Part 2

At the outbreak of the War of Independence, American artillery was an accumulation of guns, mortars, and howitzers of every sort and some 13 different calibers. Since the source of importation was cut off, the undeveloped casting industries of the Colonies undertook cannon founding, and by 1775 the foundries of Philadelphia were casting both bronze and iron guns. A number of bronze French guns were brought in later. The mobile guns of Washington's army ranged from 3- to 24-pounders, with 5-1/2- and 8-inch howitzers. They were usually bronze. A few iron siege guns of 18-, 24-, and 32-pounder caliber were on hand. The guns used round shot, grape, and case shot; mortars and howitzers fired bombs and carcasses. "Side boxes" on each side of the carriage held 21 rounds of ammunition and were taken off when the piece was brought into battery. Horses or oxen, with hired civilian drivers, formed the transport. On the battlefield the cannoneers manned drag ropes to maneuver the guns into position.

Sometimes, as at Guilford Courthouse, the ever-present forest diminished the effectiveness of artillery, but nevertheless the arm was often put to good use. The skill of the American gunners at Yorktown contributed no little toward the speedy advance of the siege trenches. Yorktown battlefield today has many examples of Revolutionary War cannon, including some fine ship guns recovered from British vessels sunk during the siege of 1781.

In Europe, meanwhile, Frederick the Great of Prussia learned how to use cannon in the campaigns of the Seven Years' War (1756-63). The education was forced upon him as gradual destruction of his veteran infantry made him lean more heavily on artillery. To keep pace with cavalry movements, he developed a horse artillery that moved rapidly along with the cavalry. His field artillery had only light guns and howitzers. With these improvements he could establish small batteries at important points in the battle line, open the fight, and protect the deployment of his columns with light guns. What was equally significant, he could change the position of his batteries according to the course of the action.

Frederick sent his 3- and 6-pounders ahead of the infantry. Gunners dismounted 500 paces from the enemy and advanced on foot, pushing their guns ahead of them, firing incessantly and using grape shot during the latter part of their advance. Up to closest range they went, until the infantry caught up, passed through the artillery line, and stormed the enemy position. Remember that battle was pretty formal, with musketeers standing or kneeling in ranks, often in full view of the enemy!

Perhaps the outstanding artilleryman of the 1700's was the Frenchman Jean Baptiste de Gribeauval, who brought home a number of ideas after serving with the capable Austrian artillery against Frederick. The great reform in French artillery began in 1765, although Gribeauval was not able to effect all of his changes until he became Inspector General of Artillery in 1776. He all but revolutionized French artillery, and vitally influenced other countries.

Gribeauval's artillery came into action at a gallop and smothered enemy batteries with an overpowering volume of fire. He created a distinct matériel for field, siege, garrison, and coast artillery. He reduced the length and weight of the pieces, as well as the charge and the windage (the difference between the diameters of shot and bore); he built carriages so that many parts were interchangeable, and made soldiers out of the drivers. For siege and garrison he adopted 12- and 16-pounder guns, an 8-inch howitzer and 8-, 10-, and 12-inch mortars. For coastal fortifications he used the traversing platform which, having rear wheels that ran upon a track, greatly simplified the training of a gun right or left upon a moving target (fig. 10). Gribeauval-type matériel was used with the greatest effect in the new tactics which Napoleon introduced.

Napoleon owed much of his success to masterly use of artillery. Under this captain there was no preparation for infantry advance by slowly disintegrating the hostile force with artillery fire. Rather, his artillerymen went up fast into closest range, and by actually annihilating a portion of the enemy line with case-shot fire, covered the assault so effectively that columns of cavalry and infantry reached the gap without striking a blow!

After Napoleon, the history of artillery largely becomes a record of its technical effectiveness, together with improvements or changes in putting well-established principles into action.

UNITED STATES GUNS OF THE EARLY 1800's

The United States adopted the Gribeauval system of artillery carriages in 1809, just about the time it was becoming obsolete (the French abandoned it in 1829). The change to this system, however, did not include adoption of the French gun calibers. Early in the century cast iron replaced bronze as a gunmetal, a move pushed by the growing United States iron industry; and not until 1836 was bronze readopted in this country for mobile cannon. In the meantime, U. S. Artillery in the War of 1812 did most of its fighting with iron 6-pounders. Fort McHenry, which is administered by the National Park Service as a national monument and historic shrine, has a few ordnance pieces of the period.

During the Mexican War, the artillery carried 6- and 12-pounder guns, the 12-pounder mountain howitzer (a light piece of 220 pounds which had been added for the Indian campaigns), a 12-pounder field howitzer (788 pounds), the 24- and 32-pounder howitzers, and 8- and 10-inch mortars. For siege, garrison, and seacoast there were pieces of 16 types, ranging from a 1-pounder to the giant 10-inch Columbiad of 7-1/2 tons. In 1857, the United States adopted the 12-pounder Napoleon gun-howitzer, a bronze smoothbore designed by Napoleon III, and this muzzle-loader remained standard in the army until the 1880's.

The naval ironclads, which were usually armed with powerful 11- or 15-inch smoothbores, were a revolutionary development in mid-century. They were low-hulled, armored, steam vessels, with one or two revolving turrets. Although most cannonballs bounced from the armor, lack of speed made the "cheese box on a raft" vulnerable, and poor visibility through the turret slots was a serious handicap in battle.

While 20-, 30-, and 60-pounder Parrott rifles soon made an appearance in the Federal Navy, along with Dahlgren's 12- and 20-pounder rifled howitzers, the Navy relied mainly upon its "shell-guns": the 9-, 10-, 11-, and 15-inch iron smoothbores. There were also 8-inch guns of 55 and 63 "hundredweight" (the contemporary naval nomenclature), and four sizes of 32-pounders ranging from 27 to 57 hundredweight. The heavier guns took more powder and got slightly longer ranges. Many naval guns of the period are characterized by a hole in the cascabel, through which the breeching tackle was run to check recoil. The Navy also had a 13-inch mortar, mounted aboard ship on a revolving circular platform. Landing parties were equipped with 12- or 24-pounder howitzers either on boat carriages (a flat bed something like a mortar bed) or on three-wheeled "field" carriages.

RIFLING

Rifling, by imparting a spin to the projectile as it travels along the spiral grooves in the bore, permits the use of a long projectile and ensures its flight point first, with great increase in accuracy. The longer projectile, being both heavier and more streamlined than round shot of the same caliber, also has a greater striking energy.

Though Benjamin Robins was probably the first to give sound reasons, the fact that rifling was helpful had been known a long time. A 1542 barrel at Woolwich has six fine spiral grooves in the bore. Straight grooving had been applied to small arms as early as 1480, and during the 1500's straight grooving of musket bores was extensively practiced. Probably, rifling evolved from the early observation of the feathers on an arrow--and from the practical results of cutting channels in a musket, originally to reduce fouling, then because it was found to improve accuracy of the shot. Rifled small-arm efficiency was clearly shown at Kings Mountain during the American Revolution.

In spite of earlier experiments, however, it was not until the 1840's that attempts to rifle cannon could be called successful. In 1846, Major Cavelli in Italy and Baron Wahrendorff in Germany independently produced rifled iron breech-loading cannon. The Cavelli gun had two spiral grooves into which fitted the 1/4-inch projecting lugs of a long projectile (fig. 12a). Other attempts at what might be called rifling were Lancaster's elliptical-bore gun and the later development of a spiraling hexagonal-bore by Joseph Whitworth (fig. 12b). The English Whitworth was used by Confederate artillery. It was an efficient piece, though subject to easy fouling that made it dangerous.

Then, in 1855, England's Lord Armstrong designed a rifled breechloader that included so many improvements as to be revolutionary. This gun was rifled with a large number of grooves and fired lead-coated projectiles. Much of its success, however, was due to the built-up construction: hoops were shrunk on over the tube, with the fibers of the metal running in the directions most suitable for strength. Several United States muzzle-loading rifles of built-up construction were produced about the same time as the Armstrong and included the Chambers (1849), the Treadwell (1855), and the well-known Parrott of 1861 (figs. 12e and 13).

The German Krupp rifle had an especially successful breech mechanism. It was not a built-up gun, but depended on superior crucible steel for its strength. Cast steel had been tried as a gunmetal during the sixteenth and seventeenth centuries, but metallurgical knowledge of the early days could not produce sound castings. Steel was also used in other mid-nineteenth century rifles, such as the United States Wiard gun and the British Blakely, with its swollen, cast-iron breech hoop. Fort Pulaski National Monument, near Savannah, Ga., has a fine example of a 24-pounder Blakely used by the Confederates in the 1862 defense of the fort.

The United States began intensive experimentation with rifled cannon late in the 1850's, and a few rifled pieces were made by the South Boston Iron Foundry and also by the West Point Foundry at Cold Spring, N. Y. The first appearance of rifles in any quantity, however, was near the outset of the 1861 hostilities, when the Federal artillery was equipped with 300 wrought-iron 3-inch guns (fig. 14e). This "12-pounder," which fired a 10-pound projectile, was made by wrapping sheets of boiler iron around a mandrel. The cylinder thus formed was heated and passed through the rolls for welding, then cooled, bored, turned, and rifled. It remained in service until about 1900. Another rifle giving good results was the cast-iron 4-1/2-inch siege gun. This piece was cast solid, then bored, turned, and rifled. Uncertainty of strength, a characteristic of cast iron, caused its later abandonment.

The United States rifle that was most effective in siege work was the invention of Robert P. Parrott. His cast-iron guns (fig. 13), many of which are seen today in the battlefield parks, are easily recognized by the heavy wrought-iron jacket reinforcing the breech. The jacket was made by coiling a bar over the mandrel in a spiral, then hammering the coils into a welded cylinder. The cylinder was bored and shrunk on the gun. Parrotts were founded in 10-, 20-, 30-, 60-, 100-, 200-, and 300-pounder calibers, one foundry making 1,700 of them during the Civil War.

All nations, of course, had large stocks of smoothbores on hand, and various methods were devised to make rifles out of them. The U. S. Ordnance Board, for instance, believed the conversion simply involved cutting grooves in the bore, right at the forts or arsenals where the guns were. In 1860, half of the United States artillery was scheduled for conversion. As a result, a number of old smoothbores were rebored to fire rifle projectiles of the various patents which preceded the modern copper rotating band (fig. 12c, d, f). Under the James patent (fig. 12c) the weight of metal thrown by a cannon was virtually doubled; converted 24-, 32- and 42-pounders fired elongated shot classed respectively as 48-, 64-, and 84-pound projectiles. After the siege of Fort Pulaski, Federal Gen. Q. A. Gillmore praised the 84-pounder and declared "no better piece for breaching can be desired," but experience soon proved the heavier projectiles caused increased pressures which converted guns could not withstand for long.

The early United States rifles had a muzzle velocity about the same as the smoothbore, but whereas the round shot of the smoothbore lost speed so rapidly that at 2,000 yards its striking velocity was only about a third of the muzzle velocity, the more streamlined rifle projectile lost speed very slowly. But the rifle had to be served more carefully than the smoothbore. Rifling grooves were cleaned with a moist sponge, and sometimes oiled with another sponge. Lead-coated projectiles like the James, which tended to foul the grooves of the piece, made it necessary to scrape the rifle grooves after every half dozen shots, although guns using brass-banded projectiles did not require the extra operation. With all muzzle-loading rifles, the projectile had to be pushed close home to the powder charge; otherwise, the blast would not fully expand its rotating band, the projectile would not take the grooves, and would "tumble" after leaving the gun, to the utter loss of range and accuracy. Incidentally, gunners had to "run out" (push the gun into firing position) both smoothbore and rifled muzzle-loaders carefully. A sudden stop might make the shot start forward as much as 2 feet.

When the U. S. Ordnance Board recommended the conversion to rifles, it also recommended that all large caliber iron guns be manufactured on the method perfected by Capt. T. J. Rodman, which involved casting the gun around a water-cooled core. The inner walls of the gun thus solidified first, were compressed by the contraction of the outer metal as it cooled down more slowly, and had much greater strength to resist explosion of the charge. The Rodman smoothbore, founded in 8-, 10-, 15-, and 20-inch calibers, was the best cast-iron ordnance of its time (fig. 14f). The 20-inch gun, produced in 1864, fired a 1,080-pound shot. The 15-incher was retained in service through the rest of the century, and these monsters are still to be seen at Fort McHenry National Monument and Historic Shrine or on the ramparts of Fort Jefferson, in the national monument of that name, in the Dry Tortugas Islands. In later years, a number of 10-inch Rodmans were converted into 8-inch rifles by enlarging the bore and inserting a grooved steel tube.

THE WAR BETWEEN THE STATES

At the opening of this civil conflict most of the matériel for both armies was of the same type--smoothbore. The various guns included weapons in the great masonry fortifications built on the long United States coast line since the 1820's--weapons such as the Columbiad, a heavy, long-chambered American muzzle-loader of iron, developed from its bronze forerunner of 1810. The Columbiad (fig. 14d) was made in 8-, 10-, and 12-inch calibers and could throw shot and shell well over 5,000 yards. "New" Columbiads came out of the foundries at the start of the 1860's, minus the powder chamber and with smoother lines. Behind the parapets or in fort gunrooms were 32- and 42-pounder iron seacoast guns (fig. 10); 24-pounder bronze howitzers lay in the bastions to flank the long reaches of the fort walls. There were 8-inch seacoast howitzers for heavier work. The largest caliber piece was the ponderous 13-inch seacoast mortar.

Siege and garrison cannon included 24-pounder and 8-inch bronze howitzers (fig. 14b), a 10-inch bronze mortar (fig. 14a), 12-, 18-, and 24-pounder iron guns (fig. 14c) and later the 4-1/2-inch cast-iron rifle. With the exception of the new 3-inch wrought-iron rifle (fig. 14e), field artillery cannon were bronze: 6- and 12-pounder guns, the 12-pounder Napoleon gun-howitzer, 12-pounder mountain howitzer, 12-, 24-, and 32-pounder field howitzers, and the little Coehorn mortar (fig. 39). A machine gun invented by Dr. Richard J. Gatling became part of the artillery equipment during the war, but was not much used. Reminiscent of the ancient ribaudequin, a repeating cannon of several barrels, the Gatling gun could fire about 350 shots a minute from its 10 barrels, which were rotated and fired by turning a crank. In Europe it became more popular than the French mitrailleuse.

The smaller smoothbores were _effective_ with case shot up to about 600 or 700 yards, and _maximum_ range of field pieces went from something less than the 1,566-yard solid-shot trajectory of the Napoleon to about 2,600 yards (a mile and a half) for a 6-inch howitzer. At Chancellorsville, one of Stonewall Jackson's guns fired a shot which bounded down the center of a roadway and came to rest a mile away. The performance verified the drill-book tables. Maximum ranges of the larger pieces, however, ran all the way from the average 1,600 yards of an 18-pounder garrison gun to the well over 3-mile range of a 12-inch Columbiad firing a 180-pound shell at high elevation. A 13-inch seacoast mortar would lob a 200-pound shell 4,325 yards, or almost 2-1/2 miles. The shell from an 8-inch howitzer carried 2,280 yards, but at such extreme ranges the guns could hardly be called accurate.

On the battlefield, Napoleon's artillery tactics were no longer practical. The infantry, armed with its own comparatively long-range firearm, was usually able to keep artillery beyond case-shot range, and cannon had to stand off at such long distances that their primitive ammunition was relatively ineffective. The result was that when attacking infantry moved in, the defending infantry and artillery were still fresh and unshaken, ready to pour a devastating point-blank fire into the assaulting lines. Thus, in spite of an intensive 2-hour bombardment by 138 Confederate guns at the crisis of Gettysburg, as the gray-clad troops advanced across the field to close range, double canister and concentrated infantry volleys cut them down in masses.

Field artillery smoothbores, under conditions prevailing during the war, generally gave better results than the smaller-caliber rifle. A 3-inch rifle, for instance, had twice the range of a Napoleon; but in the broken, heavily wooded country where so much of the fighting took place, the superior range of the rifle could not be used to full advantage. Neither was its relatively small and sometimes defective projectile as damaging to personnel as case or grape from a larger caliber smoothbore. At the first battle of Manassas (July 1861) more than half the 49 Federal cannon were rifled; but by 1863, even though many more rifles were in service, the majority of the pieces in the field were still the old reliable 6- and 12-pounder smoothbores.

It was in siege operations that the rifles forced a new era. As the smoke cleared after the historic bombardment of Fort Sumter in 1861, military men were already speculating on the possibilities of the newfangled weapon. A Confederate 12-pounder Blakely had pecked away at Sumter with amazing accuracy. But the first really effective use of the rifles in siege operations was at Fort Pulaski (1862). Using 10 rifles and 26 smoothbores, General Gillmore breached the 7-1/2-foot-thick brick walls in little more than 24 hours. Yet his batteries were a mile away from the target! The heavier rifles were converted smoothbores, firing 48-, 64-, and 84-pound James projectiles that drove into the fort wall from 19 to 26 inches at each fair shot. The smoothbore Columbiads could penetrate only 13 inches, while from this range the ponderous mortars could hardly hit the fort. A year later, Gillmore used 100-, 200-, and 300-pounder Parrott rifles against Fort Sumter. The big guns, firing from positions some 2 miles away and far beyond the range of the fort guns, reduced Sumter to a smoking mass of rubble.

The range and accuracy of the rifles startled the world. A 30-pounder (4.2-inch) Parrott had an amazing carry of 8,453 yards with 80-pound hollow shot; the notorious "Swamp Angel" that fired on Charleston in 1863 was a 200-pounder Parrott mounted in the marsh 7,000 yards from the city. But strangely enough, neither rifles nor smoothbores could destroy earthworks. As was proven several times during the war, the defenders of a well-built earthwork were able to repair the trifling damage done by enemy fire almost as soon as there was a lull in the shooting. Learning this lesson, the determined Confederate defenders of Fort Sumter in 1863-64 refused to surrender, but under the most difficult conditions converted their ruined masonry into an earthwork almost impervious to further bombardment.

THE CHANGE INTO MODERN ARTILLERY

With Rodman's gun, the muzzle-loading smoothbore was at the apex of its development. Through the years great progress had been made in mobility, organization, and tactics. Now a new era was beginning, wherein artillery surpassed even the decisive role it had under Gustavus Adolphus and Napoleon. In spite of new infantry weapons that forced cannon ever farther to the rear, artillery was to become so deadly that its fire caused over 75 percent of the battlefield casualties in World War I.

Many of the vital changes took place during the latter years of the 1800's, as rifles replaced the smoothbores. Steel came into universal use for gun founding; breech and recoil mechanisms were perfected; smokeless powder and high explosives came into the picture. Hardly less important was the invention of more efficient sighting and laying mechanisms.

The changes did not come overnight. In Britain, after breechloaders had been in use almost a decade, the ordnance men went back to muzzle-loading rifles; faulty breech mechanisms caused too many accidents. Not until one of H.M.S. _Thunderer's_ guns was inadvertently double-loaded did the English return to an improved breechloader.

The steel breechloaders of the Prussians, firing two rounds a minute with a percussion shell that broke into about 30 fragments, did much to defeat the French (1870-71). At Sedan, the greatest artillery battle fought prior to 1914, the Prussians used 600 guns to smother the French army. So thoroughly did these guns do their work that the Germans annihilated the enemy at the cost of only 5 percent casualties. It was a demonstration of using great masses of guns, bringing them quickly into action to destroy the hostile artillery, then thoroughly "softening up" enemy resistance in preparation for the infantry attack. While the technical progress of the Prussian artillery was considerable, it was offset in large degree by the counter-development of field entrenchment.