Terminology and classification

Early gunpowder artillery was known by a bewildering variety of names. (The word cannon became dominant only gradually, and the modern use of the term to describe a gun large enough to fire an explosive shell did not emerge until the 20th century.) The earliest efficient wrought-iron cannon were called bombards or lombards, a term that continued in use well into the 16th century. The term basilisk, the name of a mythical dragonlike beast of withering gaze and flaming breath, was applied to early “long” cannon capable of firing cast-iron projectiles, but, early cannon terminology being anything but consistent, any particularly large and powerful cannon might be called a basilisk.

Founders had early adopted the practice of classifying cannon by the weight of the ball, so that, for example, a 12-pounder fired a 12-pound cannonball. By the 16th century, gunners had adopted the custom of describing the length of a cannon’s bore in calibres, that is, in multiples of the bore diameter. These became basic tools of classification and remained so into the modern era with certain categories of ordnance such as large naval guns. Also by the 16th century, European usage had divided ordnance into three categories according to bore length and the type of projectile fired. The first category was the culverins, “long” guns with bores on the order of 30 calibres or more. The second was the cannons, or cannon-of-battery, named for their primary function of battering down fortress walls; these typically had barrels of 20 to 25 calibres. The third category of ordnance was the pedreros, stone-throwing guns with barrels of as little as eight to 10 calibres that were used in siege and naval warfare.

Mortars were a separate type of ordnance. With very wide bores of even fewer calibres than those of the pedreros, they were used in siege warfare for lobbing balls at a very high trajectory (over 45°). Mortars owed their name to the powder chamber of reduced diameter that was recessed into the breech; this made them similar in appearance to the mortars used to pulverize grain and chemicals by hand. Unlike the longer cannon, mortars were cast with trunnions at the breech and were elevated by placing wedges beneath the muzzle.

Special-purpose shot

Both culverins and cannon-of-battery generally fired cast-iron balls. When fired against masonry walls, heavy iron balls tended to pulverize stone and brick. Large stone cannonballs, on the other hand, were valued for the shock of their impact, which could bring down large pieces of wall. Undercutting the bottom of a wall with iron cannonballs, then using the heavy impact of large stone shot to bring it down, was a standard tactic of siege warfare. (Ottoman gunners were particularly noted for this approach.)

In the 15th century exploding shot was developed by filling hollow cast-iron balls with gunpowder and fitting a fuze that had to be lit just before firing. These ancestors of the modern exploding shell were extremely dangerous to handle, as they were known to explode prematurely or, with equally catastrophic results, jam in the gun barrel. For this reason they were used only in the short-bored mortars.

For incendiary purposes, iron balls were heated red-hot in a fire before loading. (In that case, moist clay was sometimes packed atop the wadding that separated the ball from the powder charge.) Other projectiles developed for special purposes included the carcass, canister, grapeshot, chain shot, and bar shot. The carcass was a thin-walled shell containing incendiary materials. Rounds of canister and grapeshot consisted of numerous small missiles, usually iron or lead balls, held together in various ways for simultaneous loading into the gun but designed to separate upon leaving the muzzle. Because they dispersed widely upon leaving the gun, the projectiles were especially effective at short range against massed troops. Bar shot and chain shot consisted of two heavy projectiles joined by a bar or a chain. Whirling in their trajectories, they were especially effective at sea in cutting the spars and rigging of sailing vessels.

Gunnery

During most of the black-powder era, with smoothbore cannon firing spherical projectiles, artillery fire was never precisely accurate at long ranges. (Aiming and firing were particularly difficult in naval gunnery, since the gunner had to predict the roll of the ship in order to hit the target.) Gunners aimed by sighting along the top of the barrel, or “by the line of metals,” then stepped away before firing to avoid the recoil. The basic relationship between range and elevation being understood, some accuracy was introduced through the use of the gunner’s quadrant, in which the angle of elevation of a gun barrel was measured by inserting one leg of the quadrant into the barrel and reading the angle marked on the scale by a vertically hanging plumb line. Nevertheless, the inherent inaccuracy of smoothbore artillery meant that most shooting was done at short ranges of 1,000 yards or less; at these ranges, estimating elevation by rule of thumb was sufficient. For attacking fortress walls, early modern gunners preferred a range of 60 to 80 yards; a range of 100 to 150 yards was acceptable, but 300 yards or more was considered excessive.

The matchlock

Small arms appeared during the period 1460–80 with the development of mechanisms that applied match to hand-portable weapons. German gunsmiths apparently led the way. The first step was a simple S-shaped “trigger,” called a serpentine, fastened to the side of a hand cannon’s stock. The serpentine was pivoted in the middle and had a set of adjustable jaws, or dogs, on the upper end that held the smoldering end of a length of match. Pulling up on the bottom of the serpentine brought the tip of the match down into contact with powder in the flashpan, a small, saucer-shaped depression surrounding the touchhole atop the barrel. This arrangement made it possible for one gunner to aim and fire, and it was quickly improved on. The first and most basic change was the migration of the touchhole to the right side of the barrel, where it was served by a flashpan equipped with a hinged or pivoting cover that protected the priming powder from wind, rain, and rough handling. The serpentine was replaced by a mechanism, enclosed within the gunstock, that consisted of a trigger, an arm holding the match with its adjustable jaws at the end, a sear connecting trigger and arm, and a mechanical linkage opening the flashpan cover as the match descended. These constituted the matchlock, and they made possible modern small arms.

One final refinement was a spring that drove the arm holding the match downward into the pan when released by the sear. This mechanism, called the snap matchlock, was the forerunner of the flintlock. The fabrication of these devices fell to locksmiths, the only sizable body of craftsmen accustomed to constructing metal mechanisms with the necessary ruggedness and precision. They gave to the firing mechanism the enduring name lock.

The development of mechanical locks was accompanied by the evolution of gunstocks with proper grips and an enlarged butt to transmit the recoil to the user’s body. The result was the matchlock harquebus, the dominant military small arm of the 15th century and the direct ancestor of the modern musket. The harquebus was at first butted to the breastbone, but, as the power of firearms increased, the advantages of absorbing the recoil on the shoulder came to be appreciated. The matchlock harquebus changed very little in its essentials until it was replaced by the flintlock musket in the final years of the 17th century.

The wheel lock

The principal difficulty with the matchlock mechanism was the need to keep a length of match constantly smoldering. German gunsmiths addressed themselves to this problem early in the 16th century. The result was the wheel lock mechanism, consisting of a serrated wheel rotated by a spring and a spring-loaded set of jaws that held a piece of iron pyrites against the wheel. Pulling the trigger caused the wheel to rotate, directing a shower of sparks into the flashpan. The wheel lock firearm could be carried in a holster and kept ready to fire indefinitely, but, being delicate and expensive, it did not spread beyond cavalry elites and had a limited impact on warfare as a whole.