For many centuries after the invention of gunpowder, little change took
place in the weapons used in naval warfare, the chief developments being
in the way of better workmanship and material, and the production of
guns of larger size.
About the end of the eighteenth century, however, the period from which
so many of our modern improvements begin to date, inventors began to
plan new and improved methods of disposing of the enemy. About the year
1770, the American Bushnell conceived the idea of what his
fellow-countryman Fulton afterwards called the "torpedo." This weapon
consisted of a case of powder which was to be attached to the bottom of
the enemy's ship by the aid of a submarine boat, leaving it to explode
later on by means of a clock inside.
The submarine boat was actually made in 1775; it was egg-shaped in form,
and held one man. It was propelled through the water by means of a
screw propeller, worked by manual power; a similar screw, arranged
vertically, enabled the boat to rise or sink at will. With this boat,
during the War of Independence, he, or some other operator, succeeded in
getting under a British man-of-war lying at anchor near New York.
Without her crew having the slightest suspicion of his presence, he
attempted to screw his torpedo to her bottom, but his auger encountered
what appeared to be a bar of iron. When shifting to another position he
lost the ship altogether, and being unable to find her again was forced
to cast off the torpedo and make away, as the clock-work inside had been
arranged to explode soon afterwards. And about an hour later the crew
of the warship were first roused to their danger by the explosion of the
torpedo at no great distance from them, and they were the more alarmed
as they were wholly unable to account for it.
In the beginning of the nineteenth century another American, named
Fulton, having borrowed Bushnell's ideas, came over to Europe and
endeavoured to get the French government to take up his plans for
submarine warfare. After long delay he was at length given the sum of
10,000 francs, with which he successfully constructed a submarine boat.
In this boat he remained under water for more than four hours, and
having been required to blow up a small vessel had no difficulty in
getting under her and in blowing her to pieces with his torpedo. The
torpedo in a highly developed form is now one of the most important
weapons in naval tactics.
In spite of the success of Fulton's experiments, his plans were not
adopted, either by Napoleon or by the British Admiralty, to whom Fulton
afterwards offered them. The great European wars having been brought to
an end by the downfall of Napoleon, the torpedo for a while sunk into
oblivion, although during the Crimean war the Russians used submarine
mines to protect their harbours. But during the American Civil War the
torpedo was again brought to the front, and the Southerners, or
"Confederates," used vast numbers of them, to the great damage of the
Northerners, or "Federals."
At first these torpedoes proved so harmless--so few exploding out of the
hundreds laid--that the Federal officers paid little attention to them.
But as the war went on, better methods of exploding them were devised,
and vessel after vessel was sunk in a few minutes, often with great loss
of life. Some of these were sunk by submarine mines fired by
electricity, others by floating torpedoes drifted down by the current or
tide; others again by torpedoes at the end of a long spar carried in a
small launch. In one instance, a submarine boat was employed, propelled
by a screw worked by eight men. Instead of running just beneath the
surface, however, her crew insisted on keeping the hatchway just above
water, and open, with the result that the wave caused by the explosion
of her torpedo rushed in and swamped her, so that she went to the bottom
with all on board.
Another night a large frigate was blockading Charleston harbour when a
_David_--as these torpedo boats were then called--was seen approaching.
The frigate, which carried a crew of 700 men, slipped her cable and made
off at full speed, although she was only being attacked by a small
launch, manned by four men, armed with a few pounds of powder extended
on a spar in front of her! In spite of a fierce fusillade aimed at her,
not a shot struck the _David_, which returned in safety to Charleston.
The Russo-Turkish War afforded several additional examples of the same
kind, which, as already mentioned, had not a little to do with the
alteration in naval design and tactics that took place during the last
two decades of the nineteenth century.
Torpedoes were of three kinds: the first were really submarine mines,
and were placed in a river channel, being fired by electricity when the
vessel came over them. The second kind was the floating or Harvey's
torpedo, consisting of a long narrow, but deep wooden case from 44 to 60
inches in length, which contained 30 to 80 pounds of gunpowder, inside a
copper lining. It had two levers projecting on the outside, which, on
striking an object, set off the explosive inside. This torpedo was used
in two ways: the first by setting it adrift on a river, or where there
was a well-marked current setting towards the enemy's ships, when the
current carried it to its destination; the other way was by towing it at
night, by means of a long line, across the bows of an enemy's ship; it
exploded whenever it came in contact with the ship.
The third kind of torpedo was practically a Harvey's torpedo attached to
a long boom, or pole, about 28 feet long. This was carried at the
gunwale of a fast steam launch at night; on nearing the enemy's ship
this boom was pushed forward so as to bring the torpedo ten feet below
the surface and well in advance of the boat. The torpedo exploded when
it struck the ship, and to prevent the torpedo-boat from being sunk by
the huge wave raised by the explosion, it had to be covered in front by
a shield.
The experiences of the two wars already mentioned showed the difficulty
of dealing with torpedo boats at night, and "search lights" are now
installed on all modern warships. These consist of an electric arc lamp
of 25,000 candle-power, combined with a reflector, which concentrates
the light so that it brilliantly lights up objects at a great distance.
Torpedo boats can be readily discovered when a mile or more distant and,
at the same distance from the light, the rays are so powerful that a
newspaper can be read with the greatest ease.
Torpedo attack, however, has been revolutionised by the invention of
"Whitehead's torpedo," which can be used from a distance. In shape it
is exactly like a huge cigar, 12 to 18 inches in diameter, and 6 to 10
feet long. At the head is the explosive; behind this is a reservoir
containing air compressed to an enormous pressure, which drives engines
contained in a third compartment, and which in their turn work a screw
propeller at the back of the torpedo. There is also mechanism which
automatically adjusts the depth at which the torpedo travels below the
water, and other mechanism which ensures that it will keep going in the
direction in which it was fired. Such a torpedo is now effective up to
two miles, and it will traverse this distance in about six minutes.
Torpedoes are discharged from what are called "torpedo tubes" by means
of compressed air. These tubes are to all intents and purposes, guns
made of thin steel, the torpedo being put in at the breech. Those used
on board torpedo boats or similar light fast craft are mounted on a
swivel on the deck; in larger vessels they are usually placed below the
waterline so as to be free from the serious consequences that would
ensue if the tube were struck by the enemy's shot, while a torpedo was
in it. Torpedoes have also been invented which are steered by
electricity.
The problem of protecting ships against torpedoes is a difficult one,
and no satisfactory solution has yet been arrived at. All large
warships, however, are provided with "torpedo nets" of thick iron wire,
which are hung round her at the end of long poles, which, when not in
use, are tied up alongside. But mechanism has been invented by which
the torpedo will cut through the netting, if it encounters it, so that
at present the torpedo is master of the situation, within its range. In
fairly shallow water a torpedo will throw a column of water nearly 200
feet into the air, by the impulse of the gases generated by the
explosion, and no ship yet built would be able to withstand its enormous
shock.
Reference has already been made to the huge guns of the _Inflexible_,
and to the improvements in both powder and guns made later on. The
modern gun is what is called a "wire gun," from its method of
construction. Round a central tube of steel, several layers of
immensely strong steel wire is tightly wound; a second steel tube is
then slipped on above the wire, and as this tube is hot when first put
on, when it cools it contracts and binds the layers of wire tightly
together, forming a gun of very great strength--as, indeed, it would
need to be, seeing that it has to withstand a pressure of over 16 tons
to the square inch.
The projectiles fired from naval guns are of three kinds, solid shot for
piercing the thickest armour,--as on the conning-tower, or barbettes;
"armour piercing shell," with very thick walls and small bursting
charge, which can only penetrate armour, two-thirds of that piercible by
solid shot; lastly, "common shell," in which the shell walls are much
thinner, and can thus only be used with effect against the lighter
structures of the enemy. By placing a small "cap" of iron on the points
of ordinary shot, "capped shot" are produced; and thus provided, they
will pierce a much greater thickness of hard-faced armour than the
ordinary ones. Against soft armour, however, they are not so efficient.
The armour of modern ships has also been greatly improved in resisting
power. The _Inflexible_ of 1881 was protected by wrought-iron plates 24
inches thick, which weighed 2,400 tons, or a fifth of her total weight,
yet only a third of her length was protected. Soon after her
completion, "compound" armour plates,--with a hard steel face on a
backing of wrought-iron--were introduced, which enabled a third of the
weight of the armour to be saved, yet leaving the amount of
penetrability unchanged. Later on, "Harvey" armour, made of steel
alloyed with nickel, still further reduced the weight, and recent
improvements now make the best armour equal in resisting power to three
times its thickness of wrought-iron. It may be mentioned also that the
coal bunkers are now arranged so as to further protect the engines,
being reckoned equivalent to about three inches of wrought-iron.
Facing page 464 are two "sections" of warships, which will, no doubt,
interest the reader. The first is of an old steam battleship, such as
the _Marlborough_, the other, that of a modern second-class cruiser,
like the _Minerva_, which could blow the _Marlborough_ to pieces before
the latter could get her within the range of her guns. Notice the
enormous difference in the space devoted to the engines and boilers.
The modern vessel gives a general idea of the arrangement in all classes
of modern warships. The conning-tower will be seen below the bridge, in
front of the foremast. The magazines are at the bottom, right below the
forward and aft guns, which in this type of vessel, are protected by a
shield only, with armoured ammunition hoists going down from it; the
barbettes of the more powerful vessels would simply be iron
breast-works, extending all round these guns. The curved protective
deck is also seen, about the waterline, and the projecting ram, while at
the stern is the curiously shaped rudder, made in this form, because it
takes less power to work, than that of the ordinary type.