St. Mary's beacon., 1860-01-05


adopting parabolc-spindle-shaped ends,
the next question arose as to the best shape
for the centre Of the vessel. Practical
men like the Messrs. Winans. and Of such
inventive genius. were not long in dis
> covering that the cylinder answered this
question. There is the least possible re-
sistancc If the water 10 the sides ola cvlin-
der, when 1T rest in the full, that is,
J. tends to zero, because Of Che want Of ad-
herring capacity in the water for this form.
Again ia adopting tha cylindrical form
for the centre or containing part of the
vessel, the efntre Of gravity fell. below the
centre Of tlotation, and Of necessity, such
: a body could not turn over in the direction
Il u the raglI q ss1g y ssntler. sstn expert
: mcnt at sea, tas fully proved Tts capacity
to resist rotating motion All the effect
Of the wave upon the bottom Of the evil
. lndrical part of the vessel, was to lift up
the whole body and to let it sink again.
and so on alternately with every wave and
it, successor 1t is true the vess / listed
slightly, when the wind was on her beam.
but that was owing {" the cbstructions
furnished 10 the gale by tn" life boats
which were swung up very high when
: they could have been hung within five feet
of the surface of the sea, with perfect safety.
On her late experimental trip, she be-
saycd III all directions of The wind with
perfect buoyancy, rising and falling alter
A nately with the advancing ani rctrlatinc
~wave, without the least pitching motion.
y" = tumblcr of water set upon a table in her
=, :, cabin, lost not drop of it, contents. There
a; was not the slightest difficulty in walking.
either in the cabin or on the hurricane
y deck thrown up over the cylindrical part
y Of the vessel, even wh"n the storm was at
,rits height. All this result. obtained too
rrin chopping sea, like that in the straits
of Dover, or in the Irish channel. is in
restrict conformity with the law which
governs the flotation Of cylindrical and
parabolic spindle-shapcd bodies. Ii is a
calculai'l'. result. anl doubtless the inven-
tors had fully asccrtainci beforehand
what their experiments have since 50 satis-
torily verified.
In the construction Of tubular and cur
yilIncar bodies of iron, destined to Goat in
water, scientific opinion is aadly at variance
MS TO the best mode II strengthening them
~ rs to resist the force of the waves. The
Mcssrs. " N,naus being workers in iron for
80 many years, necessarily brought TO the
solution of this problem, more facts than
workers in wood could possibly 10
Familiar 20" with all that had been written
upon The su' jcct, and thoroughly vcrscd in
tn" sclcnc" of mctallurgy. they came to
the conclusion that the necessary strength
was to be found in tha material itself.
wh'n thrown into the tubular and s,inIle-
shaped forms If iron cylindrical BOXERS
could be made IL resist the expansion of
team. under almost incredibl" prr>sures. il
Vas certainly fai. inference, that rvlin-
dri"al ship, if til" plates were properly riy-
eIted tog gta 'r with secondary plates cover
Ing their abutting joints would he CAPABLE
Of resisting the pressure Of the wares ofthc
sea from without.
Accordingly the inventors dispensed with
every thing Ike longitudinal g;rlers or
beams. 80 Necessary TO prevent l"ng wooden
vessels from hogging or bending in the
middle, ami cunt"nt.d themselves with the
native strength Of the metal, when thrown
into the cylindrical and parabolic-spindle
form. The iron plates arc Of ample thick
ness, and not too large. The joint plates
which hold the rivcts are OF the necessary
thickness and breadth, to secure the ut
most strength, aud the riv,ts are little
more than an inch apart, and armed with
heavy heads.
When 1t is considered that the parabolic-
spindles at each end of the vessel cannot
act as levers upon the cylindrical part of
the ship, owing to their shape in displacing
the water, it will be seen at once that there
IS no strain at the line where thew run into
the cylinder, SO that the whole ship NAV
be resolved into a cylinder, in estimating
the strain upon Its shell in the direction Of
Its generating axis. If cylinder i float
ed in smooth water, there would be no
strain whatever upon it lcng;hwisc. because
the upward pressure of the supporting fluid
would be the same upon every inch Of sur
face submerged. The utility of the spin
dle-shaped ends into which the cvlinder
terminates, Will now be realized if the
cylinder is propelled through disturbed
water. They prevent the waves from
pitching the cylinder lon.itudinally. as
has been seen, by their dispcrsive power
over the billows, and therefore. there is
no more strain lengthwise upon it. than
when the water is at rest. There is no
part of it below the centre Of gravity
ever out of water, nor can it be.
/ he resistibility of the cylinder and It's
parabOlic spindles. under the nIost TRYING
circumstances. was proved in the late
trial trip of this vessel. There was no
yielding. no jarring. Every part of her
WAS as firm as though she waS a solid
mass of iron. The working of the machi-
merry was not felt. notwithstanding four
piston rods we're driving the cranks at the
same moment. The diaphragms or par
titiOns of iron across the vessel. in order
to create waterSight compartments. serve
IN some measure to stay the shell of the
cylinder.