You could say that it was all the fault of the Chinese. Gunpowder – a mixture of granulated charcoal, saltpeter (potassium nitrate) and sulphur – was discovered in China, in around the 9th century AD. It is said by some to have been a byproduct of alchemical research, but whatever the genesis of this ‘black powder’, it was quickly put to war-like use against invading Mongol hoards, in rockets, hand-thrown bombs, and primitive cannon. Gunpowder, and cannon, arrived in Europe via the Ottoman Empire in the 13th century. Indeed, the learned Franciscan friar, Roger Bacon, O.F.M. (1214-1294) noted more than 100 recipes for various types of gunpowder, which included widely varying proportions of ingredients, and the best kinds of charcoal (hazel or willow seems to have been prefered).
European cannon were superior, not just for their better casting methods, but the invention of ‘corning’ gunpowder. Obviously, it is vital when milling the ingredients of gunpowder together (in a ‘flashless’ mill, using rollers of marble or bronze, for example) to avoid all sparks. Wetting the mixture prevents dust and lowers the chances of ignition; it also forms the powder into a ‘cake’, and when dry this can be broken into grains of carefully controlled sizes, so as to fit the gunpowder for various types of ordnance. Basically, the finer the grains, the smaller the gun. By 1635, the British Government had reached a prefered formula for gunpowder – 75% charcoal, 12.5% saltpetre, 12.5% sulphur. (Note: This is different from ‘modern’ gunpowder – 75% potassium nitrate, 15% charcoal, 10% sulphur). Guns had ceased to be fixed siege engines, or fitted in fortifications, and, being set on wheeled gun carriages, become moveable units of firepower on the battlefield. For example, a 9 pounder gun (a cannon capable of firing an iron shot weighing 9 lbs) could be pulled by two horses and served by a crew of three, although a typical gun crew in the American War of Independence had five members.
The weapons you can see above are replicas of 18th century originals, and belong to members of the Royal Irish Artillery, a modern-day group of American Revolutionary War re-enactors, who are named after a genuine regiment which fought on the British side during the Revolution (1775-1783). The larger of the two weapons shown is a 6 pounder, cast in brass in 2009. The classic shape of this gun would have been recognizable to gunners in the Napoleonic Wars, and even the Crimean War (1853-1856). The solid shot propelled from this muzzle-loaded cannon would have created havoc amongst the ranks of advancing infantry, or squadrons of cavalry which attempted to charge them. One problem is that they produce very large clouds of dense white smoke from the gunpowder charge. This obscures the target that the battery is aiming at, and at the same time reveals their position, leaving them open to being engaged by opposing artillery and infiltration by sharpshooters. The smaller of the two weapons is not a cannon but a 3 pounder howitzer. Howitzers are designed to engage indirect targets, that is, to be fired at high angles, and ‘lob’ their shells (explosive shells are the prefered load) into fortifications, etc. The two staffs you can see leaning against the cannon are the basic tools needed to service the weapon. The sponge is made of lambswool or sheepskin, and is dampened to sponge out residues and hot embers from the barrel; at the other end of the staff is a rammer for seating the wad of hay or similar material, and the cannon ball, firmly on top of the charge. The wadscrew (the staff with helical metal prongs) is used to remove large fragments and ensure the bore is not over-fouled (the combustion of gunpowder leaves many solid chemical residues, such as carbon, potassium carbonate, ammonium carbonate, etc).
I admire the work of the Royal Irish Artillery in bringing knowledge of the Revolutionary War period to a modern audience. Long may they continue to visit our town!