Till quite recently armor plates have been made of wrought iron only, as numerous experiments in England had served to show that notwithstanding the enormous resistance of steel to penetration it was unfit for armor plating—the damage from the impact of shot not being localized as in wrought iron. The Italians were led, however, by the experiments with the 100-ton gun on targets of both metals at Spezzia, 1876, to adopt steel for their new ships, the “Duilio” and “Dandolo.” Since that time an armor compounded of steel and wrought iron has been introduced in England which bids fair to supersede all others. It is made by casting a heavy facing of steel upon wrought-iron plates. A section of this compound armor exhibits a gradual change of structure from the hard steel face to the soft iron backing. Its resistance to penetration is equal to steel, while in toughness and endurance under the blows of shot it resembles wrought iron.
To glance at some of the heaviest armor plating afloat, the English “Inflexible” carries a maximum thickness of 24 inches of iron, the Italian frigates mentioned above 21.5 of steel, the French “Admiral Duperré” 21.6 of iron, the Russian “Peter the Great” 14 inches of iron. In regard to the power of some of the most noted of modern guns, the 12-inch calibres used now by all leading nations will penetrate, at 1000 yards, 16 to 18 inches of iron. The 38-ton English gun of this calibre has penetrated (at shorter range) 22 inches of iron and 6 inches of teak backing. The 80-ton Woolwich gun will penetrate 23 inches of iron at 1000 yards. The largest Krupp, 72 tons, will penetrate 26 inches, and the 100-ton Armstrong 30 inches at the same distance. None of the guns mentioned would penetrate at a single shot the steel armor of the Italian ships, but any of them would destroy it in a number of rounds.
Armory. A manufactory, or place of deposit for arms. See Arsenal.
Armory, National. The U. S. government establishment for the manufacture of small-arms at Springfield, Mass.
Arm-rack. A frame or fitting for the stowage of arms (usually vertical) out of harm’s way, but in readiness for immediate use. In the conveyance of troops by sea arm-racks form a part of the proper accommodation. Arm-racks are also used in soldiers’ barrack-rooms.
Arms. In a general sense, comprehend weapons both of an offensive and defensive character, but in the usual restricted sense they only embrace the former, and in modern warfare include the gun and bayonet, the rifle, the pistol, the carbine, the sword, the lance, cannon, etc., all of which are noticed under their respective heads. For punishment inflicted upon soldiers who sell or otherwise dispose of their arms, see Appendix, Articles of War, 17.
Arms. This term is used in heraldry to designate the devices borne on shields, and includes all the accompaniments, such as the crest, helmet, supporters, etc.
Arms, Bells of. Are tents, used in the English service, mostly of a conical shape, for containing the small-arms for each company in a regiment of infantry. The tent is frequently painted with the color of the facings of the regimental uniforms.
Arms, Stand of. A complete set for one soldier, as a rifle and bayonet, cartridge-box and belt, frequently the rifle and bayonet alone.
Armstrong Gun. The Armstrong gun as a breech-loading field-piece first attracted attention in England about 1850. About 1858 it was adopted by the British government. This gun was made of wrought iron, and consisted of a single coiled tube reinforced at the breech with two thin tubes, the outer one being a coiled tube, the inner being formed by bending a plate and welding the edges. The coiled tubes were formed by bending square bars of iron around a mandrel and welding the coils together. Tubes made in this way offer great resistance to tangential strains. The intermediate tube was designed to take up the longitudinal strain near the breech, and for this reason was made differently. The breech was closed with a vent-piece, slipped by the band into a slot cut in the piece near the breech, and held in its place by a breech-screw, which supported it from behind. This screw was made in the form of a tube, so that its hollow formed a part of the bore prolonged, when the vent-piece was drawn. Through the hollow screw the charge was passed into the chamber. The vent was formed in the breech-piece. This gun was a 3-inch 12-pounder, firing a lead-coated projectile. It was followed by the 40-pounder, 110-pounder, and other calibres. Muzzle-loaders were also made. The breech-loading apparatus did not prove entirely successful in large guns, and was accordingly discarded except for small calibres. The method of construction was changed for larger guns, and a plan adopted which has been adhered to ever since, and is that now used. The barrel or part surrounding the bore is made of steel tempered in oil; that portion at and in rear of the trunnions is enveloped by several layers of wrought-iron tubes, the number of layers depending upon the size of the gun. These tubes, instead of being joined at their ends by welding, are hooked on to each other by a system of shoulders and recesses. There are also projections fitting into corresponding recesses, which serve to prevent the tubes from slipping within each other. The tube which immediately surrounds the barrel opposite to the seat of the charge is called the breech-piece. It is made with its fibres and welds running longitudinally, so as to resist the recoil of the barrel against the head of the breech-plug, which is screwed into the breech-piece. The shunt system of rifling was first applied to muzzle-loading Armstrong guns, which have fewer grooves than the breech-loaders. The method of manufacturing originally proposed by Sir William Armstrong has been greatly modified by Mr. Fraser, of the Royal Arsenal, Woolwich. (See Ordnance, Armstrong Cannon). For some years large numbers of Armstrong guns were made at the Royal Arsenal, Woolwich, under the supervision of the inventor. His works are now located at Elswick, Newcastle-upon-Tyne, and are known us the Elswick Ordnance Works. To distinguish the system of gun-construction from the “Woolwich,” which it closely resembles, it is frequently called the “Elswick” system. The largest, as well as the most powerful guns ever made, are the 100-ton guns manufactured at Elswick for the Italian navy. See Cannon and Ordnance, Modern History of.
Armstrong Projectile. See Projectile.
Army. A large and organized body of soldiers, consisting of infantry, cavalry, and artillery, completely armed, and provided with the necessary stores, etc., the whole being composed of companies, battalions, regiments, brigades, divisions, and corps, under proper officers, and the entire force being under the direction of one general, who is called the general-in-chief, and sometimes the generalissimo. Armies are distinguished by different appellations; as, a covering army, a blockading army, an army of obstruction, an army of reserve, a flying army, etc. An army is said to cover a place when it is encamped or in cantonments for the protection of the different passes which lead to a principal object of defense. An army is said to blockade a place when, being well provided with heavy ordnance and other warlike means, it is employed to invest a town for the direct and immediate purpose of reducing it by assault or famine. An army of obstruction is so called because by its advanced positions and desultory movements it is constantly employed in watching the enemy. A flying army means a strong body of horse and foot, which is always in motion, both to cover its own garrisons and keep the enemy in continual alarm. For method of providing for armies, see Appropriations.
Army Corps. See Corps d’Armée.
Army Regulations. This is the name of a work published by the War Department embodying all the acts of Congress, and the rules laid down by the President for the management of the army, both in peace and war. See Regulations.
Arnaouts, or Arnouts, Corps des. Militia of Greece organized during the war of Russia against the Porte in 1769.
Arnheim. A fortified city in Holland;