Cannon
A small cast-iron cannon on a carriage
A cannon is also a modern day machine gun with a calibre of 20mm or more (see autocannon).
The word "cannon" derives from the Latin canna (a tube). The word bombarde was used for cannon but from the early 15th century came to refer only to the largest weapons. The word "cannon" serves both as the singular and plural of the noun; "cannons" is generally considered incorrect.
The use of cannon was first recorded in the battles of the early 14th century, for instance, at the siege of Metz in 1324, and by the English against the Scots in 1327. The earliest listing of firearms in an army inventory is in 1326. But the new weapons' popularity is indicated in that by 1350 cannon were regarded "as common and familiar as any [weapon]". The first cannon were of two types, either small guns of cast bronze or larger banded wrought iron cannon. Developments in gunpowder in the 1400s helped speed the military adoption of cannon. However, the actual effectiveness of these early weapons is not clear; the battle reports of the time tend to exaggerate.
The early cannon did not always fire spherical projectiles. For smaller cannon arrow-like rounds were used in the 14th century, sometimes with brass fin stabilisers or inflammable heads. Initially round shot was made of iron but this was soon replaced with stone balls, particularly for larger pieces due to the cost of metals in the 14th century (this situation lasted until the late 15th century). The round shot were sometimes covered in lead to reduce windage. For anti-personnel use massed lead pellets were quickly adopted, but in extremis any small stones, nails or iron scraps would be used as hailshot.
The introduction of wheeled carriages for cannon did not occur until the 15th century. Prior to then the weapons were mounted on sturdy wooden frames. The largest siege bombards would be strapped down to large timber baulks on earthwork platforms and aimed with either the initial platform or by hammering wedges under the front. Timber props supporting thick wooden planks were positioned to absorb the recoil.
The large amount of gunpowder required made quite a smoky mess. Hope for a calm day so you can continue to see your target
The early big guns were built up from strips of wrought iron, heated until they glowed yellow, and then hammered to weld them together to form the barrel. Rings of iron were forced over the barrel to reinforce it. Smaller guns were cast in brass or bronze, using techniques used for centuries to produce statues. In the 16th century the Dutch developed cast-iron cannon and the technique was imported into England where the first iron cannon was cast in 1543.
Various kinds of shot were fired from cannon:
- round shot, in early times made from dressed stone, but by the 17th century from iron, was the most accurate projectile that could be fired and was used to batter the wooden hulls of opposing ships, forts, or fixed emplacements
- chain shot, two sub-calibre round shot (a good deal smaller than the bore of the barrel) linked by a length of chain, was used to slash through the rigging and sails of an enemy ship so that it could no longer manoeuvre, but was inaccurate and only used at close ranges
- canister or case shot was an antipersonnel weapon included twelve or so small round shot in a metal can, which broke up when fired scattering the shot thoughout the enemy personnel
- grape shot, similar to canister, but with the shot contained in a canvas bag
The military use of cannon declined in the mid-19th century as fabrication technology improved enough to enable the rifling of gun barrels (which in turn required the introduction of breech loading) and the use of the far more destructive explosive shells.
Other large caliber guns (20mm and up) were sometimes called "cannon". During the Second World War, the Royal Air Force fitted 20mm Hispano cannon to its later model fighters. The Luftwaffe also used 20mm and 30mm cannon.
The definition of a modern 'cannon' is entwined with the term 'autocannon', and is a gun with a bore diameter of 20mm or more, capable of, but not always firing explosive ammunition, and generally possessing an automatic loading system of some kind. A typical example is the 25mm 'Bushmaster' cannon mounted on the LAV and Bradley series' of Armoured Vehicles. The caliber of a cannon, which is 20mm minimum, has been a de facto standard since WWII, when heavy machineguns of 12.7mm (0.5") and 13.2mm caliber were used side by side with 20mm and larger guns, which, in contrast to the machineguns, primarily used explosive ammunition.
A modern artillery piece is generally referred to either as a 'gun', or by the name of its specific type; IE: Howitzer.