Many of the types of cannons mentioned in this booklet can be found in various parts of the National Park System across the country. Some parks with particularly impressive collections are:

Castillo de San Marcos National Monument, 17th and 18th century field and garrison artillery.

Chickamauga and Chattanooga National Military Park, Civil War battlefield and siege artillery.

Colonial National Historical Park, 17th and 18th-century field and siege guns, 18th-century naval guns.

Fort McHenry National Monument and Historic Shrine, early 19th-century field guns and Civil War fort guns.

Fort Pulaski National Monument, Civil War military artillery.

Gettysburg National Military Park, Civil War artillery.

Petersburg National Military Park, Civil War field and siege cannons.

Shiloh National Military Park, Civil War era field guns.

Vicksburg National Military Park, Civil War battlefield and siege artillery.

The National Park System is committed to preserving the natural beauty, scientific significance, and historical heritage of the United States for the benefit and enjoyment of its citizens.

THE ARTILLERY AGE
The Ancient War Machines
Gunpowder Arrives in Europe
The Bombards
16th Century Cannon
The 17th Century and Gustavus Adolphus
The 1700s
Guns in the United States During the Early 1800s
Grooving
The Civil War
The Shift to Modern Artillery

Gunpowder
Foundations
Modern Use of Gunpowder

Cannon features
The Early Smoothbore Cannon
Later Period Smoothbores
Garrison and Ship Artillery
Siege Cannon
Field Cannon
Artillery pieces
Mortar mixer
Petards

PROJECTILES
Solid Shot
Explosive Shells
Fuses
Spread Projectiles
Incendiary and Chemical Weapons
Fixed Ammo
Rockets

tools

Gunnery Practice

GLOSSARY

SELECTED BIBLIOGRAPHY

When people see an old cannon, they usually know one thing for sure: the shot came out of the front. That’s why these pages are written; people are interested in the amazing weapon that greatly extended the warrior's reach. Their curiosity is completely justified because the gunner and his "craft" played an important role in our history.

To compare a Roman catapult with a modern trench mortar seems ridiculous. Yet the only fundamental difference is the type of energy that propels the projectile forward.

In the early days of history, war engines functioned as artillery (which can be simply described as a way to launch heavy projectiles that couldn’t be thrown by hand), and with these basic weapons, the fundamental principles of artillery were established. Historical texts mention the use of clever machines on the walls of Jerusalem eight centuries B.C.—machines that were likely forerunners of the catapult and ballista, using twisted ropes made from hair, hide, or sinew for power. The ballista had horizontal arms like a bow. The arms were set in rope; a cord, attached to the arms like a bowstring, launched arrows, darts, and stones. Similar to a modern field gun, the ballista fired low and directly at the enemy.

The catapult was the cannon or mortar of its time and could launch a hundred-pound stone 600 yards in a high arc to hit the enemy behind their wall or break down their defenses. "In the middle of the ropes, a wooden arm rises like a chariot pole," wrote the historian Marcellinus. "At the top of the arm hangs a sling. When battle starts, a round stone is placed in the sling. Four soldiers on each side of the machine pull the arm down until it's almost level with the ground. When the arm is released, it springs up and throws the stone from its sling." In earlier times, this weapon was called a "scorpion," because like this feared insect, it kept its "sting" raised.

Figure 1—Ballista. Caesar shielded his landing in Britain with fire from catapults and ballistae.

The trebuchet was another war machine widely used during the Middle Ages. Basically, it was a seesaw. Weights on the short arm swung the long throwing arm.

Figure 2—CATAPULT.

Figure 3—TREBUCHET. A large trebuchet could launch a 300-pound stone a distance of 300 yards.

These weapons were incredibly effective, as the Romans discovered from Archimedes during the siege of Syracuse (214-212 B.C.). As Plutarch recounts, "Archimedes quickly started using his machines against the Romans and their ships, firing stones that were so massive and created such a tremendous noise and speed that nothing could withstand them. Eventually, the (p. 003) Romans became so frightened that whenever they saw a rope or a beam sticking out over the walls of Syracuse, they shouted that Archimedes was directing some weapon at them and turned to run."

Long after gunpowder was introduced, the old weapons of war were still being used. They often operated alongside cannons.

Chinese "thunder of the earth" (an effect created by filling a large shell with a mixture of gunpowder) made faint echoes among Western philosophers as early as A.D. 300. Although missionaries first taught the Chinese the scientific methods of casting cannon in the 1600s, primitive cannons appear to have existed in China as early as the twelfth century and possibly before.

In Europe, a ninth-century Latin manuscript includes a formula for gunpowder. However, the first use of firearms in Western Europe might have been by the Moors at Saragossa in A.D. 1118. Later on, the Spaniards used this new weapon against their Moorish enemies during the siege of Cordova (1280) and the capture of Gibraltar (1306).

It follows that the Arabian madfaa, which likely came from an eastern predecessor, was the first cannon introduced to western civilization. This unusual weapon seems to have been a small, mortar-like device made of wood. Like an egg resting in an egg cup, the projectile sat on the muzzle end until the charge was fired, sending it flying toward the enemy. Another early cannon, with a narrow neck and flared mouth, shot an iron dart. The dart's shaft was wrapped in leather to fit snugly in the neck of the cannon. A red-hot bar inserted through a vent ignited the charge. The range was about 700 yards. The bottle shape of the weapon may have inspired the name pot de fer (iron jug) given to early cannons, and over time, the narrow neck probably widened until the bottle evolved into a straight tube.

During the Hundred Years' War (1339-1453), cannons became widely used. These early cannons were quite small, made of iron or cast bronze, and fired lead or iron balls. They were placed directly on the ground, with the muzzles raised by piling up earth underneath. Although they were heavy and not very effective in battle, they were very useful during sieges.

By the mid-1400s, the small cannons that shot one- or two-pound pellets had developed into massive siege guns. Dulle Griete, the giant cannon of Ghent, had a 25-inch caliber and fired a 700-pound granite ball. It was built in 1382. Edinburgh Castle's famous Mons Meg launched a 19.5-inch iron ball about 1,400 yards (a mile is 1,760 yards), or a stone ball twice that distance.

The (p. 004) Scottish kings used Meg between 1455 and 1513 to take down the castles of rebellious nobles. A baron's castle could be easily destroyed by the prince who owned, or could borrow, a few heavy cannons. The tall walls of the old strongholds gradually gave way to the earthwork-protected Renaissance fortifications, which are exemplified in the United States by Castillo de San Marcos, in Castillo de San Marcos National Monument, St. Augustine, Fla.

Some of the most powerful cannons were the Turks', who used extremely large cast-bronze guns during the siege of Constantinople in 1453. One of these giants weighed 19 tons and fired a 600-pound stone seven times a day. It required about 60 oxen and 200 men to transport this piece, and the challenge of moving such heavy artillery significantly limited its effectiveness. The largest caliber gun on record is the Great Mortar of Moscow. Constructed around 1525, it had a bore of 36 inches, was 18 feet long, and shot a stone projectile weighing a ton. However, by this time, these large guns were outdated, although some of the old Turkish artillery lasted through the centuries to defend Constantinople against a British fleet in 1807. During that defense, a massive stone struck the mainmast of the British flagship, and another broke through the English lines, killing or wounding 60 men.

Figure 4—EARLY SMALL BOMBARD (1330). It was made of forged iron bars, secured with hoops.

The heavy bombards were secured to flat ground, set on sturdy mounts made of thick wood, and anchored with stakes driven deep into the soil. A gunner aimed to place his bombard 100 yards from the wall he intended to break down. It would be reasonable to think that the gunner, being so close to a castle wall defended by skilled Genoese crossbowmen, was in a dangerous spot. He was; however, earthworks or a large wooden shield arranged like a seesaw over his gun provided him with decent protection. Lowering the front end of the shield created a barrier behind which he could load his muzzle loader (see fig. 49).

In those days, and for many decades afterward, neither gun crews nor transport were permanent. They had to be hired as needed. Master gunners were usually civilian "artists," not professional soldiers, and many of them built cannons to rent to customers. Artillerists obtained the right to captured metals like tools and town bells, and this loot would be melted down into guns or sold for cash. The making of guns (p. 005) and gunpowder, loading bombs, and even operating cannons were closely guarded trade secrets. Gunnery was an exclusive group, and the gunner himself was a guild member. The public saw him as somewhat of a sorcerer in league with the devil, and a captured artilleryman was likely to be tortured and mutilated. At one point, the Pope decided to excommunicate all gunners. Moreover, since these specialists kept to themselves and did not drink or loot, their behavior was clear evidence to the good soldiers of the past that artillerists were hardly human.

After 1470, the art of casting advanced significantly in Europe. Lighter cannons started to take the place of bombards. Throughout the 1500s, the focus was primarily on reducing the massive weights of guns and projectiles, as well as discovering better methods for transporting artillery. As a result, by 1556, Emperor Ferdinand was able to march against the Turks with 57 heavy and 127 light pieces of ordnance.

At the start of the 1400s, cast-iron balls became a thing. The improved efficiency of the iron ball, along with better gunpowder, encouraged the development of smaller and stronger cannons. Before 1500, siege guns were the main type of artillery. Now, forged-iron cannons for the field, garrison, and navy—and later, cast-iron pieces—were being increasingly developed, along with cast-bronze guns, some of which featured beautiful Renaissance designs. The addition of trunnions to the guns made it easier to aim and transport them, and the heavy beds of earlier times were replaced with basic artillery carriages with trails and wheels. The French invented the limber and around 1550 made a significant leap forward by standardizing their artillery calibers.

Meanwhile, the first cannon arrived in the New World with Columbus. As the Pinta's lookout spotted land on the early morning of October 12, 1492, the sound of a lombard firing alerted the flagship Santa María across the moonlit waters. Within the next century, not only galleons but also numerous fortifications along the Spanish Main were equipped with guns, booming at the pirates who challenged Spain's claim to American treasure. Sometimes the adventurers captured cannons as spoils, like Drake did in 1586 when he made off with 14 bronze guns from St. Augustine's small wooden fort of San Juan de Pinos. Drake's plunder likely included ordnance from a 1578 inventory, which gives a good idea of the armament for a significant frontier fortification: three reinforced cannons, three demiculverins, two saker guns (one broken), a demisaker, and a falcon, all properly mounted on raised platforms in the fort to cover every approach. Most of them were elaborately decorated pieces made between 1546 and 1555. The reinforced cannons, for example, which seem to have been cast from the same mold, each depicted a savage holding a club in one hand and a coin in the other. On a demiculverin, a bronze (p. 006) mermaid held a turtle, while the other guns were adorned with coats of arms, shields, the founder's name, and more.

In the English colonies during the sixteenth and seventeenth centuries, lighter artillery pieces appeared to be more common; there are no records of any "cannon." (Back then, "cannon" referred to a specific type.) Culverins are mentioned occasionally and demiculverins quite frequently, but the most common were the falconets, falcons, minions, and sakers. At Fort Raleigh, Jamestown, Plymouth, and several other settlements, the breech-loading half-pounder perrier or "Patterero" mounted on a swivel was also used. (See frontispiece.)

It was in the sixteenth century that the science of ballistics began. In 1537, Niccolo Tartaglia published the first scientific study on gunnery. Construction methods were experimented with and sometimes discarded, only to be revived successfully in later centuries. For example, breech-loading guns had already been invented. They were ineffective because the breech couldn't be sealed to prevent the escape of gunpowder gases, and the rough, chambered breechblocks, which were wedged against the barrel, often cracked when fired. Spiral rifling also isn't a new concept; it was seen in some guns during the 1500s.

Mobile artillery appeared on the battlefield with the cart guns of John Zizka during the Hussite Wars of Bohemia (1419-24). The French improved field artillery by using light guns pulled by top-quality horses instead of the usual oxen, and their maneuverable guns proved to be an effective way to break up large groups of pikemen in the early 1500s Italian campaigns. However, the Germans under Maximilian I took the lead in armament away from the French with guns that could fire up to 1,500 yards and soldiers who were known as the best gunners in Europe.

Then around 1525, the well-known Spanish Square, made up of heavily armed pikemen and musketeers, started to take control of the battlefield. In response to musket fire, field artillery started to decline. Even though artillery had gained some mobility, the carriages were still bulky. To move a heavy English cannon, even on good ground, it took 23 horses; a culverin required nine animals. Ammunition—mainly cast-iron round shots, bombs (iron shells filled with gunpowder), canisters (containers filled with small projectiles), and grape shots (clusters of iron balls)—was transported in a very basic way, using wheelbarrows, carts, or carried on a person's back. The speed of field artillery was determined by the gunner's pace: the gunner walked beside his gun! Additionally, some of these specialists were getting older. During Elizabeth's reign, several gunners at the Tower of London were over 90 years old.

Lacking mobility, guns were captured and reclaimed with every change in the battle; so for artillerymen in general, this was a tough time. The actual commander of the artillery was usually a soldier; however, transport and drivers were still hired, and the drivers naturally had a civilian's perspective on battle. Even the gunners, those civilian experts who didn't owe any special duty to the prince, were mostly worried about the safety of their weapons—and themselves, since artillerists who stayed with their guns were likely to be shot by an enemy musketeer. Fusilier companies were set up as artillery guards, but their role was just as much about keeping the gun crew from fleeing as it was about protecting them from the enemy.

Figure 5—15th-Century Breechloader.

So, over 400 years, cannons evolved from small vases, mainly useful for making noise, into the largest caliber weapons ever created, and then from bombards into smaller, more powerful cannons. A cannon from 1600 could fire a shot nearly as far as one from 1850; it wasn't in firepower, but in mobility, organization, and tactics that artillery was lacking. Because of this lack, the pike and musket dominated the battlefield.

Under the Swedish warrior Gustavus Adolphus, artillery started to find its true place on the battlefield. Gustavus recognized the need for mobility, so he removed anything heavier than a 12-pounder from his field artillery. His famous "leatheren" gun was so light that it could be pulled and operated by two men. This gun was a wrought-copper tube screwed into a chambered brass breech, reinforced with four iron hoops. The copper tube was covered with layers of mastic, tightly wrapped with cords, and then coated with a leveling layer of plaster. A covering of leather, boiled and varnished, finished off the gun. Naturally, the piece could only handle a small charge, but it was very mobile.

Gustavus ditched the leather gun for a cast-iron 4-pounder and a 9-pounder demiculverin made by his talented young artillery chief, Lennart Torstensson. The demiculverin was considered the "field piece" par excellence, while the 4-pounder was so lightweight (about 500 pounds) that two horses could easily pull it in the field.

These artillery pieces could be operated by three men. By combining the powder charge and projectile into a single cartridge, the old method of ladling the powder into the gun was eliminated, which increased the speed of fire. Previously, the standard was one cannon for every thousand infantrymen, but Gustavus raised the ratio to six cannons and added a pair of light pieces to each regiment as "battalion guns." He also understood the importance of fire concentration and often grouped guns into strong batteries. His strategy aimed to destroy enemy infantry formations with artillery fire while neutralizing the slow, immobile enemy guns with a fast cavalry charge. The strategies proved effective; Gustavus defeated the Spanish Squares at Breitenfeld in 1631.

Figure 6—LIGHT ARTILLERY OF GUSTAVUS ADOLPHUS (1630).

Following Sweden's example, all countries updated their artillery. Leadership shifted back and forth between the Germans, the French, and the Austrians. The secrets of artillery started to fade away, and gunners became professional soldiers. Bronze became the preferred material for gunmaking.

Louis XIV of France seems to have been the first to establish a permanent organization for the artillery. He created a regiment of artillerymen in 1671 and set up training schools. The "standing army" principle that started around 1500 was now widely adopted, with small armies of highly trained professional soldiers forming a distinct class separate from the rest of the population. As artillery became an organized branch of the military, expensive personnel and equipment needed to be maintained even in peacetime. However, some necessary changes were slow to arrive. French artillery officers didn’t receive military rank until 1732, and in some countries, drivers were still civilians in the 1790s. In 1716, Britain organized artillery into two permanent companies, which formed the Royal Regiment of Artillery. Yet, as late as the American Revolution, there was debate about whether a general officer whose service was in the Royal Artillery was entitled to command troops of all types. There was no such question in England in the previous century: the artillery general was someone who "always had a part of the charge, and when the chief general was absent, he was to command the entire army."

Figure 7—FRENCH GARRISON GUN (1650-1700). The gun is positioned on a sloped wooden platform at the opening. Take note of the solid base where the sides of the carriage rest and the integrated skid beneath the center of the rear axle.

During the early 1700s, cannons were used to protect an army's deployment and to prepare for troop advancement by firing on enemy formations. There was a common belief that heavy batteries, properly safeguarded by field works or permanent fortifications, represented the natural role for artillery. While artillery was rarely decisive in battle, it did become more important due to improved organization, training, and discipline. In the previous century, the number of calibers had been reduced and somewhat standardized; now, there were significant scientific and technical advancements. The English scientist Benjamin Robins combined theory with practice; his New Principles of Gunnery (1742) greatly contributed to a more scientific approach to ballistics. One outcome of Robins' research was the introduction, in 1779, of carronades, the short, lightweight cannons that were so effective on a ship's gun deck. Carronades typically had calibers ranging from 6 to 68 pounds.

In North America, cannons were usually too heavy for fighting against Native Americans. However, starting in 1565, when the French in Florida fired the first shot at the rival Spanish fleet led by Menéndez, cannons were used on both land and sea during conflicts between colonies and against pirates. Because of the vast distances in early America, moving heavy artillery was mostly done by water. Without ships, the cannons were stuck in the forest. This was the case when Moore from Carolina besieged St. Augustine in 1702. When his ships were destroyed, Moore had to abandon his cannons to the Spanish.

One of the first times organized American field artillery showed up on the battlefield was in the Northeast, where France's Louisburg fell to British and (p. 010) Colonial forces in 1745. The Ancient and Honorable Artillery Company of Boston, which started in 1637, served with the British Royal Artillery. At that time, English field artillery had "brigades" of four to six cannons, and each piece was provided with 100 rounds of solid shot and 30 rounds of grape shot. John Müller's Treatise on Artillery, which was the standard English reference, was republished in Philadelphia in 1779, and British artillery naturally served as a model for the arm in America.

Figure 8—AMERICAN 6-POUNDER FIELDPIECE (c. 1775).

At the start of the War of Independence, American artillery was a mix of guns, mortars, and howitzers of all kinds, with about 13 different calibers. With imports cut off, the developing casting industries in the Colonies began making cannons, and by 1775, the foundries in Philadelphia were producing both bronze and iron guns. Later, some bronze French guns were brought in. Washington's army had mobile guns that ranged from 3- to 24-pounders, along with 5-1/2- and 8-inch howitzers, mostly made of bronze. There were also a few iron siege guns with calibers of 18-, 24-, and 32-pounders. The guns used round shot, grape shot, and canister shot; mortars and howitzers fired bombs and carcasses. "Side boxes" on each side of the carriage held 21 rounds of ammunition and were removed when the gun was readied for firing. Horses or oxen, driven by hired civilians, were used for transport. On the battlefield, the cannoneers held drag ropes to move the guns into position.

Sometimes, like at Guilford Courthouse, the constant presence of the forest reduced the effectiveness of artillery, but still, it was often used to great advantage. The expertise of the American gunners at Yorktown played a significant role in the rapid progress of the siege trenches. The Yorktown battlefield today features many examples of Revolutionary War cannons, including some impressive ship guns recovered from British vessels that sank during the siege of 1781.

In Europe, Frederick the Great of Prussia learned how to use cannons during the Seven Years' War (1756-63). He was forced to adapt as the gradual loss of his veteran infantry made him rely more on artillery. To keep up with cavalry movements, he created a horse artillery unit that moved quickly alongside the cavalry. His field artillery consisted only of light guns and howitzers. With these upgrades, he could set up small batteries at key points in the battle line, start the fight, and protect the deployment of his columns with light guns. Equally important, he could reposition his batteries based on the flow of the battle.

Frederick sent his 3- and 6-pounder cannons ahead of the infantry. The gunners dismounted 500 yards from the enemy and moved forward on foot, pushing their cannons along, firing constantly and using grape shot during the last part of their advance. They got as close as possible until the infantry caught up, moved through the line of artillery, and charged the enemy position. Keep in mind that battles back then were quite formal, with musketeers standing or kneeling in ranks, often fully exposed to the enemy!

Figure 9—FRENCH 12-POUNDER FIELD GUN (c. 1780).

Perhaps the top artillery expert of the 1700s was the Frenchman Jean Baptiste de Gribeauval, who brought back several ideas after serving with the skilled Austrian artillery against Frederick. The major reform in French artillery started in 1765, although Gribeauval wasn't able to implement all of his changes until he became Inspector General of Artillery in 1776. He nearly revolutionized French artillery and had a significant impact on other countries.

Gribeauval's artillery moved in quickly and overwhelmed enemy batteries with intense firepower. He developed specific equipment for field, siege, garrison, and coastal artillery. He shortened and lightened the artillery pieces, as well as the charge and the windage (the gap between the diameter of the shot and the bore); he designed carriages with many interchangeable parts and trained the drivers to be soldiers. For siege and garrison operations, he used 12- and 16-pounder guns, an 8-inch howitzer, and 8-, 10-, and 12-inch mortars. For coastal defenses, he implemented a traversing platform that had rear wheels on a track, making it much easier to aim a gun left or right at a moving target (fig. 10). Gribeauval-type equipment was highly effective with the new tactics Napoleon introduced. (p. 012)

Napoleon credited a lot of his success to his excellent use of artillery. Under his command, there wasn't a slow process of breaking down the enemy troops with artillery fire before the infantry moved in. Instead, his artillery crews would quickly move in closer and, by completely destroying part of the enemy line with explosive rounds, provided such effective cover for the attacking troops that waves of cavalry and infantry could reach the breach without having to fight!

After Napoleon, the history of artillery mostly becomes a record of its technical effectiveness, along with enhancements or changes in applying well-established principles in practice.

The United States adopted the Gribeauval system of artillery carriages in 1809, right around the time it was becoming outdated (the French stopped using it in 1829). However, the switch to this system didn’t include adopting the French gun calibers. Early in the century, cast iron replaced bronze as the primary material for guns, a change driven by the expanding iron industry in the United States; it wasn’t until 1836 that bronze was readopted in this country for mobile cannons. In the meantime, U.S. Artillery in the War of 1812 did most of its fighting with iron 6-pounders. Fort McHenry, which is managed by the National Park Service as a national monument and historic site, has a few artillery pieces from that period.

Figure 10—U.S. 32-Pounder on Barbette Carriage (1860).

During the Mexican War, the artillery used 6- and 12-pound guns, the 12-pound mountain howitzer (a lightweight piece weighing 220 pounds that was added for the Indian campaigns), a 12-pound field howitzer (weighing 788 pounds), the 24- and 32-pound howitzers, and 8- and 10-inch mortars. For sieges, garrisons, and coastal defense, there were 16 types of pieces, ranging from a 1-pounder to the massive 10-inch Columbiad weighing 7.5 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 1880s.

The naval ironclads, typically equipped with strong 11- or 15-inch smoothbore cannons, represented a groundbreaking advancement in the mid-1800s. They were low-profile, armored steam ships, featuring one or two rotating turrets. While most cannonballs deflected off the armor, their lack of speed left the "cheese box on a raft" exposed, and the limited visibility through the turret slots was a significant disadvantage in combat.

Figure 11—U.S. Navy 9-Inch Shell Gun on Marsilly Carriage (1866).

While 20-, 30-, and 60-pounder Parrott rifles quickly appeared in the Federal Navy, along with Dahlgren's 12- and 20-pounder rifled howitzers, the Navy mainly relied on its "shell-guns": the 9-, 10-, 11-, and 15-inch iron smoothbores. There were also 8-inch guns weighing 55 and 63 "hundredweight" (the contemporary naval terminology), and four sizes of 32-pounders ranging from 27 to 57 hundredweight. The heavier guns required more powder and achieved slightly longer ranges. Many naval guns from this period have a hole in the cascabel, through which the breeching tackle was run to control recoil. The Navy also had a 13-inch mortar mounted on a revolving circular platform aboard ship. Landing parties were outfitted with 12- or 24-pounder howitzers on either boat carriages (a flat bed similar to a mortar bed) or three-wheeled "field" carriages.

Rifling gives the projectile a spin as it moves through the spiral grooves in the barrel, allowing for a longer projectile and ensuring it flies point-first, which significantly boosts accuracy. The longer projectile, being heavier and more aerodynamic than round shot of the same caliber, also delivers more impact energy.

Though (p. 014) Benjamin Robins was likely the first to provide solid explanations, the idea that rifling was beneficial had been recognized for a long time. A barrel from 1542 at Woolwich has six smooth spiral grooves in the bore. Straight grooving was used on small arms as early as 1480, and throughout the 1500s, straight grooving of musket bores was widely practiced. It’s likely that rifling developed from early observations of the feathers on an arrow—and from the practical effects of cutting channels in a musket, first to reduce fouling, and then because it was found to enhance the accuracy of the shot. The effectiveness of rifled small arms was clearly demonstrated at Kings Mountain during the American Revolution.

In spite of earlier experiments, it wasn't until the 1840s that attempts to create rifled cannons could be considered successful. In 1846, Major Cavelli in Italy and Baron Wahrendorff in Germany independently developed rifled iron breech-loading cannons. The Cavelli gun had two spiral grooves that accommodated the 1/4-inch projecting lugs of a long projectile (fig. 12a). Other attempts at what could be described as rifling included Lancaster's elliptical-bore gun and the later design of a spiraling hexagonal-bore by Joseph Whitworth (fig. 12b). The English Whitworth was used by Confederate artillery. It was an effective piece, though it could easily foul, making it dangerous.

Then, in 1855, Lord Armstrong from England created a rifled breechloader that featured so many improvements it was revolutionary. This gun was rifled with many grooves and fired lead-coated bullets. However, its success was mainly due to its built-up construction: hoops were shrunk over the tube, with the metal fibers oriented in the most effective directions for strength. Several muzzle-loading rifles made in the United States with built-up construction were developed around the same time as the Armstrong, including the Chambers (1849), the Treadwell (1855), and the famous Parrott from 1861 (figs. 12e and 13).

The German Krupp rifle featured an exceptionally effective breech mechanism. It wasn't an assembled gun; instead, it relied on high-quality crucible steel for its durability. Cast steel had been attempted as a gunmetal in the sixteenth and seventeenth centuries, but the metallurgical knowledge of that time couldn't produce reliable castings. Steel was also used in other mid-nineteenth century rifles, like the United States Wiard gun and the British Blakely, which had its enlarged cast-iron breech hoop. Fort Pulaski National Monument, near Savannah, GA, has a great example of a 24-pounder Blakely that was used by the Confederates during the 1862 defense of the fort.

Figure 12—DEVELOPMENT OF RIFLE PROJECTILES (1840-1900). a—Cavelli type, b—Whitworth, c—James, d—Hotchkiss, e—Parrott, f—Copper rotating band type. (Not to scale.)

The United States started extensive testing with rifled cannons in the late 1850s, and a few rifled pieces were produced by the South Boston Iron Foundry and the West Point Foundry in Cold Spring, NY. However, the first significant use of rifles occurred at the beginning of the 1861 hostilities, when the Federal artillery was armed with 300 wrought-iron 3-inch guns (fig. 14e). This "12-pounder," which shot a 10-pound projectile, was made by wrapping sheets of boiler iron around a mandrel. The resulting cylinder was heated and rolled for welding, then cooled, bored, turned, and rifled. It remained in service until around 1900. Another effective rifle was the cast-iron 4-1/2-inch siege gun. This piece was cast solid, then bored, turned, and rifled. Concerns about its strength, typical of cast iron, led to its eventual abandonment.

Figure 13—PARROTT 10-POUNDER RIFLE (1864).

The most effective rifle used in sieges in the United States was created by Robert P. Parrott. His cast-iron guns (fig. 13), many of which can still be seen today in battlefield parks, are easily identifiable by the heavy wrought-iron jacket that reinforces the breech. The jacket was made by coiling a bar in a spiral over a mandrel, then hammering the coils into a welded cylinder. This cylinder was bored and shrunk onto the gun. Parrotts were produced in 10-, 20-, 30-, 60-, 100-, 200-, and 300-pound calibers, with one foundry manufacturing 1,700 of them during the Civil War.

All nations, of course, had large stocks of smoothbore guns on hand, and various methods were created to convert them into rifles. The U.S. Ordnance Board, for example, thought the conversion was simply a matter of cutting grooves in the barrel right at the forts or arsenals where the guns were located. In 1860, half of the United States artillery was set for conversion. As a result, several old smoothbores were rebored to fire rifle projectiles based on different patents that came before the modern copper rotating band (fig. 12c, d, f). Under the James patent (fig. 12c), the weight of metal fired by a cannon was almost doubled; converted 24-, 32-, and 42-pounders shot elongated projectiles categorized as 48-, 64-, and 84-pound projectiles, respectively. After the siege of Fort Pulaski, Federal Gen. Q. A. Gillmore praised the 84-pounder and stated, "no better piece for breaching can be desired," but experience soon showed that the heavier projectiles created increased pressures that the converted guns could not handle for long.

The early rifles in the United States had a muzzle velocity similar to that of smoothbore firearms, but while the round shot from a smoothbore lost speed quickly—dropping to only a third of its muzzle velocity at 2,000 yards—the more aerodynamic rifle projectile retained its speed for much longer. However, rifles required more careful handling than smoothbores. The rifling grooves were cleaned with a damp sponge and occasionally oiled with another sponge. Lead-coated projectiles like the James often fouled the grooves, necessitating scraping after every six shots, while rifles using brass-banded projectiles did not need this extra step. With all muzzle-loading rifles, the projectile had to be pushed all the way down to the powder charge; otherwise, the blast wouldn’t fully expand its rotating band, causing the projectile to misalign with the grooves and "tumble" after leaving the gun, significantly reducing range and accuracy. Additionally, gunners had to carefully "run out" (move the gun into firing position) both smoothbore and rifled muzzle-loaders. A sudden stop could cause the shot to shift forward by as much as 2 feet.

When the U.S. Ordnance Board suggested switching to rifles, it also advised that all large caliber iron guns be made using the method perfected by Capt. T. J. Rodman, which involved casting the gun around a water-cooled core. This technique meant that the inner walls of the gun solidified first, and were compressed by the contraction of the outer metal as it cooled more slowly, giving it much greater strength to withstand an explosion from the charge. The Rodman smoothbore, available in 8-, 10-, 15-, and 20-inch calibers, was the best cast-iron artillery of its time (fig. 14f). The 20-inch gun, made in 1864, fired a 1,080-pound projectile. The 15-inch gun remained in service for the rest of the century, and these massive guns can still be seen at Fort McHenry National Monument and Historic Shrine or on the ramparts of Fort Jefferson, in the national monument of the same name, in the Dry Tortugas Islands. Later on, several 10-inch Rodmans were modified into 8-inch rifles by enlarging the bore and adding a grooved steel tube.

At the beginning of this civil war, most of the military equipment for both sides was similar—smoothbore. The various guns included weapons from the massive fortifications built along the United States coastline since the 1820s—such as the Columbiad, a heavy, long-chambered American muzzle-loader made of iron, developed from its bronze predecessor from 1810. The Columbiad (fig. 14d) was available in 8-, 10-, and 12-inch calibers and could launch shot and shell over 5,000 yards. New Columbiads were produced in the foundries at the start of the 1860s, lacking a powder chamber and featuring smoother designs. Behind the walls or in fort gunrooms were 32- and 42-pounder iron seacoast guns (fig. 10); 24-pounder bronze howitzers were positioned in the bastions to cover the long stretches of the fort walls. For heavier tasks, there were 8-inch seacoast howitzers. The largest caliber piece was the heavy 13-inch seacoast mortar.

Figure 14—U.S. Artillery Types (1861-1865). a—Siege mortar, b—8-inch siege howitzer, c—24-pounder siege gun, d—8-inch Columbiad, e—3-inch wrought-iron rifle, f—10-inch Rodman.

Siege and garrison cannons 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(p. 018) exception of the new 3-inch wrought-iron rifle (fig. 14e), field artillery cannons were bronze: 6- and 12-pounder guns, the 12-pounder Napoleon gun-howitzer, (p. 019) 12-pounder mountain howitzer, 12-, 24-, and 32-pounder field howitzers, and the small Coehorn mortar (fig. 39). A machine gun invented by Dr. Richard J. Gatling became part of the artillery equipment during the war, but it wasn't used much. Similar to the ancient ribaudequin, a repeating cannon with several barrels, the Gatling gun could fire about 350 shots a minute from its 10 barrels, which 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 around 600 or 700 yards, and the maximum range of field pieces varied from 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 that bounced down the center of a roadway and came to rest a mile away. The performance confirmed the drill-book tables. However, maximum ranges of the larger pieces ranged from the average 1,600 yards of an 18-pounder garrison gun to well over a 3-mile range for a 12-inch Columbiad firing a 180-pound shell at high elevation. A 13-inch seacoast mortar could launch a 200-pound shell 4,325 yards, or almost 2-1/2 miles. The shell from an 8-inch howitzer traveled 2,280 yards, but at such extreme distances, the guns could hardly be considered accurate.

On the battlefield, Napoleon's artillery strategies became impractical. The infantry, equipped with its own relatively long-range firearms, could usually keep the artillery out of effective range. This forced the cannons to stand back so far that their basic ammunition was not very effective. As a result, when attacking infantry moved in, the defending infantry and artillery remained fresh and steady, ready to unleash a devastating close-range fire on the attacking troops. Therefore, despite a heavy 2-hour bombardment from 138 Confederate guns at the height of Gettysburg, as the gray-coated soldiers advanced across the field, double canister shots and focused infantry volleys mowed them down in large numbers.

Field artillery smoothbores, under the conditions of the war, usually performed better than the smaller-caliber rifles. A 3-inch rifle, for example, had double the range of a Napoleon; however, in the rough, heavily wooded areas where much of the fighting occurred, the increased range of the rifle couldn't be fully utilized. Its relatively smaller and sometimes flawed projectile also wasn't as damaging to personnel as case or grape shot from a larger caliber smoothbore. At the first battle of Manassas (July 1861), more than half of the 49 Federal cannons were rifled; yet by 1863, despite many more rifles being in service, the majority of the cannons in the field were still the trusty 6- and 12-pounder smoothbores.

It was in siege operations that rifles marked the beginning of a new era. As the smoke lifted after the historic bombardment of Fort Sumter in 1861, military personnel (p. 020) were already imagining the potential of this new type of weapon. A Confederate 12-pounder Blakely had attacked Sumter with incredible precision. However, the first truly effective use of rifles in siege scenarios occurred at Fort Pulaski in 1862. With 10 rifles and 26 smoothbores, General Gillmore breached the 7-1/2-foot-thick brick walls in just over 24 hours. Remarkably, his batteries were a mile away from the target! The heavier rifles, converted from smoothbores, fired 48-, 64-, and 84-pound James projectiles that penetrated the fort wall by 19 to 26 inches with each successful shot. The smoothbore Columbiads could only penetrate 13 inches, and from that distance, the heavy mortars could barely hit the fort. A year later, Gillmore employed 100-, 200-, and 300-pounder Parrott rifles against Fort Sumter. These large guns, firing from positions about 2 miles away—well beyond the range of the fort's guns—turned Sumter into a smoking pile of rubble.

The range and accuracy of the rifles astonished the world. A 30-pounder (4.2-inch) Parrott had an impressive range of 8,453 yards with an 80-pound hollow shot; the infamous "Swamp Angel" that fired on Charleston in 1863 was a 200-pounder Parrott set up in the marsh 7,000 yards from the city. But oddly enough, neither rifles nor smoothbores could take out earthworks. As was shown several times during the war, the defenders of a well-built earthwork could quickly repair the minimal damage caused by enemy fire almost as soon as there was a break in the shooting. Learning this lesson, the determined Confederate defenders of Fort Sumter in 1863-64 refused to surrender and, under extremely challenging conditions, transformed their damaged masonry into an earthwork that was nearly immune to further bombardment.

With Rodman's gun, the muzzle-loading smoothbore represented the peak of its evolution. Over the years, significant advancements had been made in mobility, organization, and tactics. A new era was now starting, where artillery would go beyond even the crucial role it played under Gustavus Adolphus and Napoleon. Despite new infantry weapons pushing cannons further back, artillery was set to become so lethal that its fire resulted in over 75 percent of the battlefield casualties in World War I.

Many of the important changes happened during the late 1800s, as rifles took the place of smoothbores. Steel became widely used in gun manufacturing; breech and recoil mechanisms were improved; smokeless powder and high explosives were introduced. Almost equally significant was the invention of better sighting and laying mechanisms.

The changes didn’t happen right away. In Britain, after breechloaders had been around for nearly a decade, the military switched back to muzzle-loading rifles because faulty breech mechanisms led to too many accidents. It wasn't until one of H.M.S. Thunderer's guns was accidentally double-loaded that the English went back to an improved breechloader.

The (p. 021) steel breechloaders used by the Prussians, firing two rounds per minute with a percussion shell that shattered into about 30 pieces, played a significant role in defeating the French (1870-71). At Sedan, the largest artillery battle before 1914, the Prussians deployed 600 guns to overwhelm the French army. These guns were so effective that the Germans wiped out the enemy with only 5 percent casualties. It demonstrated how to use a large number of guns, quickly bringing them into action to destroy enemy artillery, and then thoroughly "softening up" enemy defenses in preparation for the infantry attack. Although the Prussian artillery made significant technical advances, these were largely countered by improvements in field entrenchment.

As the method of forging large amounts of steel improved, most countries began using built-up (reinforcing hoops over a steel tube) or wire-wrapped steel construction for their cannons. With the introduction of the metal cartridge case and smokeless powder, rapid-fire guns started to be used. The new powder, first utilized in the Russo-Turkish War (1877-78), eliminated the thick white smoke that hindered the gunner's aim, thus allowing for the development of mechanisms that could absorb recoil and automatically return the gun to the firing position. Now, gunners didn’t need to re-sight the piece after each shot, and the rate of fire increased. Shields were added to the gun—protection that would have been pretty useless back when gunners had to stay clear of a back-moving carriage.

During the early 1880s, the United States started developing a modern coastal defense system. An 8-inch breech-loading rifle was made in 1883, and the disappearing carriage, which provided more protection for both the gun and the crew, was adopted in 1886. Only a few of these weapons were set up by 1898; however, the overwhelming naval superiority of the United States helped bring the War with Spain to a quick end.

Figure 15—Ranges.

During this war, U.S. forces were equipped with several British 2.95-inch mountain rifles, which, by the way, were still in use as late as World War II in the pack artillery of the Philippine Scouts. In the following years, outdated weapons like the 3-inch wrought-iron rifle, the 4.2-inch Parrott siege gun, converted Rodmans, and the 15-inch Rodman smoothbore were gradually replaced by newer steel guns. There were various small-caliber rapid-fire guns, including a Hotchkiss 1.65-inch mountain rifle, along with Hotchkiss and Gatling machine guns. The main artillery pieces in the field were 3.2- and 3.6-inch guns, as well as a 3.6-inch mortar. Siege artillery included a 5-inch gun, 7-inch howitzers, and mortars. In seacoast batteries, the primary armament featured 8-, 10-, 12-, 14-, and 16-inch guns and 12-inch mortars; intermediate rapid-fire guns had calibers of 4-, 4.72-, 5-, and 6-inches; and the secondary armament consisted of 6- and 15-pounder rapid-fire guns.

The Japanese demonstrated the effectiveness of the French method of indirect fire (targeting something that the gunner can't see) during the Russo-Japanese War (1904-05). At the same time, the French 75-mm gun from 1897, which could fire up to 6,000 yards, rendered all other field artillery obsolete. Essentially, artillery had taken on a modern form. The following changes came from remarkable advancements in motor transport, signal communications, chemical warfare, tanks, aviation, and mass production.

Black powder was used in all firearms until smokeless and other types of propellants were invented in the late 1800s. "Black" powder (which was sometimes brown) is a mix of about 75 parts saltpeter (potassium nitrate), 15 parts charcoal, and 10 parts sulfur by weight. It explodes because the mixture has the right amount of oxygen for its own combustion. When it burns, it releases smoky gases (mainly nitrogen and carbon dioxide) that take up about 300 times the space of the powder itself.

Early European gunpowder "recipes" called for equal parts of the three ingredients, but over time the amount of saltpeter was increased until Tartaglia noted the proportions as 4-1-1. By the late 1700s, "common war powder" was made in a ratio of 6-1-1, and it wasn't until the next century that the formula was refined to the 75-15-10 composition that became widely used when newer propellants were introduced.

As the name implies, this explosive initially came as powder or dust. The early formula burned slowly and produced low pressures, which was a good thing considering the barrel-stave design of the first cannons. Around 1450, though, powder makers started to "corn" the powder. This meant they shaped it into larger grains, increasing the speed of the shot. It was "corned" into fine grains for small arms and coarser for cannons.

Making gunpowder was pretty straightforward. The three ingredients were crushed and mixed together, then pressed into cakes and cut into "corns" or grains. Rolling the grains in a barrel smoothed out the edges; getting rid of the dust pretty much finished the process. However, it has always been tricky to produce powder that's exactly the same every time and keep it in good condition, which contributed significantly to making gunnery an "art" in the past. Residue left in the gun was particularly annoying, and a disk-like tool (fig. 44) was created to clean the bore. Artillerymen at Castillo de San Marcos complained that the "heavy" powder from Mexico was especially problematic, because after a few shots, the bore became so dirty that cannonballs wouldn't fit anymore. The gunners urgently called for higher-quality powder from Spain itself.

How (p. 024) much gunpowder to use in a gun has been a debated topic for centuries. According to the Spaniard Collado in 1592, the right measure was the amount of metal in the gun. A standard culverin, for example, had enough metal to take as much powder as the ball weighed. So, a 30-pounder culverin would require 30 pounds of powder. However, since a 60-pounder battering cannon had a third less metal in proportion compared to the culverin, the charge also needed to be reduced by a third—to 40 pounds!

Figure 16—GUNPOWDER. Black powder (above) is a physical mixture; today's propellants are chemical compounds.

Other factors had to be considered, like whether the powder was coarse or fine; and a short gun used less powder than a long one. The bore length of a proper culverin, according to Collado, was 30 calibers (30 times the diameter of the bore), so its powder charge matched the weight of the ball. If the gunner found a culverin only 24 calibers long, he should load this piece with only 24/30 of the ball's weight. Collado's pasavolante was quite long at about 40 calibers and fired a 6- or 7-pound lead ball. Since it had plenty of metal "to resist, and the length to burn" the powder, it was loaded with the full weight of the ball in fine powder, or three-fourths as much with cannon powder. The lightest charge was for the pedrero, which shot a stone ball. Its charge was a third of the stone's weight.

In later years, the amount of powder used decreased for all guns. English velocity tables from the 1750s show that a 9-pounder loaded with 2.25 pounds of powder could shoot its ball at a speed of 1,052 feet per second. By nearly tripling the charge, the velocity would increase by about half. However, this increase didn't mean that the shot hit the target 50 percent harder; as the velocity rose, so did air resistance. As Müller put it: "a lot of powder doesn't always lead to a greater effect." So, standard charges went from about two-thirds the weight of the ball down to one-third or even a quarter; by the 1800s, they got even smaller. The United States manual of 1861 stated that for a 24-pounder siege gun, the powder used was between 6 to 8 pounds, depending on the range, while a Columbiad firing 172-pound shot only needed 20 pounds of powder. At Fort Sumter, Gillmore's rifles firing 80-pound shells used 10 pounds of powder. The rotating band on the rifle shell, of course, stopped the gases that had bypassed the loose-fitting cannonball.

Black (p. 025) powder was, and still is, both dangerous and unstable. It's not only sensitive to flames or sparks, but it also absorbs moisture from the air. In other words, it was no easy task to "keep your powder dry." In the mid-1700s, Spaniards at a Florida river outpost stored powder in glass bottles; earlier soldiers, fleeing into the humid forest from Sir Francis Drake, carried powder in peruleras—stoppered, narrow-necked pitchers.

As for magazines, a dry magazine was just as crucial as one that was shell-proof. Charcoal and lime chloride, hung in containers near the ceiling, were used early on as dehydrators. In the eighteenth century, standard practice in England was to build the floor 2 feet off the ground and place stone chips or "dry sea coals" beneath the flooring. Side walls had air holes for ventilation, but these were screened to stop the enemy from sending in a small animal with fire tied to its tail. Powder casks were laid on their sides and periodically rolled to a different position; "otherwise," explains a contemporary expert, "the saltpeter, being the heaviest ingredient, will settle to the bottom of the barrel, and the powder above will lose a lot of its quality."

Figure 17—SPANISH POWDER BUCKET (c. 1750).

In the early days of artillery, loose powder was delivered to the gun in a covered bucket, typically made of leather. The loader would scoop up the right amount with a ladle (fig. 44) and place it into the gun. With his experience, he could add just enough powder to achieve the desired range, similar to how modern artillerymen sometimes use only part of their charge. After Gustavus Adolphus in the 1630s, powder bags became widely used, although English gunners still preferred to ladle their powder. The powder bucket or "passing box" continued to be used and was usually large enough to hold two cartridge bags.

The origin of the word cartridge appears to be "carta," which means paper. However, paper was just one of many materials used, including canvas, linen, parchment, flannel, the "woolen stuff" from the 1860s, and even wood. Before the introduction of the silk cartridge, none of these materials worked perfectly. They didn't burn completely, and after firing several rounds, it was necessary to remove the leftover bag pieces with a wormer (fig. 44), or else they would build up and block the vent or "touch hole" used to fire the weapon. Parchment bags often shriveled and got stuck in the vent, embarrassing many a skilled gunner.

When the powder bag was introduced, the gunner had to poke the bag open so the priming fire from the vent could ignite the charge. This was done easily by inserting the gunner's pick into the vent deep enough to break the bag. After that, loose powder from the gunner's flask was used to prime the vent. The method of vent priming, which didn't see significant improvement until the nineteenth century, was a technique borrowed from the Venetians in the fourteenth century. There were many attempts to improve it, like the powder-filled tin tube from the 1700s that pierced the powder bag. However, in all cases, the slow match was still needed to ignite the fuse.

Figure 18—SPANISH POWDER BUCKET (c. 1750).

Before 1800, the slow match was commonly used to ignite the charge. The match was typically a 3-strand cotton rope, soaked in a saltpeter solution and chemically treated with lead acetate and lye to ensure it burned very slowly—about 4 or 5 inches per hour. It was connected to a linstock (fig. 18), a forked stick long enough to keep the cannoneer safe from the recoil.

Chemistry advancements, like the isolation of mercury fulminate in 1800, led to the invention of the percussion cap and other primers. On many battlefields, you might have picked up a scrap of twisted wire—the loop of a friction primer. The device was a copper tube (fig. 19) filled with powder. The tube went into the cannon's vent and buried its tip in the powder charge. Near the top of this tube was soldered a "spur"—a short (p. 027) tube containing a friction composition (antimony sulfide and potassium chlorate). Inside the composition was the roughened end of a wire "slider." The other end of the slider was twisted into a loop for attaching to the gunner's lanyard. It was like striking a match: a quick pull on the lanyard, and the rough slider ignited the composition. Then the powder in the long tube started to burn and fired the charge in the cannon. Needless to say, it happened faster than we can explain!

Figure 19—Friction Basics.

The percussion primer was even simpler: a "quill tube," filled with fine powder, was fitted into the vent. A fulminate cap was glued to the top of the tube. Pulling the lanyard made the cannon's hammer strike the cap (just like a child's cap gun) and initiate the chain of explosions.

Because the early methods of priming left the vent open when the cannon fired, the small hole tended to get bigger. Many cannons in the 1800s were designed with two vents, side by side. When the first one wore out, it was plugged, and the second vent was used. To prevent this "erosion," the sealing primer was introduced. It was similar to the common friction primer but screwed into the vent to create a seal. Early electric primers, by the way, didn't differ much from the friction primer; the wires ignited a bit of guncotton, which then set off the powder in the primer tube.

Aside from gradual improvements in the formula, there wasn't any significant change in powder making until 1860, when General Thomas J. Rodman from the U.S. Ordnance Department started customizing the powder for different gun calibers. The typical cannon powder burned too quickly. The entire charge was used up before the projectile even started moving, putting extreme stress on the gun. Rodman compressed the powder into disks that matched the gun’s bore. These disks were an inch or two thick and had holes punched through them. This setup meant that a minimal amount of powder surface was exposed at the start of combustion, but as the fire burned through the holes (see fig. 20f), the burning area actually increased, generating a greater volume of gas as the projectile moved forward. Rodman essentially laid the groundwork for the "progressive burning" pellets used in modern powders (see fig. 20).

Figure 20—MODERN GANNON POWDER. A powder grain only acts like an explosive when it's contained. Modern propellants are low explosives (meaning they burn relatively slowly), but projectiles can be loaded with high explosives, such as a—Flake, b—Strip, c—Pellet, d—Single perforation, e—Standard, 7-perforation, f—Burning grain of 7-perforation type. Ideally, the powder grain should burn in a way that increases its surface area continuously, being completely used up by the time the projectile exits the barrel, g—Walsh grain.

For several reasons, General Rodman didn't advance his "perforated cake cartridge" beyond the experimental phase, and his "Mammoth" powder, which was so common in powder magazines in the late 1800s, was a compromise. Just like a block of wood burns more steadily and for a longer time than a quick-burning pile of twigs, the 3/4-inch grains of mammoth powder produced a "smoother" explosion, but one with more "force" and more consistent pressure along the barrel of the gun.

It was in the second year of the Civil War that Alfred Nobel began producing nitroglycerin explosives in Europe. Smokeless powders came into play, the explosive qualities of picric acid were found, and melanite, ballistite, and cordite emerged in the last quarter of the century, so that by 1890, nitrocellulose and nitroglycerin-based powders had largely taken over from black powder as a propellant.

Black powder had several important uses. Its sensitivity to fire, rapid combustion rate, and high explosion temperature made it a great igniter or "booster" to ensure the complete ignition of the propellant. (p. 029) Additionally, it was a key component in modern projectile fuzes, like the ring fuze used by the U.S. Field Artillery, which was the standard for bursts under 25 seconds. This fuze was located in the shell's nose and mainly consisted of a plunger, primer, and rings designed to hold a 9-inch train of compressed black powder. To set the fuze, the fuze operator simply turned a movable ring to the correct time mark. Turning the zero mark toward the channel leading to the shell's bursting charge decreased the burning distance of the train, while turning zero away from the channel did the opposite. When the projectile was fired, the shock caused the plunger to ignite the primer (compare fig. 42e) and ignite the powder train, which then burned for the predetermined time before reaching the shell charge. It was a technical improvement over the Venetian tubular sheet-iron fuze, but the principle was essentially the same.

Figure 21—MODERN POWDER TRAIN FUSE.

Soon after he realized he could throw a rock with his strong right arm, man learned about trajectory—the curved path a projectile takes through the air. A baseball follows a "flat" trajectory whenever the pitcher throws it hard and fast. Kids throwing the ball to each other over a tall fence use a "curved" or "high" trajectory. In artillery, where trajectory is just as crucial, there are three main types of cannon: (1) the flat trajectory gun, which fires projectiles at the target in a relatively level path; (2) the high trajectory mortar, whose shell can clear tall obstacles and drop down onto the target; and (3) the howitzer, a medium-high trajectory piece that balances the mobility of a fieldpiece with the large caliber of a mortar.

The Spaniard, Luis Collado, a mathematician and historian from Lebrija in Andalusia, who in 1592 was a royal engineer for His Catholic Majesty's Army in Lombardy and Piedmont, defined artillery as "a machine of infinite importance." He categorized ordnance into three classes, following the guidelines of the "German masters, who were respected more than any other nation for their development and management of artillery." Culverins and sakers (Fig. 23a) were guns of the first class, meant to hit the enemy from a distance. The second-class weapons were battering cannons (fig. 23b), which aimed to destroy fortifications and take out the enemy's artillery. Third-class guns were designed to fire stone balls to damage and sink ships and protect batteries from attacks; these included the pedrero, mortar, and bombard (fig. 23c, d).

Collado's take on how different guns were invented might seem a bit simplistic, but it’s still quite interesting: "While the primary goal of the inventors of this machine [artillery] was to fire at and harm the enemy from various distances, they realized that they needed to do this in different ways. As a result, they developed various types: they found that people were not satisfied with the espingardas [small Moorish cannon], which led to the creation of the musket, along with the esmeril and the falconet. Although these could shoot further, they also produced the demisaker. To fix a flaw in that, they created the sakers, demiculverins, and culverins. While these were seen as adequate for long shots and hitting enemies from a distance, they weren’t very effective as battering guns because they shot a small projectile. So, they decided to develop a second type of weapon that could fire much heavier projectiles to achieve their goals. However, they later found that this second type was too powerful, heavy, and expensive for use in fortifications or for defending against attacks from ships or galleys, which led to the creation of a third type, made lighter and using less gunpowder to fire stone projectiles. These are commonly known as cañones de pedreros. All types of pieces vary in range, manufacturing processes, and design. Even the way they're loaded is different." (p. 032)

Fig. 22—TRAJECTORIES. The maximum range of 18th-century cannons was about 1 mile.

Guns could: Break through heavy construction with solid shots from a distance or up close; take out fortifications and, using ricochet fire, disable cannons; fire grape, canister, or bombs at grouped soldiers.
Mortars could: Hit targets behind obstacles; use high-angle fire to launch bombs, destroying buildings and personnel.
Howitzers could: Be easier to move in the field compared to mortars; hit targets behind obstacles with high-angle fire; fire larger projectiles than field guns of similar weight.

It was crucial for the artillery expert to understand the various types of guns. As Collado put it, "those who skip this lecture on this arte will, I guarantee, never accomplish anything worthwhile." Cannons exploded in the batteries every day because gunners lacked knowledge about how the gun was made and its intended purpose. This ignorance wasn't limited to gunners, either. The decisions made by the prince who commissioned the ordnance or "the basic opinions of the inexperienced founder" were the main factors in gun manufacturing. "I am compelled," wrote Collado, "to persuade the princes and advise the founders that the production of artillery should always consider the specific role each piece is meant to fulfill." He took this persuasion seriously and went into it in great detail.

Figure 23—16TH CENTURY SPANISH ARTILLERY. Taken from a 1592 manuscript, these drawings show the three main types of artillery used by Spain during the early colonial period in the New World: a—Culverin (Class 1). b—Cannon (Class 2). c—Pedrero (Class 3). d—Mortar (Class 3).

The first type of guns were the long-range pieces, relatively "rich" in metal. In the following table from Collado, the calibers and ranges for most Spanish guns of this type are listed, although as the second column indicates, calibers were only standardized in a general way during this period. For (p. 034) translation where applicable, and to identify those that became the most popular calibers, we have added a final column. Most of the guns were likely around culverin length: 30- to 32-caliber.

16th-century Spanish first-class cannon

Given the range that Collado attributes to the culverin, it's worth discussing the performance of these guns. "Greatest random" is what the old-time gunners referred to as their maximum range, which was indeed random. Beyond point-blank range, the gunner could never be sure of hitting the target. So, when it came to smoothbores, long-range capability wasn't very significant. Culverins, with their thick walls, long barrels, and heavy powder charges, could reach greater distances; however, lesser guns like field "cannon," which had less metal and smaller charges, had a maximum range of around 1,600 yards, but their effective range was barely over 500 yards. Heavier artillery, like the French 33-pounder battering cannon, could achieve a point-blank range of 720 yards; at 200 yards, its shot could penetrate 12 to 24 feet of earthwork, depending on how "poor and hungry" the soil was. At 130 yards, a Dutch 48-pounder cannon could drive a shot 20 feet into a solid earth rampart, while from 100 yards, a 24-pounder siege cannon could bury its shot 12 feet deep.

But generalizations about early cannons are tricky because it's hard to find two "mathematicians" from that time whose lists of artillery match up. Spanish guns from the late 1500s do seem to be larger in caliber compared to similarly named pieces from other countries, as seen when comparing the culverins: the smallest Spanish culebrina was a 20-pounder, while the French great coulevrine from 1551 was a 15-pounder, and the typical English culverin (p. 035) from that century was an 18-pounder. Additionally, in the middle of the 1500s, Henry II significantly simplified French artillery by limiting his cannons to the 33-pounder, 15-pounder great culverin, 7.5-pounder bastard culverin, 2-pounder small culverin, 1-pounder falcon, and 0.5-pounder falconet. Therefore, any list like the one that follows is likely to have its inaccuracies:

Main English guns of the sixteenth century

Like many gun names, the term "culverin" has a deeper meaning. It comes from the Latin colubra (snake). Similarly, the light gun called áspide or aspic, meaning "like an asp," was named after the venomous asp. However, these details shouldn't distract from the fact that both culverins and demiculverins were highly valued for their range and firepower. They were used for precise tasks like demolishing buildings, and a skilled shooter could quickly remove a section of stone wall with these guns.

As the fierce falcon hawk gave its name to the falcon and falconet, the saker was named after the saker hawk; rabinet, meaning "rooster," was therefore a fitting name for the falcon's smaller relative. The 9-pounder saker was effective in any military operation, and the moyana (or the French moyenne, meaning "middle-sized"), being a shorter gun of saker caliber, was a great naval weapon. However, the most powerful of the smaller guns was the pasavolante, recognizable by its great length. It measured between 40 and 44 calibers long! Additionally, it had thicker walls than any other small caliber gun, allowing for an unusually heavy charge—up to as much powder as the ball weighed. A typical pasavolante fired a 6-pound lead ball; another gun of the same caliber that fired an iron ball would be a 4-pounder. The point-blank range of this Spanish gun was a football field's length farther than either the falcon or demisaker.

In today's Spanish, pasavolante means "fast action," a term that reflects the fierce impulsiveness expected from such a small but powerful cannon. Sometimes it was called a drajón, which is the English equivalent of "drake," meaning "dragon"; but perhaps its most popular name in the early days was cerbatana, named after Cerebus, the fierce three-headed dog of mythology. Words can have strange transformations: a cerbatana in modern Spanish is a pea shooter.

16th century Spanish cannon of the second class

The second group of guns were the only ones truly referred to as "cannon" during this early period. They were used for sieges and battering, and in a few ways, they resembled the howitzers that came later. A typical Spanish cannon was about two-thirds the length of a culverin, and the walls of the bore were thinner. Naturally, the powder charge was also lower (half the weight of the ball for a standard cannon, while a culverin required double that amount).

The Germans made their light cannons 18 calibers long. Most Spanish siege and battering guns had the same length because shorter guns wouldn’t burn all the powder effectively, "which," said Collado, "is a serious problem." However, smaller cannons that were 18 calibers long were too short; the muzzle blast tended to damage the embrasure of the parapet. For this reason, Spanish demicannons were as long as 24 calibers, and the quarter-cannons went up to 28. The 12-pounder quarter-cannon, by the way, was "culverined" or reinforced so that it effectively functioned in the field as a demiculverin.

The heavy weight of its projectile gave the double cannon its name. The warden of the Castillo at Milan had some 130-pound cannons made, but these massive pieces were mostly useless except in permanent fortifications. They required a large crew to move them, their carriages broke under the immense weight, and they used up massive amounts of ammunition. The lombard, which likely originated in Lombardy, and the basilisk had the same drawbacks. The legendary basilisk was a serpent whose very gaze was deadly. Its bronze counterpart was incredibly heavy, with walls up to 4 calibers thick and a bore up to 30 calibers long. It was rarely used by Europeans, but the Turkish General Mustafa had a pair of basilisks during the siege of Malta in 1565, firing 150- and 200-pound balls. One of the 200-pound guns broke loose while being moved to a galley bound for home and sank to the bottom of the sea. Its companion was left on the island, where it became a great curiosity.

The third class of artillery included guns that fired stone projectiles, such as the pedrero (or perrier, petrary, cannon petro, etc.), mortars, and the old bombards like Edinburgh Castle's famous Mons Meg. Bars of wrought iron were welded together to create Meg's tube, and iron rings were attached around the outside of the piece. Despite many accidents, this coopering technique continued through the fifteenth century. Mons Meg was made in two sections that screwed together, making it 13 feet long and weighing 5 tons.

Pedreros (fig. 23c) were relatively lightweight. The foundryman used only half the metal he would use for a culverin, since the stone projectile weighed only a third as much as an iron ball of the same size. This meant that the wall thickness could be relatively thin. They were made in calibers up to 50-pounders. There was a chamber for the powder charge, and there was little risk of the gun bursting unless someone acted recklessly and loaded it with an iron ball. The wall thicknesses of this gun are shown in Figure 24, where the inner circle represents the diameter of the chamber, the next arc shows the bore caliber, and the outer lines indicate the respective diameters at the chase, trunnions, and vent.

Figure 24—HOW MUCH METAL WAS IN EARLY GUNS? The charts compare the wall diameters of guns from the sixteenth to seventeenth century. The center circle represents the bore, while the three outer arcs show the relative thickness of the bore wall at (1) the smallest diameter of the chase, (2) at the trunnions, and (3) at the vent. The small arc inside the bore indicates the powder chamber found in the pedrero and mortar.

Mortars (fig. 23d) (p. 038) were great for instilling "fear and terror in the souls of those under siege." Every night, the mortars would bombard the town: "it keeps them in constant distress, worrying that a projectile will strike their home." Mortars were built like pedreros, but much shorter. The easiest way to load them was with saquillos (small bags) of powder. "They need," said Collado, "a larger charge than any other types of artillery."

Just like siblings in the same family can be slim or stocky, there are light, medium, and heavy guns—all sharing the same family name. The difference comes from how the weapon was "reinforced"; specifically, how thick the manufacturer made the bore walls. The English language has clumsy terms for the three levels of "reinforcement": (1) bastard, (2) legitimate, and (3) double-fortified. Guns with thicker walls used more powder. Spanish double-fortified culverins were loaded with the full weight of the ball in powder; four-fifths of that amount was used for the legitimate, and only two-thirds for the bastard culverin. For a short culverin (like 24 calibers long instead of 30), the gunner would use 24/30 of a standard charge.

The standard for reinforcing a gun was its caliber. For example, in a proper culverin with a 6-inch caliber, the thickness of the bore wall at the vent could be one caliber (16/16 of the bore diameter) or 6 inches; at the trunnions, it would be 10/16 or 4-1/8 inches, and at the narrowest part of the chase, 7/16 or 2-5/8 inches. This table compares the three levels of fortification used in Spanish culverins:

As with culverins, so with cannons. This is Collado's table showing the fortification for Spanish cannons:

Since cast iron was weaker than bronze, the walls of cast-iron pieces were even thicker than those of culverins. Spanish iron guns were made with 300 pounds of metal for each pound of the ball, and ranged from 18 to 20 calibers in length. Collado noted that English, Irish, and Swedish iron guns of the time contained slightly more metal than even what the Spaniards recommended.

Figure 25—16TH CENTURY CHAMBERED CANNON. a—"Bell-chambered" demicannon, b—Chambered demicannon.

Another (p. 040) way the designers tried to gain strength without loading the gun with metal was by using a powder chamber. A chambered cannon (fig. 25b) could be reinforced like either the lightweight or the standard cannon, but it featured a cylindrical chamber about two-thirds the diameter of the caliber and four calibers long. Nonetheless, it wasn't always easy to get the powder into the chamber. Collado noted that many skilled artillerymen poured the powder almost in the middle of the gun. When his ladle hit the mouth of the chamber, he mistakenly thought he had reached the bottom of the bore! The cylindrical chamber was slightly improved by a cone-shaped taper, which the Spaniards referred to as encampanado or "bell-chambered." A cañon encampanado (fig. 25a) was an effective long-range gun, strong yet lightweight. However, it was challenging to create a ladle for the long, tapered chamber.

Of all these guns, the reinforced cannon was one of the best. Since it had almost as much metal as a culverin, it didn’t have the issues of the chambered pieces. A 60-pound reinforced cannon fired a manageable 55-pound ball, was easy to move, load, and clean, and performed well in any kind of service. It cooled down quickly. You could use either cannon powder or fine powder (up to two-thirds the weight of the ball) in it. Reinforced cannons were a crucial element in any venture, as King Philip's famous "Twelve Apostles" demonstrated during the Flanders wars.

Strengthening of sixteenth and seventeenth-century firearms

While there wasn’t much real progress in mobility until the time of Gustavus Adolphus, it looks like the Venetians invented the wheeled artillery carriage in the fifteenth century. The key elements of the design were established early on: two large, heavy side pieces attached to an axle and linked by beams. The gun was held between the side pieces, with the back ends forming a "trail" for stabilizing and maneuvering the artillery.

Wheels were probably the biggest challenge. As early as the 1500s, carpenters and wheelwrights were arguing about whether dished wheels were the best option. (p. 041) "They say," reported Collado, "that the [dished] wheel will never twist when the artillery is moving. Others argue that a wheel with spokes angled beyond the barrel can't support the weight of the piece without twisting the spoke, so the wheel doesn't last long. I agree, because it's clear that a perpendicular wheel can handle more weight than the other. The issue of twisting under the pieces while moving can be fixed by making the cart a little wider than usual." However, the supporters of the dished wheel ultimately prevailed.

From the cannons of Queen Elizabeth's era came the 6-, 9-, 12-, 18-, 24-, 32-, and 42-pound classifications adopted by Cromwell's government, which the English continued to use well into the eighteenth century. Meanwhile, during much of this time, the French were recognized as the leaders on the Continent. Louis XIV (1643-1715) introduced several foreign cannons into his arsenal, standardizing a set of calibers (4-, 8-, 12-, 16-, 24-, 32-, and 48-pounders) that were quite different from Henry II's from the previous century.

The cannon of the late 1600s was an ornate masterpiece of the foundryman's craft, adorned with shields, floral designs, scrolls, and heavy decorations, the most distinctive of which was probably the banded muzzle (figs. 23b-c, 25, 26a-b), that bulbous touch of decoration that had been favored by designers since the era of bombards. The flared or bell-shaped muzzle (figs. 23a, 26c, 27) didn’t replace the banded muzzle until the eighteenth century, and while the flared bell is a common feature of ordnance cast between 1730 and 1830, some banded-muzzle guns were produced as late as 1746 (fig. 26a).

By 1750, however, design and construction were fairly well standardized in a firearm with a much cleaner line than the cannon of 1650. Although there hadn't been a clear break from older traditions, the shape and weight of the cannon in relation to the forces of firing were becoming increasingly important to the designers.

Conditions in eighteenth-century England were pretty standard: in the 1730s, Surveyor-General Armstrong's formulas for gun design were mostly just extensions of the older methods. His guns were around 20 calibers long, with these outside proportions:

The trunnions, about the size of a caliber, were placed well forward (3/7 of the gun's length) "to prevent the gun from kicking up behind" when fired. Gunners blamed this bucking issue on the practice of centering the trunnions on the lower line of the bore. "But what won’t people do to uphold an old custom, no matter how ridiculous?" asked John Müller, the master gunner of Woolwich. In 1756, Müller moved the trunnions to the center of the bore, an improvement that significantly reduced the strain on the gun carriage.

Figure 26—18TH CENTURY CANNON, a—Spanish bronze 24-pounder from 1746. b—French bronze 24-pounder from the early 1700s. c—English iron 6-pounder from the mid-1700s. The 6-pounder is part of the weaponry at Castillo de San Marcos.

Figure 27—SPAIN'S 24-POUND CAST-IRON CANNON (1693). Notice the contemporary design of this cannon, featuring a flat breech and a subtle flare at the muzzle.

The size of the gun remained the standard for "strengthening" the bore walls:

For both bronze and iron guns, the figures mentioned were the same, but for bronze, Armstrong divided the caliber into 16 parts; for iron, it was only 14 parts. As a result, the walls of an iron gun were slightly thicker than those of a bronze one.

This 18th-century cannon was made of cast iron, but the hoops and rings gave it the appearance of a barrel-stave bombard, even though the hoops were actually functional parts of the cannon. Reinforcements made the gun look like "three frustums of cones joined together, so that the smaller base of the former is always greater than the largest of the succeeding one." Decorative fillets, astragals, and moldings taken from architecture enhanced the illusion of being a sectional piece. Tests with 24-pounders of various lengths showed that guns between 18 and 21 calibers long generally performed the best, but what worked for the 24-pounder didn't necessarily apply to other types. Why was the 32-pounder "brass battering piece" 6 inches longer than its 42-pounder counterpart? John Müller questioned these inconsistencies and aimed to create a new system of ordnance for England.

Like many men before him, Müller wanted to enhance the firepower of cannons without adding weight. He accomplished this in two ways: he changed the external design to use less metal, and he reduced the powder charge to allow for a shorter and lighter gun. Müller's cannons had no heavy reinforcements; the metal was spread along the barrel in a taper from the powder chamber to the muzzle. However, understanding people's hesitance to embrace new ideas, he carefully detailed the position and size of each molding on his gun, all while arguing that such embellishments were pointless. It wasn't until the latter half of the next century that experts had enough knowledge in metallurgy and internal ballistics to eliminate all the unnecessary metal.

So, using powder charges that are about one-third the weight of the projectile, Müller designed 14-caliber light field pieces and 15-caliber ship guns. His garrison and battering cannons, where weight wasn’t a significant drawback, were 18 calibers long. The figures in the table below show the main dimensions for the four types of cannons—all cast-iron except for the bronze siege guns. The first line in the table displays the length of the cannon. To proportion the rest of the piece, Müller divided the shot diameter into 24 parts and used that as a reference. The caliber of the gun, for example, was 25 parts, or 25/24ths of the shot diameter. The few other dimensions—thickness of the breech, length of the gun before the barrel started tapering, and fortification at the vent and chase—were expressed the same way.

The heaviest of Müller's garrison guns averaged about 172 pounds of iron for every pound of the shot, while a ship's gun weighed only 146 pounds, which is less than half the iron used in sixteenth-century cannons. For a maritime nation like England, these were significant details. Perhaps the opposite table will provide a good sense of the changes in English ordnance during the eighteenth century. It is based on John Müller's lists from 1756; the "old" ordnance includes cannons that were still in use during Müller's time, while the "new" ordnance is Müller's own designs.

Windage in the English guns of 1750 was about 20 percent higher than in French guns. The English shot-to-caliber ratio was 20:21, while the French ratio was 26:27. So, an English 9-pounder fired a 4.00-inch ball from a 4.20-inch bore; the French 9-pounder ball was 4.18 inches, and the bore was 4.34 inches.

The English believed that greater windage was both practical and cost-effective: they argued that windage should be just as thick as the metal in the gunner's ladle; if a shot got stuck in the barrel and couldn’t be loosened with the ladle, it had to be fired away and wasted. John Müller brushed off these arguments with annoyance. He insisted that with a proper wad over the shot, no dust or dirt could get inside; and when the muzzle was lowered, he stated, the shot "will roll out naturally." Moreover, he claimed that compared to the improvement in accuracy, losing a shot was minor. He also noted that with less space for the shot to move around in the barrel, the cannon would "not wear out as quickly." Müller set the ratio of shot to caliber at 24:25.

Sizes and lengths of major English cannons from the eighteenth century

In the 1700s, cast-iron guns became the main artillery used both at sea and on land, but cast bronze was better at handling the stresses of firing. Because it's tougher, a bronze gun required less metal than a cast-iron one, so even though bronze is about 20 percent heavier than iron, the bronze piece was usually lighter overall. For "position" guns in permanent fortifications where weight wasn’t an issue, iron was dominant until steel guns came along. However, non-rusting bronze was always the preferred choice on ships or in coastal forts.

Müller was a strong proponent of using bronze for ship guns. "Despite all the precautions taken to ensure that iron guns are strong enough," he said, "accidents can still happen, either due to poor handling by the sailors or because of cold weather, which makes iron very brittle." A bronze 24-pounder cost £156, while the iron one was just £75, but the initial savings disappeared when the gun started to wear out. The iron gun became useless except for scrap at a farthing per pound, while the bronze cannon could be recast "as often as you like."

In 1740, Maritz from Switzerland made a significant improvement in how cannons were made. Instead of hollow casting (which means forming the inside by casting the gun around a core), Maritz created the gun as a solid piece and then drilled out the bore, enhancing its consistency. Even though the bore could be drilled very smoothly, the exterior of a cast-iron gun remained rough. On the other hand, bronze cannons could be placed in lathes to smooth out the outside as well. After 1750, foundries rarely produced bronze pieces as elaborate as the Renaissance culverins, but some decorations persisted, and many guns were still personalized with names in raised letters on them. Castillo de San Marcos has a 4-pounder named "San Marcos," and in fact, it wasn't uncommon for Spanish cannons to bear saints' names. Other common names included El Espanto (The Terror), El Destrozo (The Destroyer), Generoso (Generous), El Toro (The Bull), and El Belicoso (The Quarrelsome One).

In some cases, decoration served a purpose. The French, for example, once used different shapes of cascabels to indicate specific calibers; and a decorative cascabel shaped like a lion's head was always a useful spot for securing breeching tackle or maneuvering lines. The dolphins or handles on top of bronze guns were never just for show. They were typically located at the gun’s balance point; tackle threaded through them and attached to the large tripod or "gin" lifted the cannon from its carriage.

Cannon for permanent fortifications came in different sizes and calibers, depending on the terrain that needed defending. At Castillo de San Marcos, for example, the heaviest weapons were on the waterfront, while lighter guns were positioned on the land side, which was naturally protected by the challenging terrain present during the colonial era.

Figure 28—18TH CENTURY SPANISH GARRISON GUN.

Before the Castillo was finished, guns were only placed in the bastions or the corners of the fort. A 1683 inventory clearly shows that the heaviest guns were in the San Agustín, or southeastern bastion, controlling not only the harbor and its entrance but also the town of St. Augustine. San Pablo, the northwestern bastion, overlooked the land approach to (p. 047) the Castillo and the town gate; and, although its armament was lighter, it was almost as numerous as that in San Agustín. Bastion San Pedro to the southwest was within the town limits, and its few light guns served as a backup for San Pablo. The watchtower bastion of San Carlos overlooked the northern marshland and the harbor; it also had a small armament. The following list provides details about the types and locations of the ordnance:

Cannons placed at Castillo de San Marcos in 1683

The (p. 048) total number of Castillo guns in service at this time was 27, but there were about a dozen unmounted pieces available, including two pedreros. The armament was gradually increased to around 70 guns as construction on the fort created more space, and as other factors required more weaponry. Below is a summary of Castillo armament through the years:

Armament of Castillo de San Marcos, 1683-1834

This chart clearly shows the current situation. The most significant attacks on Spanish Florida happened in the first half of the 18th century, which is exactly when the Castillo's weaponry was the strongest. While most of the cannons were ready for use, the chart includes some that were rated as only fair and might also have a few that were unusable. Due to colonial isolation, artillery often lasted longer than the typical 1,200 shots for an iron gun. A common issue was the formation of cracks around the vent or inside the barrel. Occasionally, the muzzle would blow off. The worst casualties during the 1702 siege resulted from the explosion of a 16-pound iron cannon that killed four and seriously injured six men. During that time, by the way, culverins were the only type of gun that could reach the harbor bar about 3,000 yards away.

Although the Spanish took their usable cannons with them when they turned Florida over to Britain in 1763, two cannons at Castillo de San Marcos National Monument today appear to be from the seventeenth century Spanish era. Most of the 24- and 32-pounder garrison cannons, however, were made in England, following the Armstrong specifications from the 1730s, and were part of the British arsenal in the 1760s. During the chaos and shipping issues that came with the British evacuation in 1784, some artillery seems to have been left behind, remaining part of the defenses until the transfer to the United States in 1821.

The Castillo also has some interesting U.S. cannons, including a pair of early 24-pounder iron field howitzers (c. 1777-1812). In the 1840s, the U.S. upgraded the Castillo's defenses by building a water battery in the moat behind the seawall. Many of the guns from that battery still exist, including 8-inch Columbiads, 32-pounder cannons, and 8-inch seacoast and garrison howitzers. St. Augustine's Plaza even features a converted 32-pounder rifle.

Figure 29—VAUBAN'S MARINE CARRIAGE (c. 1700).

Garrison and ship carriages were very different from field, siege, and howitzer mounts, while mortar beds belonged to a category of their own. The basic dimensions for the carriage were determined by measuring (1) the distance from the trunnion to the base ring of the gun, (2) the diameter of the base ring, and (3) the diameter of the second reinforce ring. This produced a quadrilateral shape that was crucial for designing the carriage to accommodate the gun. The cheeks, or side pieces, of the carriage were one caliber thick, so the larger the gun, the heavier the mount.

A 24-pounder cheek would be made of wood about 6 inches thick. The Spaniards often chose mahogany. At Jamestown, in the early 1600s, Capt. John Smith reported mounting seven "great pieces of ordnance on new carriages of cedar," and the French colonials also used this material. British specifications in the mid-1700s called for cheeks and transoms made of dry elm, which was very flexible and unlikely to split; however, some carriages were made of young oak, and oak was standard for (p. 050) United States garrison carriages until it was replaced by wrought iron after the Civil War.

For a four-wheeled English carriage from 1750, the height of the cheek was 4-2/3 times the diameter of the shot, unless adjustments in height were necessary to accommodate a gun port or embrasure. To stop cannons from forcing the shutters open when the ship rolled in a storm, lower tier carriages allowed the muzzle of the gun, when fully elevated, to rest against the sill above the gun port.

On the 18th-century Spanish garrison carriage (fig. 28), there were no threaded bolts; they were held in place either by a key going through a slot at the base of the bolt or by bending the base over a decorative washer. Compared to American mounts of the same type (figs. 30 and 31), the Spanish carriage was much more complex, partly due to the increased amount of decorative ironwork and partly due to the design of the wooden parts, which featured carefully crafted mortises that required a skilled craftsman. The cheek of the Spanish carriage was made from a single large plank. In contrast, English and American construction used a built-up cheek made from several planks, expertly fitted together to prevent splitting under the stress of firing.

Figure 30—ENGLISH GARRISON CARRIAGE (1756). By replacing the cast-iron wheels with wooden ones, this carriage became a standard naval gun carriage.

Müller provided details for constructing truck (four-wheeled) carriages for 3- to 42-pounders. On ships, the truck carriage was the norm for nearly everything except the small swivel guns and the mortars.

Carriage wheels, unless they were made of cast iron, had iron thimbles or bushings fitted into the hub's hole. To preserve the wood of the axletree, the spindle on which the wheel turned was partially shielded by metal. The British placed copper on the bottom of the spindle, while Spanish and French designers put copper on the top and then inserted iron "axletree bars" at the bottom. These bars reinforced the axletree and reduced wear on the spindle.

A 24-pounder front truck was 18 inches in diameter. Rear trucks were 16 inches. The size difference balanced out the slope on the gun platform or deck, which helped to control recoil. On a ship, where there wasn’t much recoil space, a heavy rope called a breeching, attached to the side of the vessel, minimized the gun's "kick" (see fig. 11). Ship carriages of either the two- or four-wheel type (fig. 31) were used throughout the Civil War, and there were no significant changes until automatic recoil mechanisms allowed for a stationary mount. (p. 051)

Figure 31—U. S. NAVAL TRUCK CARRIAGE (1866).

With garrison carriages, though, changes happened much earlier. In 1743, Fort William on the Georgia coast had a pair of 18-pounders mounted on "curious moving Platforms," which were probably similar to the traversing platforms standardized by Gribeauval later in the century. United States forts in the early 1800s used casemate and barbette carriages (fig. 10) of the Gribeauval type, and the traversing platforms of these mounts made training (aiming the gun right or left) relatively easy.

Training the old truck carriage had been tough work for the handspikemen, who also helped raise or lower the gun. The maximum angle of elevation or depression was about 15° in either direction—similar to the naval guns used during the Civil War. If one quoin wasn’t enough to ensure proper depression, a block or a second quoin was placed beneath the first. But before the gunner lowered a smoothbore below zero elevation, he needed to put either a wad or a grommet over the ball to prevent it from rolling out.

Ship and garrison cannons weren't moved around on their carriages. If the gun needed to be transported a distance, it was dismounted and secured under a sling wagon or on a "block carriage," which had big wheels that rolled easily over rough ground. Dismounting a gun wasn't difficult: the keys that locked the cap squares were removed, and then the rigging was set up to lift the gun off the carriage.

A typical garrison or ship cannon could fire any type of projectile, but solid shot, hot shot, bombs, grape shot, and canister were the most commonly used. These guns had a flat trajectory, with a point-blank range of about 300 yards. They were effective—meaning fairly accurate—up to about half a mile, although the maximum range of guns like the Columbiad from the nineteenth century, when the angle of fire wasn’t limited by gun port restrictions, neared the 4-mile range claimed by the Spanish for the sixteenth-century culverin. The ranges of United States ordnance in the 1800s aren’t significantly different from similar guns from earlier periods. (p. 052)

Ranges of U.S. smoothbore garrison guns from 1861

Ranges of U.S. Navy smoothbore cannons from 1866

Ranges of U.S. Navy rifles in 1866

In terms of accuracy and range, the rifles of the 1860s were far better than the smoothbores, but the amazing advancements made in the following decades with new propellants and steel guns made the old rifles seem less impressive. In the eighteenth century, a 24-pounder smoothbore could achieve a muzzle velocity of about 1,700 feet per second. By the late 1800s, 12-inch rifled cannons had a muzzle velocity of 2,300 feet per second. In 1900, the Secretary of the Navy proudly announced that the new 12-inch guns for Maine-class battleships achieved a muzzle velocity of 2,854 feet per second, using an 850-pound projectile and a charge of 360 pounds of smokeless powder. Such numbers would make today’s artilleryman chuckle.

The field equivalent of the garrison cannon was the siege gun—the "battering cannon" from earlier times, placed on a two-wheeled siege or "traveling" (p. 053) carriage that could be easily moved across the battlefield. While the garrison cannon aimed to take out the attacker and their equipment, the siege cannon was designed to demolish the fort. Calibers ranged from 3 to 42 pounds in eighteenth-century English records, but the 18- and 24-pounders were the most commonly used for siege operations.

Figure 32—SPANISH 18TH CENTURY SIEGE CARRIAGE.

The siege carriage looked a lot like the field gun carriage, but it was much larger, as you can see from these comparative figures taken from eighteenth-century English specifications:

Heavy siege guns were raised with quoins, and the elevation was limited to 12° or less, similar to what United States siege carriages allowed in 1861. This was seen as sufficient for these flat trajectory weapons.

Both field and siege carriages were pulled over long distances by lifting the trail to connect it to a horse- or ox-drawn limber; a hole in the trail transom fit onto an iron bolt or pintle on the two-wheeled limber. Some late eighteenth-century field and siege carriages had a second pair of trunnion holes a couple of feet back from the regular holes, allowing the cannon to be moved to the rear holes where the weight was distributed better for travel. The United States siege carriage of the 1860s didn’t have extra trunnion holes, but it did feature a "traveling bed" where the gun was held in place 2 to 3 feet behind its firing position. A well-trained gun crew could make the switch quickly, using a lifting jack, some rollers, blocks, and chocks. However, when there was a risk of straining or breaking the gun carriage, large block carriages, sling carts, or wagons were used to transport the guns.

Sling (p. 054) Wagons were necessarily used for transport during siege operations when the guns were mounted on barbette (traversing platform) carriages (fig. 10). Setting up the barbette carriage required building a large, level subplatform, but it also removed the old requirement for the gunner to mark the position of the wheels so he could return the gun to the correct firing position after each shot.

The Federal sieges of Forts Pulaski and Sumter were complex engineering efforts that included landing extremely heavy artillery (the 300-pounder Parrott weighed 13 tons) through rough waves, transporting the large guns over challenging terrain, and in some instances, constructing roads across marshlands and driving foundation piles for the gun positions.

The heavy caliber Parrotts aimed at Fort Sumter were in batteries ranging from 1,750 to 4,290 yards away from their target. They were quite accurate, but their durability was unpredictable. The infamous "Swamp Angel," for example, broke after 36 rounds.

Figure 33—SPANISH 4-POUNDER FIELD CARRIAGE (circa 1788). This carriage, designed using the "new method," utilized a handscrew instead of a wedge to elevate the piece. a—The handspike was put through eyebolts in the trail. b—The ammunition locker stored the cartridges.

The field guns were mobile artillery pieces that could move with the army and be quickly set up for firing. They were lighter than any other type of flat trajectory weapon. To achieve this light weight, the designers not only shortened the guns but also reduced the thickness of the bore walls. In the eighteenth century, calibers ranged from 3 to 24 pounds, mounted on relatively light two-wheeled carriages. Additionally, there was the 1.5-pounder (and sometimes the lighter 3- or 6-pounder) on a "galloper" carriage—a vehicle designed with its trail shaped into shafts for the horse. The elevating-screw mechanism was developed early for field guns, although heavier pieces like the 18- and 24-pounders were still elevated using quoins as late as the early 1800s.

In the Castillo collection, there are parts of early American field carriages that are not much different from the Spanish carriages that carried a number of 4-pounders along the long, continuous earthwork parapet around St. Augustine in the eighteenth century. The Spanish carriages were somewhat more complex in design than English or American ones, but not by much. Spanish pyramid-headed nails used for securing the ironwork were quite similar to the diamond- and rose-headed nails made by English craftsmen.

Each piece of hardware on the carriage had its purpose. The gunner's tools were hung on hooks on the cheeks. There were bolts and rings for the lines when the gun needed to be moved by manpower in the field. On the trail transom, pintle plates surrounded the hole that went over the pintle on the limber. Iron reinforced the carriage at weak points or where the wood was prone to wear. Iron axletrees became common by the late 1700s.

For training the field gun, the crew used a special handspike that was quite different from the garrison handspike. It was a long, round pole with an iron handle attached to its top (fig. 33a). The trail transom of the carriage had two eyebolts where the foot of the spike was inserted. A lug fit into an offset in the larger eyebolt, preventing the spike from twisting. With the handspike secured in the eyebolts, lifting the trail and positioning the gun was simple.

The single-trail carriage (fig. 13) that was widely used in the mid-1800s was a significant simplification in carriage design. It was crucial for guns like the Parrott rifles since the thick reinforcement at the breech of the otherwise slender barrel wouldn't fit the older twin-trail carriage. The single, solid "stock" or trail removed the need for transoms, as short, high cheeks were bolted to the sides of the stock, humped like a camel to hold the gun high enough for a wide range of elevation. The elevating screw was threaded through a nut in the stock, right underneath the large reinforcement of the gun.

While the larger bore siege Parrotts weren't known for their long-lasting use, Parrott field rifles had excellent durability. For performance, see the following table:

Ranges of Parrott field rifles (1863)

Amazingly, these ranges were achieved with roughly the same amount of powder used in smoothbores of similar caliber: the 10-pound Parrott required only a pound of powder; the 20-pounder needed a two-pound charge; and the 30-pounder used 3-1/4 pounds!

The howitzer was created by the Dutch in the 1600s to launch larger projectiles (usually bombs) than field guns could, in a high arc similar to a mortar, but using a lighter and more mobile weapon. The versatile effectiveness of the howitzer was recognized almost immediately, and it was quickly adopted by all European armies. The weapon's mobility came from a sturdy two-wheeled carriage similar to a field carriage, but with a shorter trail that allowed for the wide range of elevation required for this weapon.

Figure 34—SPANISH 6-INCH HOWITZER (1759-88). This bronze cannon was cast during the reign of Charles III and features his crest. a—Dolphin or handle, b—Bore, c—Powder chamber.

English howitzers from the 1750s came in three calibers: 5.8, 8, and 10 inches, but the 10-inch model was so heavy (around 50 inches long and over 3,500 pounds) (p. 057) that it was quickly discarded. Müller criticized the unnecessary weight of these pieces and designed 6-, 8-, 10-, and 13-inch howitzers that were much lighter due to a more strategic distribution of metal. Müller's howitzers were used in the early 6- to 10-inch pieces of United States artillery, and one notable little 24-pounder from the late eighteenth century is part of the armament at Castillo de San Marcos, along with some early nineteenth-century howitzers. Interestingly, the British were the first to introduce this type of gun to Florida, but none appeared on the Castillo inventory until the 1760s.

Figure 35—ENGLISH 8-INCH "HOWITZ" CARRIAGE (1756). The short trail allowed for more flexibility in adjusting the elevation of the howitzer.

In addition to the lightweight and easily portable mountain howitzer used for Indian warfare, U.S. artillery in 1850 included 12-, 24-, and 32-pounder field artillery, 24-pounder and 8-inch siege and garrison guns, and the 10-inch seacoast howitzer. The Navy had a 12-pounder heavy and a 24-pounder, which were later complemented by the 12- and 24-pounder Dahlgren rifled howitzers from the Civil War era. These guns were often used in landing operations. The following table shows some typical ranges:

Ranges of U.S. Howitzers in the 1860s

Figure 36—ENGLISH MORTAR ON ELEVATING BED (1740).

From early times, the usefulness of the mortar as an artillery weapon has been clearly recognized. Up until the 1800s, the weapon was typically made of bronze, and many mortars had a fixed elevation of 45°, which was considered the ideal angle for maximum range of any cannon in the sixteenth century. In the 1750s, Müller criticized English artillerymen for continuing to use fixed-elevation mortars, while the Spanish created a mortero de plancha, or "plate" mortar (fig. 37), as late as 1788. The range of such a fixed-elevation weapon was adjusted by using more or less powder, depending on the situation. However, the most effective mortar had trunnions and adjustable elevation through quoins.

Figure 37—SPANISH 5-INCH BRONZE MORTAR (1788).

The mortar was set on a "bed"—a pair of wooden sides connected by crosspieces. Since the bed had no wheels, the piece was moved using a mortar wagon or sling cart. In the battery, the mortar was usually placed on a flat wooden platform; on a ship, it was on a rotating platform, allowing for quick aiming to the left or right. The mortar's weight, combined with its steep angle of elevation, kept it relatively stable when fired, although English artillerymen took the extra step of securing it with straps.

The mortar didn’t use a wad because a wad would stop the shell’s fuse from igniting. To someone unfamiliar with it, it might seem odd that the shell was never loaded with the fuse pointing towards the gunpowder charge. But the fuse was always pointed towards the muzzle and away from the blast, a practice that goes back to when mortars were fired by “double firing”: the gunner would light the shell’s fuse with one hand and the mortar’s primer with the other. It wasn’t until the late 1600s that the method of letting the powder blast ignite the fuse became common. This change really simplified using the weapon and probably made the mortarman breathe a sigh of relief.

Figure 38—SPANISH 10-INCH BRONZE MORTAR (1759-88). a—Dolphin or handle, b—Bore, c—Powder chamber.]

Most mortars came with dolphins, either individually or in pairs, which were used to lift the weapon onto its base. There was often a small cup attached—a priming pan—under the vent, a useful feature that prevented a lot of powder from spilling at the almost vertical breech. Like other bronze cannons, mortars were decorated with shields, scrolls, names, and other embellishments.

Around 1750, the French mortars had a bore length of 1.5 times the diameter of the shell; in England, the bore was 2 diameters for smaller calibers and 3 for the 10- and 13-inch mortars. This extra length added significant weight to the English mortars: the 13-inch weighed 25 hundredweight, while the French version weighed only about half that. Müller criticized mortar designers for blindly copying what they saw in other guns. For example, he noted that the reinforcement was unnecessary; it "... loads the mortar with a lot of useless metal, and in a place where the least strength is needed, yet as if this unnecessary metal wasn't enough, they add a large projection at the mouth, which serves no other purpose than to make the mortar top-heavy. The moldings are also haphazardly combined, (p. 060) with no taste or method, even though they are drawn from architecture." Field mortars during Müller's time included 4.6-, 5.8-, 8-, 10-, and 13-inch "land" mortars and 10- and 13-inch "sea" mortars. Müller, of course, redesigned them.

Figure 39—Cohorn Mortar. British General Oglethorpe used 20 coehorns in his 1740 bombardment of St. Augustine. These small mortars were also widely used during the Civil War.

The small mortars known as coehorns (fig. 39) were created by the renowned Dutch military engineer, Baron van Menno Coehoorn, and he used them in 1673 to great effect against French garrisons. Oglethorpe had several of them during his 1740 bombardment of St. Augustine when the Spanish, trying to translate coehorn into their language, referred to them as cuernos de vaca—"cow horns." They were still in use during the U.S. Civil War, and some of them can be seen in battlefield parks today.

Bombs and dead bodies were common during mortar firing, but stone projectiles were still in use as late as 1800 for the pedrero class (fig. 43). Mortar projectiles were really powerful; even in the sixteenth century, missiles weighing 100 pounds or more were not unusual, and the 13-inch mortar of 1860 launched a 200-pound shell. The larger projectiles had to be hoisted up to the muzzle with pulleys.

Figure 40—THE "BOSS." This massive 13-inch mortar was used by the Union artillery during the bombardment of Petersburg, Virginia, in 1864-65.

In (p. 061) the last century, bronze mortars evolved into the massive cast-iron mortars, like "The Dictator," a huge Federal artillery piece used against Petersburg, VA. Wrought-iron beds with a pair of rollers were created for them. Despite their steep angle, mortars could reach over a mile, as shown by the data for United States mortars from the 1860s, firing at a 45° angle:

Ranges of U.S. Mortars in 1861

At the siege of Fort Pulaski in 1862, General Gillmore complained that the mortars were very inaccurate at a mile-long range. On this point, John Müller would have nodded in agreement. A hundred years before Gillmore's complaint, Müller argued that a range of less than 1,500 yards was sufficient for mortars and, really, all types of guns. "When the ranges are greater," Müller said, "they are so unpredictable, and it's so hard to judge how far the shell falls short or goes beyond the target that it only serves to waste the powder and shell, without being able to achieve any results."

"Hoist with his own petard," an old phrase meaning that someone's well-planned scheme has backfired, had a very vivid meaning back in the day when everyone knew what a petard was. Since the petard didn’t shoot any projectiles, it wasn’t exactly a gun. In simple terms, it was just a metal bucket filled with gunpowder. The person using it would attach it to a gate, similar to hanging your hat on a hook, and blow the gate open by igniting the charge.

Small petards weighed about 50 pounds; the larger ones weighed around 70 pounds. They needed to be heavy enough to be effective but light enough for two men to easily lift and attach to the target. The bucket part was filled with a powder mixture, and then a 2.5-inch-thick board was bolted to the rim to keep the powder in and the air out. An iron tube fuse was screwed into a small hole on the back or side of the device. When everything was ready, the petardiers grabbed the two handles of the petard and carried it to the troublesome door. There, they set a screw, hung the explosive device on it, lit the fuse, and "retired."

Petards (p. 062) were commonly used in King William's War of the 1680s to break down the gates of small German towns. However, on a heavily fortified double gate, the small petard was ineffective, and the large petard would only damage the front part of such a gate. Moreover, as you might expect, setting a petard was a dangerous job; it fell out of favor in the early 1700s.

There are four different types of artillery shells that have been used in various forms since ancient times:

(1) Solid shot projectiles.
(2) Explosive shells.
(3) Scatter shot (case or canister, grape, shrapnel).
(4) Incendiary and chemical projectiles.

At Havana, Cuba, in the early days, there were plenty of round stones scattered around, provided by Mother Nature. Artillerists in Havana never ran out of projectiles. Stone balls, cheap to make, relatively light, and thus well-suited to the weak construction of early cannons, were commonly used for large caliber guns in the fourteenth century. There were other experiments, like those in Tournay in the 1330s, with long, pointed projectiles. Lead-coated stones were quite popular, and solid lead balls were used in some smaller cannons, but the stone ball was more or less the standard.

Cast-iron shot was introduced by 1400, and with improvements in cannons during that century, iron shot slowly took the place of stone. By the end of the 1500s, stone was only used in pedreros, murtherers, and other remnants from the earlier period. Iron shot for smoothbore cannons was a solid, round shot, cast in fairly precise molds; the mold marks that were always present on all cannonballs didn’t matter much, as the ball didn’t fit snugly in the bore. After casting, the shot was checked with a ring gauge (fig. 41)—a hoop that each ball had to pass through. The Spanish term for this tool is quite descriptive: pasabala, meaning "ball-passer."

Shot was mainly used in flat-trajectory cannons. The small caliber guns only fired shot because smaller versions of other types of projectiles weren't effective. Shot was the go-to choice when the situation required "great accuracy at very long range" and penetration. When fired at ships, a shot could breach the planks (at a 100-yard range, a 24-pounder shot could penetrate 4-1/2 feet of "sound and hard" oak). With decent aim at the waterline, a gunner could sink or seriously damage a vessel with just a few rounds. However, against ironclad targets like the Monitor and Merrimac, round shot did little more than bounce off; it took long, armor-piercing rifle projectiles to prompt the creation of the incredibly thick plates seen in modern times.

Figure 41—18TH CENTURY PROJECTILES. (Not to scale.)

Round shot was really effective for taking out enemy artillery. The gunner positioned his cannon on the side of the enemy guns and used ricochet firing so that the ball, just clearing the defensive wall, would bounce among the enemy artillery, injure the crews, and damage the gun carriages. When it came to destroying fort walls, shot was crucial. After neutralizing the enemy pieces, the siege guns moved in close enough to break down the walls. The process (p. 065) wasn't as random as it sounds. Cannons were brought as close as possible to the target, and the gunner literally carved out a low section with gunfire so that the wall above would collapse into the moat, creating a ramp right up to the breach. Firing at the upper part of the wall undermined the goal, as the rubble that fell only shielded the foundation area, and the breach was so high that assault troops needed to use ladders.

The most effective bombardment of Castillo de San Marcos happened during the 1740 siege, and the cannon fire caused the most damage. The biggest English siege cannons were 18-pounders, positioned over 1,000 yards from the fort. Spanish Engineer Pedro Ruiz de Olano reported that the cannonballs didn’t penetrate the thick main walls more than a foot and a half, but the parapets, which were only 3 feet thick, took a lot of damage. Some of the old parapets, Engineer Ruiz noted, "have been demolished, and the new ones have suffered very much owing to their recent construction." (He meant that the new mortar hadn’t properly hardened yet.) Ruiz was clear about what would happen if enemy batteries got closer; in that case, he believed the enemy "will no doubt succeed in destroying the parapets and dismounting the guns."

Variations of round shot included bar shot and chain shot (fig. 41), which were two or more projectiles linked together for simultaneous firing. Bar shot is mentioned in a Castillo inventory from 1706, and like chain shot, it was used for specialized tasks such as cutting a ship's rigging. There is one apocryphal story, though, about an experiment with chain shot being used as anti-personnel weapons: instead of loading both balls into a single cannon, two guns were placed side by side. The ball in one gun was chained to the ball in the other. The idea was for the projectiles to shoot out, stretching the long chain between them and mowing down a significant portion of the enemy forces. Instead, the chain ensnared the gun crews in a deadly embrace; one gun fired late.

The word "bomb" comes from French, which took it from Latin. But the Romans originally got it from the Greek bombos, meaning a deep, hollow sound. "Bombard" is a related term. Nowadays, bomb is pronounced "balm," but back in the day, it was usually pronounced "bum." The modern equivalent of "bum" is an HE shell.

The first known use of explosive shells was by the Venetians in 1376. Their bombs were half-spheres made of stone or bronze, connected by hoops and detonated using a basic powder fuse. Shells filled with explosive or incendiary mixtures became standard for mortars after 1550, but they didn't see widespread use for flat-trajectory weapons until the early nineteenth century, after which the term "shell" gradually replaced "bomb."

In any case, this projectile was one of the most effective ever used in smoothbore cannons against fortifications, buildings, and for general bombardment. A delayed-action shell, cleverly timed to roll among the ranks while its fuse burned, was designed to "disrupt even the bravest men," as they had no way of knowing when the bomb would explode.

A bombshell was just a hollow, cast-iron sphere. It had a single hole where the powder was poured in—full, but not so packed that it was too tight when the fuse was inserted. Until the 1800s, larger bombs weren’t always smooth spheres; they often had a protruding neck or collar for the fuse hole, or a couple of rings on each side of the hole for easier handling (fig. 41). However, in later years, these projections were replaced by two "ears," small indentations next to the fuse hole. A pair of tongs (like ice tongs) would grab the shell by the ears and lift it up to the gun bore.

During most of the eighteenth century, shells were made thicker at the base than at the fuze hole based on the belief that they (1) could better withstand the shock of being fired from the cannon and (2) were more likely to land with the heavy part facing down, keeping the fuze on top and less likely to be put out. Müller dismissed the idea of "choking" a fuze, arguing that it burned just as well in water as in any other substance. He also preferred to use shells that were "equally thick all around, since they would then break into a greater number of pieces." In later years, the shells were scored on the inside to ensure they would shatter into many fragments.

Figure 42—19th Century Projectile Fuses. a—Cross-section of Bormann fuse, b—Top of Bormann fuse, c—Wooden fuse for spherical shell, d—Wood-and-paper fuse for spherical shell, e—Percussion fuse.]

The eighteenth-century fuse was a wooden tube several inches long, with a powder composition packed into its hole similar to the nineteenth-century fuse (fig. 42c). The hole was only a quarter of an inch in diameter, but the head of the fuse was hollowed out like a cup, and fine powder, moistened with alcohol, was pressed into the hollow to create a larger igniting surface. To time the fuse, a cannoneer would cut the cylinder to the right length with his fuse saw or drill a small hole (G) where the fire could flash out at the right time. Some English fuses from this period were also made by placing two strands of quick match into the hole instead of filling it with powder. The ends of the match were crossed into a sort of rosette at the head of the fuse. Paper caps protecting the powder composition covered the heads of these fuses and had to be removed before the shell was loaded into the gun.

Bombs weren't filled with powder until just before they were used, and the fuzes weren't put into the projectiles until it was time to fire them. To push the fuze into the shell's hole, the cannoneer covered the fuze head with some cloth, placed a fuze setter on top, and struck the setter with a mallet, "drifting" the fuze until the head was protruding from the shell by only 2/10 of an inch. If the fuze needed to be removed, a fuze extractor was available for that. This tool clamped onto the fuze head securely, and by turning a screw, it slowly pulled the fuze out.

Wooden tube fuses have been used almost since the introduction of the spherical shell. A United States 12-inch mortar fuse (fig. 42c), measuring 7 inches long and burning for 49 seconds, was very similar to the earlier fuse. However, during the 1800s, other types became widely adopted.

The conical paper-case fuse (fig. 42d), fitted into a metal or wooden plug that matched the fuse hole, contained a composition whose burn rate was indicated by the color of the paper. A black fuse burned at one inch every 2 seconds. Red burned in 3 seconds, green in 4 seconds, and yellow in 5 seconds per inch. Paper fuses were 2 inches long and could be trimmed shorter if needed. Since firing a shell from a 24-pounder to explode at 2,000 yards required a flight time of 6 seconds, a red fuse would work without any cutting, or a green fuse could be shortened to 1-1/2 inches. Sea-coast fuses of a similar type were used in the 15-inch Rodmans until these large smoothbores were finally retired sometime after 1900.

The Bormann fuze (fig. 42a), the fastest of the older designs to set, was used for many years by the U.S. Field Artillery in spherical shells and shrapnel. Its pewter case, which screwed into the shell, held a time ring of powder composition (A). On this ring, the top of the fuze case was marked in seconds. To set the fuze, the gunner just had to cut the case at the right mark—four for 4 seconds, three for 3 seconds, and so on—to expose the powder ring to the blast from the gun. The ring burned until it reached the zero end, which triggered the fine powder in the center of the case; the powder flash then blew out a tin plate at the bottom of the fuze and ignited the shell charge. Its short burning time (about 6 seconds) made the Bormann fuze outdated as artillery ranges increased. The main issue with this fuze, however, was that it didn't always ignite!

The (p. 068) percussion fuse was a crucial advancement of the nineteenth century, especially for long-range rifles. The impact triggered this fuse to explode the shell almost instantly upon contact. Percussion fuses came in two main types: the front fuse, located at the tip of an elongated projectile, and the base fuse, positioned at the center of the projectile's base. The base fuse was used with armor-piercing projectiles where it was important for the shell to penetrate the target for a distance before detonating. Both types operated on the same principles.

A Hotchkiss front percussion fuze (fig. 42e) had a brass casing that screwed into the shell. Inside the casing was a plunger (A) filled with a priming charge of powder, topped with a cap of fulminate. A brass wire at the base of the plunger acted as a safety device to keep the cap away from a sharp point at the top of the fuze until the shell hit the target. When the gun was fired, the shock of discharge dropped a lead plug (B) from the base of the fuze into the projectile cavity, allowing the plunger to drop to the bottom of the fuze and stay there, held by the spread wire, while the shell was in flight. Upon impact, the plunger was pushed forward, the cap hit the point and ignited the priming charge, which then fired the bursting charge of the shell.

When one of our ancestors angrily grabbed a handful of pebbles and threw them at the flock of birds in his garden, he discovered the principle of the scatter projectile. One of its simplest uses was in the stone mortar (fig. 43). For this weapon, round stones about the size of a man's fist (and, by 1750, hand grenades) were dumped into a two-handled basket and lowered into the bore. This basic charge was used at close range against personnel in a fortification, where the impact of the falling projectiles would be very similar to a short but intense barrage of oversized hailstones. There were 6,000 stones in the ammunition inventory for Castillo de San Marcos in 1707.

Figure 43—SPANISH 16-INCH PEDRERO (1788). This mortar shot baskets of stones.

One of the earliest types of scatter projectiles was case shot, or canister, used at Constantinople in 1453. The name comes from its case, or can, which was usually metal and filled with scrap, musket balls, or slugs (fig. 41). A similar type, but with larger iron balls and no metal case, was grape shot, named for its grape-like appearance with clustered balls. A stand of grape in the 1700s consisted of a wooden disk at the base of a short wooden rod that served as the core around which the balls were arranged (fig. 41). The entire assembly was bagged in cloth and reinforced with a heavy cord net. In later years, grape was made by bagging two or three tiers of balls, with each tier separated by an iron disk. Grape could disable men at almost 900 yards and was widely used during the 1700s. Eventually, it was mostly replaced by case shot, which was more effective at shorter ranges (400 to 700 yards). Incidentally, there were 2,000 sacks of grape at the Castillo in 1740, more than any other type of projectile.

Spherical case shot (fig. 41) was an effort to extend the effectiveness of grape and canister shot beyond its previous limitations, using a bursting shell. It was the precursor to the shrapnel that saw extensive use in World War I and was created by Lt. Henry Shrapnel of the British Army in 1784. There had been earlier attempts to make a projectile like this, such as the German Zimmerman's "hail shot" in 1573—case shot with a bursting charge and a basic time fuse—but Shrapnel's invention was the first air-bursting case shot that, in technical terms, "imparted directional velocity" to the bullets it contained. Shrapnel's new shell was first deployed against the French in 1808, but it wasn’t referred to by his name until 1852.

Incendiary missiles, like buckets or barrels filled with a raging burning substance, have been used since ancient times, long before cannons. These basic incendiaries continued to be used through the 1700s, such as the burning loads of fire ships that were sent into enemy fleets. However, in 1672, an iron shell known as a carcass (fig. 41) was introduced, filled with pitch and other materials that burned at extremely high temperatures for about 8 minutes. Flames escaped through three to five vents around the fuze hole of the shell. The carcass remained standard ammunition until smoothbores were phased out. The United States ordnance manual of 1861 lists carcasses for 12-, 18-, 24-, 32-, and 42-pounder guns, as well as 8-, 10-, and 13-inch mortars.

During the late 1500s, the idea of heating iron cannonballs to use as incendiaries was proposed, but it wasn't until 200 years later that the concept was successfully implemented. Hot shot was simply round shot that was heated until it glowed red over a grate or in a furnace. It was fired from cannons at highly combustible targets like wooden ships or powder magazines. During the siege of Gibraltar in 1782, the British fired hot shot and destroyed part of Spain's fleet; and in the United States, seacoast fort shot furnaces were standard equipment during the first half of the 1800s. The small shot furnace at Castillo de San Marcos National Monument was built in the 1840s; a (p. 070) large furnace from 1862 still exists at Fort Jefferson National Monument. There are few other examples remaining.

Loading hot shot wasn’t especially risky. After the powder charge was loaded into the gun with a dry wad in front, another wad made of wet straw or clay was placed in the barrel. When the cherry-red shot was pushed in, the wet wad kept the charge from exploding too soon. According to the Ordnance Manual, the shot could cool in the gun without igniting the charge! Hot shot was replaced around 1850 by Martin's shell, which was filled with molten iron.

The smoke shell was introduced in 1681, but it was never widely used. Likewise, a type of gas projectile known as a "stink shell" was created by a Confederate officer during the Civil War. Due to its "inhumanity," and likely because it wasn't considered valuable enough to justify its propaganda impact on the enemy, it didn’t catch on. These were the early stages of modern chemical shells.

In relation to chemical warfare, it's worth looking back at the Hussite siege of Castle Karlstein, near Prague, in the early 1400s. The Hussites set up 46 small cannons, 5 large cannons, and 5 catapults. The large cannons would fire once or twice a day, while the smaller ones would fire between six to a dozen rounds.

Marble pillars from Prague churches were used to make the cannonballs. However, many projectiles for the catapults were decaying carcasses and other garbage, thrown over the castle walls to spread disease and undermine the morale of those inside. But the brave defenders countered these "chemical attacks" with lime and arsenic. After firing 10,930 cannonballs, 932 stone fragments, 13 fire barrels, and 1,822 tons of waste, the Hussites surrendered.

In the early days, partly because the balls were roughly made, wads were very important for keeping the powder contained and making it more efficient. Wads could be made from almost any suitable material available, but straw or hay ones were probably the most common. The hay was first twisted into a 1-inch rope, then a piece of the rope was folded together several times and finally rolled up into a short cylinder slightly larger than the bore. However, once the more convenient sabots were introduced, wads were only needed to prevent the ball from rolling out when the muzzle was pointed down or for firing hot shots.

Gunners started to organize ammunition for quicker and easier loading. For example, after placing the powder charge in a bag, the next step was to attach the wad and the cannonball so that loading could be done in one simple motion—pushing the complete round into the bore (fig. 48). To achieve this, the sabot or "shoe" (fig. 41) replaced the wad. The sabot was a wooden disk with a diameter similar to the shot. It was secured to the ball with a pair of metal straps to create "semi-fixed" ammunition; if the neck of the powder bag was tied around the sabot, it resulted in one cartridge containing powder, sabot, and ball, called "fixed" ammunition. Fixed ammunition became common for lighter field pieces by the end of the 1700s, while the larger guns used "semi-fixed."

In transportation, cartridges were shielded by strong paper cylinders and caps. Sabots were sometimes made of paper or compressed wood chips to reduce the risk of a heavy, unbroken sabot landing among friendly troops. A large mortar sabot was a deadly projectile on its own!

Today's rocket projectiles aren't exactly new inventions. Around the time artillery first started, military pyrotechnicians began creating explosive devices for warfare; later, their role also included the impressive fireworks displays that were set off to celebrate victory or peace.

Artillery manuals from very early times include sections on making and using fireworks. However, significant advancements in war rockets didn't happen until the late 1700s. Around 1780, the British Army in India observed the locals using them; and within the next 25 years, William Congreve, who aimed to create a rocket that could carry an incendiary or explosive payload up to 2 miles, achieved such promising results that English ships launched rocket salvos at Boulogne in 1806. The British Field Rocket Brigade effectively used rockets at Leipsic in 1812, marking the first time they were employed in European land warfare. They were used again two years later at Waterloo. The warheads of these rockets were made of cast iron, packed with black powder, and equipped with percussion fuzes. They were fired from trough-like launching stands that could be adjusted for elevation.

Rockets appeared to have a demoralizing impact on untrained soldiers, and their use by the British against inexperienced American troops at Bladenburg in 1814 may have played a role in the defeat of U.S. forces and the capture of Washington. They also inspired Francis Scott Key. Whether or not he understood the technical aspects of the rocket, every schoolkid remembers the "rocket's red glare" from the National Anthem, where Key described his firsthand experience of the bombardment of Fort McHenry. The U.S. Army in Mexico (1847) included a rocket battery, and in fact, war rockets were a significant part of artillery resources until the rapid advancements in gunnery in the late 1800s rendered them outdated.

Gunner's equipment was extensive. There were the tompion (a cap that covered the end of the gun to keep out wind and rain) and the lead cover for the vent; water buckets for the sponges and passing boxes for the powder; scrapers and tools for "searching" the bore to detect dangerous cracks or holes; chocks for the wheels; blocks and rollers, lifting jacks, and gins for moving guns; and drills and augers for clearing the vent (figs. 17, 44). But among the most essential tools for daily firing were the following:

The sponge was a wooden cylinder about a foot long, the same diameter as the shot, and covered with lambskin. Like all bore tools, it was attached to a long handle; after being dampened with water, it was used to clean the barrel of the gun after firing. Basically, sponging ensured there were no sparks in the barrel when the new charge was loaded. Often, the sponge was on the opposite end of the rammer, and sometimes, instead of being covered in lambskin, the sponge was a bristle brush.

The wormer was a double screw, resembling a pair of twisted corkscrews, attached to a long handle. When inserted into the gun bore and twisted, it grabbed and pulled out wads or leftover cartridge bags stuck in the gun after firing. Worm screws were sometimes attached to the head of the sponge, allowing the piece to be sponged and wormed simultaneously.

The ladle was the most important of all the gunner's tools in the early years, since it was not only the measure for the powder but the only way to dump the powder in the bore at the proper place. It was generally made of copper, the same gauge as the windage of the gun; that is, the copper was just thick enough to fit between the ball and the bore.

Essentially, the ladle is just a scoop, a metal cylinder attached to a wooden disk on a long handle. But before the introduction of the powder cartridge, getting the ladle to the right size was one of the most crucial skills a gunner needed to master. Collado, that Spanish mathematician from the sixteenth century, used the culverin ladle as the standard model (fig. 45). It was 4-1/2 calibers long and could hold exactly the weight of the ball in powder. Ladles for smaller guns could be adjusted (that is, shortened) from the standard model.

Figure 44—18TH CENTURY GUNNER'S EQUIPMENT. (Not to scale.)

The scoop full of powder was pushed down into the barrel. Turning the handle dumped the charge, which then had to be packed down with the rammer. As powder charges decreased in later years, the scoop was shortened; by 1750, it was only three shot diameters long. With cartridges, the scoop wasn't needed for loading the gun anymore, but it was still useful for removing the round.

The rammer was a wooden cylinder roughly the same diameter and length as the shot. It was used to compact the powder charge, the wad, and the shot. To prevent mistakes like faulty or double loading, there were marks on the rammer handle that indicated to the loaders when the different components of the charge were correctly positioned.

The (p. 075) gunner's pick or priming wire was a sharp, pointed tool that looked like a regular ice pick blade. It was used to clean out the gun's vent and to poke a hole in the powder bag so that the flame from the primer could ignite the charge.

Figure 45—SIXTEENTH CENTURY PATTERN FOR GUNNER'S LADLE.

Handspikes were large pinch bars used for handling cannon. They helped move the carriage and lift the back of the gun so that the elevating quoin or screw could be adjusted. They came in different types (figs. 33a, 44), but were basically 6-foot-long wooden poles with iron tips. Some, like the Marsilly handspike (fig. 11), had rollers at the end so that the wheelless back of the carriage could be lifted with the handspike and rolled more easily.

The gunner's quadrant (fig. 46), created by Tartaglia around 1545, was a simple aiming device whose principle is still used today. The instrument resembled a carpenter's square, with a quarter-circle joining the two arms. A plumb bob hung from the angle of the square. The gunner would place the long arm of the quadrant in the gun's bore, and the line of the bob against the marked quarter-circle indicated the gun's angle of elevation.

The addition of the quadrant to artillery created an entirely new opportunity for mathematicians, who began creating long, complex, and closely guarded tables to help gunners. But the concept was straightforward: (p. 076) a cannon fired ten times farther at a 45° elevation than it did when the barrel was level (at zero° elevation), so the quadrant should be divided into ten equal sections; thus, the range of the gun would increase by one-tenth each time the gun was raised to the next mark on the quadrant. In other words, the gunner could achieve the desired range simply by adjusting the cannon to the correct mark on the instrument.

Figure 46—17TH CENTURY GUNNER'S QUADRANT. The long end of the quadrant was placed in the cannon's bore. The plumb bob showed the angle of elevation on the scale.

Collado explained how it worked in the 1590s. "We tested a culverin that fired a 20-pound iron ball. At point-blank range, the first shot traveled 200 paces. At a 45-degree angle, it shot ten times farther, or 2,000 paces.... If the point-blank range is 200 paces, then elevating to the first position, or one-tenth of the quadrant, will add 180 paces more, and moving another point will add the same amount again. This is true for all the other points up to the elevation of 45 degrees; each one adds the same 180 paces." Collado acknowledged that results weren't always in line with theory, but it took many years for physicists to grasp how air resistance affected the projectile's trajectory.

Sights on cannons were often noticeably absent in the early days. A dispart sight (a device similar to the modern infantry rifle sight), which accounted for the size difference between the breech and the muzzle, was used in 1610. However, the average artilleryman still aimed by looking over the barrel. The Spanish gunner, on the other hand, performed a technique that aligned the bore with the gunner's line of sight, which was called "killing the vivo" (matar el vivo). The impact of vivo on aiming is clear: when the bore was level, a 4-pounder falconet could shoot up to 250 paces. But when the top of the gun was level, the bore was slightly raised, and the range nearly doubled to 440 paces.

To "kill the vivo," you first had to locate it. The gunner inserted his pick into the vent all the way to the bottom of the bore and marked it to indicate the depth. Then, he moved the pick to the muzzle, stood it upright in the bore, and marked the height of the muzzle. The difference between the two marks, (p. 077) with an adjustment for the base ring (which was higher than the vent), represented the vivo. A small wedge of the appropriate size, placed under the breech, would then remove the pesky vivo.

During the first half of the 1700s, Spanish cannons with the "new invention" had a notch at the top of the base ring and a sighting button on the muzzle, and these features were also picked up by the French. However, they quickly fell out of use. There was some debate, even into the 1750s, about whether the muzzle should be cast to the same size as the base ring, so that the sighting line over the cannon would always be parallel to the bore. But since the cannon usually had to be aimed higher than the target, gunners argued that a wide muzzle obstructed their view of the target!

Figure 47—17TH CENTURY GUNNER'S LEVEL. This tool was handy in various ways, but mainly for determining the line of sight on the gun's barrel.

Common practice for aiming, as late as the 1850s, was to find the center line at the top of the piece, mark it with chalk or filed notches, and use it as a sighting line. To find this center line, the gunner first placed his level (fig. 47) on the base ring, then on the muzzle. When the instrument was level on these rings, the plumb bob was theoretically positioned over the center line of the cannon. However, since guns were poorly made, this line on the outside of the piece didn't always match up perfectly with the center line of the bore, leaving plenty of room for the gunner to apply his skill. Still, the marked lines were helpful, as the gunner learned through trial and error how to adjust for mistakes.

Fixed rear sights were introduced in the early 1800s, and tangent sights (adjustable rear sights) were used during the Civil War. The trunnion sight, which is a graduated sight attached to the trunnion, was helpful when the muzzle had to be elevated so much that it obstructed the gunner's view of the target.

Naval gunnery officers would sometimes order all their guns aimed at the same angle and elevated to the same height. The gunner might not even see the target. While the basic traversing mechanism of the early (p. 078) 1800s meant the gunners might not have aimed their pieces too precisely, it was at least a step toward the indirect firing technique of later years that would fully utilize the longer ranges achievable with modern cannons. The use of tangent and trunnion sights pushed gunnery further into the field of mathematical science; telescopic sights were introduced around the middle of the nineteenth century; gunners were evolving into technicians whose job was mainly to load the piece and adjust the instruments as directed by officers stationed some distance away in fire control posts.

The old-time gunner was not just an artist, far better than the average soldier, but, when the situation allowed, he showcased his skills with great ceremony. Diego Ufano, Governor of Antwerp, observed a gun crew in action around 1500:

"The cannon arrives at the battery with all the necessary materials, and the gunner and his assistants take their positions, while the drummer prepares to play a roll. The gunner carefully cleans the cannon with a dry rammer, and as he pulls it out, he gives it a couple of taps at the mouth to remove any dirt stuck to it." (At this point, it was customary to make the sign of the cross and ask for the help of St. Barbara.)

"Then he has his assistant hold the sack, suitcase, or box of powder, and fills the charger to the top, giving it a slight shake with the other hand to remove any excess, and then places it into the gun as far as it will go. Once that’s done, he turns the charger so that the powder fills the breech and doesn’t spill out onto the ground, because when it catches fire there, it can be very frustrating for the gunner." (And probably for the person holding the sack too.)

"After this, he will take the rammer and insert it into the gun, giving it two or three solid punches to pack the powder tightly into the chamber, while his assistant keeps a finger over the vent to prevent the powder from spilling out. Once that's done, he takes a second charge of powder and puts it in just like the first; then he adds a wad of straw or rags that are packed tightly to absorb any loose powder. After ensuring it’s well seated with strong strikes from the rammer, he sponges out the piece."

"Then the ball, properly cleaned by his assistant, since dirt or sand on the ball poses a risk to the gunner, is placed into the barrel without forcing it until it gently rests on the wad. The gunner must be careful not to position himself in front of the gun, as it's foolish to take unnecessary risks. Finally, he adds one more wad, and with another roll of drums, the gun is ready to fire."

Maximum firing rate for field pieces in the early days was eight rounds an hour. It later increased to 100 rounds a day for light guns and 30 for heavy pieces. (p. 080) (Modern non-automatic guns can fire 15 rounds per minute.) After about 40 rounds, the gun became so hot that it was unsafe to load, at which point it was "refreshed" with an hour's rest.

Figure 48—LOADING A CANNON. Muzzle-loading smoothbore cannons were in use for nearly 700 years.

The approved aiming procedure was to make the first shot definitely short, to get a measurement of the error. The second shot would be at a higher elevation, but still carefully short. After the third round, the gunner could expect to get hits. Beginners were warned against the urge to hit the target on the first shot, because, as a famous artillerist said, "... you will overshoot and can’t estimate how much over."

As gunners gradually became professional soldiers, gun drills took on a more military feel, as these seventeenth-century commands demonstrate:

1. Put your gun back together.
2. Load your gun.
3. Check your gun.
4. Clean your gun.
5. Fill your scoop.
6. Add your powder.
7. Empty your scoop.
8. Store your powder.
9. Seat your wad firmly.
10. Check your shot.
11. Insert your shot gently.
12. Push your wad in with three strokes.
13. Measure your gun.

Gunners had no trouble finding work, as shown by the story of Andrew Ransom, an Englishman captured near St. Augustine in the late 1600s. He was sentenced to death. The execution device failed, (p. 081) and the priests present saw it as an act of God and took Ransom to safety at the friary. Meanwhile, the Spanish governor discovered that Ransom was an artillery expert and a maker of "artificial fires." The governor offered to "protect" him if he would stay at the Castillo and use his skills. Ransom agreed.

Figure 49—A SIEGE BOMBARD FROM THE 1500s.

By 1800, even though it was possible to operate guns with as few as three people, effective drills typically required a much larger team. The smallest crew mentioned in the United States Navy manual of 1866 was seven: a first and second gun captain, two loaders, two spongers, and a "powder monkey" (powder boy). An 11-inch pivot gun on its rotating carriage needed 24 crew members plus one powderman. In the field, moving a 24-pounder siege gun required 10 horses and 5 drivers.

Twelve rounds per hour was good practice for heavy artillery during the Civil War, although that could be increased to 20 rounds. By this time, while the principles of muzzle loading hadn’t changed, the actual loading process was much easier thanks to fixed and semi-fixed ammunition. Loading techniques varied depending on the gun, but the following summary of the drill from the United States Heavy Ordnance Manual of 1861 provides a clear idea of how the crew managed a siege gun:

First of all, make sure all the equipment is in its right place. The cannon is on a two-wheeled carriage and is “in battery,” meaning it’s pushed forward on the platform until the muzzle is positioned in the earthwork opening. On either side of the cannon are three handspikes resting against the parapet. On the right side of the cannon, there’s a sponge and a rammer propped up about 6 feet away from the carriage. Close to the left muzzle of the cannon, there’s a stack of cannonballs, wads, and a "passbox" or powder bucket. Two pouches are hanging from the cascabel: one pouch holds friction "tubes" (the primers for the vent) and the lanyard; the other pouch is the gunner's pouch containing the gunner's level, breech-sight, pick, gimlet, vent-punch, chalk, and fingerstall (a leather cover for the gunner's second left finger when the cannon gets too hot). Under the wheels, there are two chocks; a vent-cover is on the vent, and a tompion is in the muzzle. A broom is leaning against the parapet beyond the stack of cannonballs. A wormer, ladle, and wrench are also part of the battery equipment.

The crew included a gunner and six cannoneers. At the command Take implements, the gunner moved to the cascabel and handed the vent-cover to No. 2; he passed the tube-pouch to No. 3; then he put on his fingerstall, adjusted the gun with the elevating screw, used his level on the base ring and muzzle to find the highest points of the barrel, and marked these points with chalk for a line of sight. His six crew members took their positions about a yard apart, with three men on each side of the gun, ready with handspikes.

From battery was the first command of the drill. The gunner stepped away from the gun, while the handspikemen secured their spikes. Cannoneers Nos. 1, 3, and 5 were on the right side of the gun, and the even-numbered men were on the left. Nos. 1 and 2 placed their spikes under the front of the wheels; Nos. 3 and 4 secured them under the carriage cheeks to press down on the rear spokes of the wheel; Nos. 5 and 6 had their spikes under the maneuvering bolts of the trail to guide the piece away from the parapet. With the gunner's command Heave, the men at the wheels applied pressure, and with repeated heaves, the gun moved backward until the muzzle was a yard clear of the embrasure. The crew then removed their spikes, and Nos. 1 and 2 chocked the wheels.

Figure 50—GUN DRILL IN THE 1850s.

Load was the second command. Numbers 1, 2, and 4 put down their spikes; Number 2 removed the tompion; Number 1 took the sponge and placed its fuzzy end into the muzzle; Number 2 stepped up to the muzzle and grabbed the sponge staff to assist Number 1. In five counts, they pushed the sponge to the bottom of the bore. Meanwhile, Number 4 took the passbox and headed to the magazine for a cartridge. (p. 084)

The gunner placed his finger over the vent and used his right hand to turn the elevating screw, positioning the piece for easy loading. No. 3 picked up the rammer.

At the command Sponge, the crew at the sponge pressed the tool against the bottom of the bore and made three turns to the left, then three turns to the right. Next, the sponge was pulled out, and while No. 1 traded it for No. 3's rammer, No. 2 took the cartridge from No. 4 and placed it in the bore. He assisted No. 1 in pushing it down with the rammer, while No. 4 went to get a ball and, if needed, a wad.

Ram! The guys on the rammer pulled it out an arm's length and slammed the cartridge with one solid hit. No. 2 grabbed the ball from No. 4, while No. 1 tossed out the rammer. With the ball in the barrel, both men took the rammer again to push the shot in and delivered one last solid ram. No. 1 put the rammer back on its stand. The gunner used his pick to pierce the powder bag in the vent.

The command In battery was the signal for the cannoneers to take their positions at the handspikes again, with Nos. 1, 2, 3, and 4 working on the wheels and Nos. 5 and 6 guiding the trail as before. After several heaves, the gunner stopped the piece with the wheels pressing against the hurter—the timber placed at the bottom of the parapet to prevent the wheels from rolling.

Point was the next command. No. 3, the guy with the tube-pouch, took out his lanyard and hooked it to a primer. Nos. 5 and 6 slid their handspikes under the trail, ready to shift the gun left or right. The gunner went to the back of the gun, pulled his pick from the vent, and, looking down the barrel, instructed the spikemen: he would tap the right side of the breech, and No. 5 would pull on his handspike to inch the trail to the left. A tap on the left side would signal No. 6 to move in the opposite direction. Then, the gunner carefully placed the breech-sight (if he needed it) on the chalk line of the base ring and adjusted the elevating screw to the correct height.

As soon as the gun was set up, the gunner called out Ready and signaled with both hands. He removed the breech-sight from the gun and walked to the side where he could see the impact of the shot. Crew members 1 and 2 had the chocks, ready to stop the wheels after the recoil. Crew member 3 placed the primer in the vent, unwound the lanyard, and took a full step back with his left foot. He held the lanyard taut in his right hand.

At Fire! No. 3 gave a quick pull on the lanyard. The gun went off, the carriage jolted back, and Nos. 1 and 2 secured the wheels. No. 3 rewound his lanyard, and the gunner, after observing the shot, went back to his station.

The evolution of heavy weaponry over time is a topic with many intriguing aspects, but this overview has necessarily been concise. It (p. 085) has only been possible to outline the general trends. Most of the compelling details will have to wait for the release of much larger works. However, it is hoped that enough information has been provided here to enhance the experience of exploring the wide range of cannons and projectiles found in the National Park System.

Most technical terms are explained in the text and illustrations (see fig. 51). For easy reference, some important words are defined below:

Ballistics—the study of how projectiles move.

Barbette carriage—in this context, a moveable platform that holds a cannon for firing over a low protective wall.

Bomb, bombshell—see __A_TAG_PLACEHOLDER_0__.

Breechblock—a movable part that closes the back of a cannon.

Caliber—the diameter of the bore; it's also used to indicate the length of the bore. A 30-caliber gun has a bore length that is 30 times the diameter of the bore.

Cartridge—a bag or container that holds a full powder charge for the cannon, and in some cases, it also contains the projectile.

Casemate carriage—in this context, a movable platform in a fort's gunroom (casemate). The gun fired through an opening or slot in the wall of the room.

Chamber—the section of the bore that contains the propelling charge, especially when it has a different diameter from the rest of the bore; in chambered muzzle-loaders, the chamber's diameter was smaller than that of the bore.

Elevation—the angle between the axis of a piece and the horizontal plane.

Fuze—a device used to trigger the explosive in a shell or other projectile.

Grommet—a rope ring used as a cushioning support to keep a cannonball securely in place in the barrel.

Gun—any firearm; more specifically, a long cannon with high muzzle velocity and a flat trajectory.

Howitzer—a short cannon that is in between a gun and a mortar.

Aim a gun.

Limber—a two-wheeled vehicle that the gun trail is connected to for transport.

Mandrel—a metal rod used as a core around which metal can be forged or otherwise shaped.

Mortar—a small cannon designed for firing at a high or curved angle.

Point-blank—as (p. 088) used here, refers to the distance at which the projectile, when shot from a level barrel, first hits the horizontal ground right in front of the cannon.

Projectiles—canister or case shot: a canister filled with small missiles that spread out when fired from the gun. Grape shot: a bunch of small iron balls that scatter when shot. Shell: an explosive missile; a hollow cast-iron ball filled with gunpowder and equipped with a fuse for detonation; a long, hollow projectile filled with explosive material and fitted with a fuse. Shot: a solid projectile that is non-explosive.

Quoin—a wedge put under the back of a gun to secure its angle.

Range—The horizontal distance from a gun to its target or to the point where the projectile first hits the ground. Effective range is the distance at which you can expect effective results, and it's usually not the same as maximum range, which refers to the absolute limit of range.

Rotating band—a band made of soft metal, like copper, that wraps around the projectile near its base. By connecting with the lands of the spiral rifling in the bore, the band makes the projectile spin. Rotating bands for muzzle-loading cannons were expansion rings, and the force of the gunpowder expanded the ring into the rifling grooves.

Train—to aim a firearm.

Trajectory—the curved path that a projectile follows as it travels through the air.

Transom—the horizontal beam that connects the sides of a gun carriage.

Traverse carriage—in this context, a fixed gun mount made up of a gun carriage on a wheeled platform that can rotate around a pivot to aim the gun to the right or left.

Windage—in this context, the difference between the diameter of the shot and the diameter of the bore.

Figure 51—THE PARTS OF A CANNON.

The following is a list of the key sources related to the development of artillery that were referenced in the creation of this booklet. None of the German or Italian sources are included, as very few German or Italian guns were used in this country.

SPANISH ORDNANCE. Luis Collado, "Manual on Artillery" ms., Milan 1592, and Diego Ufano, Artillery, n. p., 1621, provide detailed information on guns from the sixteenth century. Tomás de Morla, Illustrations Related to the Treatise on Artillery, Madrid, 1803, shows materials from the eighteenth century. Thor Borresen, "Spanish Guns and Carriages, 1686-1800" ms., Yorktown, 1938, summarizes changes in Spanish and French artillery during the eighteenth century. Information about the colonial use of cannons can be found in the manuscripts of the Archivo General de Indias as follows: Inventories of the Castillo de San Marcos armament in 1683 (58-2-2,32/2), 1706 (58-1-27,89/2), 1740 (58-1-32), 1763 (86-7-11,19), Zuñiga's report on the 1702 siege of St. Augustine (58-2-8,B3), and Arredondo's "Plan of the City of St. Augustine, Florida" (87-1-1/2, ms. map); along with other works including [Andres Gonzales de Barcía,] Chronological Essay for the General History of Florida, Madrid, 1723; J. T. Connor, editor, Colonial Records of Spanish Florida, Deland, 1930, Vol. II; Manuel de Montiano, Letters of Montiano (Collections of the Georgia Historical Society, v. VII, pt. I), Savannah 1909; and Albert Manucy, "Ordnance Used at Castillo de San Marcos, 1672-1834," St. Augustine, 1939.

ENGLISH ORDNANCE. For detailed information, John Müller’s Treatise of Artillery, London, 1756, is the primary source for eighteenth-century material. William Bourne’s The Arte of Shooting in Great Ordnance, London, 1587, covers sixteenth-century artillery; and the anonymous New Method of Fortification, London, 1748, contains a lot of seventeenth-century information. For colonial artillery data, there’s John Smith’s The Generall Historie of Virginia, New-Englande, and the Summer Isles, Richmond, 1819; [Edward Kimber]’s Late Expedition to the Gates of St. Augustine, Boston, 1935; and C. L. Mowat’s East Florida as a British Province, (p. 092) 1763-1784, Los Angeles, 1939. Charles J. Foulkes’ The Gun-Founders of England, Cambridge, 1937, discusses the construction of early cannon in England.

FRENCH ORDNANCE. M. Surirey de Saint-Remy, Mémoires d'Artillerie, 3rd edition Paris, 1745, is the go-to source for French artillery equipment in the seventeenth and early eighteenth centuries. Col. Favé, Études sur le Passé et l'Avenir de L'Artillerie, Paris, 1863, offers a solid general history. Louis Figurier, Armes de Guerre, Paris, 1870, is also helpful.

UNITED STATES ORDNANCE. A key resource is Louis de Tousard, American Artillerist's Companion, 2 vols., Philadelphia, 1809-13. For insights on the performance and use of artillery during the 1860s, the following sources are helpful: John Gibbon, The Artillerist's Manual, New York, 1863; Q. A. Gillmore, Engineer and Artillery Operations against the Defences of Charleston Harbor in 1863, New York, 1865; his Official Report ... of the Siege and Reduction of Fort Pulaski, Georgia, New York, 1862; and the Official Records of Union and Confederate Armies and Navies. Manuals from that period include: Instruction for Heavy Artillery, U.S., Charleston, 1861; Ordnance Instructions for the United States Navy, Washington, 1866; J. Gorgas, The Ordnance Manual for the Use of the Officers of the Confederate States Army, Richmond, 1863. For developments in the United States after 1860: L. L. Bruff, A Text-book of Ordnance and Gunnery, New York, 1903; F. T. Hines and F. W. Ward, The Service of Coast Artillery, New York, 1910; the U.S. Field Artillery School's Construction of Field Artillery Matériel and General Characteristics of Field Artillery Ammunition, Fort Sill, 1941.

GENERAL. For the history of artillery, as well as more biographical and technical details, there's the Field Artillery School's excellent booklet, History of the Development of Field Artillery Matériel, Fort Sill, 1941. Henry W. L. Hime's The Origin of Artillery, New York, 1915, is very helpful, as is the standard reference, the Encyclopedia Britannica, 1894 edition: Arms and Armour, Artillery, Gunmaking, Gunnery, Gunpowder; 1938 edition: Artillery, Coehoorn, Engines of War, Fireworks, Gribeauval, Gun, Gunnery, Gunpowder, Musket, Ordnance, Rocket, Small arms, and Tartaglia.

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