The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1870-05-30
SUBMARINE WARFARE.

In some recent letters from Captain j.
Ericsson to the editor Of "Engineertpg, tne
writer offers the following solution TO the
problem, "How to defeat monitors superior
in thickness of armor to our own
A heavy body of regular form, whatever be
its specific gravity, projected laterally through
the air, commences to fall from the instant
of leaving the muzzle of the gun; describing
during its progress q parabolic curve con-
siderably fore-shortened, owing to atmos-
pheric resistance. But body of regular
form projected under the surface of water or
other fluid, in a horizontal or inclined direc-
ton, win move in straight line, provided
its specific gravity be equal with that of the
fluid. In other words, heavy body of any
density whatever moving through the atmos-
phere, is inexorably under the influence of
the gravitating force of the earth; while a
submerged body, the weight of which is
equal with its displacement, is not affected by
gravitation. If put in motion under the sur
face of a quiescent fluid of unlimited extent,
such body will continue to move in straight
line until the motive energy which propels it
becomes less than the resisting force of the
urrounding medium.
Starting with these cardinal propositions,
entered, some twenty-five years ago, on the
task of solving the problem of submarine
attack, viz, the propelling or projecting be-
low the surface of the water of an elongated
shell containing explosive substances to be
ignited when reaching some point under the
bottom or bilge of an opponents vessel. The
most obvious method of carrying out the idea
is that of projecting the elongated shell by
means of some contrivance applied near the
bottom of the aggressive vessel. Such
method proposed to the Emperor of France
in the month of September, 1854. The de-
vice consists of long narrow chamber
arranged near the bottom of the vessel,
communicating with the sea and provided
with a sliding valve at each end. The
outer valve next the sea being closed, the
shell is inserted in the chamber, after
which the inner valve is closed and the
outer valve opened. The means adopted
for projecting or pushing out the shell is
simply rod connected with steam piston.
The forward end of the shell being provided
with suitable percussion lock fitted with O
protruding trigger, it will be readily under
stood that when this strikes against an object,
the lock, as in ordinary firearms, will cause
the ignition of the charge within the she'll
At close quarters such method of attack
will uDquestionably be found very effective
indeed, infallible; but unless the opponents
vessel can be approached very near, it will
prove abortive. Evidently, if the she'll be
projected in any direction not parallel with
the line of keel while the aggressive vessel is
in motion, side resistance will be offered by
the stationary water of the sea, which will
divert the course of the missile the instant it
is deprived of the guiding power of the cham
ber from which it is elected. Currents WILL
from the same cause, change the intended
course. 1t need scarcely be observed that,
in addition to the difficulty of controlling the
direction of the shell, the force impaired
to the latter, whether steam or compressed
air be employed, is insufficient to propel
it to any considerable distance. Ia order
to meet these serious practical objections,
viz, that the shell cannot be propelled far
enough, and that its course cannot be con-
trolled, have resorted to device by which
any desirable amount of propulsive force
may be impaired irrespective of the distance
traversed, and by which the course of the
missile is under perfect control during its
progress to the intended point. Persons of
a mechanical turn of mind, in almost every
country, have for long time been engaged
in contriving torpedoes to be propelled under
water by Independent motive power of
various kinds, for the purpose of blowing up
vessels. The Austrian torpedo, urged through.
the water by means of screw propellers ac-
tuated by compressed air, may be classed as
one of this numerous tribe, the reported
terrible nature of which has from time to
time frightened naval constructors, and
amazed some unmechanical sailors who
have witnessed the trials, and found that
the mysterious body actually can move
under water. Proper investigation of the
subject, however, exposes imperfections of
the Austrian torpedo which render it,
like all its predecessors, q mere mechanical
toy, it should be borne in mind that atmos-
pheric air compressed, SO as to exert pres
sure of only 800 lbs. to the square inch, weighs
nearly two pounds to the cubic foot. Con-
sequently, the amount of motive force which
the torpedo is capable of containing will be
found wholly insufficient for its effective pro-
pulsion; while the want of means for direct
ing it to the desired point presents an in
contrived torpedo that may be pro-
superable objection. As stated, I have
PEELED with any requisites amount of force,
irrespective of distance, the course of which
is under perfect control, notwith-
standing currents, and which may be
directed with perfect certainty to an
object in motion. In contradistinction
to the term shell, applied to the structure of
1854, which was propelled alone by Uis vt0a
impaired, as before described, propose to
apply the term torpedo to the contrivance
now to be considered.
1t should be observed that nearly all at
tempts to propel bodies under water have
been successful as regards maintaining a
given depth. The self-evident device of ap-
plying fin or horizontal rudder on each side,
operated by piston or elastic bag actuated
by hydrostatic pressure, has been adopted in
all. 1t readily suggests itself to the
mind that an increase or diminution of
draught, attended as it is with correspond
ing variation of pressure, may be made sub
servient in changing the inclination, thereby
establishing tendency Of the horizontal rud-
der, either to elevate or depress the torpedo
during its forward motion. Thus, by proper
adjustment and application of the hydro
static pressure, the torpedo may be made to
Of IL IL.