PRISMATIC POWDER.
PRISMATIC POWDER.
Before the adoption of smokeless powder, the cake powder invented by General Rodman had been highly developed and improved in the form of “cocoa powder.” This was made in hexagonal prisms, each perforated longitudinally, so as to have a hollow core. These grains were carefully arranged in the cartridges so as to have this core continuous from one grain to another, in order that upon ignition the combustion would begin in the interior and produce a constantly increasing volume of gas as the exterior surface of the grain was reached. Though the time of combustion was too rapid to be appreciated by the ordinary senses, it was, nevertheless, quite different from the practically instantaneous combustion of the old small-grain powder, and was susceptible of accurate measurement. Much difficulty was experienced in overcoming the detonating tendencies of the smokeless powders, but at last the requisite slow-burning properties were obtained. The smokeless powder for large guns is made in cartridges composed of bundles of strips or cords, or in the same prismatic form as the cocoa powder, and the process of combustion is the same.
MORTAR ON REVOLVING HOIST.
MORTAR ON REVOLVING HOIST.
The form of the gun is dependent entirely upon the nature of the powder used. As the pressure of the gas constantly increases with the burning of the powder, the maximum force will be reached at the moment the combustion is complete. The length of the bore should, therefore, be just sufficient to enable the powder to be entirely consumed at the exact instant the projectile leaves the muzzle of the piece. A shorter bore would cause much of the powder to be thrown out unconsumed, while a much greater length would retard the projectile by subjecting it to the friction of the bore after the maximum force of the powder had been reached. This accounts for the greatly increased length of the modern cannon. A change in the method of gun construction has accordingly become necessary. Guns are no longer made of cast iron, but are “built up” of steel. The explosion of the powder is, of course, exerted in every direction, against the bore and sides of the piece as well as against the base of the projectile. This produces two strains; a longitudinal strain which is exerted in the direction of the axis of the piece, and a transverse strain which tends to burst the gun. It is necessary, therefore, to have the piece so strong, especially at the points of first explosion, as to counteract these strains, and thus cause the entire force to be exerted upon the projectile in the direction of the “least resistance.” This strength, or “initial tension,” isobtained by shrinking cylinders of steel over the original cylinder of the piece, each outer cylinder or jacket being a few thousandths of an inch smaller in its interior diameter than the outer diameter of the cylinder which it incloses, and being expanded by heating to a sufficient degree to enable it to be slipped over the latter. Upon cooling, the jacket exerts a constant and powerful force of compression, which counteracts the outward pressure of the force of explosion. The longitudinal strain is less dangerous than the other, and is usually counteracted by an interlocking of some of the cylinders or hoops, to which the strain is transmitted from the breech-plug. The art of building up guns has been of slow growth, the first efforts in this direction having been made by Sir W. G. Armstrong nearly half a century ago. The weight of the projectile of the present 16-inch gun in the United States service is 2370 pounds; the charge of powder weighs 1060 pounds, and the extreme range is more than 14 miles. The cost of each shot is $450, and when we consider that this does not include the wear and tear of the gun, it is evident that money has become more than ever before “the sinews of war.”
Not less remarkable than the improvement in cannon is the improvement in mortars. These mortars are very unlike the clumsy weapons of that name manipulated by hand-spikes, which were known in our great war. They are now mounted on a platform which turns on rollers. They are elevated or depressed by a mechanical appliance, are loaded at the breech, are accurately rifled, and can drop their projectiles on the decks of hostile vessels at a range of six miles. They are placed in groups of four, each in a separate pit, some batteries containing as many as four groups, or sixteen mortars. In all important sea-coast batteries both guns and mortars are so arranged as to be fired by electricity, either singly or in volleys.
A dynamite gun has been devised by Captain Zalinsky for the purpose, as the name implies, of throwing a projectile containing dynamite. Attempts to fire dynamite projectiles by means of powder have thus far failed. In the Zalinsky gun the propelling power is compressed air. The projectile contains from fifty to sixty pounds of gelatine dynamite, the explosion of which is terrific. Excellent results have been obtained with Zalinsky’s gun up to a range of 2000 yards, but as this is insignificant in comparison with the enormous range of high-power cannon using powder as a charge, the dynamite gun is still a weapon of limited usefulness. Although the dynamite gun has not as yet fulfilled the desired requirements as to range, promising experiments have been made in firing shells charged with high explosives from mortars using charges of powder, and it is probably a question of only a short time before means will be found for successfully firing dynamite in a similar manner.
The great improvements in field artillery make the cannon of the early battlefields of the century seem, in comparison, almost like harmless toys. The modern field gun is made of steel, is rifled, loads at the breech, and has great rapidity and accuracy of fire. The extreme range of the 3.2-inch field gun in the United States service is about four miles. This, in fact, is beyond the ordinary range of human vision, and it is but rarely that the ground for so great a distance is free from features that obstruct the view. For these reasons the fire of field guns can seldom be utilized beyond a range of two miles.The projectile of the 3.2-inch field gun weighs 13½ pounds, and the charge of powder 3½ pounds. The 3.6-inch gun is a still more powerful weapon, the weight of the projectile and charge being 20 and 4½ pounds respectively. Shells are used against inanimate objects, such as earthworks or buildings; but the great artillery projectile for the battlefield is shrapnel. It is now very different from the crude projectile known by the same name in the early years of the century. The bullets are assembled in circular layers and held in position by “separators,” which are short cast-iron cylinders with hemispherical cavities into which the bullets fit. The bottom separator fits by means of lugs into recesses at the base of the shrapnel, and prevents independent rotation of the charge of bullets. The top separator is smooth on its upper side, and is kept firmly in place by the head of the projectile, which screws against it. The separators prevent movement or deformation of the bullets under shock of discharge, and being weakened by radial cuts, increase the effect by furnishing additional fragments of effective weight. The shrapnel for the 3.2-inch gun contains 162 bullets one half inch in diameter and weighing 41 to the pound. The total number of bullets and individual pieces in the shrapnel is 201.
MODERN SHRAPNEL.
MODERN SHRAPNEL.
The heavy sea-coast guns are now mounted either in armored turrets,en barbette, or on disappearing gun-carriages. The first system is very costly and is not generally used in the United States. The second system, in which the guns are fired over a parapet and are constantly exposed, is used only in rare cases. The third has been perfected in the United States in the Buffington-Crozier and the Gordon disappearing gun-carriages. These carriages enable the gun to be loaded in safety under cover of the carriage pit, and then to be raised by means of counterweights or compressed air to a position from which it can fire over the parapet. With trained cannoneers, the gun can be raised and fired in twenty seconds, and this brief period of exposure, especially when smokeless powder is used, renders it almost impossible for the enemy to locate the gun with any degree of accuracy. The shock of the recoil, taken up by pneumatic or hydraulic cylinders, brings the piece back, quickly but gently, to the loading position, whence it is again raised for firing.
The siege artillery of the United States army consists of the 5-inch gun, the 7-inch howitzer, and the 7-inch mortar. They all use shell, and their effective range is from three to four miles.
When the enemy is sheltered behind entrenchments it is difficult to reach him with shrapnel fired from field guns. Field mortars have accordingly been devised for this purpose and have given excellent results. The United States 3.6-inch field mortar is rifled, and carries a shrapnel weighing twenty pounds. The weight of the field mortar is only 500 pounds, and it can be easily carried in a cart drawn by a single mule.
KRAG-JORGENSEN RIFLE.
KRAG-JORGENSEN RIFLE.
But great as the improvements have been in artillery, they are less important than the changes effected in the infantry rifle; for upon the quality of the infantry depends, more than upon anything else, the efficiency of an army. There are many kinds of rifles now in use in the different armies of the world, but in their essential principles they are very similar. All use smokeless powder, and all are provided with a magazine which admits of firing a number of shots without reloading. The Springfield rifle formerly in use in the United States army has been replaced by the Krag-Jorgensen, which has a magazine holding live cartridges, and is provided with a cut-off which enables the piece to be used as a single-shooter. When an emergency demands rapid fire, the opening of the cut-off enables the cartridges in the magazine to be fired in rapid succession. The range of the Krag-Jorgensen is 4066 yards, being practically equal to that of the Mauser, which, in the hands of the Spaniards, inflicted casualties upon our men when they were more than two miles from the hostile position. The difference in the penetrating power of the Krag-Jorgensen and the Springfield is shown in the accompanying illustration, taken from the report of the chief of ordnance for 1893. The Springfield lead bullet was fired with 69 grains of black powder, and penetrated 3.3 inches of poorly seasoned oak, the bullet being badly deformed. With a bullet covered with a German silver jacket the penetration was 5.3 inches, the bullet being again deformed. The Krag-Jorgensen used a bullet consisting of a lead core and a cupronickeled jacket, which was fired with 37 grains of smokeless powder. The bullet penetrated well-seasoned oak to a distance of 24.2 inches and was taken out in perfect condition. The new rifle, at short ranges, has an almost explosive effect and produces a shocking wound; but at ordinary ranges the wounds inflicted by it may be almost characterized as merciful, for the bullet makes a clean puncture, and unless a vital organ is struck the wound heals easily and quickly. The old expression of “forty rounds,” so familiar to veterans of the Civil War, is now obsolete; for no soldier now thinks of going into action with less than 150 cartridges on his person. Not only is the firing more rapid than was formerly the case,but the lighter weight of the cartridge enables a greater number to be carried.
SPRINGFIELD, CAL. 45 (LEAD BULLET).SPRINGFIELD, CAL. 45 (GERMAN SILVER JACKET).KRAG-JORGENSEN, CAL. 30 (NICKEL STEEL BULLET).
SPRINGFIELD, CAL. 45 (LEAD BULLET).SPRINGFIELD, CAL. 45 (GERMAN SILVER JACKET).
SPRINGFIELD, CAL. 45 (LEAD BULLET).
SPRINGFIELD, CAL. 45 (GERMAN SILVER JACKET).
KRAG-JORGENSEN, CAL. 30 (NICKEL STEEL BULLET).
KRAG-JORGENSEN, CAL. 30 (NICKEL STEEL BULLET).
From the rifle to the Gatling gun is only a step, for the latter is essentially a collection of rifle barrels fired by machinery. It consists of a number—generally ten—of rifle barrels grouped around, and parallel to, a central shaft, each barrel being provided with a lock. By turning a crank at the breech, the barrels and locks are made to revolve together around the shaft, the locks having also a forward and backward motion, the first of which inserts the cartridge into the barrel and closes the breech at the time of the discharge, while the latter extracts the cartridge after firing. Upon the gun, near the breech, is a hopper which receives the cartridges from the feed case. The cartridge falls from the hopper into the breech-block of the uppermost barrel, and in the course of the first half-revolution of the barrel it is inserted, the hammer is drawn back, and at the lowest point of the revolution the breech is closed and the cartridge is fired. As the barrel comes up in the second half-revolution the cartridge shell is extracted, and when the barrel reaches the top it receives another cartridge. The Gatling gun can be fired at the rate of 1000 to 1500 shots a minute. It generally uses the same cartridgeas the infantry rifle; but some patterns of the gun fire a projectile an inch in diameter, and approximate closely in their effect to a field gun. The gun is mounted either on a carriage similar to that of a field-piece or on a tripod. Gatling guns were very successfully used by the British in the Zulu War and in the Soudan, and by our own troops in the battles around Santiago.
GATLING GUN.
GATLING GUN.
The Gardner is a lighter machine gun than the Gatling. It consists of two parallel rifle barrels, and is operated by means of mechanism at the breech, which, as in the case of the Gatling, is worked with a crank. It can fire 500 shots a minute without danger of overheating, as the breeches are enclosed in a metallic water-jacket. Its extreme portability makes it a most valuable weapon, though its firing capacity is not equal to that of the Gatling.
NORDENFELT RAPID FIRE GUN.
NORDENFELT RAPID FIRE GUN.
There are several other types of machine guns, but the most ingenious, and perhaps the most effective, is the Maxim automatic gun. This has a single barrel, about two thirds of which, from the muzzle towards the breech, is surrounded by a water-jacket into which water is automatically injected at each discharge, thus rendering overheating impossible. The mechanism for operating the gun is at the breech, covering the remaining third of the barrel. All that is necessary is to draw back the trigger to fire the first shot; the recoil of the piece again cocks it, and the gun is then automatically fired, the process being kept up until the cartridges in the feed-belt are all expended. The cartridges are fed to the piece by means of belts holding 333 rounds, two or more of the belts being joined together if desired. The Maxim gun can easily fire ten shots a second, and if every man at the piece were killed the moment the first shot was fired the gun would keep on until it fired at least 332 more shots.
The Gatling, Gardner, Maxim, and similar guns are known as machine guns. Of the same general family, so to speak, are rapid-fire guns, which are, however, distinguished from machine guns by having a larger calibre, loading by hand, having only one barrel, and being provided with artificial means of checking recoil and returning the piece to the firing position. They use metallic ammunition, and have a breech mechanism which cocks the firing pin and extracts the empty case by the same motion which opens the breech for reloading.
Rapid-firing guns were first designed as a means of naval defense against torpedo boats. They deliver a rapid and easily aimed fire, and use projectiles of sufficient power to penetrate the plates of the boats. In the naval service the gun is mounted on a spring return carriage fixed to the vessel, so that the piece, when discharged, is brought back to the firing position without any derangement of aim. On land a rigid carriage is used. This carriage has a spade at the end of the trail, which is forced into the ground by the recoil and holds the gun and carriage in place. The principal rapid-fire guns are the Hotchkiss, Driggs-Schroeder, Nordenfelt, Krupp, Canet, and Armstrong, which fire from five to ten shots a minute, and use either shell or shrapnel. Experiments are now being made in different armies with a view to adopting rapid-fire guns for field artillery.
The principle of rapid fire, or “quick fire,” has been successfully applied to guns having a caliber as great as six inches. The metallic cartridge used in rapid-fire guns is, in appearance, simply a “big brother” of the cartridge used in the infantry rifle.
Closely allied with guns, both in coast defense and in naval warfare, are torpedoes. The crude weapons of this type, used in the War of Secession, have been developed into formidable engines of war, before whose destructive power the strongest vessels are helpless. For their classification and descriptionsee“The Century’s Naval Progress,” pages84, 85.
The destructive power of torpedoes is so well known as to give them a great moral weight as a means of defense. The fact that the German harbors on the Baltic were known to be protected by torpedoes saved them from an attack by the French navy in 1870–71, and Cervera’s fleet in the harbor of Santiago, in 1898, was safe from our squadron so long as the mouth of the channel was closed with Spanish torpedoes.
Though necessarily brief, the foregoing sketch will show that in the course of the nineteenth century armies have increased enormously in size, and in the power of rapid movement and certainty of supply. Infantry has increased in relative numbers and in importance. Extended order fighting, in which the individuality of the soldier comes into play, has taken the place of the old rigid shoulder-to-shoulder line of battle. The private soldier’s vocation has risen, in many branches of the military service, from a trade to a profession, and now, more than ever before, is extensive training and a high order of intellect necessary for the command of armies. Wars have become shorter, sharper, more decisive and more terrible; and increased emphasis has been placed upon the warning, “In time of peace prepare for war.”