Some of the contrivances to which naval engineers are directing their attention are called outrigger torpedoes. A small swift steamer has an outrigger or pole projecting twenty or twenty-five feet from one side; a torpedo case is fastened to the outer end of the pole, and a concussion-fuse is fitted to it, or an electric-wire extends along the pole. When the steamer has cautiously and silently brought the torpedo (which may be either a little above or a little below the surface of the water) under the bottom of an enemy's ship, the composition within it is fired by the fuse or current, and the explosion left to do its destructive work. It is supposed and intended that the distance of twenty or twenty-five feet between the steamer and the torpedo will keep the former free from peril. Some torpedoes are self-explosive on touching the enemy's ship. One variety is a hollow iron cone, kept at a certain depth under water by a mooring chain; the cone contains from one to three hundred pounds of powder; above this is an air-space to give buoyancy, over this a small apparatus of chemicals, and at the top of all a projecting rod. If the bottom or lower part of the hull of a passing ship happens to strike against this rod, a kind of trigger explodes the chemicals and then the powder—with what result the evil fates are left to determine. Another kind, not self-explosive, is ignited from the shore. The torpedo-cone is moored as in the former case, and electric wires extend from it to a battery on shore. When an enemy's ship is seen to be passing just over the torpedo, a shock is sent from shore, and the demon of mischief explodes. A self-exploding torpedo has the disadvantage of destroying one's own ships occasionally, by a mishap; while the others are with difficulty coaxed to explode just at the desired instant.
Six or eight years ago, the public were a good deal mystified about Captain Harvey's torpedo, what it was and what it was intended to accomplish. It was described as an oblong box, to be towed beside a steamer by means of a long rope. It was charged with a powerful explosive composition; it had projecting levers at the top, a tube containing a detonating compound, and a bolt that could be pressed down upon the detonator by the levers. Towed out to its place by a steamer of great speed, it is brought close to the side of a hostile ship, the tow-rope is then slightly slackened, the torpedo sinks a little, and as the rope tightens again, it comes with a violent blow against the ship's bottom, exploding and making (theoretically at anyrate) a big hole in the ship's hull: a short process, but by no means a merry one. (The English authorities are said to be manufacturing Harvey's torpedoes at Woolwich Arsenal at the time we write, June 1877.)
Rather more recently, Captain Ericsson's torpedo attracted the attention of the American government. It had one feature of a remarkable character—a hempen cable utilised as a tube or pipe by making the centre hollow. The torpedo, a cylinder of light galvanised iron, was about ten feet long by nineteen inches in diameter, and was charged with nearly four hundred pounds of nitro-glycerine. It was towed by a steamer, with a tubular cable or rope half a mile long. When brought into a desired position, the torpedo was propelled swiftly in any direction by compressed air driven through the tubular rope. The torpedo could be wound in so as to be any less distance than half a mile from the steamer. One rather fails, however, to see how the commander of the steamer is to send the explosive matter against an enemy's ship exactly at the right time and in the right direction.
The Whitehead or fish torpedo, one of the kinds now being experimented upon by the English government, appears to be a very elaborate contrivance. It is a sort of submarine rocket, a cigar-shaped iron case five or six yards long by about half a yard in diameter at the thickest part. At one end is a charge of three or four hundred pounds of dynamite or of compressed gun-cotton, with a pistol or trigger-detonator to ignite it; then a pneumatic chamber for compressed air, with an apparatus for maintaining the torpedo at any predetermined depth below the surface of the water; then an air-chamber, tested to a thousand pounds on the square inch, and containing an air-engine with compressed air; and lastly, a double action screw propeller. So much for the torpedo; but how to make it travel along and then explode? It is either driven into the sea out of an apparatus called an ejector, fitted in the bow of a steamer built for the purpose, or it can be launched from a special carriage placed on deck. The arrangements can be so made that the torpedo will travel along at any depth below the water varying from one foot to thirty feet, for a horizontal distance of a thousand yards, and with a speed of seven miles an hour. A torpedo-vessel called the Lightning has just been built by Messrs Thorneycroft and Donaldson for the Admiralty, to contain two or more of these torpedoes, and to eject them one at a time against an enemy's ships. The idea is, to steam to a distance of a few hundred (less than a thousand) yards from the enemy, and eject a torpedo, with its engine, screw, &c. working, in the right direction; the head of the missile, if it dashes under water against an enemy's ship, will explode, and burst a huge hole in the ship's bottom. Or by another adjustment the explosion can be timed to occur in a definite number of minutes after the ejection. A missile of great cost this will be, whether it hits the enemy or not; seeing that the whole of it will be hurled to fragments if it explodes at all; a cost, per missile, of four or five hundred pounds sterling.
A school of torpedo-warfare has been established at Portsmouth; and there can be little doubt that foreign powers are doing the like. Alas for humanity and civilisation! It is contended, however, that all this diablerie will lessen slaughter, by deterring armed ships from coming within torpedo-distance; but a great naval war can alone determine the matter.
As to infernal machines, contrivances planned for some dastardly and nefarious purpose, an incident about four years ago gave us a little insight into them. A cargo of highly insured but worthless goods was shipped at a French port in a steamer, and in the midst of the cargo an infernal machine, intended to explode, destroy the ship and cargo, and earn the insurance money for the miscreant conspirators. The machine was a sort of chest, provided with explosive compound, an exploding apparatus, train of clockwork, primed cartridge, trigger or striking needle—the clockwork being timed to produce the explosion in a given number of days after leaving port. An occurrence at Bremerhaven a year or so ago afforded a further illustration of this application of scientific discovery and mechanical invention to purposes at once fraudulent and barbarous. Whether any case is on record of the coal-torpedo having been really applied to its Satanic purpose, we do not know; but that such a thing exists is certain. It is a hollow shell of iron, carefully moulded from a lump of coal, and blacked to look like coal; an irregular cube of a few inches on each side, and filled with terrible combustibles of the dynamite kind. What does this mean? It means that a steamer laden with almost worthless goods insured at a very high value has a coal-torpedo purposely mixed with the coal in her bunkers, ready to explode whenever thrown into the furnace, or perhaps before! Another infamous contrivance, darkly hinted at, is the rat-torpedo, which, placed secretly in the hull of a ship, will after a time explode, and burst a hole in the ship's bottom. Specimens of these two kinds have come into the hands of European and American governments.
The Easter Monday torpedo in a place of public amusement, whatever it may have meant, was only one (the reader will perceive) among many forms of cylindrical, cigar, cubic, and globular missiles, of the 'Infernal Machine' character.
In the war lately commenced between Russia and Turkey, torpedoes are playing a notable part. The Russians, having a weaker navy than their antagonists, supplement the deficiency by employing these subtle agents. One Turkish war-vessel, guarding the passage of the Danube, has unquestionably been blown to pieces by Russian torpedoes, and its crew destroyed. The Russians have shewn much daring in approaching Turkish ships during the dark hours of night, attaching torpedoes to the ships' bottoms, retiring quietly and swiftly, and leaving the explosive monsters to do their fell work. On the other hand, torpedo-defence has been practised with some success by the Turks—preventing the approach of torpedo-vessels, or fishing up the torpedoes themselves before they explode. Torpedo-tactics, in the naval warfare of the future, will evidently embrace the two parts of torpedo-attack and torpedo-defence. Where is it all to end?