Evening journal., 1906-11-12

house Board, who shan operate II for
four years more at the cost OF the United
States Eells and his associates shall
then be entitled from the United States
TO the sum Of ST5OOO0. provided the
structure Is IN substantial and satisfac-
tory condition.
Hartman Brothers, the engineers who
have been lntrusted with the designing
and erection Of the lighthouse, present
the following description OF the proposed
structure
The foundation for the lighthouse will
ne q massive steel caisson IN the form
OF truncated cone with a cylindrical
base. Upon this will be erected a tower
comprising essentially a plate-steel CYL.
inder with a slight batter from base 10
top, which tower will support n lantern
at a height Of $50 feet above sea level.
The foundation caisson Will be los feet
In diameter at the bottom. so feet high
and 90 feet IN diameter at the top IL
will have a double shell Of steel plates
parallel TO each other, spaced six feet
apart and attached 10 "a upright inclined
plate girders, which VIII divide the space
between the shells into "a watertlght
compartments. IL Will have a double
bottom about seven feet higher than the
outer bottom edge OF the caisson. The
space between the two floors OF the bot
tom. about seven feet apart, Is 10 be d.
vided into "a frames or trusses extending
radially from near the bottom OF the "a
outer inclined slrders. horizontally. 10
within eight feet Of the center OF the
calsson.
The central part Of the calsson Will be
10 the form OF an open vertical shaft, 10
feet In diameter, extending from top TO
bottom, inclosed by steel plates rlveted
together and rlveted TO the steel girders
extending horizontally from this shaft
70 the inner edge Of the "A inclined grid
ers mentioned. These horizontal cirders
being about l3 feet one above the other
are to act as temporary noor beams that
VIII divide the caisson into ave large
circular rooms.
The estimated weight OF the entire
structure, Including the lighthouse aud
contents, Is 20 be 2I.0OO tons. The dis
piacement OF water will be about 10000
tons, which VIII leave an effective WEIGHT
resting on the sands Of the Diamond
shoals OF about 1900 tons, covering mn
Snectiye area on the base Of 5000 square
rect. The caisson Is to be built M soma
shlpyard and towed 10 Its destination
The central tube In the caisson, which
extends from top TO bottom Is 10 he
made or curved rolled steel plates AZ
taehed 70 the ends Of the horizontal door
, eiruerr ~ 70 the braclngs, all OF which
Wen rlFeted together viii form a vessel.
ncienty strong TO stand It's sea VOYAGE
and the wind and wave pressure, after
Its nnal settlement into the sands.
All the inside horizontal gl.ders are TO
be covered at the different elevations to
make temporary floors aud rooms 10 the
same calsson. It is proposed TO place In
these rooms, at the time OF towing the
boiler, engines, pumps, derricks. dredging
apparatus. concrete mixing machinery
water, sand and cement and the differ
ent materials necessary for sinking and
hllirg as well as supplies and equipment
for the workmen.
A portion OF the space between the two
outer shells and part OF the bottom will
be dlled with concrete before leaving the
shipyard, so that the calsson will draw
about p feet Of water.
After reaching its destination the cais.
son Will be held in place by suitable
anchors and cables. IT will be scuttled
by pumping water into the Interior com.
partments until II rests on the sands IN
about "a feet OF water. leaving the top or
deck about SO feet above the surface OF
the ocean.
The lighthouse will be located some dis
lance back from the outer edge OF the
shoals, so that Il viii be protected from
the unoroken force OF the waves In time
OF storm. The shoals below the four
rathom contour extend over an area Of
about SIX miles by two miles. and the 10.
cation selected. as shown by studies OF
the government maps made during the
last % years, has suffered but slight alter
ations In depth
After the caisson has been ecuttled
water ballast Will be pumped into the "a
sloe compartments above the sea level
a. - then proposed to sink the foundation