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Gunpowder

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 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, and it is no longer used for industrial purposes due to its relative inefficiency compared to newer alternatives such as dynamite and ammonium nitrate/fuel oil.

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.

China

The first confirmed reference to what can be considered gunpowder in China occurred in the 9th century AD during the Tang dynasty, first in a formula contained in the Taishang Shengzu Jindan Mijue (太上聖祖金丹秘訣) in 808, and then about 50 years later in a Taoist 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, 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% saltpeter—not 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 the year 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, it was invading Mongols who introduced gunpowder to the Islamic world. 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" (ثلج الصين ), 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", 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" namak-i chīnī) or "salt from Chinese salt marshes" (نمک شوره چینی ).

Hasan al-Rammah included 107 gunpowder recipes in his text al-Furusiyyah wa al-Manasib al-Harbiyya (The Book of Military Horsemanship and Ingenious War Devices), 22 of which are for rockets. If one takes the median of 17 of these 22 compositions for rockets (75% nitrates, 9.06% sulfur, and 15.94% charcoal), it is nearly identical to the modern reported ideal recipe of 75% potassium nitrate, 10% sulfur, 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 evidently 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 Mamluks 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 to be 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), then 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 Mamluks certainly used cannons by 1342. According to J. Lavin, cannons were used by Moors at the siege of Algeciras in 1343. A metal cannon firing an iron ball was described by Shihab al-Din Abu al-Abbas al-Qalqashandi 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 book Wu Pei Chih (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, sulfur and high-quality charcoal from oaks in Anatolia contributed significantly to its expansion between the 15th and 18th century. It was not until later in the 19th century when the syndicalist production of Turkish gunpowder was greatly reduced, which coincided with the decline of its military might.

Europe

The earliest Western accounts of gunpowder appears 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

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

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

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.

Historiography

On the origins of gunpowder technology, historian Tonio Andrade remarked, "Scholars today overwhelmingly concur that the gun was invented in China." Gunpowder and the gun are widely believed by historians to have originated from China due to the large body of evidence that documents the evolution of gunpowder from a medicine to an incendiary and explosive, and the evolution of the gun from the fire lance to a metal gun, whereas similar records do not exist elsewhere. As Andrade explains, the large amount of variation in gunpowder recipes in China relative to Europe is "evidence of experimentation in China, where gunpowder was at first used as an incendiary and only later became an explosive and a propellant... in contrast, formulas in Europe diverged only very slightly from the ideal proportions for use as an explosive and a propellant, suggesting that gunpowder was introduced as a mature technology."

However, the history of gunpowder is not without controversy. A major problem confronting the study of early gunpowder history is ready access to sources close to the events described. Often the first records potentially describing use of gunpowder in warfare were written several centuries after the fact, and may well have been colored by the contemporary experiences of the chronicler. Translation difficulties have led to errors or loose interpretations bordering on artistic licence. Ambiguous language can make it difficult to distinguish gunpowder weapons from similar technologies that do not rely on gunpowder. A commonly cited example is a report of the Battle of Mohi in Eastern Europe that mentions a "long lance" sending forth "evil-smelling vapors and smoke", which has been variously interpreted by different historians as the "first-gas attack upon European soil" using gunpowder, "the first use of cannon in Europe", or merely a "toxic gas" with no evidence of gunpowder. It is difficult to accurately translate original Chinese alchemical texts, which tend to explain phenomena through metaphor, into modern scientific language with rigidly defined terminology in English. Early texts potentially mentioning gunpowder are sometimes marked by a linguistic process where semantic change occurred. For instance, the Arabic word naft transitioned from denoting naphtha to denoting gunpowder, and the Chinese word pào changed in meaning from trebuchet to a cannon. This has led to arguments on the exact origins of gunpowder based on etymological foundations. Science and technology historian Bert S. Hall makes the observation that, "It goes without saying, however, that historians bent on special pleading, or simply with axes of their own to grind, can find rich material in these terminological thickets."

Another major area of contention in modern studies of the history of gunpowder is regarding the transmission of gunpowder. While the literary and archaeological evidence supports a Chinese origin for gunpowder and guns, the manner in which gunpowder technology was transferred from China to the West is still under debate. It is unknown why the rapid spread of gunpowder technology across Eurasia took place over several decades whereas other technologies such as paper, the compass, and printing did not reach Europe until centuries after they were invented in China.

Components
Gunpowder is a granular mixture of:

 * a nitrate, typically potassium nitrate (KNO3), which supplies oxygen for the reaction;
 * charcoal, which provides carbon and other fuel for the reaction, simplified as carbon (C);
 * sulfur (S), which, while also serving as a fuel, lowers the temperature required to ignite the mixture, thereby increasing the rate of combustion.

Potassium nitrate is the most important ingredient in terms of both bulk and function because the combustion process releases oxygen from the potassium nitrate, promoting the rapid burning of the other ingredients. To reduce the likelihood of accidental ignition by static electricity, the granules of modern gunpowder are typically coated with graphite, which prevents the build-up of electrostatic charge.

Charcoal does not consist of pure carbon; rather, it consists of partially pyrolyzed cellulose, in which the wood is not completely decomposed. Carbon differs from ordinary charcoal. Whereas charcoal's autoignition temperature is relatively low, carbon's is much greater. Thus, a gunpowder composition containing pure carbon would burn similarly to a match head, at best.

The current standard composition for the gunpowder manufactured by pyrotechnicians was adopted as long ago as 1780. Proportions by weight are 75% potassium nitrate (known as saltpeter or saltpetre), 15% softwood charcoal, and 10% sulfur. These ratios have varied over the centuries and by country, and can be altered somewhat depending on the purpose of the powder. For instance, power grades of black powder, unsuitable for use in firearms but adequate for blasting rock in quarrying operations, are called blasting powder rather than gunpowder with standard proportions of 70% nitrate, 14% charcoal, and 16% sulfur; blasting powder may be made with the cheaper sodium nitrate substituted for potassium nitrate and proportions may be as low as 40% nitrate, 30% charcoal, and 30% sulfur. In 1857, Lammot du Pont solved the main problem of using cheaper sodium nitrate formulations when he patented DuPont "B" blasting powder. After manufacturing grains from press-cake in the usual way, his process tumbled the powder with graphite dust for 12 hours. This formed a graphite coating on each grain that reduced its ability to absorb moisture.

Neither the use of graphite nor sodium nitrate was new. Glossing gunpowder corns with graphite was already an accepted technique in 1839, and sodium nitrate-based blasting powder had been made in Peru for many years using the sodium nitrate mined at Tarapacá (now in Chile). Also, in 1846, two plants were built in south-west England to make blasting powder using this sodium nitrate. The idea may well have been brought from Peru by Cornish miners returning home after completing their contracts. Another suggestion is that it was William Lobb, the plant collector, who recognised the possibilities of sodium nitrate during his travels in South America. Lammot du Pont would have known about the use of graphite and probably also knew about the plants in south-west England. In his patent he was careful to state that his claim was for the combination of graphite with sodium nitrate-based powder, rather than for either of the two individual technologies.

French war powder in 1879 used the ratio 75% saltpeter, 12.5% charcoal, 12.5% sulfur. English war powder in 1879 used the ratio 75% saltpeter, 15% charcoal, 10% sulfur. The British Congreve rockets used 62.4% saltpeter, 23.2% charcoal and 14.4% sulfur, but the British Mark VII gunpowder was changed to 65% saltpeter, 20% charcoal and 15% sulfur. The explanation for the wide variety in formulation relates to usage. Powder used for rocketry can use a slower burn rate since it accelerates the projectile for a much longer time—whereas powders for weapons such as flintlocks, cap-locks, or matchlocks need a higher burn rate to accelerate the projectile in a much shorter distance. Cannons usually used lower burn-rate powders, because most would burst with higher burn-rate powders.

Other compositions
Besides black powder, there are other historically important types of gunpowder. "Brown gunpowder" is cited as composed of 79% nitre, 3% sulfur, and 18% charcoal per 100 of dry powder, with about 2% moisture. Prismatic Brown Powder is a large-grained product the Rottweil Company introduced in 1884 in Germany, which was adopted by the British Royal Navy shortly thereafter. The French navy adopted a fine, 3.1 millimeter, not prismatic grained product called Slow Burning Cocoa (SBC) or "cocoa powder". These brown powders reduced burning rate even further by using as little as 2 percent sulfur and using charcoal made from rye straw that had not been completely charred, hence the brown color.

Lesmok powder was a product developed by DuPont in 1911, one of several semi-smokeless products in the industry containing a mixture of black and nitrocellulose powder. It was sold to Winchester and others primarily for .22 and .32 small calibers. Its advantage was that it was believed at the time to be less corrosive than smokeless powders then in use. It was not understood in the U.S. until the 1920s that the actual source of corrosion was the potassium chloride residue from potassium chlorate sensitized primers. The bulkier black powder fouling better disperses primer residue. Failure to mitigate primer corrosion by dispersion caused the false impression that nitrocellulose-based powder caused corrosion. Lesmok had some of the bulk of black powder for dispersing primer residue, but somewhat less total bulk than straight black powder, thus requiring less frequent bore cleaning. It was last sold by Winchester in 1947.

Sulfur-free powders

The development of smokeless powders, such as cordite, in the late 19th century created the need for a spark-sensitive priming charge, such as gunpowder. However, the sulfur content of traditional gunpowders caused corrosion problems with Cordite Mk I and this led to the introduction of a range of sulfur-free gunpowders, of varying grain sizes. They typically contain 70.5 parts of saltpeter and 29.5 parts of charcoal. Like black powder, they were produced in different grain sizes. In the United Kingdom, the finest grain was known as sulfur-free mealed powder (SMP). Coarser grains were numbered as sulfur-free gunpowder (SFG n): 'SFG 12', 'SFG 20', 'SFG 40' and 'SFG 90', for example where the number represents the smallest BSS sieve mesh size, which retained no grains.

Sulfur's main role in gunpowder is to decrease the ignition temperature. A sample reaction for sulfur-free gunpowder would be:

Smokeless powders
The term black powder was coined in the late 19th century, primarily in the United States, to distinguish prior gunpowder formulations from the new smokeless powders and semi-smokeless powders. Semi-smokeless powders featured bulk volume properties that approximated black powder, but had significantly reduced amounts of smoke and combustion products. Smokeless powder has different burning properties (pressure vs. time) and can generate higher pressures and work per gram. This can rupture older weapons designed for black powder. Smokeless powders ranged in color from brownish tan to yellow to white. Most of the bulk semi-smokeless powders ceased to be manufactured in the 1920s.

Serpentine
The original dry-compounded powder used in 15th-century Europe was known as "Serpentine", either a reference to Satan or to a common artillery piece that used it. The ingredients were ground together with a mortar and pestle, perhaps for 24 hours, resulting in a fine flour. Vibration during transportation could cause the components to separate again, requiring remixing in the field. Also if the quality of the saltpeter was low (for instance if it was contaminated with highly hygroscopic calcium nitrate), or if the powder was simply old (due to the mildly hygroscopic nature of potassium nitrate), in humid weather it would need to be re-dried. The dust from "repairing" powder in the field was a major hazard.

Loading cannons or bombards before the powder-making advances of the Renaissance was a skilled art. Fine powder loaded haphazardly or too tightly would burn incompletely or too slowly. Typically, the breech-loading powder chamber in the rear of the piece was filled only about half full, the serpentine powder neither too compressed nor too loose, a wooden bung pounded in to seal the chamber from the barrel when assembled, and the projectile placed on. A carefully determined empty space was necessary for the charge to burn effectively. When the cannon was fired through the touchhole, turbulence from the initial surface combustion caused the rest of the powder to be rapidly exposed to the flame.

The advent of much more powerful and easy to use corned powder changed this procedure, but serpentine was used with older guns into the 17th century.

Corning
For propellants to oxidize and burn rapidly and effectively, the combustible ingredients must be reduced to the smallest possible particle sizes, and be as thoroughly mixed as possible. Once mixed, however, for better results in a gun, makers discovered that the final product should be in the form of individual dense grains that spread the fire quickly from grain to grain, much as straw or twigs catch fire more quickly than a pile of sawdust.

In late 14th century Europe and China, gunpowder was improved by wet grinding; liquid such as distilled spirits were added during the grinding-together of the ingredients and the moist paste dried afterwards. The principle of wet mixing to prevent the separation of dry ingredients, invented for gunpowder, is used today in the pharmaceutical industry. It was discovered that if the paste was rolled into balls before drying the resulting gunpowder absorbed less water from the air during storage and traveled better. The balls were then crushed in a mortar by the gunner immediately before use, with the old problem of uneven particle size and packing causing unpredictable results. If the right size particles were chosen, however, the result was a great improvement in power. Forming the damp paste into corn-sized clumps by hand or with the use of a sieve instead of larger balls produced a product after drying that loaded much better, as each tiny piece provided its own surrounding air space that allowed much more rapid combustion than a fine powder. This "corned" gunpowder was from 30% to 300% more powerful. An example is cited where 34 lb of serpentine was needed to shoot a 47 lb ball, but only 18 lb of corned powder.

Because the dry powdered ingredients must be mixed and bonded together for extrusion and cut into grains to maintain the blend, size reduction and mixing is done while the ingredients are damp, usually with water. After 1800, instead of forming grains by hand or with sieves, the damp mill-cake was pressed in molds to increase its density and extract the liquid, forming press-cake. The pressing took varying amounts of time, depending on conditions such as atmospheric humidity. The hard, dense product was broken again into tiny pieces, which were separated with sieves to produce a uniform product for each purpose: coarse powders for cannons, finer grained powders for muskets, and the finest for small hand guns and priming. Inappropriately fine-grained powder often caused cannons to burst before the projectile could move down the barrel, due to the high initial spike in pressure. Mammoth powder with large grains, made for Rodman's 15-inch cannon, reduced the pressure to only 20 percent as high as ordinary cannon powder would have produced.

In the mid-19th century, measurements were made determining that the burning rate within a grain of black powder (or a tightly packed mass) is about 6 cm/s (0.20 feet/s), while the rate of ignition propagation from grain to grain is around 9 m/s (30 feet/s), over two orders of magnitude faster.

Modern types

Modern corning first compresses the fine black powder meal into blocks with a fixed density (1.7 g/cm3). In the United States, gunpowder grains were designated F (for fine) or C (for coarse). Grain diameter decreased with a larger number of Fs and increased with a larger number of Cs, ranging from about 2 mm for 7F to 15 mm for 7C. Even larger grains were produced for artillery bore diameters greater than about 17 cm. The standard DuPont Mammoth powder developed by Thomas Rodman and Lammot du Pont for use during the American Civil War had grains averaging 0.6 in in diameter with edges rounded in a glazing barrel. Other versions had grains the size of golf and tennis balls for use in 20 in Rodman guns. In 1875 DuPont introduced Hexagonal powder for large artillery, which was pressed using shaped plates with a small center core—about 1+1/2 in diameter, like a wagon wheel nut, the center hole widened as the grain burned. By 1882 German makers also produced hexagonal grained powders of a similar size for artillery.

By the late 19th century manufacturing focused on standard grades of black powder from Fg used in large bore rifles and shotguns, through FFg (medium and small-bore arms such as muskets and fusils), FFFg (small-bore rifles and pistols), and FFFFg (extreme small bore, short pistols and most commonly for priming flintlocks). A coarser grade for use in military artillery blanks was designated A-1. These grades were sorted on a system of screens with oversize retained on a mesh of 6 wires per inch, A-1 retained on 10 wires per inch, Fg retained on 14, FFg on 24, FFFg on 46, and FFFFg on 60. Fines designated FFFFFg were usually reprocessed to minimize explosive dust hazards. In the United Kingdom, the main service gunpowders were classified RFG (rifle grained fine) with diameter of one or two millimeters and RLG (rifle grained large) for grain diameters between two and six millimeters. Gunpowder grains can alternatively be categorized by mesh size: the BSS sieve mesh size, being the smallest mesh size, which retains no grains. Recognized grain sizes are Gunpowder G 7, G 20, G 40, and G 90.

Owing to the large market of antique and replica black-powder firearms in the US, modern black powder substitutes like Pyrodex, Triple Seven and Black Mag3 pellets have been developed since the 1970s. These products, which should not be confused with smokeless powders, aim to produce less fouling (solid residue), while maintaining the traditional volumetric measurement system for charges. Claims of less corrosiveness of these products have been controversial however. New cleaning products for black-powder guns have also been developed for this market.

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

 * 2 KNO3 + S + 3 C → K2S + 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. However, it is more hygroscopic than powders made from potassium nitrate. Muzzleloaders have been known to fire after hanging on a wall for decades in a loaded state, provided they remained dry. By contrast, gunpowder made with sodium nitrate must be kept sealed to remain stable. 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

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.

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 Model Regulations on the Transportation 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.

title: Gunpowder


text:
Grampus

Grampus may refer to:

Animals

 * Grampus, the genus and another name for Risso's dolphin, Grampus griseus
 * A synonym of the genus Orcinus
 * Another name for Orcinus orca, the killer whale or orca
 * Another name for the hellbender, a species of salamander
 * Another name for Mastigoproctus giganteus, a species of whip scorpion

Ships

 * CSS Grampus, an American river steamer built in 1856 and used by the Confederate States Army during the American Civil War
 * HMS Grampus, the name of a number of Royal Navy ships and submarines
 * USFC Grampus, a fisheries research and fish-culture ship in commission with the United States Commission on Fish and Fisheries from 1886 to 1903 and as USFS Grampus with the United States Bureau of Fisheries from 1903 to 1917
 * USS Grampus, the name of a number of ships of the United States Navy
 * Grampus-class submarines, a group of minelaying submarines built for the British Royal Navy in the late 1930s
 * Grampus, a fictional submarine in the anime series Blue Submarine No. 6
 * Grampus, a fictional character in the British television series Tugs, based on the USS Grampus SS-4 - see List of Tugs characters

Sports

 * Nagoya Grampus, an association football club based in Nagoya, Japan

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Grampus


text:
Gary Kildall

Gary Arlen Kildall (May 19, 1942 – July 11, 1994) was an American computer scientist and microcomputer entrepreneur. During the 1970s, Kildall created the CP/M operating system among other operating systems and programming tools, and subsequently founded Digital Research, Inc. (or "DRI") to market and sell his software products. In 1974 in Pacific Grove, Kildall demonstrated the first working prototype of CP/M (Control Program for Microcomputer). Together with his invention of the BIOS (Basic Input Output System), his operating system allowed a microprocessor-based computer to communicate with a disk storage. Kildall was among the earliest individuals to recognize microprocessors as fully capable computers (rather than simply as equipment controllers), and to organize a company around this concept. Due to his accomplishments during this era, Kildall is considered a pioneer of the personal computer revolution.

During the 1980s, Kildall also appeared on PBS as co-host (with Stewart Cheifet) of Computer Chronicles, a weekly informational program which covered the latest developments in personal computing. Although Kildall's entrepreneurial career in computing spanned more than two decades, he is mainly remembered in connection with his development of the CP/M operating system, an early multi-platform microcomputer OS, to which the later MS-DOS used on the IBM PC has many parallels.

Early life
Gary Kildall was born and grew up in Seattle, Washington, where his family operated a seamanship school. His father, Joseph Kildall, was a captain of Norwegian heritage. His mother Emma was of half Swedish descent, as Kildall's grandmother was born in Långbäck, Sweden, in Skellefteå Municipality, but emigrated to Canada at 23 years of age.

Education
Kildall earned a Bachelor's degree in Mathematics in 1967 and a Master's degree in Computer Science in 1968, both from the University of Washington (UW). At one point, he had hoped to become a mathematics teacher. During his studies, Kildall became increasingly interested in computer technology and enrolled to attain a Ph. D. in Computer Science.

Gary fulfilled a draft obligation to the United States Navy by teaching at the Naval Postgraduate School (NPS) in Monterey, California. Being within an hour's drive of Silicon Valley, Kildall heard about the first commercially available microprocessor, the Intel 4004. He bought one of the processors and began writing experimental programs for it. To learn more about the processors, he worked at Intel as a consultant on his days off.

Kildall briefly returned to UW and finished his doctorate in computer science in 1972, then resumed teaching at NPS. He published a paper that introduced the theory of data-flow analysis used today in optimizing compilers (sometimes known as Kildall's method), and he continued to experiment with microcomputers and the emerging technology of floppy disks.

Intel lent him systems using the 8008 and 8080 processors, and in 1973, he developed the first high-level programming language for microprocessors, called PL/M. For Intel he also wrote 8008 and 8080 instruction set simulators named INTERP/8  and INTERP/80. He created CP/M the same year to enable the 8080 to control a floppy drive, combining for the first time all the essential components of a computer at the microcomputer scale. He demonstrated CP/M to Intel, but Intel had little interest and chose to market PL/M instead.

CP/M
Kildall and his wife Dorothy established a company, originally called "Intergalactic Digital Research" (later renamed as Digital Research, Inc.), to market CP/M through advertisements in hobbyist magazines. Digital Research licensed CP/M for the IMSAI 8080, a popular clone of the Altair 8800. As more manufacturers licensed CP/M, it became a de facto standard and had to support an increasing number of hardware variations. In response, Kildall pioneered the concept of a BIOS, a set of simple programs stored in the computer hardware (ROM or EPROM chip) that enabled CP/M to run on different systems without modification.

CP/M's quick success took Kildall by surprise, and he was slow to update it for high density floppy disks and hard disk drives. After hardware manufacturers talked about creating a rival operating system, Kildall started a rush project to develop CP/M 2. By 1981, at the peak of its popularity, CP/M ran on $3,000$ different computer models and DRI had US$5.4 million in yearly revenues.

IBM dealings
IBM approached Digital Research in 1980, at Bill Gates' suggestion, to negotiate the purchase of a forthcoming version of CP/M called CP/M-86 for the IBM PC. Gary had left initial negotiations to his wife, Dorothy, as he usually did, while he and colleague and developer of MP/M operating system Tom Rolander used Gary's private aeroplane to deliver software to manufacturer Bill Godbout. Before the IBM representatives would explain the purpose of their visit, they insisted that Dorothy sign a non-disclosure agreement. On the advice of DRI attorney Gerry Davis, Dorothy refused to sign the agreement without Gary's approval. Gary returned in the afternoon and tried to move the discussion with IBM forward, and accounts disagree on whether he signed the non-disclosure agreement, as well as whether he ever met with the IBM representatives.

Various reasons have been given for the two companies failing to reach an agreement. DRI, which had only a few products, might have been unwilling to sell its main product to IBM for a one-time payment rather than its usual royalty-based plan. Dorothy might have believed that the company could not deliver CP/M-86 on IBM's proposed schedule, as the company was busy developing an implementation of the PL/I programming language for Data General. Also possible, the IBM representatives might have been annoyed that DRI had spent hours on what they considered a routine formality. According to Kildall, the IBM representatives took the same flight to Florida that night that he and Dorothy took for their vacation, and they negotiated further on the flight, reaching a handshake agreement. IBM lead negotiator Jack Sams insisted that he never met Gary, and one IBM colleague has confirmed that Sams said so at the time. He accepted that someone else in his group might have been on the same flight, and noted that he flew back to Seattle to talk with Microsoft again.

Sams related the story to Gates, who had already agreed to provide a BASIC interpreter and several other programs for the PC. Gates' impression of the story was that Gary capriciously "went flying", as he would later tell reporters. Sams left Gates with the task of finding a usable operating system, and a few weeks later he proposed using the operating system 86-DOS—an independently developed operating system that implemented Kildall's CP/M API—from Seattle Computer Products (SCP). Paul Allen negotiated a licensing deal with SCP. Allen had 86-DOS adapted for IBM's hardware, and IBM shipped it as IBM PC DOS.

Kildall obtained a copy of PC DOS, examined it, and concluded that it infringed on CP/M. When he asked Gerry Davis what legal options were available, Davis told him that intellectual property law for software was not clear enough to sue. Instead Kildall only threatened IBM with legal action, and IBM responded with a proposal to offer CP/M-86 as an option for the PC in return for a release of liability. Kildall accepted, believing that IBM's new system (like its previous personal computers) would not be a significant commercial success. When the IBM PC was introduced, IBM sold its operating system as an unbundled option. One of the operating system options was PC DOS, priced at US$40. PC DOS was seen as a practically necessary option; most software titles required it and without it the IBM PC was limited to its built-in Cassette BASIC. CP/M-86 shipped a few months later six times more expensive at US$240, and sold poorly against DOS and enjoyed far less software support.

Multi-Programming Monitor Control Program (MP/M)
With the loss of the IBM deal, Gary and Dorothy found themselves under pressure to bring in more experienced management, and Gary's influence over the company waned. He worked in various experimental and research projects, such as a version of CP/M with multitasking (MP/M), it was a multi-user and multi-tasking version of the CP/M operating system created by Digital Research developer Tom Rolander in 1979. Kildall also worked on an implementation of the Logo programming language. He hoped that Logo, an educational dialect of LISP, would supplant BASIC in education, but it did not.

Graphics Environment Manager (GEM)
After seeing a demonstration of the Apple Lisa, Kildall oversaw the creation of DRI's own graphical user interface, called GEM. Novell acquired DRI in 1991 in a deal that netted millions for Kildall.

Kildall resigned as CEO of Digital Research on 28 June 1985, but remained chairman of the board.

Computer Chronicles
Kildall co-hosted a public television program produced by PBS called Computer Chronicles. It followed trends in personal computing. Gary co-hosted the program for seven years during the first eight seasons from 1983 to 1990. After this time the program continued through its 19th season, with the last episode aired on June 25, 2002.

Activenture
In 1984 Gary started another company, Activenture, which adapted optical disc technology for computer use. In early 1985 it was renamed KnowledgeSet and released the first computer encyclopedia in June 1985, a CD-ROM version of Grolier's Academic American Encyclopedia  named The Electronic Encyclopedia, later acquired by Banta Corporation.

Prometheus Light and Sound (PLS)
Kildall's final business venture, known as Prometheus Light and Sound (PLS) and based in Austin, Texas, developed a modular PBX communication system that integrated land-line telephones with mobile phones (called "Intelliphone") to reduce the then-high online costs and to remotely connect with home appliances.

Prometheus Light and Sound system included a UUCP-based store and forward system to exchange emails and files between the various nodes and was planned to include TCP/IP support at a later point in time.

Computer Animation
According to Brian Halla, Intel's technical liaison to Digital Research in the 1970s, Gary Kildall showed him a VAX 11/780 running in his house generating a Coke bottle spinning. According to Halla, Kildall sold it a few months later to Pixar.

Personal life
Kildall self-described as a "greaser" during high school, and his colleagues recall him as creative, easygoing, and adventurous. In addition to flying, he loved sports cars, auto racing, and boating, and had a lifelong love of the sea.

Although Kildall preferred to leave the IBM affair in the past and to be known for his work before and afterward, he continually faced comparisons between himself and Bill Gates, as well as fading memories of his contributions. A legend grew around the fateful IBM-DRI meeting, encouraged by Gates and various journalists, suggesting that Kildall had irresponsibly taken the day off for a recreational flight.

In later years, Kildall privately expressed bitter feelings about being overshadowed by Microsoft, and began suffering from alcoholism.

Selling DRI to Novell had made Kildall a wealthy man, and he moved to the West Lake Hills suburb of Austin. His Austin house was a lakeside property, with stalls for several sports cars, and a video studio in the basement. Kildall owned and flew his own Learjet and had at least one boat on the lake. While in Austin he also participated in volunteer efforts to assist children with HIV/AIDS. He also owned a mansion with a panoramic ocean view in Pebble Beach, California, near the headquarters of DRI.

Computer Connections
In 1992, Kildall was invited to the University of Washington computer science program's 25th anniversary event. As a distinguished graduate of the program, Kildall was disappointed when asked to attend simply as an audience member. He also took offense at the decision to give the keynote speech to Bill Gates, a Harvard dropout who had donated to UW, but had never attended.

In response, Kildall began writing a memoir, entitled Computer Connections: People, Places, and Events in the Evolution of the Personal Computer Industry. The memoir,  which Kildall sought to publish, expressed his frustration that people did not seem to value elegance in computer software.

Writing about Bill Gates, Kildall described him as "more of an opportunist than a technical type, and severely opinionated, even when the opinion he holds is absurd."

In an appendix, he called DOS "plain and simple theft" because its first 26 system calls worked the same as CP/M's. He accused IBM of contriving the price difference between PC DOS and CP/M-86 in order to marginalize CP/M.

Kildall had completed a rough draft of the manuscript by the end of 1993, but the full text remains unpublished. Journalist Harold Evans used the memoir as a primary source for a chapter about Kildall in the 2004 book They Made America, concluding that Microsoft had robbed Kildall of his inventions. IBM veterans from the PC project disputed the book's description of events, and Microsoft described it as "one-sided and inaccurate."

In August 2016, Kildall's family made the first seven chapters of Computer Connections available as a free public download.

Death
On July 8, 1994, at the age of 52, Kildall sustained a head injury at the Franklin Street Bar & Grill, a biker bar in Monterey, California. The exact circumstances of the injury are unclear. Various sources have claimed he fell from a chair, fell down steps, or was assaulted because he had entered the establishment wearing Harley-Davidson leathers. Harold Evans, in They Made America, states that Kildall "stumbled and hit his head" inside the premises, and "was found on the floor."

Following the injury, Kildall was discharged from the hospital twice. He was pronounced dead at the Community Hospital of the Monterey Peninsula, on July 11, 1994.

An autopsy, conducted on July 12, did not conclusively determine the cause of death. Evans states that Kildall's head injury triggered a cerebral hemorrhage, causing a blood clot to form inside the skull. A CP/M Usenet FAQ states that Kildall was concussed due to his injury, and died of a heart attack; the connection between the two is unclear.

Initial news reports and police investigation viewed Kildall's death as a possible homicide. According to the coroner's report, Kildall's fatal injury may have taken place "as a result of foul play," and the case was referred to the Monterey Police Department. "We're going to investigate it as a possible homicide," said police Sgt. Frank Sollecito. "I'm not going to flat-out say it's a homicide".

Kildall's body was cremated. His remains were buried in Evergreen Washelli Memorial Park, in north Seattle.

Recognition
Following the announcement of Kildall's death, Bill Gates commented that he was "one of the original pioneers of the PC revolution" and "a very creative computer scientist who did excellent work. Although we were competitors, I always had tremendous respect for his contributions to the PC industry. His untimely death was very unfortunate and his work will be missed."

In March 1995, Kildall was posthumously honored by the Software Publishers Association (SPA) for his contributions to the microcomputer industry:

 * The first programming language and first compiler specifically for microprocessors: PL/M. (1973)
 * The first microprocessor disk operating system, which eventually sold a quarter of a million copies: CP/M. (1974)
 * The first successful open system architecture by segregating system-specific hardware interfaces in a set of BIOS routines.   (1975)
 * Creation of the first diskette track buffering schemes, read-ahead algorithms, file directory caches, and RAM drive emulators.
 * Introduction of operating systems with preemptive multitasking and windowing capabilities and menu-driven user interfaces (with Digital Research): MP/M, Concurrent CP/M, Concurrent DOS, DOS Plus, GEM.
 * Introduction of a binary recompiler: XLT86. (1981)
 * The first computer interface for video disks to allow automatic nonlinear playback, presaging today's interactive multimedia. (1984, with Activenture)
 * The file system and data structures for the first consumer CD-ROM. (1985, with KnowledgeSet)

In April 2014, the city of Pacific Grove installed a commemorative plaque outside Kildall's former residence, which also served as the early headquarters of Digital Research.

In popular culture
Steve Hauk wrote a play A Mild Concussion. Later, with Stewart Cheifet, a second version of the play was written under the title The Forgotten Computer Genius. The play looks at the final days of a computer genius.

title: Gary Kildall


text:
Gesta Danorum

Gesta Danorum ("Deeds of the Danes") is a patriotic work of Danish history, by the 12th-century author Saxo Grammaticus ("Saxo the Literate", literally "the Grammarian"). It is the most ambitious literary undertaking of medieval Denmark and is an essential source for the nation's early history. It is also one of the oldest known written documents about the history of Estonia and Latvia.

Consisting of sixteen books written in Latin on the invitation of Archbishop Absalon, Gesta Danorum describes Danish history and to some degree Scandinavian history in general, from prehistory to the late 12th century. In addition, Gesta Danorum offers singular reflections on European affairs in the High Middle Ages from a unique Scandinavian perspective, supplementing what has been handed down by historians from Western and Southern Europe.

Books
The sixteen books, in prose with an occasional excursion into poetry, can be categorized into two parts: Books 1–9, which deal with Norse mythology and semi-legendary Danish history, and Books 10–16, which deal with medieval history. Book 9 ends with Gorm the Old. The last three books (14–16), which describe Danish conquests on the south shore of the Baltic Sea and wars against Slavic peoples (the Northern Crusades), are very valuable for the history of West Slavic tribes (Polabian Slavs, Pomeranians) and Slavic paganism. Book 14 contains a unique description of the temple on the island of Rügen.

Book 1
The first book is mostly Saxo's original work, sharing little with other primary works, but taking some inspiration from Ancient Greek epics. It very briefly covers the rule of the eponymous founder of the Danish nation, Dan, but also his brother Angul, his sons Humble and Lother, and Dan's grandson, Skiold, whose son, Gram is the first Danish king to be given some detail, his reign revolves around conquering Sweden and Finland, only to die in a battle. Most of the book deals with the adventures of Hading, the son of Gram and Finnish princess, Signe. Here the adventure concerns the loss of Denmark to the Swedes as well as Hading's attempts to reclaim it with the help of giants and Odin. The book concludes with Hading's suicide after hearing of his friend's death.

Book 2
Follows adventures of Hading's descendants, who perform cunning raids across the Baltic Sea and far as England, while encountering many supernatural events and being forced to solve disputes via single combat.

Book 3
Introduces Amleth as a grandson of a Danish king, whose father was murdered by his uncle, the governor of Jylland. Amleth pretends to be a fool in fear of his uncle who has married his mother.

Book 4
Deals with Amleth securing his place as the king of the Danes, and return to Britain where he ends up marrying a Britanian princess, whose father plots the demise of Amleth, and the queen of Scotland who is famous for murdering all her suitors.

Book 5
Focused on empire-building of Frotho III and his brilliant Norwegian advisor, Erick the Eloquent. Ultimately Frotho ends up ruling over Britain, Scandinavia, the Slavs, and the Huns. Saxo makes many parallels to Augustus.

Book 6
Follows the adventurers of the legendary hero, Starkad who is disappointed in the decadent ways of Frothi III's descendants.

Book 7
Is a collection of short and unrelated love stories, many of these ventures feature shieldmaidens.

Book 8
Covers the famous Battle of Brávellir, between Harald Wartooth and Sigurd Ring. Danish involvement in the Saxon wars against Charlemagne, voyages to Biarmia, and the death of Starkad.

Book 9
The book deals with Ragnar Lothbrok and his rising empire, he appoints many of his sons to govern parts of his empire all the way from Scotland to Scythia.

Chronology
When exactly Gesta Danorum was written is the subject of numerous works; however, it is generally agreed that Gesta Danorum was not finished before 1208. The last event described in the last book (Book 16) is King Canute VI of Denmark subduing Pomerania under Duke Bogislaw I, in 1186. However the preface of the work, dedicated to Archbishop Anders Sunesen, mentions the Danish conquest of the areas north of the Elbe in 1208.

Book 14, comprising nearly one-quarter of the text of the entire work, ends with Absalon's appointment to archbishop in 1178. Since this book is so large and Absalon has greater importance than King Valdemar I, this book may have been written first and comprised a work on its own. It is possible that Saxo then enlarged it with Books 15 and 16, telling the story of King Valdemar I's last years and King Canute VI's first years.

It is believed that Saxo then wrote Books 11, 12, and 13. Svend Aagesen's history of Denmark, Brevis Historia Regum Dacie (circa 1186), states that Saxo had decided to write about "The king-father and his sons," which would be King Sweyn Estridson, in Books 11, 12, and 13. He would later add the first ten books. This would also explain the 22 years between the last event described in the last book (Book 16) and the 1208 event described in the preface.

Manuscripts
The original manuscripts of the work are lost, except for four fragments: the Angers Fragment, Lassen Fragment, Kall-Rasmussen Fragment and Plesner Fragment. The Angers Fragment is the biggest fragment, and the only one attested to be in Saxo's own handwriting. The other ones are copies from c. 1275. All four fragments are in the collection of the Danish Royal Library in Copenhagen, Denmark.

The text has, however, survived. In 1510–1512, Christiern Pedersen, a Danish translator working in Paris, searched Denmark high and low for an existing copy of Saxo's works, which by that time was nearly all but lost. By that time most knowledge of Saxo's work came from a summary located in Chronica Jutensis, from around 1342, called Compendium Saxonis. It is also in this summary that the name Gesta Danorum is found. The title Saxo himself used for his work is unknown.

Christiern Pedersen finally found a copy in the collection of Archbishop Birger Gunnersen of Lund, Skåne (Skåne is now part of Sweden, but at the time was still part of Denmark), which he gladly lent him. With the help of printer Jodocus Badius, Gesta Danorum was refined and printed.

Printing
The first printed press publication and the oldest known complete text of Saxo's works is Christiern Pedersen's Latin edition, printed and published by Jodocus Badius in Paris, France, on 15 March 1514 under the title of Danorum Regum heroumque Historiae ("History of the Kings and heroes of the Danes"). The edition features the following colophon: ...''impressit in inclyta Parrhisorum academia Iodocus Badius Ascensius Idibus Martiis. MDXIIII. Supputatione Romana.'' (the Ides of March, 1514).

The full front page reads (with abbreviations expanded) in Latin: "Danorum Regum heroumque Historiae stilo eleganti a Saxone Grammatico natione Zialandico necnon Roskildensis ecclesiae praeposito, abhinc supra trecentos annos conscriptae et nunc primum literaria serie illustratae tersissimeque impressae."

English language: "Histories of the Kings and heroes of the Danes, composed in elegant style by Saxo Grammaticus, a Zealander and also provost of the church of Roskilde, over three hundred years ago, and now for the first time illustrated and printed correctly in a learned compilation."

Latin versions
The source of all existing translations and new editions is Christiern Pedersen's Latin Danorum Regum heroumque Historiae. There exist a number of different translations today, some complete, some partial:

Danish translations

 * Christiern Pedersen, never published ca. 1540, Lost
 * Jon Tursons, lost, never published ca. 1555
 * , 2 volumes
 * , 2 volumes
 * , 2 volumes
 * , 2 volumes
 * , 2 volumes
 * , 2 volumes

English translations

 * (Volume 1: English text; volume 2: Commentary by Hilda Ellis Davidson)
 * (Volume 1: Books I-X; Volume 2: Books XI-XVI).
 * (Volume 1: Books I-X; Volume 2: Books XI-XVI).
 * (Volume 1: Books I-X; Volume 2: Books XI-XVI).
 * (Volume 1: Books I-X; Volume 2: Books XI-XVI).

Other translations

 * [Full translation on Russian by Andrey Dosaev in two vols.]
 * Daniel Palmqvist (2021), Gesta Danorum, Saxo Grammaticus, En del av Sveriges historia. [The first nine of the 16 books translated into Swedish].
 * [Full translation on Russian by Andrey Dosaev in two vols.]
 * Daniel Palmqvist (2021), Gesta Danorum, Saxo Grammaticus, En del av Sveriges historia. [The first nine of the 16 books translated into Swedish].
 * [Full translation on Russian by Andrey Dosaev in two vols.]
 * Daniel Palmqvist (2021), Gesta Danorum, Saxo Grammaticus, En del av Sveriges historia. [The first nine of the 16 books translated into Swedish].

Gesta Danorum is also translated partially in other English, French and German releases.

Hamlet
Certain aspects of Gesta Danorum formed the basis for William Shakespeare's play Hamlet. Saxo's version, told of in Books 3 and 4, is very similar to that of Shakespeare's Hamlet. In Saxo's version, two brothers, Orvendil and Fengi are given the rule over Jutland by King Rørik Slyngebond of the Danes. Soon after, Orvendil marries King Rørik's daughter, Geruth (Gertrude in Hamlet). Amleth is their first and only child.

Fengi becomes resentful of his brother's marriage, and also wants sole leadership of Jutland, so therefore murders Orvendil. After a very brief period of mourning, Fengi marries Geruth, and declares himself sole leader of Jutland. Eventually, Amleth avenges his father's murder and plans the murder of his uncle, making him the new and rightful King of Jutland. However, while Hamlet dies in Shakespeare's version just after his uncle's death, in Saxo's version Amleth survives and begins ruling his kingdom, going on to other adventures.

title: Gesta Danorum