Represents the anchored Torpedo, so arranged as to blow up a vessel which
should run against it; B is a copper case two feet long, twelve inches
diameter, capable of containing one hundred pounds of powder. A is a
brass box, in which there is a lock similar to a common gun-lock, with a
barrel two inches long, to contain a musket charge of powder: the box,
with the lock cocked and barrel charged, is screwed to the copper case
B. H is a lever which has a communication to the lock inside of the box,
and in its present state holds the lock cocked and ready to fire. C is
a deal box filled with cork, and tied to the case B. The object of the
cork is to render the Torpedo about fifteen or twenty pounds specifically
lighter than water, and give it a tendency to rise to the surface. It is
held down to any given depth under water by a weight of fifty or sixty
pounds as at F: there is also a small anchor G, to prevent a strong tide
moving it from its position. With Torpedoes prepared, and knowing the
depth of water in all our bays and harbours, it is only necessary to fix
the weight F at such a distance from the Torpedo, as when thrown into the
water, F will hold it ten, twelve, or fifteen feet below the surface at
low water, it will then be more or less below the surface at high water,
or at different times of the tide; but it should never be so deep as the
usual draught of a frigate or ship of the line. When anchored, it will,
during the flood tide, stand in its present position; at slack water it
will stand perpendicular to the weight F, as at D; during the ebb it will
be at E. At ten feet under water the waves, in boisterous weather, would
have little or no tendency to disturb the Torpedo; for that if the hollow
of a wave should sink ten feet below what would be the calm surface,
the wave would run twenty feet high, which I believe is never the case
in any of our bays or harbours. All the experience which I have on this
kind of Torpedo is, that in the month of October 1805, I had one of
them anchored nine feet under water, in the British Channel near Dover;
the weather was severe, the waves ran high, it kept its position for
twenty-four hours, and, when taken up, the powder was dry and the lock in
good order. The Torpedo thus anchored, it is obvious, that if a ship in
sailing should strike the lever H, the explosion would be instantaneous,
and she be immediately destroyed; hence, to defend our bays or harbours,
let a hundred, or more if necessary, of these engines be anchored in the
channel, as for example, the Narrows, to defend New-York.
[Illustration: PLATE II.]
The figure to the right of the plate is an end view of the Torpedo H. H
shews its lever forked, to give the better chance of being struck.
Having described this instrument in a way which I hope will be
understood, I may be permitted to put the following question to my
readers, which is, knowing that the explosion of one hundred pounds of
powder, or more if required, under the bottom of a ship of the line,
would destroy her, and seeing, that if a ship in sailing should strike
the lever of an anchored torpedo, she would be blown up, would he have
the courage, or, shall I say, temerity, to sail into a channel where one
or more hundred of such engines were anchored? I rely on each gentleman's
sense of prudence and self-preservation, to answer this question to my
satisfaction. Should the apprehension of danger become as strong on the
minds of those who investigate this subject as it is on mine, we may
reasonably conclude that the same regard to self-preservation, will make
an enemy cautious in approaching waters where such engines are placed;
for, however brave sailors may be, there is no danger so distressing to
the mind of a seaman, or so calculated to destroy his confidence, as that
which is invisible and instantaneous destruction.
The consideration which will now present itself, is, that the enemy might
send out boats to sweep for and destroy the Torpedoes. It is therefore
proper to examine the nature of such an operation, and its chance of
success. Suppose two hundred Torpedoes to be placed in three miles of
channel, the enemy's boats, in attempting to sweep for them, would be
exposed to the fire of our land batteries, or necessitated to fight our
boats, for whenever they leave their ships and take to boats, we can
be as well armed and active at boat fighting as they; and thus opposed
by batteries and boats, they would have three or more square miles of
channel to sweep, which, even if successful, would be a work of time,
and were they to get up some of the Torpedoes, they could not ascertain
if all were destroyed, for they could not know whether five or five
hundred had been put down; nor could they prevent our boats throwing
in additional numbers each day and night. It therefore amounts to an
impossibility for an enemy to clear a channel of Torpedoes, provided it
were reasonably guarded by land batteries and row boats. Added to the
opposition which might be made to the enemy, there is a great difficulty
in clearing a channel of Torpedoes with any kind of sweep or drag, so
as to establish full confidence in sailing through it. It is only they
who put them down and know the number, that could tell when all were
taken up. To facilitate the taking of them up, I have, since Plate II
was engraved, thought of a very useful and simple piece of mechanism
which, being screwed to the box C, will hold the Torpedo under water at
any given depth, and for any number of days. They may be set to stay
under water a day, week, month, or year, and on the day which shall be
previously determined, they will rise to the surface; at the same instant
each will lock its lever H so that it cannot strike fire, and the Torpedo
may be handled with perfect safety. Not having time to engrave this
improvement, it shall be exhibited to Congress in a working model, by
which it will also be better understood.
I will now suppose the enemy to be approaching a port; a signal announces
them; our boats run out and throw into the channel two hundred Torpedoes,
set each to 15 days. Should the enemy sail among them, the consequence
will teach future caution; should they cruise or anchor at a distance,
what could they do? They not knowing the number of Torpedoes which were
put down, nor the day on which they were to rise to the surface, could
not have their boats out exposed to our fire, and waiting from day to day
for a time uncertain. Whereas, our officers, knowing the number which
were put down, and the day they were to rise to the surface, would have
their boats ready to take them in, and at the same time replace them
with others set for ten, fifteen, twenty, or more days. Viewing this
subject in all its bearings, the impression on my mind is, that it would
be impossible for an enemy to enter a port where anchored Torpedoes were
thus used, without their incurring danger of such a kind, that courage
could not guard them from its consequences. Prudence and justice would
warrant their abandoning such an enterprise; and the probability is, that
knowing us to be thus prepared, they never would attempt it, or should
they, and only one vessel were to be destroyed, we might calculate on its
good effect to protect us from future hostile enterprises.
[Illustration: PLATE III.]