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Gunpowder facts for kids

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Black Powder-1
Gunpowder for muzzleloading firearms in granulation size
Veterans Weekend, Hull - panoramio
American Civil War re-enactors volley firing with black powder
Zündkraut mit Zündkrautspender
Flash pan starter dispenser

Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate (saltpeter). The sulfur and charcoal act as fuels while the saltpeter is an oxidizer. Gunpowder has been widely used as a propellant in firearms, artillery, rocketry, and pyrotechnics, including use as a blasting agent for explosives in quarrying, mining, building pipelines, tunnels, and roads.

Gunpowder is classified as a low explosive because of its relatively slow decomposition rate, low ignition temperature and consequently low brisance (breaking/shattering). Low explosives deflagrate (i.e., burn at subsonic speeds), whereas high explosives detonate, producing a supersonic shockwave. Ignition of gunpowder packed behind a projectile generates enough pressure to force the shot from the muzzle at high speed, but usually not enough force to rupture the gun barrel. It thus makes a good propellant but is less suitable for shattering rock or fortifications with its low-yield explosive power. Nonetheless, it was widely used to fill fused artillery shells (and used in mining and civil engineering projects) until the second half of the 19th century, when the first high explosives were put into use.

Gunpowder is one of the Four Great Inventions of China. Originally developed by Taoists for medicinal purposes, it was first used for warfare around AD 904. Its use in weapons has declined due to smokeless powder replacing it, whilst its relative inefficiency led to newer alternatives such as dynamite and ammonium nitrate/fuel oil replacing it in industrial applications.

Effect

Gunpowder is a low explosive: it does not detonate, but rather deflagrates (burns quickly). This is an advantage in a propellant device, where one does not desire a shock that would shatter the gun and potentially harm the operator; however, it is a drawback when an explosion is desired. In that case, the propellant (and most importantly, gases produced by its burning) must be confined. Since it contains its own oxidizer and additionally burns faster under pressure, its combustion is capable of bursting containers such as a shell, grenade, or improvised "pipe bomb" or "pressure cooker" casings to form shrapnel.

In quarrying, high explosives are generally preferred for shattering rock. However, because of its low brisance, gunpowder causes fewer fractures and results in more usable stone compared to other explosives, making it useful for blasting slate, which is fragile, or monumental stone such as granite and marble. Gunpowder is well suited for blank rounds, signal flares, burst charges, and rescue-line launches. It is also used in fireworks for lifting shells, in rockets as fuel, and in certain special effects.

Combustion converts less than half the mass of gunpowder to gas; most of it turns into particulate matter. Some of it is ejected, wasting propelling power, fouling the air, and generally being a nuisance (giving away a soldier's position, generating fog that hinders vision, etc.). Some of it ends up as a thick layer of soot inside the barrel, where it also is a nuisance for subsequent shots, and a cause of jamming an automatic weapon. Moreover, this residue is hygroscopic, and with the addition of moisture absorbed from the air forms a corrosive substance. The soot contains potassium oxide or sodium oxide that turns into potassium hydroxide, or sodium hydroxide, which corrodes wrought iron or steel gun barrels. Gunpowder arms therefore require thorough and regular cleaning to remove the residue.

Gunpowder loads can be used in modern firearms as long as they are not gas-operated. The most compatible modern guns are smoothbore-barreled shotguns that are long-recoil operated with chrome-plated essential parts such as barrels and bores. Such guns have minimal fouling and corrosion and are easier to clean.

History

Chinese Gunpowder Formula
Earliest known written formula for gunpowder, from the Wujing Zongyao of 1044 AD.
てつはう(震天雷)
Stoneware bombs, known in Japanese as Tetsuhau (iron bomb), or in Chinese as Zhentianlei (thunder crash bomb), excavated from the Takashima shipwreck, October 2011, dated to the Mongol invasions of Japan (1274–1281 AD).

China

Ming Dynasty eruptor proto-cannon
A 'flying-cloud thunderclap-eruptor' firing thunderclap bombs from the Huolongjing

The first confirmed reference to what can be considered gunpowder in China occurred in the 9th century during the Tang dynasty, first in a formula contained in the Taishang Shengzu Jindan Mijue (Chinese: 太上聖祖金丹秘訣) in 808, and then about 50 years later in a Daoist text known as the Zhenyuan miaodao yaolüe (真元妙道要略). The Taishang Shengzu Jindan Mijue mentions a formula composed of six parts sulfur to six parts saltpeter to one part birthwort herb. According to the Zhenyuan miaodao yaolüe, "Some have heated together sulfur, realgar and saltpeter with honey; smoke and flames result, so that their hands and faces have been burnt, and even the whole house where they were working burned down." Based on these Taoist texts, the invention of gunpowder by Chinese alchemists was likely an accidental byproduct from experiments seeking to create the elixir of life. This experimental medicine origin is reflected in its Chinese name huoyao (Chinese: 火药/火藥; pinyin: huǒ yào), which means "fire medicine". Saltpeter was known to the Chinese by the mid-1st century AD and was primarily produced in the provinces of Sichuan, Shanxi, and Shandong. There is strong evidence of the use of saltpeter and sulfur in various medicinal combinations. A Chinese alchemical text dated 492 noted saltpeter burnt with a purple flame, providing a practical and reliable means of distinguishing it from other inorganic salts, thus enabling alchemists to evaluate and compare purification techniques; the earliest Latin accounts of saltpeter purification are dated after 1200.

The earliest chemical formula for gunpowder appeared in the 11th century Song dynasty text, Wujing Zongyao (Complete Essentials from the Military Classics), written by Zeng Gongliang between 1040 and 1044. The Wujing Zongyao provides encyclopedia references to a variety of mixtures that included petrochemicals—as well as garlic and honey. A slow match for flame-throwing mechanisms using the siphon principle and for fireworks and rockets is mentioned. The mixture formulas in this book contain at most 50% saltpeternot enough to create an explosion, they produce an incendiary instead. The Essentials was written by a Song dynasty court bureaucrat and there is little evidence that it had any immediate impact on warfare; there is no mention of its use in the chronicles of the wars against the Tanguts in the 11th century, and China was otherwise mostly at peace during this century. However, it had already been used for fire arrows since at least the 10th century. Its first recorded military application dates its use to 904 in the form of incendiary projectiles. In the following centuries various gunpowder weapons such as bombs, fire lances, and the gun appeared in China. Explosive weapons such as bombs have been discovered in a shipwreck off the shore of Japan dated from 1281, during the Mongol invasions of Japan.

By 1083 the Song court was producing hundreds of thousands of fire arrows for their garrisons. Bombs and the first proto-guns, known as "fire lances", became prominent during the 12th century and were used by the Song during the Jin-Song Wars. Fire lances were first recorded to have been used at the Siege of De'an in 1132 by Song forces against the Jin. In the early 13th century the Jin used iron-casing bombs. Projectiles were added to fire lances, and re-usable fire lance barrels were developed, first out of hardened paper, and then metal. By 1257 some fire lances were firing wads of bullets. In the late 13th century metal fire lances became 'eruptors', proto-cannons firing co-viative projectiles (mixed with the propellant, rather than seated over it with a wad), and by 1287 at the latest, had become true guns, the hand cannon.

Middle East

According to Iqtidar Alam Khan, the Mongols introduced gunpowder in their invasion of Persia and Mesopotamia. The Muslims acquired knowledge of gunpowder sometime between 1240 and 1280, by which point the Syrian Hasan al-Rammah had written recipes, instructions for the purification of saltpeter, and descriptions of gunpowder incendiaries. It is implied by al-Rammah's usage of "terms that suggested he derived his knowledge from Chinese sources" and his references to saltpeter as "Chinese snow" (Arabic: ثلج الصين thalj al-ṣīn), fireworks as "Chinese flowers", and rockets as "Chinese arrows", that knowledge of gunpowder arrived from China. However, because al-Rammah attributes his material to "his father and forefathers", Ahmad Y. al-Hassan argues that gunpowder became prevalent in Syria and Egypt by "the end of the twelfth century or the beginning of the thirteenth". In Persia saltpeter was known as "Chinese salt" (Persian: نمک چینی}, romanized: namak-i chīnī) or "salt from Chinese salt marshes" (نمک شوره چینی namak-i shūra-yi chīnī).

Hasan al-Rammah included 107 gunpowder recipes in The Book of Military Horsemanship and Ingenious War Devices (Arabic: الـفـروسـيـة و الـمـنـاصـب الـحـربـيـة, romanized: al-Furūsiyya wal-Manāsib al-Ḥarbiyya), 22 of which are for rockets. The median of 17 of these 22 compositions for rockets (75% nitrates, 9.06% sulphur, and 15.94% charcoal) are nearly identical to the modern reported ideal recipe of 75% potassium nitrate, 10% sulphur, and 15% charcoal. The text also mentions fuses, incendiary bombs, naphtha pots, fire lances, and an illustration and description of the earliest torpedo. The torpedo was called the "egg which moves itself and burns". Two iron sheets were fastened together and tightened using felt. The flattened, pear-shaped vessel was filled with gunpowder, metal filings, "good mixtures", two rods, and a large rocket for propulsion. Judging by the illustration, it was supposed to glide across the water. Fire lances were used in battles between the Muslims and Mongols in 1299 and 1303.

Al-Hassan claims that in the Battle of Ain Jalut of 1260, the Mamluk Sultanate used "the first cannon in history" against the Mongols, utilizing a formula with near-identical ideal composition ratios for explosive gunpowder. Other historians urge caution regarding claims of Islamic firearms use in the 1204–1324 period, as late medieval Arabic texts used the same word for gunpowder, naft, that they used for an earlier incendiary, naphtha.

The earliest surviving documentary evidence for cannons in the Islamic world is from an Arabic manuscript dated to the early 14th century. The author's name is uncertain but may have been Shams al-Din Muhammad, who died in 1350. Dating from around 1320–1350, the illustrations show gunpowder weapons such as gunpowder arrows, bombs, fire tubes, and fire lances or proto-guns. The manuscript describes a type of gunpowder weapon called a midfa which uses gunpowder to shoot projectiles out of a tube at the end of a stock. Some consider this a cannon, while others do not. The problem with identifying cannons in early 14th-century Arabic texts is the term midfa, which appears from 1342 to 1352 but cannot be proven to be true hand-guns or bombards. Contemporary accounts of a metal-barrel cannon in the Islamic world do not occur until 1365. Needham believes that in its original form the term midfa refers to the tube or cylinder of a naphtha projector (flamethrower). After the invention of gunpowder, it meant the tube of fire lances, and eventually it applied to the cylinder of hand-guns and cannons.

According to Paul E. J. Hammer, the Mamluk Sultanate certainly used cannons by 1342. According to J. Lavin, cannons were used by Moors at the siege of Algeciras in 1343. Shihab al-Din Abu al-Abbas al-Qalqashandi described a metal cannon firing an iron ball between 1365 and 1376.

The musket appeared in the Ottoman Empire by 1465. In 1598, Chinese writer Zhao Shizhen described Turkish muskets as being superior to European muskets. The Chinese military work Wubei Zhi (1621) later described Turkish muskets that used a rack and pinion mechanism, which was not known to have been used in European or Chinese firearms at the time.

The state-controlled manufacture of gunpowder by the Ottoman Empire through early supply chains to obtain nitre, sulphur and high-quality charcoal from oaks in Anatolia contributed significantly to its expansion between the 15th and 18th centuries. It was not until later in the 19th century that the systemic production of Turkish gunpowder was reduced considerably, coinciding with the decline of its military might.

Europe

EarlyCannonDeNobilitatibusSapientiiEtPrudentiisRegumManuscriptWalterdeMilemete1326
Earliest depiction of a European cannon, "De Nobilitatibus Sapientii Et Prudentiis Regum", Walter de Milemete, 1326.
De la pirotechnia 1540 Title Page AQ1 (1)
De la pirotechnia, 1540

The earliest Western accounts of gunpowder appear in texts written by English philosopher Roger Bacon in 1267 called Opus Majus and Opus Tertium. The oldest written recipes in continental Europe were recorded under the name Marcus Graecus or Mark the Greek between 1280 and 1300 in the Liber Ignium, or Book of Fires.

Some sources mention possible gunpowder weapons being deployed by the Mongols against European forces at the Battle of Mohi in 1241. Professor Kenneth Warren Chase credits the Mongols for introducing into Europe gunpowder and its associated weaponry. However, there is no clear route of transmission, and while the Mongols are often pointed to as the likeliest vector, Timothy May points out that "there is no concrete evidence that the Mongols used gunpowder weapons on a regular basis outside of China." May also states, "however [, ...] the Mongols used the gunpowder weapon in their wars against the Jin, the Song and in their invasions of Japan."

Records show that, in England, gunpowder was being made in 1346 at the Tower of London; a powder house existed at the Tower in 1461, and in 1515 three King's gunpowder makers worked there. Gunpowder was also being made or stored at other royal castles, such as Portchester. The English Civil War (1642–1645) led to an expansion of the gunpowder industry, with the repeal of the Royal Patent in August 1641.

In late 14th century Europe, gunpowder was improved by corning, the practice of drying it into small clumps to improve combustion and consistency. During this time, European manufacturers also began regularly purifying saltpeter, using wood ashes containing potassium carbonate to precipitate calcium from their dung liquor, and using ox blood, alum, and slices of turnip to clarify the solution.

During the Renaissance, two European schools of pyrotechnic thought emerged, one in Italy and the other at Nuremberg, Germany. In Italy, Vannoccio Biringuccio, born in 1480, was a member of the guild Fraternita di Santa Barbara but broke with the tradition of secrecy by setting down everything he knew in a book titled De la pirotechnia, written in vernacular. It was published posthumously in 1540, with 9 editions over 138 years, and also reprinted by MIT Press in 1966.

By the mid-17th century fireworks were used for entertainment on an unprecedented scale in Europe, being popular even at resorts and public gardens. With the publication of Deutliche Anweisung zur Feuerwerkerey (1748), methods for creating fireworks were sufficiently well-known and well-described that "Firework making has become an exact science." In 1774 Louis XVI ascended to the throne of France at age 20. After he discovered that France was not self-sufficient in gunpowder, a Gunpowder Administration was established; to head it, the lawyer Antoine Lavoisier was appointed. Although from a bourgeois family, after his degree in law Lavoisier became wealthy from a company set up to collect taxes for the Crown; this allowed him to pursue experimental natural science as a hobby.

Without access to cheap saltpeter (controlled by the British), for hundreds of years France had relied on saltpetremen with royal warrants, the droit de fouille or "right to dig", to seize nitrous-containing soil and demolish walls of barnyards, without compensation to the owners. This caused farmers, the wealthy, or entire villages to bribe the petermen and the associated bureaucracy to leave their buildings alone and the saltpeter uncollected. Lavoisier instituted a crash program to increase saltpeter production, revised (and later eliminated) the droit de fouille, researched best refining and powder manufacturing methods, instituted management and record-keeping, and established pricing that encouraged private investment in works. Although saltpeter from new Prussian-style putrefaction works had not been produced yet (the process taking about 18 months), in only a year France had gunpowder to export. A chief beneficiary of this surplus was the American Revolution. By careful testing and adjusting the proportions and grinding time, powder from mills such as at Essonne outside Paris became the best in the world by 1788, and inexpensive.

Two British physicists, Andrew Noble and Frederick Abel, worked to improve the properties of gunpowder during the late 19th century. This formed the basis for the Noble-Abel gas equation for internal ballistics.

The introduction of smokeless powder in the late 19th century led to a contraction of the gunpowder industry. After the end of World War I, the majority of the British gunpowder manufacturers merged into a single company, "Explosives Trades limited", and a number of sites were closed down, including those in Ireland. This company became Nobel Industries Limited, and in 1926 became a founding member of Imperial Chemical Industries. The Home Office removed gunpowder from its list of Permitted Explosives. Shortly afterwards, on 31 December 1931, the former Curtis & Harvey's Glynneath gunpowder factory at Pontneddfechan in Wales closed down. The factory was demolished by fire in 1932. The last remaining gunpowder mill at the Royal Gunpowder Factory, Waltham Abbey was damaged by a German parachute mine in 1941 and it never reopened. This was followed by the closure and demolition of the gunpowder section at the Royal Ordnance Factory, ROF Chorley, at the end of World War II, and of ICI Nobel's Roslin gunpowder factory which closed in 1954. This left ICI Nobel's Ardeer site in Scotland, which included a gunpowder factory, as the only factory in Great Britain producing gunpowder. The gunpowder area of the Ardeer site closed in October 1976.

India

Rocket warfare
In the year 1780 the British began to annex the territories of the Sultanate of Mysore, during the Second Anglo-Mysore War. The British battalion was defeated during the Battle of Guntur, by the forces of Hyder Ali, who effectively used Mysorean rockets and rocket artillery against the closely massed British forces.

Gunpowder and gunpowder weapons were transmitted to India through the Mongol invasions of India. The Mongols were defeated by Alauddin Khalji of the Delhi Sultanate, and some of the Mongol soldiers remained in northern India after their conversion to Islam. It was written in the Tarikh-i Firishta (1606–1607) that Nasiruddin Mahmud the ruler of the Delhi Sultanate presented the envoy of the Mongol ruler Hulegu Khan with a dazzling pyrotechnics display upon his arrival in Delhi in 1258. Nasiruddin Mahmud tried to express his strength as a ruler and tried to ward off any Mongol attempt similar to the Siege of Baghdad (1258). Firearms known as top-o-tufak also existed in many Muslim kingdoms in India by as early as 1366. From then on the employment of gunpowder warfare in India was prevalent, with events such as the "Siege of Belgaum" in 1473 by Sultan Muhammad Shah Bahmani.

The shipwrecked Ottoman Admiral Seydi Ali Reis is known to have introduced the earliest type of matchlock weapons, which the Ottomans used against the Portuguese during the Siege of Diu (1531). After that, a diverse variety of firearms, large guns in particular, became visible in Tanjore, Dacca, Bijapur, and Murshidabad. Guns made of bronze were recovered from Calicut (1504)- the former capital of the Zamorins

Meister der Shâh-Jahân-Nâma-Memoiren 001
Mughal Emperor Shah Jahan, hunting deer using a matchlock

The Mughal emperor Akbar mass-produced matchlocks for the Mughal Army. Akbar is personally known to have shot a leading Rajput commander during the Siege of Chittorgarh. The Mughals began to use bamboo rockets (mainly for signalling) and employ sappers: special units that undermined heavy stone fortifications to plant gunpowder charges.

The Mughal Emperor Shah Jahan is known to have introduced much more advanced matchlocks, their designs were a combination of Ottoman and Mughal designs. Shah Jahan also countered the British and other Europeans in his province of Gujarāt, which supplied Europe saltpeter for use in gunpowder warfare during the 17th century. Bengal and Mālwa participated in saltpeter production. The Dutch, French, Portuguese, and English used Chhapra as a center of saltpeter refining.

Ever since the founding of the Sultanate of Mysore by Hyder Ali, French military officers were employed to train the Mysore Army. Hyder Ali and his son Tipu Sultan were the first to introduce modern cannons and muskets, their army was also the first in India to have official uniforms. During the Second Anglo-Mysore War Hyder Ali and his son Tipu Sultan unleashed the Mysorean rockets at their British opponents effectively defeating them on various occasions. The Mysorean rockets inspired the development of the Congreve rocket, which the British widely used during the Napoleonic Wars and the War of 1812.

Southeast Asia

Madrid canons indiens
A double barrelled cetbang on a carriage, with swivel yoke, ca. 1522. The mouth of the cannon is in the shape of Javanese Nāga.

Cannons were introduced to Majapahit when Kublai Khan's Chinese army under the leadership of Ike Mese sought to invade Java in 1293. History of Yuan mentioned that the Mongol used cannons (Chinese: 炮—Pào) against Daha forces. Cannons were used by the Ayutthaya Kingdom in 1352 during its invasion of the Khmer Empire. Within a decade large quantities of gunpowder could be found in the Khmer Empire. By the end of the century firearms were also used by the Trần dynasty.

Even though the knowledge of making gunpowder-based weapons was known after the failed Mongol invasion of Java, and the predecessor of firearms, the pole gun (bedil tombak), is recorded as being used by Java in 1413, the knowledge of making "true" firearms came much later, after the middle of the 15th century. It was brought by the Islamic nations of West Asia, most probably the Arabs. The precise year of introduction is unknown, but it may be safely concluded to be no earlier than 1460. Before the arrival of the Portuguese in Southeast Asia, the natives already possessed primitive firearms, the Java arquebus. Portuguese influence to local weaponry after the capture of Malacca (1511) resulted in a new type of hybrid tradition matchlock firearm, the istinggar.

When the Portuguese came to the archipelago, they referred to the breech-loading swivel gun as berço, while the Spaniards call it verso. By the early 16th century, the Javanese already locally producing large guns, some of them still survived until the present day and dubbed as "sacred cannon" or "holy cannon". These cannons varied between 180- and 260-pounders, weighing anywhere between 3 and 8 tons, length of them between 3 and 6 m.

Saltpeter harvesting was recorded by Dutch and German travelers as being common in even the smallest villages and was collected from the decomposition process of large dung hills specifically piled for the purpose. The Dutch punishment for possession of non-permitted gunpowder appears to have been amputation. Ownership and manufacture of gunpowder was later prohibited by the colonial Dutch occupiers. According to colonel McKenzie quoted in Sir Thomas Stamford Raffles', The History of Java (1817), the purest sulfur was supplied from a crater from a mountain near the straits of Bali.

Chemistry

A simple, commonly cited, chemical equation for the combustion of gunpowder is:

2 KNO3 + S + 3 CK2S + N2 + 3 CO2.

A balanced, but still simplified, equation is:

10 KNO3 + 3 S + 8 C → 2 K2CO3 + 3 K2SO4 + 6 CO2 + 5 N2.

The exact percentages of ingredients varied greatly through the medieval period as the recipes were developed by trial and error, and needed to be updated for changing military technology.

Gunpowder does not burn as a single reaction, so the byproducts are not easily predicted. One study showed that it produced (in order of descending quantities) 55.91% solid products: potassium carbonate, potassium sulfate, potassium sulfide, sulfur, potassium nitrate, potassium thiocyanate, carbon, ammonium carbonate and 42.98% gaseous products: carbon dioxide, nitrogen, carbon monoxide, hydrogen sulfide, hydrogen, methane, 1.11% water.

Gunpowder made with less-expensive and more plentiful sodium nitrate instead of potassium nitrate (in appropriate proportions) works just as well. Gunpowder releases 3 megajoules per kilogram and contains its own oxidant. This is less than TNT (4.7 megajoules per kilogram), or gasoline (47.2 megajoules per kilogram in combustion, but gasoline requires an oxidant; for instance, an optimized gasoline and O2 mixture releases 10.4 megajoules per kilogram, taking into account the mass of the oxygen).

Gunpowder also has a low energy density compared to modern "smokeless" powders, and thus to achieve high energy loadings, large amounts are needed with heavy projectiles.

Production

Irvinepowderhouse2
The old Powder or Pouther magazine dating from 1642, built by order of Charles I. Irvine, North Ayrshire, Scotland

For the most powerful black powder, meal powder, a wood charcoal is used. The best wood for the purpose is Pacific willow, but others such as alder or buckthorn can be used. In Great Britain between the 15th and 19th centuries charcoal from alder buckthorn was greatly prized for gunpowder manufacture; cottonwood was used by the American Confederate States. The ingredients are reduced in particle size and mixed as intimately as possible. Originally, this was with a mortar-and-pestle or a similarly operating stamping-mill, using copper, bronze or other non-sparking materials, until supplanted by the rotating ball mill principle with non-sparking bronze or lead. Historically, a marble or limestone edge runner mill, running on a limestone bed, was used in Great Britain; however, by the mid 19th century this had changed to either an iron-shod stone wheel or a cast iron wheel running on an iron bed. The mix was dampened with alcohol or water during grinding to prevent accidental ignition. This also helps the extremely soluble saltpeter to mix into the microscopic pores of the very high surface-area charcoal.

Hagley Mill Equipment
Edge-runner mill in a restored mill, at The Hagley Museum
Martello Tower barrels
Gunpowder storing barrels at the Martello tower in Point Pleasant Park, Halifax, Nova Scotia, Canada
Barout khaneh near Tehran by Eugène Flandin
1840 drawing of a gunpowder magazine near Tehran, Persia. Gunpowder was extensively used in the Naderian Wars.

Around the late 14th century, European powdermakers first began adding liquid during grinding to improve mixing, reduce dust, and with it the risk of explosion. The powder-makers would then shape the resulting paste of dampened gunpowder, known as mill cake, into corns, or grains, to dry. Not only did corned powder keep better because of its reduced surface area, gunners also found that it was more powerful and easier to load into guns. Before long, powder-makers standardized the process by forcing mill cake through sieves instead of corning powder by hand.

The improvement was based on reducing the surface area of a higher density composition. At the beginning of the 19th century, makers increased density further by static pressing. They shoveled damp mill cake into a two-foot square box, placed this beneath a screw press and reduced it to half its volume. "Press cake" had the hardness of slate. They broke the dried slabs with hammers or rollers, and sorted the granules with sieves into different grades. In the United States, Eleuthere Irenee du Pont, who had learned the trade from Lavoisier, tumbled the dried grains in rotating barrels to round the edges and increase durability during shipping and handling. (Sharp grains rounded off in transport, producing fine "meal dust" that changed the burning properties.)

Another advance was the manufacture of kiln charcoal by distilling wood in heated iron retorts instead of burning it in earthen pits. Controlling the temperature influenced the power and consistency of the finished gunpowder. In 1863, in response to high prices for Indian saltpeter, DuPont chemists developed a process using potash or mined potassium chloride to convert plentiful Chilean sodium nitrate to potassium nitrate.

The following year (1864) the Gatebeck Low Gunpowder Works in Cumbria (Great Britain) started a plant to manufacture potassium nitrate by essentially the same chemical process. This is nowadays called the 'Wakefield Process', after the owners of the company. It would have used potassium chloride from the Staßfurt mines, near Magdeburg, Germany, which had recently become available in industrial quantities.

During the 18th century, gunpowder factories became increasingly dependent on mechanical energy. Despite mechanization, production difficulties related to humidity control, especially during the pressing, were still present in the late 19th century. A paper from 1885 laments that "Gunpowder is such a nervous and sensitive spirit, that in almost every process of manufacture it changes under our hands as the weather changes." Pressing times to the desired density could vary by a factor of three depending on the atmospheric humidity.

Legal status

The United Nations Recommendations on the Transport of Dangerous Goods and national transportation authorities, such as United States Department of Transportation, have classified gunpowder (black powder) as a Group A: Primary explosive substance for shipment because it ignites so easily. Complete manufactured devices containing black powder are usually classified as Group D: Secondary detonating substance, or black powder, or article containing secondary detonating substance, such as firework, class D model rocket engine, etc., for shipment because they are harder to ignite than loose powder. As explosives, they all fall into the category of Class 1.

Other uses

Besides its use as a propellant in firearms and artillery, black powder's other main use has been as a blasting powder in quarrying, mining, and road construction (including railroad construction). During the 19th century, outside of war emergencies such as the Crimean War or the American Civil War, more black powder was used in these industrial uses than in firearms and artillery. Dynamite gradually replaced it for those uses. Today, industrial explosives for such uses are still a huge market, but most of the market is in newer explosives rather than black powder.

Beginning in the 1930s, gunpowder or smokeless powder was used in rivet guns, stun guns for animals, cable splicers and other industrial construction tools. The "stud gun", a powder-actuated tool, drove nails or screws into solid concrete, a function not possible with hydraulic tools, and today is still an important part of various industries, but the cartridges usually use smokeless powders. Industrial shotguns have been used to eliminate persistent material rings in operating rotary kilns (such as those for cement, lime, phosphate, etc.) and clinker in operating furnaces, and commercial tools make the method more reliable.

Gunpowder has occasionally been employed for other purposes besides weapons, mining, fireworks and construction:

  • After the Battle of Aspern-Essling (1809), Dominique-Jean Larrey, the surgeon of the Napoleonic Army, lacking salt, seasoned a horse meat bouillon for the wounded under his care with gunpowder. It was also used for sterilization in ships when there was no alcohol.
  • British sailors used gunpowder to create tattoos when ink wasn't available, by pricking the skin and rubbing the powder into the wound in a method known as traumatic tattooing.
  • Christiaan Huygens experimented with gunpowder in 1673 in an early attempt to build an gunpowder engine, but he did not succeed. Modern attempts to recreate his invention were similarly unsuccessful.
  • Near London in 1853, Captain Shrapnel demonstrated a mineral processing use of black powder in a method for crushing gold-bearing ores by firing them from a cannon into an iron chamber, and "much satisfaction was expressed by all present". He hoped it would be useful on the goldfields of California and Australia. Nothing came of the invention, as continuously operating crushing machines that achieved more reliable comminution were already coming into use.
  • Starting in 1967, Los Angeles-based artist Ed Ruscha began using gunpowder as an artistic medium for a series of works on paper.

Gunpowder had originally been produced for medicinal purposes. It was eaten, in hopes of curing digestive ailments; inhaled, for respiratory disorders; and, as mentioned, rubbed onto skin level disorders like rashes or burns.

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