The New York herald., 1875-09-13
our uarhor Defences.

ONN DCANh~N@"
In no particular has the art Of war under
gone such marked changes as in its relation
to the attack and defence of harbors. Form
erly the tactics of an attacking feet were to
enter the channels leading to the points of
defence, and, by a persistent and vigorous
cannonade or vigilant blockade, to reduce
the defensive works. There was nothing to
be feared from the defenders side but a
powerful artillery response or a stealthy ap-
proAch at night of incendiary freships, i'm
provised to destroy the attacking squadron.
Redhot shot were sometimes fired at ship
ping when the action was fought at close
range. When it was discovered that by
reason of certain improvements in artillery
forts were no longer able to resist the fire Of
shipping, or prevent the entrance of hostile
fleet into fortified harbors, distractions to
the channels of approach were adopted as
auxiliary defences notably at the siege and
blockade of Sebastopol. These in turn have
been found to be unreliable against heavy
iron-plated, sharp proved war ships, armed
with long range rifle guns, and n new system
of harbor and channel defence has gradually
come into use. The torpedo system, which,
judging from the results obtained at Cron-
stadt during the late war between the allies
and Russia and the defence of the North Ger
man coasts against the French fleet in 1870,
but more particularly and completely
during the war Of the rebellion in this coun-
try, promises to revolutionize naval tactics in
the attack and defence of harbors A marine
torpedo is portable mine, loaded with the
most powerful explosives, and submerged
during time of war in such portions of the
channels of approach to harbors as are prac-
ticable for the enemy's war ships. They are
divided into two classes, one of which en-
braces all torpedoes fired by electricity from
the shore or from boat stations the other,
the torpedoes which carry with themselves
the means of ignition by friction, and explode
by contact with the attacking ships during
their progress through the torpedo-defended
channel. The former class are positively re-
liable so long as the insulated conducting
wire or cable which connects them with the
electric battery remains intact, and can be
fired at any moment desired by the operator.
The latter class must be actually touched
by the object to be destroyed, and by reason
of their necessarily delicate arrangement of
friction fuses are very liable to arrangement
or premature explosion during handling or
by floating wreck. The effects of torpedo
explosions under, or even at. considerable
distance from the hull of o ship, are terrific;
they completely shatter and disable the
vessel when they do not annihilate
her. During the late war of the
rebellion several of the heaviest gun
boats were literally blown to atoms by
the explosion of torpedoes beneath them,
and so complete and instantaneous was their
destruction that scarcely any of their crews
survived to tell the tale, while even the sur
rounding ships were made aware of the loss
only by the sudden disappearance of their
consorts in q wild whirl of smoke and
water. While the recent torpedo expert
ments at Newport have been most salts
factory, both as regards their management
and results, and reflect the highest
credit on the officers who conducted
them, we do not consider that such
public exhibitions are expedient or bene-
fetal to that branch Of the service. We
would much prefer that foreign nations that
may become future enemies should learn our
system of harbor defence at the expense of
their navies. This may seem to be an un-
generous sentiment, but really it is a very
safe one to be guided by in this particular
instance.