Wilmington journal. [volume] (Wilmington, N.C.) 1844-1895, 1856-02-15

confirmed its alluyial character rock was struck
depth of ii feet supposed to be Of shell limestone
remarkable change has taken place mouth Of >.
river since the survey Of Lieut. Mat 1861 The cSaCa
of that date has closed and opened to the r
Importance may expected The begun to wsss
passage for itself through this island Serious obstruc
may result from this. l0n
We now come to the consideration of the Bar ~
REIMBURSEMENT of Investigations The more impohe
observations taken after dsbanding the party
1t will be observed that the river debouches upon an
coast exposed to all the fury of the and stom n
the Southern quarters. 1t has ALSO the disadvantage
and Cape Fear for its too extremities with ver-sine
of less than Is its chord. The tide running %
head of to feet, and greatly diminished velocity
though counter flow to the gulf stream might be i9fA
unable to discover literal current, the predoio
force being with the tide wave, perpendicular to tho b
the coast The variable character of the quicksand ba
pear present nsurmountabe obstacles to ameiop
of its condition Much be done by strict confoon
Guilty is due the equilibrium of certain forces Cum
determination of the value of these forces will enable
bring about new equilibrium, which will give srsy to
depth of water History of the successive difficulties S
the value Of the expedens designed to meet them
1t is evident that plan for the complete improyem
should embrace three requisites
LIST channel of sufficient dimensions through or .,
ing the Oyster Shoals. Ot"
End The ixatOn of the tortuou variable terminus
the channel through the marsh. And,
3rd. That the plan should be such to give eraot
depth of water upon the bar. e"'N
have two plans to offer for the attainment of these a.
jects: w.
Plan 1st propose to avoid the shell distractions h,
dredging channel through the marsh, which shall et
the marsh at Cedar Creek Cove and passing thr0uob M
to join the main channel by easy curve This St
will have idchanne 90 feet wide bv seven deem t
mating with surface width of 800 feet The stream sb
be confined at the entrance between dykes submersabe %
haf-tde The direction of the cut should be adn
to curves, which shall compel the momentum of the d
invariabe line of exertion In case except betWe
lncorrodable banks, are straight advisable Nau
| heir
to invariable law which determines the enacity of ba
tfcal development conformable to this prnciple tbt
1t important to close the old channel at its junction with M
by hearng of clay and fascnes in embankm.p
Of earth Wood cannot be used, unless protected from G
action of the toredo. Shells the most available mae
loses its weight and cohesion after short exposure H.
cost of imported stone will greatly increase the estimate @
structures which require the Of that material prono
therefore, it is found less expensive Biton or hydrp
| spot of any required Size
| estimate for the through marsh, 62 900 cubic
va {aF Sa ,o at a 20 cents ts per seyy yard
Add for transportation of material for dykes. $50 @
Add for closing old channel so m
$l6,lO %
This plan proposes another cut through Wrighs Island
ter The principle which should determine its dimeT sion
should De that by which the supply was made equal to the
available tidal capacity. propose to commence the nt
with three hundred feet, gradually widening.
Permanently can be given to the banks by the Use
Bton would recommend closing the N branch and
also the closing of the old channel by the nerposton Of
solid embankment between the cut and the N F
branch " ~ L.
would advise against the closing channels which
can be permitted to remain without injury the imnrov
ment The banks would be unable to withstand the in
creased velocity of the current without additional protec
ton Nature meets the demand upon her by network Of
small channels The objection therefore, economy
The necessary increase of velocity be opng the
bank and protecting by shells at exposed points Sketch
exhibits the appearance of the river after this improve
ment The letters show the points of deposit and the
centre of sc0urage The red lines show the position the
The length of the cut feet, having
40 feet wide by 10 deep.
Amount of drudging 173, 48O cubic yards OF
lighter material at Is per yard. s27765 m
1000 yards Hydraulic Concrete, at cents per
yard. 10000 On
OoSC OF closing water way ....... $50 %
Cost of improvement through Wrights Island sSS 645 m
This plan would, believe, give foot greater depth
The second plan proposed, is to channel through the
oyster shoals and Shell Islands, sixty feet wide and seven
feet deep. The dredged material should be placed on ea
side of the Channel between those shoals which are ne
dcuar to its course and the heads of the shoals afterwards
linked together so as to become ubservient the place
Improvement The dredging should be continued through
the sand h1al opposite Swans Point From the s. W. point
dimensions Commencing at the marsh extend 54 deg
min: W, ls2 metres then 81 deg 45 min and 80
metres Lastly 63 deg 20 min w los metres its total
length being l64O feet 1t be composed chiefly Of
shell dredged from the channel and from nearer points
ne dredging tor this cut mill amount to 10000
c9olc yards at ~ cents per yard $40 600 %
Add 70 per cent for refow. NEUTRALITY-SUSPICIOUS.. S00 m
Material for jetty 400 cubic yards 20 cents $50
Cost of dredging through the oyster Islands 4I68O On
This cut is longer by of mile than that through thu
marsh. "
1t will be necessary to remove the natural shell etty
should be freed from shoa the sharp angles cut off and
uniform section formed for the alvous of the river The
W. branch should be closed, and aso the passage next
the dry middle shoa 1t may be found necessary to form
shoal at the mouth of the N. E. Branch.
Wrghts Island should be protected from abrasion The
entrance to the should be enlarged depend and
guiding walls of Hydraulic stone should built
!, as shown upon the sketch No. 3.
These objects be accomplished by the expenditure
$151O o..
few words in regard to the peramamcy the improve
ment The marsh being aluvial deposit at the point
conflict between the landfood the ocean, question ve
naturally arises at to its rate of increase The gradua
elevation of the bed of the
also be looked for comparison the survey of 1873
shows remarkable permanance in the boundaries of m
below Snead Ferry detected The small amount of The
deposit and the space afforded by the large ndens furnish
good grounds for the conclusion that many wears must
before danger need be apprehended this source The
will cause the deposit take place in the ndens
he river, however, labors under difficulties that
gneerng science can hardly obViate The growth the
accoon oyster has constant tendency to obstruct and
divert the channel thus producing serious changes The
ulcksand Bar must be subject the VARYING
of storms.
must acknowledge myself greatly indebted to the Super
nenden OF the coast Survey for instruments and projections
used in the progress of the operations.
am, very respectfully, gentlemen,
Your obedent Servant,
S. MAYER ALERT,
Civil Engineer
decision between these two plans involving question
expenditure with limited means leave the selection the
judgement of the Board.