Читать книгу Triumphs and Wonders of the 19th Century: The True Mirror of a Phenomenal Era - James P. Boyd - Страница 24

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At Trafalgar, the Victory drifted before the wind into action. In her slow advance, at a speed of one and one half knots through but 1200 yards, she was for half an hour under the prolonged fire of 200 guns, and yet she closed, practically unhurt, with her foes, and lived, not only to win the day, but to bring undying glory to the English flag. What a contrast the latest sea-fight of the century presents in the power of modern ordnance as compared with the puny guns of Nelson’s time! Our battleship Oregon, at a range of nearly five miles, with one 1100-pound shell, drove the Colon, an armored cruiser, not only shoreward, but to surrender, stranding, and wreck.

The largest naval guns in the year 1800 were the long 32 and 42-pounders, smooth-bore muzzle-loaders, with a range of about 1200 yards. Carronades—short pieces with a heavy shot but limited range—found favor also, especially with British sailors, eager for that close-quarter fighting in which the “Smasher”—as General Melville called his carronade—would be most effective in shattering timbers and in sending clouds of splinters among the foe. The projectiles were spherical shot, canister, and grape, the diabolical shriek of the shell being yet unheard. Both gun and shot were of cast metal, and the mount was a wooden carriage on low trucks. The training, or horizontal angle of the gun, was effected by rope tackles, and the amount of elevation of its muzzle depended upon the position of a “quoin,” or wooden wedge, thrust beneath the breech. The recoil was limited by rope “breeching,” passing through the cascabel,—a knob behind the breech,—and secured to ring-bolts in the ship’s side. The gun was harnessed, as a horse is, in the shafts.

BATTLE OF TRAFALGAR.

Aiming was largely a perfunctory process, since the gun had no sights and the shot had excessive “windage,” its calibre being from one fifth to one third inch less than the bore, making its outward passage a series of rebounds and its final direction a matter of chance. “Windage,” however, was essential to facilitate muzzle-loading and to provide for the expanded diameter of red-hot shot. It is true that in 1801 a proposition to use sights was made to Lord Nelson. He, however, rejected it with the words:—

“I hope we shall be able, as usual, to get so close to our enemies that our shot cannot miss the object.”

His blind courage in this cost his countrymen dearly when, in 1812–14, their shot flew wild, while their ships were hulled and their gallant tars fell before the then sighted guns of the United States.

To ignite the charge the slow-match was still used, as is shown by the sharp words of a sailor of that time. Hailed in the darkness by a British ship and ordered to send a boat, his quick answer was:—

“This is the United States frigate Constitution, Edward Preble, commodore, commanding, and I’ll be d—d if I send a boat!”

Then to his men, silent and eager by the shrouded battle-lanterns:—

“Blow your matches, boys!”

A full crew for a 32-pounder consisted of 14 men. An old rule as to this was one man to every 500-lbs. weight of the gun, which would give the Oregon 1100 men to handle the four 13-inch rifles of her main battery, or more than twice her whole crew. Steam and mechanism have wrought a magic change in this.

The slow-match remained in use until well into the nineteenth century, although, until 1842, the flint lock was generally employed in the British navy, having replaced the priming horn and match in 1780. In 1807 there was discovered a composition which could be ignited by friction or concussion, and in 1839 the French had adopted the percussion lock, which exploded the cap and retracted, uncovering the vent before the backward rush of the gas could strike it. Later, a similar composition was used with “friction-primers,” or tubes filled with mealed powder and capped with composition, the tube forming a train leading to the charge, and the composition being fired by the friction of a rough wire drawn briskly through it. Percussion and friction have been in turn largely displaced by the electric primer, which consists essentially of a fine wire, or “bridge,” passing through a highly inflammable mixture. The bridge offers a resistance to the electric current, is heated thereby, ignites the composition, and fires the gun.

The older type of the cast-iron smooth-bore gun for solid shot reached its ultimate development in the 68-pounder, which endured until the advent of armor. In 1819 the system of firing shells loaded with gunpowder from smooth-bore guns was suggested by General Paixhans, of France. In 1824, it was introduced into the French navy, and about 1840 into that of the United States. At Sinope, in 1853, the terrible effect of shell fire upon wooden ships startled the world, when a Russian fleet destroyed absolutely 11 Turkish vessels, with their force of 4000 men. The Paixhans gun was modified and its form improved by Admiral Dahlgren, U.S.N., and in the late 50’s the armament—designed by him—of United States vessels was superior to that of any other in the world. The 9, 11, and 15-inch Dahlgrens formed the bulk of our guns afloat during the Civil War, the remainder being almost wholly rifles of the Parrott type.

The Growth of Ordnance

32pdr 6m Smooth-bore, Muzzle-loader Weight 3600 lbs. Muzzle Energy, 642 Foot-tons U S (Dahlgren) 440pdr 15m Smooth-bore, Muzzle-loader Weight 42000 lbs. Muzzle Energy, 7273 Foot-tons Italian (Armstrong) 2000pdr 17in Rifle, Breech-loader Weight 101.5 tons, Muzzle Energy, 51930 Foot-tons U S Naval 1100pdr 13in Rifle, Breech-loader Weight 60 tons, Muzzle Energy, 33627 Foot-tons

PLATE V.

The resistance which spherical projectiles met from the air, their deviation in flight, owing to the frequent lack of coincidence of the centres of gravity and form, their excessive “windage,” and their light weight relatively to calibre, led to the adoption of the rifled gun and the cylindrical projectile. The principle of the former—making the shot act as a screw-bolt and the bore as a screw-thread—is very old, there being at Woolwich a barrel of this type bearing date of 1547. The objects aimed at in rifling are to give a pointed cylindrical shot rotation on its axis that it may keep steady during flight, and secondly, to obtain increased weight in the projectile from its elongated form. As to the latter consideration, it may be noted that the old 32-pounder smooth-bore was of 6-inch calibre, while the United States 6-inch rifle of to-day throws a shot of 100 lbs. weight.

France, during the Crimean War, brought out the first heavy rifled gun. In 1860–61, Armstrong rifles were introduced in the British navy. The labors of Krupp met such success that at Paris, in 1867, he exhibited a rifle weighing 50 tons with a projectile of 1080 pounds. The Parrott rifle was brought out about 1856 in the United States, and was so developed that in 1862 it was the most powerful gun, for its weight and size, in existence. The adoption of rifling was the first great step on the road which engineering had laid toward the growth in power of modern ordnance.

Having thus secured a projectile of great weight and moderate calibre which would bore through the air a true path to the distant mark, there remained to seek but four chief elements in the magnificent advance made within a generation by the naval artillery of our day. These factors were: 1st. Increased strength in the material of the gun. 2d. A method of construction which would not only permit enormous pressures in the powder-chamber, but would make possible the continuous acceleration of the projectile during its passage through the bore. 3d. An explosive which would satisfy the objects of the method of construction; and, 4th. A system of loading which would enable guns of great length to be charged with ease. The mounting of ordnance of any weight, its control, and its rapid and facile handling were but minor matters of engineering.

In a paper such as this, of limited length and addressed to laymen, it is possible to give but a glance at the progress in the various elements of gun-construction which have been noted. Of material, little need be said. The rifle of Crimean days was a cast-iron piece; Parrott ordnance was of cast and wrought iron; and the first Armstrong gun was built of wrought iron and steel. Cast and compound materials, however, have vanished with the past. Steel—hardened and toughened to the last degree by every refinement of manufacture—forms the “reeking tube” for the “iron shard” of the century’s close.

The method of construction is the “built-up” process, shown by the partial section on Plate V., the barrel being reinforced by tubes which are shrunk on—like the tire of a wagon-wheel—so as to produce initial compression. The explosion in the powder chamber strains and expands temporarily the barrel, and the application of the shrinkage principle enables a portion of the strength of the tubes to be employed in preliminary internal pressure. The barrel thus supported can be strained by the charge, not only to its own limit of safety, but to an additional amount equal to this initial compression. The all-steel, built-up gun has a possible rival in wire-wound ordnance, a system which replaces the tubes, to a greater or less extent, by layers of wire, wound while in tension around the barrel.

Powder is the soul of the gun; it transforms the huge inert mass into a flaming engine of death. The great development of explosives began but a generation since. The researches of Robins and Rumford in the last century, and of Hutton in the dawn of this, formed the world’s knowledge of the gun’s internal ballistics until the year 1870. To the genius of Noble and Abel is due the stimulus to growth since then. The powders have kept pace with gun-construction in its advance. The increased strength of the chamber has been met by heavier and slow-burning charges—cocoa, brown prismatic, and the like—which have given not only greater initial velocity, but a continuous acceleration through bores whose maximum length has exceeded 47 feet. Indeed, to the production of this lingering combustion is due the great linear dimension and power of modern guns. Initial pressure had its limit; advance lay only in the subsequent acceleration given by late ignition of a portion of the charge.

Gunpowder, however, after a reign of more than five hundred years, has been dethroned. The “villainous saltpetre” of the monk, with its allies, charcoal and sulphur, yields now to nitro compounds, which produce not only far greater energy, but are as well smokeless. The sea-fights of our war with Spain saw the last contending fleets to be wrapped in a cloud, lingering and baffling, of their own making. Cordite, one of these compounds in use abroad, is prepared in long “cords” from di-nitro-cellulose and nitro-glycerine. The new smokeless “powder” of the United States navy is made from nitro-cellulose dissolved in ether alcohol. France was the first in employing explosives such as these, which, in their offensive and tactical advantages, form one of the signal triumphs of the century’s last years.

The long gun of modern days is of necessity breech-loading. The development of other elements gave, as a resultant, great length; and this, in turn, required a system of charging which would permit protection for the men while loading, and would obviate the intolerable inconvenience of ramming home powder and shot in a long muzzle-loader—an operation which was, in fact, impossible beyond a certain limit of length. The advocates of the older construction, especially in England, urged long and earnestly its simplicity and the superior strength of a solid breech; but the logic of events was against them, and the breech-loader won a complete triumph. It is worthy of note that it, like rifling and the principle of building up, was but a revival. From the warship Mary Rose, sunk in 1545 in action off Spithead, there were recovered in 1836 a number of guns, some of which are of wrought iron, built-up and breech-loading. There are in use two methods of closing the breech when the gun is loaded from the rear. In French, English, and American ordnance an axial screw-plug is inserted; in the Krupp system a cylindro-prismatic breech-block slides in a horizontal opening cut across the bore. The former, or interrupted screw mechanism, was first set forth in the United States’ patent of 1849 to Chambers.

In projectiles the tendency of the modern era has been towards simplification. Bar-shot, chain-shot, and grape have disappeared, while canister and solid shot are becoming obsolete. There remain shrapnel as the “man-killer” of this age, and explosive shell, differentiated into armor-piercing and that for attack on unarmored structures. Lieutenant Shrapnel, in 1796, invented the projectile which bears his name. In its modern form, it consists of a steel case containing lead or iron balls and a light bursting charge of powder, ignited by a time-fuse carried in the head. This projectile is most formidable against bodies of men, boats, and the embrasures of forts, since, when it is ruptured, the balls are dispersed, covering a wide area.

The use of explosive shell in high-angle discharge dates back to the fifteenth century. From Paixhans’ works, “La Nouvelle Arme,” published in 1821, came the stimulus to its development and to its deadly service, in our time, in horizontal fire. The “common shell” for the United States 13-inch rifle is made of forged steel, weighs 1100 pounds, and carries within it a bursting charge of 50 pounds of powder, ignited by a percussion fuse set in its base. It will penetrate 6 or 7 inches of armor and then explode within the ship. The United States “armor-piercing shell” is manufactured from crucible steel, alloyed with chromium; it is tempered to extreme hardness at the point, which carries a cap of soft metal. The function of the latter would appear to be that of a support to the shoulder of the projectile, or as a lubricant thereto, since, without the cap, the shell is broken or deformed in the attack on armor of surface hardened steel. To resist the crushing strain in its passage through massive plate, the walls of this shell must be so thick that no charge of gunpowder will burst it. Hence, as a rule, the shell is fired unloaded, although recently there have been adopted to some extent bursting charges of some high explosive, such as gun-cotton, joveite, or picric acid.

In closing this brief review of the progress of ordnance, but passing mention can be made of matters minor, but in themselves of much importance. Gun carriages, or mounts, are now intricate mechanisms, practically the whole service of large ordnance being performed by electric and hydraulic machinery. The rapid fire principle has been extended to pieces of 6-inch calibre, and bids fair to pass beyond that limit. Its success in increasing largely the number of shots within a given time lies in special breech-blocks, aiming devices, and prepared cartridges. Machine guns of rifle-calibre, partly or wholly automatic, have been so developed as to be capable of firing 1200 rounds per minute. The discharge of high explosives in large quantity was effected with success by the United States steamer Vesuvius off Santiago. The torpedo-gun afloat, however, would appear to be still in a tentative condition.

A brief lapse into technical terms may be permitted in summarizing the gun’s growth in power. The term “muzzle energy” is used to describe the work which the projectile is capable of performing when it leaves the bore. It is expressed in foot-tons, i.e., the number of tons which the energy stored in the shot would lift to a height of one foot. The figures as to this for the 32-pounder of the century’s beginning, for the United States 13-inch rifle and for the 111-ton English gun, are, respectively, 642, 33,627, and 54,690 foot-tons. Again, the round shot from the 32-pounder lost from the resistance of the air, in a range of 1200 yards, 76 per cent of its energy; while this loss, with the United States 13-inch, in a range of 1000 yards, is but 11 per cent. Finally, if the cast-iron shot of the 32-pounder were fired against armor-plate, it would lose, in breaking itself up, two thirds of its remaining energy, leaving at 1200 yards but 51 foot-tons for effective work; while with the modern armor-piercing shell the entire energy left at the end of the range is expended upon the armor-plate.

It will be seen then that the immeasurable superiority of modern guns is owing both to their great increase in energy and to their wiser disposition of that which has been attained. The gun has maintained fully during the century its primacy among naval weapons. It is true that, in theory and on paper, its supremacy has at times been questioned; but as to its two rivals, the ram would seem to be rather the weapon of accident than action, and the torpedo has yet to score in battle against ships in motion, while the precision, rapidity, and power of the gun grow more deadly with every passing year.