History of gunpowder
Earliest known written formula for gunpowder, from the Wujing Zongyao
of 1044 AD.
A 'magic fire meteor going against the wind' bomb as depicted in the Huolongjing
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
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). Based on a 9th-century Taoist text, 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 of gunpowder is reflected in its Chinese name huoyao, which means "fire medicine". The first military applications of gunpowder were developed around 904 AD. The earliest chemical formula for gunpowder appeared in the 11th century Song dynasty text, Wujing Zongyao, however gunpowder had already been used for fire arrows since at least the 10th century. In the following centuries various gunpowder weapons such as bombs, fire lances, and the gun appeared in China.
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 first reference to the incendiary properties of such mixtures is the passage of the Zhenyuan miaodao yaolüe, a Taoist text tentatively dated to the mid-9th century: "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." The Chinese word for "gunpowder" is Chinese: 火药/火藥; pinyin: huŏ yào /xuo yɑʊ/, which literally means "Fire Medicine"; however this name only came into use some centuries after the mixture's discovery. In the following centuries a variety of gunpowder weapons such as rockets, bombs, and land mines appeared before the first metal barrel firearms were invented. 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.
The Chinese Wujing Zongyao (Complete Essentials from the Military Classics), written by Zeng Gongliang between 1040 and 1044, 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 do not contain enough saltpeter to create an explosive however; being limited to at most 50% saltpeter, they produce an incendiary. The Essentials was however 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 gunpowder 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, 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 utilized 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.
An arrow strapped with gunpowder ready to be shot from a bow. From the Huolongjing c. 1350.
The oldest known depiction of rocket arrows, from the Huolongjing. The right arrow reads "fire arrow", the middle is an "arrow frame in the shape of a dragon", and the left is a "complete fire arrow".
An illustration of a thunderclap bomb as depicted in the 1044 text Wujing Zongyao. Considered to be a pseudo-explosive. The top item is a through awl and the bottom one is a hook awl.
The "flying-cloud thunderclap-eruptor" cannon from the Huolongjing c. 1350.
An organ gun known as the "mother of a hundred bullets gun" from the Huolongjing c. 1350.
An illustration of a bronze "thousand ball thunder cannon" from the Huolongjing c. 1350.
The "self-tripped trespass land mine" from the Huolongjing c. 1350.
A picture of a 15th-century Granadian
cannon from the book Al-izz wal rifa'a
The Muslims acquired knowledge of gunpowder some time between 1240 and 1280, by which point the Syrian Hasan al-Rammah had written, in Arabic, recipes for gunpowder, 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", 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) 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 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 gunpowder recipe of 75% potassium nitrate, 10% sulfur, and 15% charcoal.
Al-Hassan claims that in the Battle of Ain Jalut of 1260, the Mamluks used against the Mongols in "the first cannon in history" gunpowder 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.
Khan claims that it was invading Mongols who introduced gunpowder to the Islamic world and cites Mamluk antagonism towards early musketeers in their infantry as an example of how gunpowder weapons were not always met with open acceptance in the Middle East. Similarly, the refusal of their Qizilbash forces to use firearms contributed to the Safavid rout at Chaldiran in 1514.
The arquebus first appeared in the Ottoman Empire at some point between 1394 and the early 15th century. The arquebus was later used in substantial numbers by the Janissaries of the Ottoman army by the mid-15th century. The matchlock arquebus was first used by the Janissary corps of the Ottoman army in the first half of the 15th century, possibly as early as 1394 but certainly by the 1440s.
The musket first 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.
Earliest depiction of a European cannon, "De Nobilitatibus Sapientii Et Prudentiis Regum", Walter de Milemete
Büchsenmeysterei : von Geschoß, Büchsen, Pulver, Salpeter und Feurwergken
Deutliche Anweisung zur Feuerwerkerey
The earliest Western accounts of gunpowder appear in texts written by English philosopher Roger Bacon in the 13th century.
Several sources mention Chinese firearms and 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." However, Timothy May also points out "However... the Mongols used the gunpowder weapon in their wars against the Jin, the Song and in their invasions of Japan."
In Europe, one of the first mentions of gunpowder use appears in a passage found in Roger Bacon's Opus Maius of 1267 and Opus Tertium in what has been interpreted as being firecrackers. The most telling passage reads: "We have an example of these things (that act on the senses) in [the sound and fire of] that children's toy which is made in many [diverse] parts of the world; i.e., a device no bigger than one's thumb. From the violence of that salt called saltpeter [together with sulfur and willow charcoal, combined into a powder] so horrible a sound is made by the bursting of a thing so small, no more than a bit of parchment [containing it], that we find [the ear assaulted by a noise] exceeding the roar of strong thunder, and a flash brighter than the most brilliant lightning." In the early 20th century, British artillery officer Henry William Lovett Hime proposed that another work tentatively attributed to Bacon, Epistola de Secretis Operibus Artis et Naturae, et de Nullitate Magiae contained an encrypted formula for gunpowder. This claim has been disputed by historians of science including Lynn Thorndike, John Maxson Stillman and George Sarton and by Bacon's editor Robert Steele, both in terms of authenticity of the work, and with respect to the decryption method. In any case, the formula claimed to have been decrypted (7:5:5 saltpeter:charcoal:sulfur) is not useful for firearms use or even firecrackers, burning slowly and producing mostly smoke. However, if Bacon's recipe is taken as measurements by volume rather than weight, a far more potent and serviceable explosive powder is created suitable for firing hand-cannons, albeit less consistent due to the inherent inaccuracies of measurements by volume. One example of this composition resulted in 100 parts saltpeter, 27 parts charcoal, and 45 parts sulfur, by weight.
The Liber Ignium, or Book of Fires, attributed to Marcus Graecus, is a collection of incendiary recipes, including some gunpowder recipes. Partington dates the gunpowder recipes to approximately 1300. One recipe for "flying fire" (ignis volatilis) involves saltpeter, sulfur, and colophonium, which, when inserted into a reed or hollow wood, "flies away suddenly and burns up everything." Another recipe, for artificial "thunder", specifies a mixture of one pound native sulfur, two pounds linden or willow charcoal, and six pounds of saltpeter. Another specifies a 1:3:9 ratio.
Some of the gunpowder recipes of De Mirabilibus Mundi of Albertus Magnus are identical to the recipes of the Liber Ignium, and according to Partington, "may have been taken from that work, rather than conversely." Partington suggests that some of the book may have been compiled by Albert's students, "but since it is found in thirteenth century manuscripts, it may well be by Albert." Albertus Magnus died in 1280.
A major advance in manufacturing began in Europe in the late 14th century when the safety and thoroughness of incorporation was improved by wet grinding; liquid, such as distilled spirits was 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 also 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 pounds of serpentine was needed to shoot a 47-pound ball, but only 18 pounds of corned powder. The optimum size of the grain depended on its use; larger for large cannon, finer for small arms. Larger cast cannons were easily muzzle-loaded with corned powder using a long-handled ladle. Corned powder also retained the advantage of low moisture absorption, as even tiny grains still had much less surface area to attract water than a floury powder.
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. The German printer and publisher Christiaan Egenolff adapted an earlier work on pyrotechnics from manuscript to print form, publishing his Büchsenmeysterei in 1529 and reprinting it in 1531. Now extremely rare, the book discusses the manufacturing of gunpowder, the operation of artillery and the rules of conduct for the gunsmith.
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.
In the Spanish Empire, the crown held a monopoly on gunpowder and the terms were set out during eighteenth-century Bourbon Reforms.
Great Britain and Ireland
Gunpowder production in Britain appears to have started in the mid 14th century with the aim of supplying the English Crown. 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. By the early 14th century, according to N.J.G. Pounds's study The Medieval Castle in England and Wales, many English castles had been deserted and others were crumbling. Their military significance faded except on the borders. Gunpowder had made smaller castles useless.
Henry VIII of England was short of gunpowder when he invaded France in 1544 and England needed to import gunpowder via the port of Antwerp in what is now Belgium.
The English Civil War (1642–1645) led to an expansion of the gunpowder industry, with the repeal of the Royal Patent in August 1641.
One of the most notable uses of gunpowder in Great Britain was the Gunpowder Plot of 1605: a failed assassination attempt on King James I and VI. The plot was foiled when Guy Fawkes was found under the House of Lords with hidden barrels of gunpowder. All assailants who had a role in the plot escaped but were eventually caught. King James later decreed that 5 November become a day of celebration, which is a tradition that carries on today known as Bonfire Night.
Two British physicists, Andrew Noble and Frederick Abel, worked to improve the properties of black powder 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 United Kingdom 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; and shortly afterwards, on 31 December 1931, the former
Curtis & Harvey's Glynneath gunpowder factory at Pontneddfechan, in Wales, closed down, and it 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 of the gunpowder section at the Royal Ordnance Factory, ROF Chorley, the section was closed and demolished at the end of World War II; and ICI Nobel's Roslin gunpowder factory, which closed in 1954.
This left the sole United Kingdom gunpowder factory at ICI Nobel's Ardeer site in Scotland; it too closed in October 1976. Since then gunpowder has been imported into the United Kingdom. In the late 1970s/early 1980s gunpowder was bought from eastern Europe, particularly from what was then the German Democratic Republic and former Yugoslavia.
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 utilized during the Napoleonic Wars and the War of 1812.
The Javanese Majapahit Empire was arguably able to encompass much of modern-day Indonesia due to its unique mastery of bronze-smithing and use of a central arsenal fed by a large number of cottage industries within the immediate region. Documentary and archeological evidence indicate that Arab traders introduced gunpowder, gonnes, muskets, blunderbusses, and cannons to the Javanese, Acehnese, and Batak via long established commercial trade routes around the early to mid 14th century. The resurgent Singhasari Empire overtook Sriwijaya and later emerged as the Majapahit whose warfare featured the use of fire-arms and cannonade. 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: Pao) against Daha forces. Javanese bronze breech-loaded swivel-guns, known as cetbang, or erroneously as lantaka, was used widely by the Majapahit navy as well as by pirates and rival lords. The demise of the Majapahit empire and the dispersal of disaffected skilled bronze cannon-smiths to Brunei, modern Sumatra, Malaysia and the Philippines lead to widespread use, especially in the Makassar Strait. It led to near universal use of the swivel-gun and cannons in the Nusantaran archipelago.
Portuguese and Spanish invaders were unpleasantly surprised and even outgunned on occasion. c. 1540, the Javanese, always alert for new weapons found the newly arrived Portuguese weaponry superior to that of the locally made variants. Majapahit-era cetbang cannons were further improved and used in the Demak Sultanate period during the Demak invasion of Portuguese Malacca. During this period, the iron, for manufacturing Javanese cannons was imported from Khorasan in northern Persia. The material was known by Javanese as wesi kurasani (Khorasan iron). When the Portuguese came to the archipelago, they referred to it as Berço, which was also used to refer to any breech-loading swivel gun, while the Spaniards call it Verso. By 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 180-260-pounders, weighing anywhere between 3–8 tons, length of them between 3–6 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 a 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.
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 because there is a large body of evidence that documents the evolution of the gun from the Chinese fire lance to a metal gun and the evolution of gunpowder from a medicine to an incendiary and an explosive, whereas similar records do not exist in Europe. 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 catapult to referring 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.