Editing Cannon (section)

== Composition ==
[[file:Cannon-diagram2.svg|thumb|upright|Side elevation of a typical 18th-century cannon]]

Cannons 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.<ref name=kingsbury>{{Cite book |title=An elementary treatise on artillery and infantry |last=Kingsbury |first=Charles P. |year=1849 |publisher=GP Putnam |place=New York |url=https://books.google.com/books?id=z9xVAAAAYAAJ&q=windage&pg=PA59 |oclc=761213440 |access-date=7 November 2020 |archive-date=20 October 2021 |archive-url=https://web.archive.org/web/20211020080058/https://books.google.com/books?id=z9xVAAAAYAAJ&q=windage&pg=PA59 |url-status=live }}</ref>{{rp|61}} 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",<ref name=kingsbury/>{{rp|61}} 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 [[Muzzleloader|muzzle-loading]] as opposed to [[Breech-loading weapon|breech-loading]]—to be used they had to have their ordnance packed down the bore through the muzzle rather than inserted through the breech.

The following terms refer to the components or aspects of a classical western cannon (c. 1850) as illustrated here.<ref name=kingsbury/>{{rp|66}} In what follows, the words ''near'', ''close'', and ''behind'' will refer to those parts towards the thick, closed end of the piece, and ''far'', ''front'', ''in front of'', and ''before'' to the thinner, open end.

=== Negative spaces ===

; Bore: The hollow cylinder bored lengthwise down the centre of the cannon, including the ''base of the bore'' or ''bottom of the bore'', the nearest end of the bore in which the [[Artillery|ordnance]] ([[wadding]], [[Round shot|shot]], etc.) rests just before firing. A cannon's [[Caliber (artillery)|calibre]] is determined by the diameter of its bore.
; Chamber: The cylindrical, conical, or spherical recess at the nearest end of the bottom of the bore into which the [[gunpowder]] is packed.
; Vent: A thin tube on the near end of the cannon connecting the explosive charge inside with an ignition source outside and often filled with a length of [[fuse (explosives)|fuse]]; always located near the ''breech''. Sometimes called the ''fuse hole'' or the ''touch hole''. On the top of the vent on the outside of the cannon is a flat circular space called the ''vent field'' where the charge is lit. If the cannon is bronze, it will often have a ''vent piece'' made of copper screwed into the length of the vent.

=== Solid spaces ===

The main body of a cannon consists of three basic extensions: the foremost and the longest is called the ''chase'', the middle portion is the ''reinforce'', and the closest and briefest portion is the ''[[cascabel (artillery)|cascabel]]'' or ''cascable''.{{citation needed|reason=unusual spelling|date=December 2023}}

The chase is simply the entire conical part of the cannon in front of the ''reinforce''. It is the longest portion of the cannon, and includes the following elements:

; Neck: the narrowest part of the chase, always located near the foremost end of the piece.
; [[Muzzle (firearms)|Muzzle]]: the portion of the chase forward of the ''neck''. It includes the following:
* ''Swell of the muzzle'' refers to the slight swell in the diameter of the piece at the very end of the chase. It is often chamfered on the inside to make loading the cannon easier. In some guns, this element is replaced with a wide ring and is called a ''muzzle band''.
* ''Face'' is the flat vertical plane at the foremost edge of the muzzle (and of the entire piece).
* ''Muzzle mouldings'' are the tiered rings which connect the face with the rest of the muzzle, the first of which is called the ''lip'' and the second the ''fillet''
* ''Muzzle [[astragal]] and fillets'' are a series of three narrow rings running around the outside of the chase just behind the neck. Sometimes also collectively called the ''chase ring''.
; Chase astragal and fillets: these are a second series of such rings located at the near end of the chase.
; Chase girdle: this is the brief length of the chase between the chase astragal and fillets and the ''reinforce''.
; Reinforce: This portion of the piece is frequently divided into a ''first reinforce'' and a ''second reinforce'', but in any case is marked as separate from the chase by the presence of a narrow circular ''reinforce ring'' or ''band'' at its foremost end. The span of the reinforce also includes the following:
* ''[[Trunnions]]'' are located at the foremost end of the reinforce just behind the reinforce ring. They consist of two cylinders perpendicular to the bore and below it which are used to mount the cannon on its carriage.
* ''Rimbases'' are short broad rings located at the union of the trunnions and the cannon which provide support to the carriage attachment.
* ''Reinforce band'' is only present if the cannon has two reinforces, and it divides the first reinforce from the second.
* ''Breech'' refers to the mass of solid metal behind the bottom of the bore extending to the ''base of the breech'' and including the ''base ring''; it also generally refers to the end of the cannon opposite the ''muzzle'', i.e., the location where the explosion of the gunpowder begins as opposed to the opening through which the pressurized gas escapes.
* ''Base ring'' forms a ring at the widest part of the entire cannon at the nearest end of the reinforce just before the ''cascabel''.
; Cascabel: This is that portion of the cannon behind the reinforce(s) and behind the ''base ring''. It includes the following:
* ''Knob'' which is the small spherical terminus of the piece;
* ''Neck'', a short, narrow piece of metal holding out the knob; and
* ''Fillet'', the tiered disk connecting the neck of the cascabel to the ''base of the breech''.
* ''Base of the breech'' is the metal disk that forms the most forward part of the cascabel and rests against the breech itself, right next to the ''base ring''.

To pack a muzzle-loading cannon, first gunpowder is poured down the bore. This is followed by a layer of wadding (often nothing more than paper), and then the cannonball itself. A certain amount of [[windage]] (in this case meaning that the bore is designed slightly wider than the cannonball) allows the ball to fit down the bore, though the greater the windage the less efficient the propulsion of the ball when the gunpowder is ignited. To fire the cannon, the fuse located in the vent is lit, quickly burning down to the gunpowder, which then explodes violently, propelling wadding and ball down the bore and out of the muzzle. A small portion of exploding gas also escapes through the vent, but this does not dramatically affect the total force exerted on the ball.

Any large, [[smoothbore]], muzzle-loading gun—used before the advent of [[breech-loading]], [[rifled]] guns—may be referred to as a cannon, though once standardised names were assigned to different-sized cannon, the term specifically referred to a gun designed to fire a {{convert|42|lb|adj=on}} shot, as distinct from a [[demi-cannon]] – {{convert|32|lb}}, [[culverin]] – {{convert|18|lb}}, or [[demi-culverin]] – {{convert|9|lb}}. ''Gun'' in this context specifically refers to a type of cannon that fires projectiles at high speeds, and usually at relatively low angles;<ref name = "mutuur">{{cite web|url=http://www.merriam-webster.com/dictionary/Gun|title=Definition of "Gun"|access-date=26 May 2008|publisher=[[Merriam-Webster's Dictionary]]|archive-date=4 April 2013|archive-url=https://web.archive.org/web/20130404232706/http://www.merriam-webster.com/dictionary/gun|url-status=live}}</ref> they have been used in warships,<ref>{{cite book|title=Naval Gun|year=1978|publisher=Blandford Press|first=Ian V.|last=Hogg|author2=John H. Batchelor|isbn=978-0-7137-0905-6}}</ref> and as [[field artillery]].<ref>{{cite book|title=The Encyclopædia Britannica A Dictionary of Arts, Sciences, Literature and General Information, volume 2|last=Baynes|first=Thomas S.|year=1888|page=667|access-date=26 May 2008|url=https://books.google.com/books?id=hakMAAAAYAAJ|publisher=H.G. Allen|archive-date=11 July 2012|archive-url=https://web.archive.org/web/20120711155545/http://books.google.com/books?id=hakMAAAAYAAJ|url-status=live}}</ref> The term ''cannon'' is also used for [[autocannon]], a modern repeating weapon firing explosive projectiles. Cannon have been used extensively in fighter aircraft since [[World War II]].<ref name="Aircraft Cannon">{{cite web|url=http://www.defencenews.com.au/article-archive.cfm?ID=513&currentpage=2&detail=yes&thiscatid=0|title=Aircraft cannon|publisher=Strike Publications|author=Carlo Kopp|access-date=26 May 2008|archive-date=6 July 2011|archive-url=https://web.archive.org/web/20110706103251/http://www.defencenews.com.au/article-archive.cfm?ID=513&currentpage=2&detail=yes&thiscatid=0|url-status=live}}</ref>