the under-water torpedo room, and immediately below the protective deck are kept the paymaster's stores and life preservers. In the next compartment, below on the platform, are the anchor gear and chain lockers, and above this the navigator's stores. Passing through the next bulkhead we come to the vitals of the ship proper, with the 6inch gun magazines on the floor, the 12-inch magazines and handling rooms on the deck above, and above this the 14-pounder ammunition and blower rooms. Above the magazines, and resting on the protective deck, is the barbette of the forward pair of 12-inch guns, the armor and its relative thickness being shown by heavy, black lines; while in front of the barbette the heavy sloping black line indicates the athwartship sloping bulkhead, placed there to prevent raking projectiles from passing through the entire structure of the ship. Immediately to the rear of the forward barbette is seen the coning tower, with the heavily ar mored tube which protects the telephones, electric wires, fuse tubes, etc., that pass from the tower down below the protective deck. In the next com partment, aft of the magazines, are the dynamo rooms; and then between the next two bulkheads is placed an athwartship coal bunker. A similar athwartship coal bunker extends athwartship on the other side of the boiler rooms; and it must be understood that at the side of the boiler rooms are the wing bunkers which run aft for the whole length of the boiler rooms and engine rooms. The boiler installation on this particular ship is entirely of the water-tube type, and it consists of twenty-four units arranged in six separate water-tight compartments, three on each side of the center line of the vessel. Aft of the boiler rooms comes the athwartship coal bunker above referred to, and then in two separate water-tight compartments are the twin-screw engines. Aft of the engines in another compartment is contained a complete set of magazines similar to that beneath the forward barbette, and above them, resting on the protective deck is the after barbette and turret, with its pair of 12-inch guns. Aft of the magazines come more compartments, devoted to stores. In the next compartment, down on the platform, are the fresh-water tanks and two trim.ming tanks, and on the deck above, below the protective deck are, first, the steering-machinery room, and then the steering-gear room, each being in a separate water-tight compartment. This completes the description of the space below the protective deck. The protective deck is known more generally among seamen as the berth deck. Above that, at a distance of about 81⁄2 feet, comes the main deck, and 82 feet above that the upper deck, while amidships, between the two main turrets, is the superstructure, the deck of which is known as the superstructure or boat deck. The berth deck and main deck are devoted to the living accommodations of the officers and crew, the crew being amidships and forward, and the officers aft. The berth deck, as its name would indicate, is largely devoted to the berthing and general living accommodation of the crew. Here are also to be found, in the wake of the forward gun turrets, on one side the sick bay, and on the other side the refrigerating room and ice machine. Aft of that, on the port side, are the sick bay, lavatory, dispensary, machinists' quarters, ordnance workshop and blowers; while on the starboard side are the petty officers' quarters, the laundry, and the drying-room. Then, in the wake of the boiler-rooms, on each side of the ship, are coal bunkers which add their protection to that of the side armor of the vessel. In the center of the ship are washrooms for the crew and firemen. Aft of the coal bunkers on this deck come the officers' quarters. On both sides of the ship are the staterooms of the junior officers, and the wardroom staterooms, while between them is a large wardroom and dining-room with its pantry. The extreme aft portion of the berth deck is taken up by officers' lavatories, etc. On the main deck above, forward, is more berthing accommodation for the crew, also shower baths and lavatories, while amidships are found the various galleys for the crew and the officers, arranged between the basco of the smokestacks, while amidships in the wings of the vessel is more berthing space for the crew. Aft on the main deck the space is given up largely to accommodations for the senior officers and for the admiral, which, by the way, give one an impression more of commodiousness than of rich or extravagant furnishing. Forward. above the conning tower, are the pilothouse, chartroom and the room of the commanding officer. In the particular ship shown, the heavier guns are mounted on the upper deck, two 12 inch guns in a turret forward and two aft, and eight 8-inch guns in two armored turrets, two on each broadside amidships. The intermediate battery of twelve 6-inch guns is mounted on the main deck, the guns firing through casemates. On this deck are also eight 3-inch guns, four forward and four aft; there are also four 3-inch guns, mounted in broadside on the upper deck, within the superstructure. The new method of emplacing guns on our warships, by which it is possible to swing the guns around until their muzzles are flush with the side of the ship, has the good effect of leaving the side of the ship free from projecting objects when the vessel is in harbor, and of leaving the living spaces of the crew but very slightly obstructed. SECTION THROUGH THE TURRET AND BARBETTE OF A In the foregoing illustration, showing the interior of a turret and barbette on a modern American battle ship, the section has been carried down through the structure of the ship to the keel. It is taken on a vertical plane in the line of the keel and includes enough of the ship in the fore and aft direction to take in the ammunition and handling rooms, and show the methods of storing the shot and shell and powder and the means for bringing it up to the breech of the gun. Commencing at the bottom of the section we have, first, the outside plating of the ship; then about four feet above that is the inside plating, or inner bottom, as it is called. This space is divided laterally by the frames of the ship, which run across the bottom and up the sides to the shelf, upon which the side armor rests. Upon the double bottom, and between that and the first deck above, is a magazine where the ammunition is stored in racks as shown in the illustration, this particular ammunition being for the rapid-fire guns of six-inch calibre. On the deck above and centrally below the turret, is located the handling room into which open by water-tight doors the magazines, where are stored the powder charges and the shells for the 12-inch guns above. Two decks above we come to the steel protective deck, 22 to 3 inches in thickness. Upon this deck is erected a great circular structure known as the barbette, whose walls will be from eight to twelve inches in thickness. The barbette is actually a circular steel fort. and it is thick enough and its steel protection hard enough, to break up and keep out the heaviest projectiles of the enemy, except when they are fired at close ranges. At about twothirds of the height of the barbette is a heavy circular track upon which runs a massive turntable. The framing of this turntable extends to a point slightly above the top edge of the barbette, and upon it is imposed the massive structure of the turret, which is formed, like the barbette, of heavy steel armor carried upon framing, the form of the turret in plan being elliptical. Its front face, which slopes at an angle of about 40 degrees, is pierced with two ports, through which project the two heavy 12-inch guns. The mounting of these guns is carried also upon the turntable and revolves with the turret. From the handling room below a steel elevator track extends up through the barbette and curves back to the rear of the gun; and upon this there travel two ammunition cages which are loaded below upon the handling room floor and carry the projectiles and powder up to the breech of the guns, where it is thrust into the gun by mechanical rammers. THE SUBMARINE MINE. Broadly speaking, there are three different kinds of submarine mines. First, observation mines, which are fired from the shore when a ship is known to be in range; second, automatic mines, which are exploded on being struck by a ship, which is the kind with which the Russians claim that the "Petropavlovsk" was sunk: third. electric-contact mines, which on being struck by a passing vessel give notification to an operator on shore, who fires the mine by the throw of a switch. The accompanying illustrations show a system of electric-contact ground mines, laid across a channel, with a battery of rapid-fire guns on shore so placed that they command the whole of the mine field, and render it impossible for the small boats of the enemy to attempt to explode the mines before the big battleships and armored cruisers pass over them. The battery is placed rather low down near the water, and above it is a battery of heavy 8 and 10-inch breech-loading rifles mounted either en barbette, or on disappearing mounts, while above these, carefully masked by shrubbery, is a firing station, which is connected by cables with the mines in the channel. Sometimes, by preference, the firing station is placed in a massive concrete casemate, which is built into the structure of the fortification. The submarine mines would be laid out in a series of parallel lines, and so spaced that the mines in each line would cover the spaces left in the adjacent lines, with the result that on whatever course a ship might be steering, she would be certain to strike one or more of the mines before she passes over the field. The ground mine, which, as we have said, is usually a hemispherical metal case, contains several hundred pounds of high explosive, and is held in place on the bed of the river or channel by its own weight, sometimes assisted by heavy hooks cast upon the outer sheil. Anchored to the mine, and floating above it, at a depth below water that is less than the draft of the enemy's vessels, is a hollow buoyant sphere in which is placed the electric circuit-closer. The second engraving of the two herewith shown represents a section through the floating sphere, and shows the details of a type of circuit-closer which has been very widely used. It consists of a horseshoe magnet, M, M, within which is hung by a coiled wire a ball, B. A silken cord is hung from the top of the magnet. passes down through the ball, and is attached to an armature, A. When the vessel strikes the buoy, the ball is thrown to one side, draws aside the silken cord and lifts the armature, A. To the poles, N, S, of the magnet are secured two small magnets, C, C, one end of the coil wire being connected to line and the other to a contact point, b. The armature A is secured by a spring to an insulated point, P. from which a wire passes through the firing fuse in the ground mine to earth. The other end of the armature carries a contact point Rapid-fire battery to prevent countermining. Battery of 8 and 10-inch disappearing guns. Firing station and range-finders. METHOD OF DEFENDING HARBOR CHANNEL WITH SUBMARINE MINES AND BATTERIES OF RAPID-FIRE AND HIGH-POWERED GUNS. Field of ground mines, showing submerged electric-contact-floating buoys attached. GROUND MINE, ELECTRIC-CONTACT, BUOY, AND SHUTTER AT FIRING STATION. ship. The instant the vessel strikes the buoy, the suspended ball, B, swings to one side, draws aside the cord, pulls up armature A, into contact with b, and causes the signal-battery current to pass by way of the 1,000-ohm resistance-coil down through the ground fuse to earth. This current is too weak to ignite the fuse. At the same time the armature a (in the firing station), is attracted to the the case of an automatic mine of the kind that is claimed to have sunk the "Petropavlovsk," the instant the floating sphere or case is struck by the ship, there is an explosion of the charge, which is carried in the floating case, if the water is very deep, or in the ground mine at the bottom if the water is sufficiently shallow to bring the mine within striking distance of the ship's bottom. |