Black powder

Black powder is a type of gunpowder invented in the 9th century and was practically the only known propellant and explosive until the middle of the 19th century. It has been superseded by more efficient explosives such as smokeless powders and TNT. It is still manufactured today but primarily for use in fireworks, model rocket engines, and reproductions of muzzleloading weapons.

Description

Black powder consists of the granular ingredients sulfur (S), charcoal (provides carbon to the reaction) and saltpeter (saltpetre, potassium nitrate, KNO₃; provides oxygen to the reaction).

The chemical equation for the combustion of Black Powder is

2(KNO₃) + S + 3C → K₂S + N₂ + 3(CO₂)

The optimum proportions for gunpowder are: 74.64% saltpetre, 13.51% charcoal, and 11.85% sulfur (by weight). The current standard for black powder manufactured by pyrotechnicians today is 75% potassium nitrate, 15% softwood charcoal and 10% sulfur.

For the most powerful black powder "meal" a wood charcoal is used. The best wood for the purpose is buckthorn, but others such as balsa or willow can be used. The ingredients are mixed as thoroughly as possible. This is achieved using a ball mill with non-sparking grinding apparatus (lead), or similar device.

Black powder is also corned to change its burn rate. Corning is a process which first compresses the fine black powder "meal" into blocks with a fixed density (1.7 g/cm³). The blocks are then broken up into granules. These granules are then sorted by size to give the various grades of black powder. Standard grades of black powder run from the coarse Fg grade used in large bore rifles and small cannon though FFg (medium and smallbore rifles), FFFg (pistols), and FFFFg (smallbore, short pistols and priming flintlocks). Very coarse black powder was used in mining before the development of nitroglycerine and dynamite.

Although black powder is not a true high explosive, the United States Department of Transportation classifies it as a "Class A High Explosive" for shipment because it is so easily ignited. Highly destructive explosions at fireworks manufacturing plants are rather common events, especially in Asia. Complete manufactured devices containing black powder are usually classified as "Class C Firework", "Class C Model Rocket Engine", etc. for shipment because they are harder to ignite than the loose powder.

History

Gunpowder was invented in China in the 9th century during the late Tang dynasty (618 - 907 CE). The invention appears to have been made accidentally, by alchemists seeking the elixir of immortality, or possibly as a fire starter for the easy ignition of tinder by sparks. The first references to gunpowder appear as warnings in alchemy texts not to mix certain materials together. However these early mixtures contain large amounts of incombustible material, in one recipe, even human sperm! By the 11th century, gunpowder began to be used for military purposes in China in the form of rockets and explosive bombs fired from catapults. The first reference to missile throwing weapons appears in 1259 when bamboo tubes were used to launch baked clay bullets at the enemy. This type of weapon was primarily a nuisance, rather than a danger on the battlefield. Many early mixtures of Chinese gunpowder contained toxic substances such as mercury and arsenic compounds, and could be considered an early form of chemical warfare. The oldest metal cannon in China dates from 1323. From China, the military use of gunpowder appears to have spread to the rest of the world. It was used by the Mongols (1279 - 1368) against the Russians and was mentioned in a European manuscript by Roger Bacon in 1248. The first European reference to cannon is a record of them being exported from Ghent in 1313. By the mid 14th century, early cannons are mentioned extensively both in Europe and in China. However, it was the Europeans who realized that only three ingredients were necessary for effective gunpowder, and who realized the importance of potassium nitrate in the mixture.

In China as in Europe, the use of gunpowder to produce firearms and cannon was delayed by difficulties in creating metal tubes that would contain an explosion. This problem may have led to the myth that the Chinese used their invention only for the manufacture of fireworks. In fact, gunpowder powered cannon and rockets were extensively used in the Mongol conquests of the 13th and 14th centuries and were a feature of East Asian warfare afterwards. The low, thick city walls of Beijing (started in 1406) for example, were specifically designed to withstand an artillery attack, and the Ming dynasty(1368-1644) moved the capital from Nanjing to Beijing in 1421 specifically because the hills around Nanjing were good locations for invaders to place artillery.

The subject of the origins of gunpowder and cannon remains controversial, however, because most of the Chinese written sources are 17th century revisions of earlier texts. Chinese firearms failed to develop beyond the most primitive stage until after contact with European traders. Japanese sources state that hand held firearms were completely unknown (or forgotten) before the Portuguese landed (or rather were shipwrecked) at Tanegashima in 1543. The military adventurism of the Mongols (1279 - 1368) seems to have been the impetus for the development of gunpowder weapons in China, but at the period older forms of siege equipment such as the trebuchet still dominated for some time.

The 15th through 17th century saw widespread development in gunpowder technology mainly in Europe. Advances in metallurgy led to portable weapons and the development of hand-held firearms such as Muskets. Cannon technology in Europe gradually outpaced that of China and these technological improvements transferred back to China through Jesuit missionaries who were put in charge of cannon manufacture by the late Ming and early Qing emperors.

The latter half of the 19th Century saw the invention of nitroglycerin, nitrocellulose and smokeless powders which rapidly led to the replacement of gunpowder in many applications.

See also

• Meal powder
• Green mix
• Smokeless powder
• Early modern warfare
• Gonne

Reference

• Gunpowder: Alchemy, Bombards, & Pyrotechnics by Jack Kelly, Basic Books, ISBN 0-465-03718-6.
• A History of Greek Fire and Gunpowder by J.R. Partington ISBN 0801859549
• Guns and Rifles of the World by Howard Blackmore ISBN 0670357804

External links

• Ulrich Bretscher's Blackpowder page (http://www.musketeer.ch/blackpowder/powder_frameset.html)
• Cannons: That diabolical instrument of war (http://www.middelaldercentret.dk/cannon2.htm)af:Buskruit

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