construct
thoroughly substantial and permanent
works, by which said channel may be main
aimed for all time after their completion"
We find that in general plan the jetties of
lr. Eads correspond substantially with
hose designed by the board. The materi-
Is to be used, as recommended by the
oard, were, after methods long employed
Holland, to be of layers of mattresses, of
,lllows or other suitable twigs or saplings,
laced IN layers, with intervening layers of |
uarry stone. Still this design was in no .
spect obligatory upon Mr.. Eads, nor
aOuld 1t have been upon an engineer Off |
er OF the United States charged to execute
ais work. With no experience in this country .
the execution of such q work, in such
'cality, and on this scale. it was impossible ,
foresee exactly what the work should be.
he board expressly states that sit is of
pinlon that experience in construction
Jay very probably show that the cross Sec
on of the bikes may be reduced, thus
ssening the cost" 1t was also an opinion
the board and other engineers that the
ethods Of Holland would undergo ma
rial modification in their actual applica-
on In this country, and that experience in
le work on the locality would also show s
lo ch0aDeat and heat methoda Mr. Eada | J