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THE GUN VERSUS ARMOR-PLATE

HUDSON MAXIM

The victory of the Monitor over the Merrimac at Hampton Roads, half a century ago, was far less decisive than was the victory of armor-plate over the gun of that time.

The whole world well remembers the story of how the Monitor arrived in the nick of time and saved the Federal fleet from destruction. But the salvation of the Northern fleet was of but little advantage, for the advent of the Monitor rendered obsolete and useless every warship of every fleet in the world.

Great Britain found herself without a navy. There was universal consternation. It was a world-wonder that no government had before resorted to so simple an expedient, and one whose utility was so very evident.

It must be borne in mind, however, that the guns of that period were muzzle-loading, smooth bores, and that the round solid projectiles thrown by them were intended merely to knock holes in the sides of wooden warships and to pound down the stone and brick walls of forts. Bombshells were then thin hollow spheres of cast iron charged with black gunpowder, and they were not intended for penetration, their destructive value depending upon the fragments hurled by their explosion, or by their ignition of inflammable material.

It is a curious phase of human progress that that which is old and tried is venerated and conserved with solicitous regard out of all proportion to merit. Innovations. must not only have evident merit, but their merit must also be so indubitably proven by application and use as to replace the old and revered, in spite of the opposition of over-zealous conservatism. The substitution of the sail for the galley slave was a very slow process, until it received especial stimulus in the fierce forays of the marauding Northmen and the raids of the Mediterranean Corsairs.

Similarly did the sail slowly give way to steam.

A modern wooden steam-launch or a forty-foot motor-boat, with cedar sides, driven by gasoline engines and armed with a single three-inch gun, would be able to-day to attack and destroy the famous Monitor of Ericsson, in spite of its armor-plate, for the reason that the launch or motor-boat would have vastly greater speed, and alsofor the reason that its gun would have vastly greater range and be able to penetrate the iron armor of the Monitor with projectiles charged with high explosives to explode inside. The motor-boat, lying outside the range of the huge eleven-inch guns of the Monitor, could hold a position of perfect safety during the conflict, and, by consequence, would need no armored protection.

Thus we see that the sufficiency of armor-plate must inevitably depend upon insufficiency in range and penetrating power of the gun to which it is opposed; and that when one vessel is armed with a gun capable of penetrating the armor-plate of an opposing vessel having shorter range guns, the unarmored craft needs only to have a speed superior to that of its armored opponent in order to choose its position out of range of the armorclad's guns and to destroy it without itself being exposed to any danger whatsoever.

The first improvements following the advent of armorplate, as might be supposed, were made in the gun and in the projectile. The old smooth bore, with spherical projectile, was replaced by the breech-loading rifle and the conical projectile having a copper driving ring and gas check, by which a projectile possessing enormously greater mass for its caliber could be hurled at much higher velocity and kept point on.

Extraordinary improvements have been continuously made in armor-plate to harden and toughen it and to give it greater powers of resistance, while battleships have been made larger and larger to support heavier and heavier armor-plate. Nevertheless, the first improvement in guns and projectiles that followed the advent of the armorclad gave the gun the lead, and the gun has kept the lead ever since.

To-day, the long range, high power naval gun, charged with smokeless powder and throwing a projectile made. of tempered steel, inconceivably tough and hard and charged with high explosive, is the most powerful dynamic instrument ever produced by man.

A twelve-inch naval gun throws a projectile weighing nearly half a ton, at a velocity nearly three times the speed of sound. The muzzle energy of the projectile is fifty thousand foot tons-equal to fifty thousand tons falling from the height of a foot, or one ton falling from a height of 50,000 feet. It is as though the projectile which weighs half a ton were to be dropped from a height of twenty miles, making no deduction for the resistance of the atmosphere.

A charge of three hundred and seventy-five pounds of smokeless powder is employed, strong as dynamite, for the projectile's propulsion.

The heat represented by the muzzle energy of the projectile, which must be abstracted from the powder charge, is enough to melt seven hundred and fifty pounds of cast iron.

When an armor-piercing projectile strikes the plate, either the plate or the projectile must yield under the blow, for the energy of the impact is so great as to develop heat enough to melt more than half the weight of

the projectile, and to fuze a hole clear through the plate far greater than the diameter of the projectile. If the projectile is incapable of penetrating, it must yield under the impact upon the plate, becoming greatly heated, distorted, or broken into fragments; whereas, if it is strong enough to penetrate the plate and pass through it, the hard tempered steel of the plate is softened by the intense heat developed, and flows like soft wax from the projectile's path.

It may be safely assumed that the residual velocity of a twelve-inch, armor-piercing, half-ton projectile, thrown from one of the most powerful twelve-inch naval guns, is sufficient, at fighting ranges, to develop heat enough upon impact to fuse its way through a twelve-inch plate.

When a solid body comes into collision with another solid body, the energy of motion is instantly converted into heat, except such portion of it as may be consumed in fragmentation and retained in the motion of the flying pieces. If two armor-plates twelve inches in thickness could be brought together face to face, each with a velocity equal to that of a modern twelve-inch projectile, the energy of the impact would be sufficient to melt both plates.

New suns are created by the occasional collision of great celestial bodies in their flights through space. However, the heat generated by such collisions is vastly greater than that developed by the collision of a projectile against armor-plate, for the reason that the velocity of celestial bodies is so much greater, being commonly from thirtyfive to fifty miles per second, and sometimes as high as two hundred miles a second, instead of but three thousand feet per second. The heat developed by the collision of worlds is sufficient not only to fuse them, but also is sometimes so great as to gasefy them, and reduce them to their ultimate elements. All the suns that emblazon the evening sky have been created in this manner, and the heat generated by their natal impact is sufficient to maintain their light and radiant heat for hundreds of millions of years, and their planets are born, some of them to become inhabited worlds, finally to grow old and die, with the extinguishment of all life upon them, while their parent sun is still blazing hot.

The earth is being constantly bombarded with meteorites, usually of very small size. But the earth is armorplate with its envelope of air. The impact of meteorites upon this envelope at the enormous speed at which they are travelling through space is fatal to them, and they are dashed to pieces and consumed upon it, as though it were a solid shield of hardest tempered steel. It is seldom, indeed, that a meteorite has sufficient size and mass to penetrate through the atmosphere to the

earth's surface. If it were not for the protection offered by the earth's envelope of air, every living thing upon its surface would be very soon destroyed by the meteoric bombardment of the heavens. A particle of meteoric dust travelling at celestial velocity would be more deadly than a bullet from a shoulder rifle.

When a projectile is fired from a gun it encounters the same atmospheric resistance, in accordance with its velocity and mass, as is encountered by a meteorite, the resistance increasing in a ratio something like the cube of the velocity. When a battleship fires a twelve-inch shot at another war vessel five miles away, the velocity is greatly reduced during flight, for an enormous amount of energy is consumed in punching a twelve-inch hole eight miles long through the atmosphere.

Gravitation, also, is drawing the projectile toward the earth with a constant pull of half a ton, to counteract which the trajectory must be made an upward curve. This makes the path longer, with the consumption of additional energy; and also makes it necessary to expend otherwise useful energy in raising the projectile to the top of the trajectory.

If a projectile could be thrown from a gun at a velocity equal to that of a meteor, it would blaze like the sun during flight, for the metal upon its surface would be fused and gasefied by the resistance and friction of the air, and it would not make any difference whether it were made of the toughest, hardest tempered steel, or whether it were made of soft iron, the velocity would be so great that it would pass through the heaviest armor-plate without appreciable reduction of velocity. If it were of lead it would require armor-plate of a greater thickness to stop it than if it were of steel, for the reason that its mass or its weight for its bulk would be greater.

Distance, and the intervening air, is now our most efficient protection. No armorel projection now employed is effectual, except the range be long. By consequence, then, future naval warfare must be between guns and guns, and speed and speed; while armored protection, which lessens speed and limits the size of the gun, must inevitably be largely abandoned.

Were two modern dreadnoughts to battle at as close range as did the Monitor and the Merrimac, immediate destruction would be mutual. They would cripple each other more in four minutes than did the Monitor and the Merrimac in the four long hours during which they pounded each other.

The Alabama and Kearsarge fought for more than an hour within bowshot of each other, before the Alabama was destroved. Were two of the biggest and most

heavily armored battleships in the world to fight to-day at as close range as did the Kearsarge and the Alabama, one or the other of them would be destroyed in a very few minutes.

The projectiles fired from our monster naval guns now weigh ten times as much as those thrown from the guns of either the Monitor or the Merrimac, and our huge projectiles have a velocity more than ten times as great. The total thickness of the armor of the Monitor's turret was ten inches. An iron wall of the same character as that used in Ericsson's turret, ten feet in thickness, would not afford protection against our monster, modern high power naval guns.

Of course, the character of armor-plate has since that time been vastly improved. Instead of being merely soft iron, as was that of the Monitor, armor-plate is now made of the hardest and toughest of temperel steel that science can produce. So, also, is the projectile. In fact, the projectile has more than held its own.

It is necessary, therefore, that the most heavily armored ships, as well as those which are unarmored, must to-day fight at long range, depending mainly upon skilled marksmanship and power and range of guns, rather than upon armored protection. A battle at close range between two huge modern Dreadnoughts would be about as deadly to both combatants as would be a duel between two men standing close together, face to face, holding pistols at each other's breasts.

When a chemical engineer makes an invention and needs capital to put it into practice on a commercial scale, he first interests capitalists by letting them see the invention practised on a laboratory scale, embodying essentially the same conditions as would be involved in the larger application on a commercial scale. Similarly, we may get a very just and dependable idea of the relative efficiency of guns and armor-plate on an actual naval battle scale, by taking into consideration what would be the result of a battle embodying essentially the same conditions on a much smaller scale.

Suppose two men were to fight a duel, one wearing armor capable of protecting him as efficiently against rifle balls as the heaviest armor carried by any war-ship to-day is capable of protecting it against modern cannon fire; the other wearing no armor, and being thereby enabled to run much faster than his armor-clad opponent. Obviously, if the unarmored man had a gun of longer range than that carried by the protected man, he would be able to keep out of range of his enemy's gun, while still keeping him well within range. Thus he would be able to continue firing at him until he killed him, without in return being hit at all.

Let us, in imagination, picture a battle between the crews of two motor-boats on some fine summer day, on Lake Erie, where there would be plenty of sea-room:

Let each boat have a crew of three men-one man to steer, one to keep look-out with a field glass and rangefinder, and one to do the fighting with a shoulder-rifle. Let one of these boats be protected by hanging chain armor over the sides, the three men being also partially protected by coats of mail. Let the other boat and its crew be wholly unprotected, but let this boat have a speed twenty-five per cent greater than the other, and let the shoulder-rifle operated by the fighting man on board have a range twenty-five per cent greater than that of his antagonist. It is perfectly evident that the crew upon the unarmored, swifter boat would be able to keep wholly out of range of their enemy's gun-fire, while still keeping their enemy easily within range of their own gun, with the result that the crew on board the slower boat would, in spite of protection, be ultimately destroyed. while neither the swifter boat nor its crew would receive any injury.

If we should build an unarmored cruiser, having a speed of thirty-five knots and carrying sixteen-inch guns, we should be able to approach within bombarding distance of the coast fortifications of an enemy armed with guns as large as thirteen-inch caliber, and to throw high explosive shell into a fortification without coming within range of its guns. It would make no difference whether the fortification attacked were a fort or a floating battery. Neither would it make any difference whether it were a coast fortification or a battleship at anchor.

A battleship with a speed of twenty knots carrying twelve-inch or thirteen-inch guns opposed to our thirtyfive knot cruiser carrying sixteen-inch guns would be in essentially the same position as though it were at anchor and our cruiser had a speed of fifteen knots; for it would be the excess of speed that would count in the fight, because, by excess of speed, our cruiser would be able to maintain the same relative position with regard to it as though our cruiser were a fifteen-knot boat and the battleship were at anchor, while its thirteeen-inch guns would be rendered absolutely useless because of their shorter range.

Our thirty-five-knot cruiser would be able to meet in the open sea and destroy in detail every battleship of any navy in the world, one after another, provided none of them carried guns of a larger caliber than thirteen-inch, and provided there were sea room enough, and that the would stay in the fight to a finish.

The only thing which could very well prevent our success would be the exhaustion of our coal, an accident t›

our engines, the exhaustion of our ammunition, or the wearing out of our guns.

I do not, however, recommend that we should stop building Dreadnoughts of the regular armor-clad type and build instead only cruisers of the character I have suggested. On the contrary, until an actual demonstration of the fighting cruiser be made, I should strongly recommend a more conservative course, and that we continue to build at least two battleships a year of the Dreadnought type, in order to be on the safe side. We are the richest country in the world, and in national defence can well afford, as Secretary Meyer has said, to match dollars with any other nation.

But I do believe that we ought to build at least one big trial cruiser like that I have suggested, armed with sixteen-inch guns, and having a speed of thirty-five knots.

"THE GUN VERSUS ARMOR-PLATE"

BYRON T. LONG AND WILLIAM LEIGH PRYOR
Lieutenants, U.S. Navy

Many of the deductions and figures brought out in the article by Mr. Hudson Maxim are in the main approximately correct, but the vital feature and the real object of the entire article,—it being a dissertation on the superiority of a high speed unprotected vessel carrying heavy armament over an armored vessel with moderate speed and lighter battery, is based on assumptions which can be proved to be fallacious. The first is that of a 16-inch gun with markedly greater range than a 12-inch or 13inch gun; the second is that such a gun could be used effectively at its extreme range or at a range greater than that of the modern 12-inch gun. The range of all guns depends on the initial velocity and the weight and form. of the projectile. The velocity can be increased in two ways: (1) by increasing the powder charge, or (2) by reducing the weight of the projectile. It is assumed that Mr. Maxim prefers the former; for otherwise, the remarkable striking energy of the large caliber loses by comparison with that of the smaller.

The velocity which we can assign to a modern highpowered gun is limited by the "life of the gun," which is expressed in the number of rounds that can be fired before it is worn out, i. e., loses its accuracy due to what is termed "erosion." With any given projectile, every increase in velocity is accompanied by an increase in erosion and a consequent decrease in the life of the gun. A 16-inch gun, with twenty-five per cent greater range than the latest type of 12-inch gun, would have, in all probability, not more than one-half the life of the latter.

So the 16-inch gun, for all practical purposes, must necessarily be confined to velocities which will give no greater range than the 12-inch gun.

Battle ranges depend upon two main factors: 1st, visibility, and 2d, probability of hitting. The first de'pends directly upon atmospheric conditions; the number of perfectly clear days in a year-days when there is no haze or other atmospheric obstructions to vision at seaare very few, and, in fact, it is very seldom that one can see beyond 15,000 yards.

Those familiar with big gun shooting recognize the difficulty of hitting at long ranges. The probability of hitting decreases in percentage very remarkably as the range increases beyond 10,000 yards, and amounts to less than one per cent with present targets at 20,000 yards, and yet our 12-inch gun has an appreciably greater range than this. The commander of a fleet will necessarily be governed by the above mentioned factors in choosing his battle range, and we are of the opinion that no one would assume the responsibility of throwing away his ammunition when his probability of hitting factor is less than that which obtains at 15,000 yards.

Mr. Maxim's argument is fallacious, due to the simple fact that the 12-inch gun has a greater range than can be used practically, and the same would be true of a 16-inch gun.

Greater speed is undoubtedly an advantage but 35 knots is unnecessary. About sixty per cent of the ofal tonnage or displacement of a 30-knot destroyer is taken up by machinery and fuel, and then it has only a small radius of action. Our battleships should possess a radius of action of at least 5,000 miles. In all probability 35knot 30,000-ton cruiser would be practically all machinery and fuel, without much left for anımunition and 15inch guns with the necessary appliances for handling and serving them. So a lesser number of 16-inch guns would have to be carried than are carried by the latest type of Dreadnoughts fitted with 12-inch guns, and thus the latter would, owing to its greater number of guns, have a better probability of hitting.

One well-placed 12-inch high explosive projectile on an unprotected ship filled with boilers, machinery, and magazines might very readily reduce her to a 20-knot ship, and, as a matter of fact, might well be fatal.

It may be that the future will develop something which will overcome the difficulties we now have to contend with; but, until it has been brought to light and has passed the laboratory stage, we strongly concur in Mr. Maxim's recommendation that we continue to construct armored battleships of the Dreadnought type, in order to be on the safe side.

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The hydroplane has brought the airman, the boatman, and the seaman together; but airmen, in order fully to appreciate and enjoy the use of that attractive machine, will have to combine airmanship with some of the instincts and experiences of boatmen and seamen. *

I have been much amused, as well as surprised, to discover that certain aviators have curious ideas about the sea. For example, one of our best land flyers wants the navy to furnish a torpedo boat, capable of steaming at the modest speed of forty-seven miles per hour, to be placed at his disposal (loaded down with press representatives and invited guests, of course) to follow him in a flight across the Atlantic, lying to at night near the positions where he may alight on the water. Another, an amateur, conceived the idea of being the first in such a flight, without knowing that he could not depend upon the ordinary mariner's compass to guide him. **

The following suggestions on hydro-aeroplane flights have occurred to me in watching such flights, both as spectator and as passenger. I do not know whether they meet the views of the aviators or not, but they show the trend of experimental activities that are desired in the endeavor to reach the goal of safety in flight.

The hydro aeroplane may be placed in the category of a "heavily loaded machine." Its range of speed, i. e., the sector between the "critical limits," is considerably less than in the same machine when used without the hydroplane attachment, but a wide range of speed is desirable.

The use of a standard speed, well within the critical limits, is also desirable during hydro-aeroplane flights in fickle winds, and it should always be possible to increase the speed of the motor in turning. The turns should not be made too sharp in high winds or at a low altitude. With the considerable head resistance and load of the hydroplane, the acceleration of speed required for sustentation, on turning to run before a strong wind, requires an ap

*The qualities required are worthy of a new term. Shall it be Hydroairmanship, Seairmanship, Airseamanship, Boat-airmanship or Airboatmanship? I incline to the latter term, airboatmanship. And now that the French are adopting the term "avion," I would like to see aeroplane changed to airplane, fuselage to body, chassis to landing gear, hydropla (when applied to airplanes) to boat and hydroaeroplane to airboat.

**For the benefit of the ocean-crossing aspirants I will announce that I expect o have, ere long, a practical compass designed to permit of navigating an airship accurately either in fog or at sea. Cecil Grace would have appreciated such an aid in his unfortunate Channel Flight, and the Italian aviator who started for Sicily and fetched up at Corgona, as far away from his destination as that point was from the point of departure, would have accomplished his object with such an instrument to guide him.

preciable time during which, if too sharp an angle of descent is given for acceleration, the center of horizontal head resistance on the upper surface of the hydroplane, which is applied considerably below and usually forward of the center of pressure of the sustaining surfaces, may suddenly force the machine to dive quickly.

On landing, it is always desirable to take the water at a small rearing angle, to avoid sticking the bows of the hydroplane in the water first.

I am disposed to think that it will be possible, by coming down before the wind, to land in rough water that has curling wave crests, and that it may be possible also, by starting with the wind, to rise from such water, provided the hydroplane is of the single boat type with balancing hydroplanes on the wings.

During a trial of the new navy model hydroplanes for the Wright machine, at the Naval Aviation Camp, San Diego, California, Lieutenant John Rodgers went up in a good stiff breeze, with Asst. Naval Constructor H. C. Richardson as an observer. After circling about the bay at about two-hundred feet altitude, he proceeded up the Spanish Bight towards the Curtiss Camp, when two cylinders started missing and a descent was obligatory. To go straight into the wind was dangerous, as the telephone wires to the camp were just ahead, so Rodgers made a left spiral. There was no room to make a complete turn, and there was nothing left to do but land. before the wind, which was blowing about twenty-five miles per hour. He landed at a speed of between fifty and sixty miles, and, although the boats hit rather hard, they took the water as cleanly as could be desired, without any tendency to bury the bows, and slipped ahead at a high rate of speed without shipping any water. A good landing on the beach resulted.

The landing should always be made either before the wind or directly into the wind, and with double hydroplanes special care should be used to prevent side-swiping and to have both boats touch the water at the same time. Lieutenant Rodgers, on one occasion, at Annapolis, had his first hydroplanes swiped off during a forced landing, on a turn, when the machine struck the water sideways.

The speed should not be cut off until after touching the water, as the water resistance will deaden the headway quickly. The sensation of coming down on smooth water is that of softly landing on a cushion.

In running on a beach, the speed should not be cut off entirely until the bow almost touches the sand, unless, of course, there be stones or obstructions that may injure the boat. Lieutenant Ellyson frequently runs the robust Curtiss hydroplane well up on the beach before cutting off the speed.

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