The Early Origins
A cannon is a type of gun classified as artillery that launches a projectile using propellant. In the past, gunpowder was the primary propellant before the invention of smokeless powder during the 19th century. Cannon vary in caliber, range, mobility, rate of fire, angle of fire, and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. The word cannon is derived from several languages, in which the original definition can usually be translated as tube, cane, or reed. In the modern era, the term cannon has fallen into decline, replaced by guns or artillery if not a more specific term such as howitzer or mortar, except for high calibre automatic weapons firing bigger rounds than machine guns, called autocannons.
The earliest known depiction of cannon appeared in Song dynasty China as early as the 12th century, however solid archaeological and documentary evidence of cannon do not appear until the 13th century. In 1288 Yuan dynasty troops are recorded to have used hand cannons in combat, and the earliest extant cannon bearing a date of production comes from the same period. By the early 14th century, depictions of cannon had appeared in the Middle East and Europe, and almost immediately recorded usage of cannon began appearing. By the end of the 14th century cannon were widespread throughout Eurasia. Cannon were used primarily as anti-infantry weapons until around 1374 when cannon were recorded to have breached walls for the first time in Europe. Cannon featured prominently as siege weapons and ever larger pieces appeared. In 1464 a 16,000 kg (35,000 lbs) cannon known as the Great Turkish Bombard was created in the Ottoman Empire. Cannon as field artillery became more important after 1453 with the introduction of limber, which greatly improved cannon maneuverability and mobility. European cannon reached their longer, lighter, more accurate, and more efficient "classic form" around 1480. This classic European cannon design stayed relatively consistent in form with minor changes until the 1750s.
Cannon in general have the form of a truncated cone with an internal cylindrical bore for holding an explosive charge and a projectile. The thickest, strongest, and closed part of the cone is located near the explosive charge. As any explosive charge will dissipate in all directions equally, the thickest portion of the cannon is useful for containing and directing this force. The backward motion of the cannon as its projectile leaves the bore is termed its recoil and the effectiveness of the cannon can be measured in terms of how much this response can be diminished, though obviously diminishing recoil through increasing the overall mass of the cannon means decreased mobility.
Field artillery cannon in Europe and the Americas were initially made most often of bronze, though later forms were constructed of cast iron and eventually steel. Bronze has several characteristics that made it preferable as a construction material: although it is relatively expensive, does not always alloy well, and can result in a final product that is "spongy about the bore", bronze is more flexible than iron and therefore less prone to bursting when exposed to high pressure; cast iron cannon are less expensive and more durable generally than bronze and withstand being fired more times without deteriorating. However, cast iron cannon have a tendency to burst without having shown any previous weakness or wear, and this makes them more dangerous to operate.
The older and more-stable forms of cannon were muzzle-loading as opposed to breech-loading— in order to be used they had to have their ordnance packed down the bore through the muzzle rather than inserted through the breech.
Round shot or solid shot or a cannonball or simply ball
A solid spherical projectile made, in early times, from dressed stone but, by the 17th century, from iron. The most accurate projectile that could be fired by a smooth-bore cannon, used to batter the wooden hulls of opposing ships, forts, or fixed emplacements, and as a long-range anti-personnel weapon.
Chain shot or Split shot
Two sub-calibre round shot (a good deal smaller than the bore of the barrel) linked by a length of chain or a solid bar, and used to slash through the rigging and sails of an enemy ship so that it could no longer manoeuver. It was inaccurate and only used at close range. Two-headed bullets (angels) were similar but made of two halves of a ball rather than two balls.
An anti-personnel projectile which included many small iron round shot or lead musket balls in a metal can, which broke up when fired, scattering the shot throughout the enemy personnel, like a large shotgun.
Shrapnel or spherical case shot
An iron anti-personnel projectile containing an interior cavity packed with lead or iron round balls around a small bursting charge of just enough force to break open the thin-walled iron projectile. A powder train in a thin iron sleeve led to a time fuse inserted into a holder at the outer edge or the projectile. The fuse was designed to be ignited by flame from the propellant charge. Ideally the case shot fuse would detonate the central bursting charge when the projectile was six to ten feet above the heads of enemy infantry thereby showering them with the iron balls and fragments of the casing. (Invented 1784 by Lt. Henry Shrapnel, Royal Artillery).
An explosive anti-materiel and counter-battery projectile, of iron with a cavity packed with a high explosive bursting charge of powder used to destroy enemy wagons, breastworks, or opposing artillery. Two types of fuses were used—impact fuses that detonated the bursting charge by percussion, and time fuse cut to length measured in seconds and ignited by flame from the propellant charge.
An anti-personnel weapon, similar to canister shot, but with the shot being contained in a canvas bag, and generally of a larger caliber. So called because of the resemblance of the clustered shot in the bag to a cluster of grapes on the vine. In one variation of this, the shot was held together by a coiled bar, and was spread by a fused charge in the same way as a shell. It was very effective against infantry, but its main shortcomings included very short range and ineffectiveness against infantry who had taken cover. Grapeshot was the starting point for the creation of shrapnel.
An incendiary/antipersonnel projectile designed to burn fiercely and produce poisonous fumes. It was constructed of an iron frame bound with sack cloth and filled with various ingredients such as pitch, antimony, sulfur, saltpeter, tallow and Venetian turpentine. It was ignited by the cannon's propellant charge, bursting on impact with the target and releasing noxious fumes while setting fire to its surroundings. It was effectively an early chemical weapon as well as an incendiary and area denial weapon. The name is possibly a reference to the medieval practice of hurling dead animals from trebuchet as a form of biological warfare, or to the projectile's superficial resemblance to a human carcass.
Heated (or hot) shot
A process where a solid iron cannonball is heated red hot in a specially-designed wood- or coal-fired furnace and then is loaded in a muzzle-loading cannon, cushioned by a substantial thickness of wet wads, and is then fired while still red hot, at flammable targets with the intention of setting them on fire. This was a much advocated tactic (and many times a very successful one) for shore-based forts defending against attacks by wooden warships. Examples of these small brick furnaces may still be seen at permanently constructed pre-1860 forts in Europe and the United States. The adoption by most navies of iron-hulled ships generally made these obsolete. The shot was carried on a specially designed iron barrow or two-man litter and, in the era of black-powder cannon charges contained in cloth bags, occasioned much fanfare and notice as it was conveyed to the cannon muzzle as the red-hot projectile would easily ignite any carelessly handled loose powder. Any reckless or somewhat dangerous individual who seemed to draw trouble to themselves and those around them was referred to as a "Hot Shot", giving rise to the term in common use to this day.
Spider shot is a chain shot, but it has many chains instead of just one. It was not often used, despite its effectiveness against small ships and morale.