ture of the between-decks is higher than in vessels of any other class,— that in hot weather the iron walls suck up heat with the avidity of a salamander, and that it is far from improbable that the practicability of keeping the "bilges" sweet has been forgotten in the progress of building (as in the case of the Warrior), -we may also reasonably infer that the principal conditions which concur in increasing the foulness of the between-decks in wooden are also found in a higher degree in armor-plated vessels. Hence we are led to the ultimate conclusion that these latter ships promise to be much more destructive to their crews than any enemy; at any rate, to estimate the power of destruction by their offensive capabilities alone is a delusion.

The truth is, that, until the subject of ventilation enters as systematically into the scientific estimate of the construction of a ship as speed and fighting qualities, the problem of ventilation will never be rightly solved, the needless waste of life which now exists in our navy in peace as well as war put an end to, and the chances of a catastrophe amongst the crew of our ironsides by the ravages of fever diminished. What would be the fate of the sailors of the Warrior or Defence if typhus or yellow fever broke out on board? to say nothing of the chances of both officers and men being ignominiously suffocated in their iron-cased domicil, under the blazing sun of the torrid zone, after the fashion of certain doughty knights of old.

French Results. - - Of the results and inferences arrived at by the French authorities touching the construction and armament of ironclad vessels, the world knows but little beyond what has been necessarily disclosed to the observer. It is believed, however, that they have no faith in the Armstrong gun, or in any breech-loading gun whatever; and, also, that they reject the plan, followed to some extent in England, of plating iron upon iron, but plate iron upon wood.

The following is the reported strength of the French iron-clad navy: Ten iron-cased floating batteries constructed during the Crimean war; two floating batteries of fourteen guns each, which have a speed of six and one-half knots per hour, and are covered with fourand-one-half-inch iron plates; four iron-cased frigates afloat, namely, the La Gloire, Normandie, Invincible, and Couronne, each of which has engines of nine hundred horse-power, and a plating of four-and-threefourths-inch plates; two armor-clad rams, which have engines of one thousand horse-power; from ten to fifteen large iron-cased frigates of the La Gloire class on the stocks; and about the same number of armor-clad batteries in preparation, which are mainly intended for harbor defences.

A recent writer in the London Times, who professes to be posted, states that "it is extremely doubtful whether any naval guns at present introduced into the armament of iron ships could inflict any serious damage on the French frigates La Gloire and the Normandie; and it is certain that the French have introduced a gun which will throw a flat-headed shot through four-and-one-half-inch plates with a thick timber backing. The armament of the Gloire itself consists of guns (called pièces de 30) which, with a charge of rather more than fifteen pounds of powder, throw a ninety-pound shot through twelve centimetres of iron plating at forty metres. But the French

artillerists have accomplished far more than this. As long ago as August, 1861, they constructed a rifled gun which, with a charge of twenty-five pounds of powder, threw a projectile through the ironplated target at one thousand metres; and, although this gun is not yet in common use in the French service, several specimens of it have been manufactured, and the experiments have been carried on in the present year with increasing success." The writer also asserts that the French model gun is not unlike the weapons with which Mr. Whitworth has obtained the startling results detailed in the preceding part of this article.

English Iron-clad Navy. The English have four iron-cased frigates completed and in service, namely, the Warrior, Black Prince, Defence and Resistance. The two former are the most formidable armor-clad frigates afloat; have engines of twelve hundred and fifty nominal horse-power, and carry forty guns; the two latter have engines of six hundred horse-power, and carry eighteen guns Armstrong one-hundred-pounder rifled, and sixty-eight-pounder smoothbores. Besides these, the English have seventeen other iron-clads in the course of completion, four of which are larger than the Warrior, and will be plated from stem to stern with five-and-one-half-inch plates. The English admiralty are also transforming a number of thirty-six-gun frigates into iron-clad sloops, by cutting them down and attaching plates only a little above and below the load line, and the midship part of the vessel containing the guns.

New Austrian Guns. The improved cannons adopted by the Austrian government are formed from a new alloy, called Aich metal, from its inventor. It is composed of copper six hundred parts, zinc three hundred and eighty-two, iron eighteen. Its tenacity is said to be excessive; it is easily forged and bored, and when cold may be bent considerably without breaking; its resistance, it is also stated, is far greater than that of iron of the best quality.

Breech-Loaders vs. Muzzle-Loaders. Some interesting experiments to test the comparative efficiency of "breech" and "muzzle” loading field artillery were made in England, Oct., 1862, under government direction. The muzzle-loading guns were four in number, of Whitworth's pattern, brass twelve-pounders, rifled. The breechloaders were of Armstrong's pattern, iron twelve-pounders, with all the latest improvements. The trials began by firing at a floating target distant five hundred yards. As the shot fell in the sea, no very close comparison could be made as to the accuracy of the respective hits, but both at the five hundred yards range, and afterward at the twelve hundred yards, the shot from the Whitworth was the first to carry away the flag aimed at, and it was generally conceded that at both ranges this gun fired closer to the mark than the Armstrong. Both guns were then tried with shell, the Armstrong firing compound percussion shells, and the Whitworth firing a new kind of shrapnel. It was observed that a considerable number of the Armstrong shells burst in the air before reaching the mark, and, of course, without effect; but the Whitworth shell, being used with a time-fuse, which is ignited in front like the old shell, was found to be more regular and effective in its action.

But perhaps the most interesting part of the experiments was a

comparison made between the two different kinds of ordnance as to rapidity of fire. It has always been held that the one great advantage of the breech-loader was its superiority in handiness and quick firing. The result of this trial does not, however, confirm this opinion. The artillery-men were ordered to fire twenty rounds from each gun as rapidly as they could be served. The Whitworth gun finished the twenty rounds first, completing the task in thirteen minutes; the Armstrong followed two and a half minutes later. This superiority was attributed to the simplicity of the loading and serving the Whitworth gun, the drill being, in fact, precisely the same as in working one of the old smooth-bore guns; whereas the Armstrong drill requires three or four extra movements. All the guns were further tried by firing from each one hundred consecutive rounds. The Armstrongs were fired with lubricating wads, and were also washed out and had their breech pieces changed as often as they became heated so as to be unsafe; the Whitworths all completed their one hundred rounds without being washed out at all, and without using any lubricating wads. It was remarked, too, that the loading was as easy at the last round as at the first.

New Rockets. Lieut. Samuel Parlby, of the Bengal Artillery, has recently published a paper on the use of rockets for war purposes, in which he says, that it is perfectly practicable to produce rockets of one thousand pounds weight, which can be thrown with equal exactness as shells from mortars. One of these falling upon the deck of a ship, he claims, would immediately destroy it.

American Iron-clad Vessels. — During the past year, the United States Government, encouraged by the success of the Monitor, built and modeled by Capt. Ericsson in 1861, have caused to be constructed nine additional iron-clad vessels for use on the Atlantic coast; all of them being built on substantially the same plan as the Monitor, but rendered more formidable both for attack and defence. The following are the details of the construction of one of the largest of these vessels, viz., the Weehawken: - Extreme length of armor two hundred feet; extreme length on water-line one hundred and ninety feet; extreme breadth over armor forty-six feet; breadth of moulded beam thirty-seven feet. The bulwark armor-timbers are oak, seventeen inches in thickness. The plating of the bulwarks is five inches in thickness, in layers of one-inch plates, planed at the edges and breaking joints. This armor extends three and one-half feet below the water-line, and projects three feet eight inches beyond the hull proper. The deck beams are of oak, twelve inches thick, covered with pine planking seven inches thick, and over these two courses of half-inch plates are fastened.

The Weehawken is provided with one revolving turret of twentyone feet internal diameter, nine feet height, and covered with eleven courses of one-inch wrought-iron plates. This turret rests on a flat ring of gun-metal, and revolves on a central shaft one foot in diameter. The armament of the turret is two fifteen-inch Dahlgren guns, manufactured at the Fort Pitt foundry, Pittsburg, Pa. The pilothouse is round like the gun turret, and in this respect is an improvement over the square pilot-house first built for the Monitor. The smoke-pipe is shot-proof, eight feet in height, six inches in thickness,

telescopic in shape, and covered on the top with a grating to keep out shells. The vessel is propelled by a pair of horizontal engines, each having a cylinder forty inches in diameter, with a stroke of twentytwo inches. Ventilating blowers are used, and the cold air is drawn through the top of the turret.

The fifteen-inch guns carried in the turret of the Weehawken, and upon other of her companion vessels, weigh nineteen tons each, and are the largest pieces of ordnance ever tried on shipboard. They are easily worked, however, through the aid of newly devised machinery, by three men; and are fired through a muzzle box from within and through the port-hole, and not, as usual, from the exterior, -the porthole being only seventeen inches in diameter, while the face of the muzzle of the gun is twenty-nine inches.

Of other iron-clad vessels, one called the Keokuk, designed and built for the U. S. Government by Mr. C. W. Whitney, of New York City, differs essentially in its construction from any of the above referred to constructions. She is one hundred and fifty-nine feet long, thirty-six feet three inches beam, and has thirteen feet six inches depth of hold. There are two fixed turrets and a short smoke-pipe visible above deck; these alone break the smooth surface which everywhere slopes to the water's edge. The side armor extends four feet below the fighting draft, which will be about eight feet six inches, and for a portion of the length, amidships, presents an angle of thirtyseven degrees to the horizon. This inclined armor runs up to the main deck on each side, which is but little wider than the turrets. The bow and stern of the Keokuk round away to the water, and present the same appearance to the eye that a wasp's body would immersed. The deck beams are a continuation of the ship's ribs, which are of iron, four inches deep by one inch thick, placed eighteen inches apart. Over these ribs a half-inch plate is laid, and that relaid again with a five-inch wooden deck; this latter is caulked water-tight, and then armed with two half-inch iron plates, somewhat similar to the Ericsson Monitors. The casemated portion of the vessel, five and three-fourths inches thick, is laid with iron four inches deep by one inch thick, placed one inch apart, the interstices being filled in with yellow pine. The remaining one and three-fourths inches are made up by the outside sheets. This armor is fastened on with countersunk bolts one and one-eighth inches in diameter and twelve inches apart, secured inside with strong, six-sided nuts. The deck has only seveneighth bolts through it.

The turrets, two in number, are stationary, and mount one eleveninch gun each. They are fourteen feet in diameter at the top, and twenty feet at the base, extending seven feet above the deck, and twenty inches below it; and upon a platform constructed at that line the guns are mounted. The turrets proper consist of wrought-iron skeletons, made of flat iron, five inches deep by one inch thick, placed edgewise, fifteen inches apart, and secured to a half-inch sheet by four wrought-iron clamps four inches deep by one inch thick. The fifteeninch spaces remaining inside are filled up with wood, and afterward covered with a thin sheet-iron lining, to make a smooth finish; outside of the turret-skin, half-inch plate, the protection is the same as that of the casemates. Each turret has its own shot, shell, and pow

der-magazine, communicating from the deck, just underneath the tower, by hatches. In the after-end of the forward turret is the pilothouse, which is two feet higher than the main structure.

The turret gun decks, twenty inches below the main deck, consist of a circular iron frame six inches deep by three-quarters of an inch thick, supported by twelve wrought-iron beams two and a half inches in diameter. This frame is further crossed at regular intervals by fourteen wrought-iron beams, also six inches deep and three quarters of an inch thick. At right angles with the latter a strong box girder, twelve inches by eighteen inches across the angles, is riveted to the circular frame, being strengthened in the middle by a heavy wroughtiron column five inches thick. Upon the top of the fourteen beams, previously mentioned, a wooden deck five inches thick is laid, to which the gunways are made fast. In the centre of the turret the gun is pivoted; three ports are made for it in the turret-two broadside, and one aft or forward, as the case may be. A lateral range of eight degrees and a vertical one of ten degrees can be obtained for the missile. From the lower deck, inside the turrets, two doors permit communication with the forecastle, and also the engine-room and officers' quarters. There are two water-tight compartments in the vessel, one fore-and-aft, to which access is had by the usual manholes; these can be filled with water, if desirable, in a short time, and will, it is calculated, settle the ship one foot. The forecastle is large and roomy, so much so that one hundred men can swing their hammocks in it. Alongside of the vessel, just behind the casemates, are the coal-bunkers, and immediately enclosed by them and two fore-andaft bulkheads are the steam boilers. Before a shot can strike the latter it must pass through the inclined side, the coal, and also the two stiff bulkheads or partitions just mentioned; they are, therefore, very fully protected.

The Keokuk is propelled by engines of five hundred horse power, which drive a true screw under each quarter of the vessel of about seven feet diameter.

Contracts have also been entered into between the United States Government and Captain Ericsson for the construction of two ironplated vessels of a more formidable character than any hitherto essayed by him. They will bear a general resemblance to the Monitor, with such modifications as have been suggested by experience. One of them is to be three hundred and twenty feet in length, and the other three hundred and forty-one, with fifty feet beam: The vertical sides are six feet in depth, and are to be protected with iron armorplating ten and a half inches in thickness, backed with four feet of solid oak.

The turrets are to be absolutely invulnerable. The contract provides that they shall be two feet in thickness, but the contractor has leave to reduce the thickness, provided he can satisfy the navy department that less will be sufficient. The engines are to be of sufficient size and power to give an average guaranteed speed of sixteen knots per hour. The armament will consist of fifteen-inch guns. But it is as rams that these two new vessels are expected to be most efficient. Where the plates of the sides meet at the bow they