History of science and technology in Africa
From Wikipedia, the free encyclopedia
From Wikipedia, the free encyclopedia
Africa has the world's oldest record of human technological achievement: the oldest surviving stone tools in the world have been found in eastern Africa, and later evidence for tool production by humans' hominin ancestors has been found across West, Central, Eastern and Southern Africa.[1] The history of science and technology in Africa since then has, however, received relatively little attention compared to other regions of the world, despite notable African developments in mathematics, metallurgy, architecture, and other fields.
The Great Rift Valley of Africa provides critical evidence for the evolution of early hominins. The earliest tools in the world can be found there as well:
In 295 BCE, the Library of Alexandria was founded by Greeks in Egypt. It was considered the largest library in the classical world.[citation needed]
Al-Azhar University, founded in 970~972 as a madrasa, is the chief centre of Arabic literature and Sunni Islamic learning in the world. The oldest degree-granting university in Egypt after the Cairo University, its establishment date may be considered 1961 when non-religious subjects were added to its curriculum.[8]
Three madrasas or Islamic schools existed in Mali during the country's "golden age" from the 14th to the 16th centuries: Sankore Madrasah, Sidi Yahya Mosque, and Djinguereber Mosque, all in Timbuktu.[9][10][11] The schools consisted of independent scholars who gave instruction to individuals or small groups of students, with special lectures sometimes given in the mosques.[12] There was no overall school administration or prescribed course of study,[13] and libraries consisted of individual private collections of manuscripts.[12] Scholars were drawn from the city's wealthiest families, and instruction was explicitly religious.[12][14] The main subjects studied by advanced scholars and students were Qur'anic studies, Arabic language, Muhammad, theology, mysticism, and law.[15]
In the 16th century, Timbuktu also housed as many as 150–180 maktabs (Qur'anic schools), where basic reading and recitation of the Qur'an were taught. These schools had an estimated peak enrollment of 4,000–5,000 pupils, including pupils from the surrounding areas.[12]
Within West Africa Timbuktu was a major center of book copying, religious groups,[16][17] the Islamic sciences, and arts.[18][19] Books were imported from North Africa and paper was imported from Europe. Books/manuscripts were written primarily in Arabic.[20][21]
The most famous scholar from Timbuktu was Ahmad Baba (1556–1627), who wrote primarily about Islamic law.[22]
Three types of calendars can be found in Africa: lunar, solar, and stellar. Most African calendars are a combination of the three.[23] African calendars include the Akan calendar, Egyptian calendar, Berber calendar, Ethiopian calendar, Igbo calendar, Yoruba calendar, Shona calendar, Somali calendar, Swahili calendar, Xhosa calendar, Borana calendar, and Luba calendar and Ankole calendar.
A stone circle located in the Nabta Playa basin may be one of the world's oldest known archeoastronomical devices. Built by the ancient Nubians about 4800 BCE, the device may have approximately marked the summer solstice.
Since the first modern measurements of the precise cardinal orientations of the Egyptian pyramids were taken by Flinders Petrie, various astronomical methods have been proposed as to how these orientations were originally established.[24][25] Ancient Egyptians may have observed, for example, the positions of two stars in the Plough / Big Dipper which was known to Egyptians as the thigh. It is thought that a vertical alignment between these two stars checked with a plumb bob was used to ascertain where North lay. The deviations from true North using this model reflect the accepted dates of construction of the pyramids.[26]
Egyptians were the first to develop a 365-day, 12 month calendar. It was a stellar calendar, created by observing the stars.
During the 12th century, the astrolabic quadrant was invented in Egypt.[27]
Based on the translation of 14 Timbuktu manuscripts, the following points can be made about astronomical knowledge in Timbuktu during the 14th–16th centuries:
At this time, Mali also had a number of astronomers including the emperor and scientist Askia Mohammad I.[30]
Megalithic "pillar sites", known as "namoratunga", date to as early as 5,000 years ago and can be found surrounding Lake Turkana in Kenya.[31] Although somewhat controversial today, initial interpretations suggested that they were used by Cushitic speaking people as an alignment with star systems tuned to a lunar calendar of 354 days.[32]
Today, South Africa has cultivated a burgeoning astronomy community. It hosts the Southern African Large Telescope, the largest optical telescope in the southern hemisphere. South Africa is currently building the Karoo Array Telescope as a pathfinder for the $20 billion Square Kilometer Array project. South Africa is a finalist, with Australia, to be the host of the SKA.
Due to archeological findings it has been speculated that the kingdoms of Zimbabwe such as Great Zimbabwe and mapungubwe used astronomy. Monolith stones with special engravings thought to be used to track Venus were found. They were compared to Mayan calendars and were found to be more accurate than them[33][34][35][36]
According to Paulus Gerdes, the development of geometrical thinking started early in African history, as early humans learned to "geometricize" in the context of their labor activities. For example, the hunter-gatherers of the Kalahari Desert in southern Africa learned to track animals, learned to recognize and interpret spoors. They got to know that the shape of the spoor provided information on what animal passed by, how long ago, if it was hungry or not, etc. Such developments propelled Louis Liebenberg to posit that the critical attitude of contemporary Kalahari Desert trackers and the role of critical discussion in tracking suggest that the rationalist tradition of science may well have been practiced by hunter-gatherers long before the advent of the Greek philosophic schools. Rock paintings and engravings from all over Africa have been reported. Some of these artifacts date back to several hundreds of years, and others several thousands. They often have geometric structures. Other archaeological finds that indicate geometrical explorations by African hunters, farmers and artisans are stone and metal tools and ceramics. Particularly exceptional are archaeological finds of perishable materials such as baskets, textiles, and wooden objects. The finds from the Tellem are extremely important, as they provide ideas of earlier geometrical explorations. Clear evidence of the exploration of forms, shapes and symmetries exists in the archaeological finds from caves in the Cliff of Bandiagara in the center of Mali. The earliest buildings in the caves are cylindrical granaries made of mud coils that date from the 3rd to the 2nd century BCE.[37]
The Lebombo bone from the mountains between Swaziland and South Africa may be the oldest known mathematical artifact.[38] It dates from 35,000 BCE and consists of 29 distinct notches that were deliberately cut into a baboon's fibula.[39][40]
The Ishango bone is a bone tool from the Democratic Republic of Congo dated to the Upper Paleolithic era, about 18,000 to 20,000 BCE. It is also a baboon's fibula,[41] with a sharp piece of quartz affixed to one end, perhaps for engraving or writing. It was first thought to be a tally stick, as it has a series of tally marks carved in three columns running the length of the tool, but some scientists have suggested that the groupings of notches indicate a mathematical understanding that goes beyond counting. Various functions for the bone have been proposed: it may have been a tool for multiplication, division, and simple mathematical calculation, a six-month lunar calendar,[42] or it may have been made by a woman keeping track of her menstrual cycle.[43]
The Bushong people can distinguish graphs that have Eulerian paths and those that do not. They use such graphs for purposes including embroidery or political prestige.[44] According to a European ethnologist in 1905, Bushong children were not only aware of the conditions which determine whether a given graph is traceable, but they also knew the procedure that permitted it to be drawn most expeditiously.[45] There are various textbooks made by mathematicians using such culturally based graphs and designs to teach mathematics, such as those made by Paulus Gerdes.[46] According to ethnomathematician Claudia Zaslavsky;
Students of all ages and all ethnic backgrounds, as well as their instructors, are fascinated by the Bushoong and Chokwe networks and are impressed by the failure of the European ethnologist Emil Torday to solve the problem set to him by Bushoong children, a problem that presents a challenge to American students and their teachers as well, but was solved easily by African children.
— Africa Counts: Number and Pattern in African Cultures[47]
The "sona" drawing tradition of Angola also exhibit certain mathematical ideas.[48][49][50]
In 1982, Rebecca Walo Omana became the first female mathematics professor in the Democratic Republic of the Congo.[51][52]
By the predynastic Naqada period in Egypt, people had fully developed a numeral system.[citation needed] The importance of mathematics to an educated Egyptian is suggested by a New Kingdom fictional letter in which the writer proposes a scholarly competition between himself and another scribe regarding everyday calculation tasks such as accounting of land, labor and grain.[53] Texts such as the Rhind Mathematical Papyrus and the Moscow Mathematical Papyrus show that the ancient Egyptians could perform the four basic mathematical operations—addition, subtraction, multiplication, and division—use fractions,[54] knew the formula to compute the volume of a frustum, and calculate the surface areas of triangles, circles and even hemispheres.[55] They understood basic concepts of algebra and geometry, and could solve simple sets of simultaneous equations.[56]
| ||
| 2⁄3 in hieroglyphs | ||
|---|---|---|
Mathematical notation was decimal, and based on hieroglyphic signs for each power of ten up to one million. Each of these could be written as many times as necessary to add up to the desired number; so to write the number eighty or eight hundred, the symbol for ten or one hundred was written eight times respectively.[57] Because their methods of calculation could not handle most fractions with a numerator greater than one, ancient Egyptian fractions had to be written as the sum of several fractions. For example, the fraction two-fifths was resolved into the sum of one-third + one-fifteenth; this was facilitated by standard tables of values.[58] Some common fractions, however, were written with a special glyph; the equivalent of the modern two-thirds is shown on the right.[59]
Ancient Egyptian mathematicians had a grasp of the principles underlying the Pythagorean theorem, knowing, for example, that a triangle had a right angle opposite the hypotenuse when its sides were in a 3–4–5 ratio.[60] They were able to estimate the area of a circle by subtracting one-ninth from its diameter and squaring the result:
a reasonable approximation of the formula πr2.[60][citation needed]
The golden ratio seems to be reflected in many Egyptian constructions, including the pyramids, but its use may have been an unintended consequence of the ancient Egyptian practice of combining the use of knotted ropes with an intuitive sense of proportion and harmony.[61]
Based on engraved plans of Meroitic King Amanikhabali's pyramids, Nubians had a sophisticated understanding of mathematics and an appreciation of the harmonic ratio. The engraved plans is indicative of much to be revealed about Nubian mathematics.[62]
Most of Africa moved from the Stone Age to the Iron Age. The Iron Age and Bronze Age occurred simultaneously. North Africa and the Nile Valley imported its iron technology from the Near East and followed the Near Eastern pattern of development from the Bronze Age to the Iron Age.
Many Africanists accept an independent development of the use of iron south of the Sahara. Among archaeologists, it is a debatable issue. The earliest dating of iron outside of North Africa is 2500 BCE at Egaro, west of Termit, making it contemporary with iron smelting in the Middle East.[63] The Egaro date is debatable with archaeologists, due to the method used to attain it.[64] The Termit date of 1500 BCE is widely accepted. Iron at the site of Lejja, Nigeria, has been radiocarbon dated to approximately 2000 BCE.[65] Iron use, in smelting and forging for tools, appears in West Africa by 1200 BCE, making it one of the first places for the birth of the Iron Age.[66][67][64] Before the 19th century, African methods of extracting iron were employed in Brazil, until more advanced European methods were instituted.[68]
John K. Thornton concludes that Africans metalworkers were producing their goods at the same or higher levels of productivity as their European counterparts.[69]
Archaeometallurgical scientific knowledge and technological development originated in numerous centers of Africa; the centers of origin were located in West Africa, Central Africa, and East Africa; consequently, as these origin centers are located within inner Africa, these archaeometallurgical developments are thus native African technologies.[70] Iron metallurgical development occurred 2631 BCE – 2458 BCE at Lejja, in Nigeria, 2136 BCE – 1921 BCE at Obui, in Central Africa Republic, 1895 BCE – 1370 BCE at Tchire Ouma 147, in Niger, and 1297 BCE – 1051 BCE at Dekpassanware, in Togo.[70]
Besides being masters in iron, Africans were masters in brass, copper, and bronze. Ife showed artistic mastery in their striking naturalistic statues of brass and copper, a lost wax tradition beginning in the 11-12th centuries. Ife was also a manufacturer of glass and glass beads.[71] Benin later mastered a mix of brass and bronze during the 16th century, producing portraiture and reliefs in the metals.[72]
In West Africa, several centres of iron production using natural draft furnaces emerged from the early second millennium CE. Iron production in Banjeli and Bassar for example in Togo reached up to 80,000 cubic meters(which is more than the production at places such as Meroe), analyses indicate that fifteenth-and sixteenth-century CE slags from this area were just bloomery waste products, while preliminary metallographic analyses of objects indicate them to be made of low-carbon steels.[73] In Burkina Faso, the Korsimoro district reached up to 169,900 cubic meters. In the Dogon region, the sub-region of Fiko has about 300,000 cubic meters of slag produced.[74]
Brass barrel blunderbuss are said to have been produced in some states of the Gold Coast in the eighteenth and nineteenth centuries. Various accounts indicate that Asante blacksmiths were not only able to repair firearms, but that barrels, locks and stocks were on occasion remade.[75]
In the Aïr Mountains region of Niger, copper smelting was independently developed between 3000 and 2500 BCE. The undeveloped nature of the process indicates that it was not of foreign origin. Smelting in the region became mature around 1500 BCE.[76]
Africa was a major supplier of gold in world trade during the Medieval Age. The Sahelian empires became powerful by controlling the Trans-Saharan trade routes. They provided 2/3 of the gold in Europe and North Africa.[77] The Almoravid dinar and the Fatimid dinar were printed on gold from the Sahelian empires. The ducat of Genoa and Venice and the florine of Florence were also printed on gold from the Sahelian empires.[78] When gold sources were depleted in the Sahel, the empires turned to trade with the Ashanti Empire.
The Swahili traders in East Africa were major suppliers of gold to Asia in the Red Sea and Indian Ocean trade routes.[79] The trading port cities and city-states of the Swahili East African coast were among the first African cities to come into contact with European explorers and sailors during the European Age of Discovery. Many were documented and praised in the recordings of North African explorer Abu Muhammad ibn Battuta.
Nubia was a major source of gold in the ancient world. Gold was a major source of Kushitic wealth and power. Gold was mined East of the Nile in Wadi Allaqi and Wadi Cabgaba.[80]
Around 500 BCE, Nubia, during the Meroitic phase, became a major manufacturer and exporter of iron. This was after being expelled from Egypt by Assyrians, who used iron weapons.[81]
The Aksumites produced coins around 270 CE, under the rule of King Endubis. Aksumite coins were issued in gold, silver, and bronze.
Since 500 BCE, people in Uganda had been producing high grade carbon steels using preheated forced draft furnaces, a technique achieved in Europe only with the siemons process in the mid 19th century.[82][83] Anthropologist Peter Schmidt discovered through the communication of oral tradition that the Haya in Tanzania have been forging steel for around 2000 years. This discovery was made accidentally while Schmidt was learning about the history of the Haya via their oral tradition. He was led to a tree which was said to rest on the spot of an ancestral furnace used to forge steel. When later tasked with the challenge of recreating the forges, a group of elders who at this time were the only ones to remember the practice, due to the disuse of the practice due in part to the abundance of steel flowing into the country from foreign sources. In spite of their lack of practice, the elders were able to create a furnace using mud and grass which when burnt provided the carbon needed to transform the iron into steel. Later investigation of the area yielded 13 other furnaces similar in design to the recreation set up by the elders. These furnaces were carbon dated and were found to be as old as 2000 years, whereas steel of this caliber did not appear in Europe until several centuries later.[84][85][86][87]
Two types of iron furnaces were used in most of Africa: the trench dug below ground and circular clay structures built above ground. Iron ores were crushed and placed in furnaces layered with the right proportion of hardwood. A flux such as lime sometimes from seashells was added to aid in smelting. Bellows on the side would be used to add oxygen. Clay pipes on the sides called tuyères would be used to control oxygen flow.[88][89]
Two examples of European efforts to compete with African iron production highlight the degree of skill possessed by Kongo smiths. The first was a Portuguese effort to establish an iron foundry in Angola in the 1750s. The foundry was unsuccessful in transferring technology to Kongo black smiths; rather, "it concentrated smiths from across the colony in one area under one wage-labor system. Such methods were a tacit recognition of Kongo ironworking skill. The Portuguese foundry at Novas Oerias utilized European techniques was unsuccessful, never becoming competitive with Angolan smiths. The iron produced by Kongo smiths was superior to that of European imports produced under European processes. There was no incentive to replace Kongo iron with European iron unless Kongo iron was unavailable. European iron of the period contained a high amount of sulfur and when compared to the high carbon steel produced by Kongo iron processes, was less durable, a "rotten" metal. European iron was the second choice, whether the purchaser was from Asante, Yoruba or Kongo. The key to the gradual acceptance of European iron was ecological disaster. Gaucher (1981) believes that deforestation led to increased reliance on pre-forged European iron bars that could be carbonized in furnaces using less charcoal than smelting iron from ore. In a similar development elsewhere in the world, English iron production was crippled by the depletion of English forests for charcoal for English forges. In 1750 the Iron Act would force their American colonies to export their iron exclusively to England. This was amongst other well known reasons one of the grievances the colonists had against the English crown and a contributory factor the American Revolution". Another series of wars in Kongo however would ensure that the technical expertise to support English demand was in existence in America, albeit as slave labor. When African techniques could no longer create high quality carbon steel the lower quality European iron became a necessity. Lower quality iron also became more acceptable as the need to supply large numbers of warriors (numbering in the hundreds of thousands) with weapons quickly pushed out considerations of artisan-quality steel versus "rotten iron" imports. War broke out in the Kingdom of Kongo and after 1665; much of the stability and access to iron ore and charcoal necessary for smiths to ply their craft was disrupted. Many Kongo people were sold as slaves and their skills became invaluable in New World settings as blacksmiths, charcoal makers and ironworkers for their colonial masters. Slaves were relied upon to produce vital components for the forges and as their skills in iron working became evident, their importance to colonial economies grew.[90]
At Oboui they excavated an undated iron forge yielding eight consistent radiocarbon dates of 2000 BCE. This would make Oboui the oldest iron-working site in the world, and more than a thousand years older than any other dated evidence of iron in Central Africa.[91][92]
Traditional African plants such as Ouabain, capsicum, yohimbine, ginger, white squill, african kino, African copaiba, African myrrh, Buchu, physostigmine, and Kola nut have been adopted and continue to be used by Western doctors.[93]
The knowledge of inoculating oneself against smallpox seems to have been known to West Africans, more specifically the Akan. A slave named Onesimus explained the inoculation procedure to Cotton Mather during the 18th century; he reported to have gotten the knowledge from Africa.[94]
Bonesetting is practiced by many groups of West Africa (the Akan,[95] Mano,[96] and Yoruba,[97] to name a few).
In Djenné the mosquito was isolated to be the cause of malaria, and the removal of cataracts was a common surgical procedure[98] (as in many other parts of Africa[93]). The dangers of tobacco smoking were known to African Muslim scholars, based on Timbuktu manuscripts.[99]
Palm oil was important in health and hygiene. A German visiting in 1603-1604 reported that people washed themselves three times a day, "after which they anoint themselves with tallow or with palm oil, which is an excellent medicine". Palm oil protected the skin and hair, and it had cosmetic value in many cultures. Women (and sometimes men) spread palm oil on their skin to "shine the whole day". Palm oil was also a useful way of applying decorative color and perfumes, like powdered camwood. Many Africans considered palm oil to be a medicine in its own right, and it served as a medium for delivering other curative substances. Historical sources recount healers mixing herbs with palm oil to treat skin conditions or ease headaches. A seventeenth-century Portuguese source describes palm oil as a "popular cure" in Angola, while the "leaves, roots, bark and fruit" of the oil palm were used to treat conditions ranging from arthritis to snake and insect bites. Foreign visitors praised the quality of soap made from palm and palm kernel oils, mixed with ashes from palm fronds. One writer attested that "the Negroes Cloathes are very clean" as a result. The roasting method often used to extract kernel oil produced the characteristic color of the famous "black soap" made by West African artisans. Palm and palm kernel soaps were traded extensively in regional markets.[100]
Admiring West African medicinal prowess, Johannes Rask concluded that "Africans are much better suited than we are, as regards their health care".[101][102][103]
During the Atlantic slave trade, European sailors reported how African slaves would be able to recover from outbreaks of diseases like smallpox within the ships by using their traditional medicine which included palm oil. Europeans would use these themselves to help against dysentery. The bark of yams were used to treat worm infestations.[104][105]
The negroes are so innocent to the smallpox, that few ships that carry them escape without it, and sometimes it makes vast havoc and a destruction among them; but though we had 100 at a time sick of it, and that it went through the ship, yet we lost not above a dozen by it. All the assistance we gave the diseased was only as much water as they desired to drink, and some palm oil to anoint their sores, and they would generally recover without any other help but what kind nature gave them.
— Thomas Phillips, A Collection of Voyages and Travels (1732)
Ancient Egyptian physicians were renowned in the ancient Near East for their healing skills, and some, like Imhotep, remained famous long after their deaths.[106] Herodotus remarked that there was a high degree of specialization among Egyptian physicians, with some treating only the head or the stomach, while others were eye-doctors and dentists.[107] Training of physicians took place at the Per Ankh or "House of Life" institution, most notably those headquartered in Per-Bastet during the New Kingdom and at Abydos and Saïs in the Late period. Medical papyri show empirical knowledge of anatomy, injuries, and practical treatments.[108] Wounds were treated by bandaging with raw meat, white linen, sutures, nets, pads and swabs soaked with honey to prevent infection,[109] while opium was used to relieve pain. Garlic and onions were used regularly to promote good health and were thought to relieve asthma symptoms. Ancient Egyptian surgeons stitched wounds, set broken bones, and amputated diseased limbs, but they recognized that some injuries were so serious that they could only make the patient comfortable until he died.[106]
Around 800, the first psychiatric hospital and insane asylum in Egypt was built by Muslim physicians in Cairo.
In 1285, the largest hospital of the Middle Ages and pre-modern era was built in Cairo, Egypt, by Sultan Qalaun al-Mansur. Treatment was given for free to patients of all backgrounds, regardless of gender, ethnicity or income.[110]
Tetracycline was being used by Nubians, based on bone remains between 350 CE and 550 CE. The antibiotic was in wide commercial use only in the mid 20th century. The theory is earthen jars containing grain used for making beer contained the bacterium streptomycedes, which produced tetracycline. Although Nubians were not aware of tetracycline, they could have noticed people fared better by drinking beer. According to Charlie Bamforth, a professor of biochemistry and brewing science at the University of California, Davis, said "They must have consumed it because it was rather tastier than the grain from which it was derived. They would have noticed people fared better by consuming this product than they were just consuming the grain itself."[111]
European travelers in the Great Lakes region of Africa during the 19th century reported cases of surgery in the kingdom of Bunyoro-Kitara.[112] Medical historians, such as Jack Davies argued in 1959 that Bunyoro's traditional healers were perhaps the most highly skilled in precolonial sub-Saharan Africa, possessing a remarkable level of medical knowledge. One observer noted a "surgical skill which had reached a high standard".[113] Caesarean sections and other abdominal and thoracic operations were performed on a regular basis with the avoidance of haemorrhage and sepsis using antiseptics, anaesthetics and cautery iron.[114] The expectant mother was normally anesthetized with banana wine, and herbal mixtures were used to encourage healing. From the well-developed nature of the procedures employed, European observers concluded that they had been employed for some time.[115] Bunyoro surgeons treated lung inflammations, Pneumonia and pleurisy by punching holes in the chest until the air passed freely. Trephining was carried out and the bones of depressed fractures were elevated. Horrible war wounds, even penetrating abdominal and chest wounds were treated with success, even when this involved quite heroic surgery. Amputations were done by tying a tight ligature just above the line of amputation and neatly cutting off the limb, stretched out on a smooth log, with one stroke of a sharp sword. Banyoro surgeons had a good knowledge of anatomy, in part obtained by carrying out autopsies. Inoculation against smallpox was carried out in Bunyoro and its neighbouring kingdoms. Over 200 plants are used medicinally in eastern Bunyoro alone and recent tests have shown that traditional cures for eczema and post-measles bloody diarrhoea were more effective than western medications. Bunyoro's Medical elite, the "Bafumu", had a system of apprenticeship and even "met at periods for conferences". In Bunyoro, there was a close relationship between the state and traditional healers. Kings gave healers "land spread in the different areas so that their services would reach more people". Moreover, "in the case of a disease hitting a given area", the king would order healers into the affected district. Kabaleega is said to have provided his soldiers were anti-malarial herbs, and even to have organized medical research. A Munyoro healer reported in 1902 that when an outbreak of what he termed sleeping sickness occurred in Bunyoro around 1886–87, causing many deaths, Kabaleega ordered him "to make experiments in the interest of science", which were "eventually successful in procuring a cure".[113][93] Barkcloth, which was used to bandage wounds, has been proven to be antimicrobial.[116]
Brain surgery was also practiced in the Great Lakes region of Africa[117]
In the Kingdom of Rwanda, people afflicted with Yaws were put into quarantine and if necessary, kings closed the kingdom's borders to combat the spread of smallpox.[118]
General and local anesthesia were widely used by traditional doctors in many parts of central Africa. Beer containing an extract of kaffir was orally given to those who sustained deep wounds from animal attacks or from warfare in order to alleviate pain, and alkeloid containing leaves were also applied topically to injuries. Many tribes in central africa performed cataract surgery under local anesthesia, squeezing juices from alkaloid plants directly into the eyes to desentisize them and then pushing the cataract aside with a sharp stick, with many cases turning out successful. "The surgical skill itself was also astonishing and suggested a long experience of this practice".[93][119]
A South African, Max Theiler, developed a vaccine against yellow fever in 1937.[120] Allan McLeod Cormack developed the theoretical underpinnings of CT scanning and co-invented the CT-scanner.
The first human-to-human heart transplant was performed by South African cardiac surgeon Christiaan Barnard at Groote Schuur Hospital in December 1967. See also Hamilton Naki.
During the 1960s, South African Aaron Klug developed crystallographic electron microscopy techniques, in which a sequence of two-dimensional images of crystals taken from different angles are combined to produce three-dimensional images of the target.
The Zulu king represented the ultimate public health official. As Ndukwana, one of Stuart's respondents, explains, "All people like the land they lived on belonged to the king. If any man got seriously ill, his illness would be notified to the mnumzana[head-man], who would instantly report the fact to the izinduna (chiefs) and they to the king. The king would then most likely give the order to consult diviners so as to discover the nature and cause of his illness. A sick man in Zululand was always an object of great importance.' In theory the Zulu king and his local chiefs took responsibility for the well-being of their people and surrounded themselves with a variety of different doctors to assist them in this function. While not all illness was brought to the attention of the king, kraal heads had to report illness to their local chiefs. Depending on the social status of the ill person or number of persons afflicted, a report would be sent to the king. The Zulu proverb inkosi yinkosi ngabantu-a king is a king by the people, emphasized the reciprocal relationship between a king and his people. In exchange for the labor and loyalty of his subjects, the king provided for the welfare of his people, and his failure to do so could lead people to konza to another ruler. Zulu-speakers who konza'ed white rulers in neighboring Natal thus could not understand why such responsibilities were not also assumed by their new rulers. Another reason sickness and death sometimes gained attention at the highest levels of the state was the link between illness and witchcraft. Illness represented the possibility of persons who sought to destabilize the chiefdom or nation, and consequently chiefs could get in trouble for not reporting illness. Upon learning of an illness, a chief or the king would sometimes provide his own doctors, presumably the best in the area, or send for doctors or medicines from the surrounding regions. In some cases the king provided his own personal medicines. The state of public health thus also represented the metaphorical health of the nation state. During periods of crisis, such as droughts, epidemics, locust infestations, or epizootics, the king would summon his best doctors and mobilize a national response. One notable medical phenomenon led state healers to connect a number of unexplained deaths to the wearing of a whitish metal (perhaps tin or silver). By order of either Tshaka or Dingane, the sources seem unclear on this point, this metal was banned and collected from around the nation and buried. This shows the reach and power of the Zulu state in carrying out public health initiatives. Another example, perhaps more typical, were the bands of soldiers who were marshaled to kill locusts during times of infestation. Likewise periods of drought led the king not only to hire reputed raindoctors for the nation but to mobilize people to look for inkhonkwanes-herbs (over 240 medicinal plants were used by the Zulu) and medicine pegs put on mountaintops by umthakathis seeking to prevent rain and thus cause social disruption. Whereas these examples point to a reactive form of public health, a number of preventative measures and rituals occurred during public festivals such as the yearly Inyatela (First Fruits) and umkhosi (royal) celebrations. At these celebrations, large groups of people from around the nation came to witness and participate in ceremonies that took place within a short span of each other in December and January. At these festivals, the king, as the preeminent healer of the land, accompanied Healing the Body by his doctors and regiments, performed preventative measures aimed at ensuring the well-being of the nation and all who lived in it.[121]
Bone-setting was commonly practiced in Southern Africa by the native communities. Even broken fingers were treated.[122] Abdominal wounds with protruding intestines were manipulated successfully by inserting a small calabash to hold the intestines in place and suturing the skin over it.[93]
Tropical soils are typically low in organic matter and so present special problems to agriculturalists. Indeed African soils, (outside alluvial and volcanic areas) are in large part deficient in the characteristics of structure, texture, and chemistry which mainly determine soil fertility. Tropical areas do not have a winter season, so micro-organisms continue to break down organic matter throughout the year. Tropical soils typically have very small percentages of organic matter or humus (sometimes as little as 1%) as a result. Soils in temperate climates may, in contrast, consist of 12 to 14 or (in virgin soils in the U.S.) up to 16% organic materials, because the cold winters slow the processes of decomposition and allow organic material to build up over time. In many tropical regions, farmers practice a semi-sedentary form of agriculture, using fields for two or three years and then abandoning them for a decade or more (up to 25 years after two years of cultivation in the case of savanna woodlands in Africa), until the humus content has been restored by natural processes.[123][124][125]
Through careful observation, experimentation and selection of desirable traits over the course of 2,000 years, africans managed to create a rich diversity of Banana and plantain types (120 different types of plantains and 60 different types of bananas). Due to this there emerged a second area of Banana diversification outside of Asia, one with the Highland cooking banana in the African Great Lakes and the Plantain in West and Central Africa. This shows the agricultural skills and innovative practices africans mastered and continuously developed in the millennia before europeans arrived into the continent.[126]
Like the natives of the Amazon rainforest, Africans also utilized dark earths similar to Terra preta.[127][128]
Archaeologists have long debated whether or not the independent domestication of cattle occurred in Africa as well as the Near East and Indus Valley. Possible remains of domesticated cattle were identified in the Western Desert of Egypt at the sites of Nabta Playa and Bir Kiseiba and were dated to c. 9500–8000 BP, but those identifications have been questioned.[129] Genetic evidence suggests that cattle were most likely introduced from Southwest Asia, and that there may have been some later breeding with wild aurochs in northern Africa.[130]
Genetic evidence also indicates that donkeys were domesticated from the African wild ass.[131] Archaeologists have found donkey burials in early dynastic contexts dating to ~5000 BP at Abydos, Middle Egypt, and examination of the bones shows that they were used as beasts of burden.[132]
Cotton (Gossypium herbaceum Linnaeus) may have been domesticated 5000 BCE in eastern Sudan near the Middle Nile Basin region, where cotton cloth was being produced.[133]
Finger millet is originally native to the highlands of East Africa and was domesticated before the third millennium BCE in Uganda and Ethiopia. Its cultivation had spread to South India by 1800 BCE.[134]
Engaruka is an Iron Age archaeological site in northern Tanzania known for the ruins of a complex irrigation system. Stone channels were used to dike, dam, and level surrounding river waters. Some of these channels were several kilometers long, channelling and feeding individual plots of land totaling approximately 5,000 acres (20 km2).[135][136] Seven stone-terraced villages along the mountainside also comprise the settlement.
The Shilluk Kingdom gained control of the west bank of the white Nile as far north as Kosti in Sudan. There they established an economy based on cereal farming and fishing, with permanent settlements located along the length of the river. The Shilluk developed an extremely intensive system of agriculture based on sorghum, millet and other crops. By the 1600s, shillukland had a population density similar or exceeding that of the Egyptian Nile lands.[137][138]
Ethiopians, particularly the Oromo people, were the first to have discovered and recognized the energizing effect of the coffee bean plant.[139]
Ox-drawn plows seems to have been used in Ethiopia for two millennia, and possibly much longer. Linguistic evidences suggests that the Ethiopian plow might be the oldest plow in Africa.[140]
Teff is believed to have originated in Ethiopia between 4000 and 1000 BCE. Genetic evidence points to E. pilosa as the most likely wild ancestor.[141] Noog (Guizotia abyssinica) and ensete (E. ventricosum) are two other plants domesticated in Ethiopia.
Ethiopians used terraced hillside cultivation for erosion prevention and irrigation. A 19th century European described Yeha:
All the surrounding hills have been terraced for cultivation, and present much the same appearance as the hills in Greece and Asia Minor, which have been neglected for centuries; but nowhere in Greece or Asia Minor have I ever seen such an enormous extent of terraced mountains as in this Abyssinian valley. Hundreds and thousands of acres must here have been under the most careful cultivation, right up almost to the tops of the mountains, and now nothing is left but the regular lines of the sustaining walls, and a few trees dotted about here and there. This valley is most completely shut in, quite such a one as one can imagine Rasselas to have lived in
— James T. Bent, The sacred city of the Ethiopians, being a record of travel and research in Abyssinia in 1893 (1896)
within the African Great Lakes advanced agriculture practices were employed such as "hydraulic practices in the mountains, man-made watering places, river diversions, hollowed-out tree-trunk pipes, irrigation on cultivated slopes, mounding in drained marshes, and irrigation of banana and palm tree gardens" as well as extensive use of terraces and the practice of double and triple cropping. The agrarian success of the Great Lakes civilization accounts for its exceptionally high levels of human density. Many foreign experts were impressed by the sophistication of the areas traditional methods of intensive farming.[142] The agriculture of the great lakes was described below:
The "beautiful irrigated fields", the steep terraced slopes of the thousand hills, where every patch of ground is put to use, the "well-fed cattle with colossal horns" were "wonderful discoveries" to the Europeans. But even greater surprises awaited them.
— Christian P. Scherrer, Genocide and Crisis in Central Africa: Conflict Roots, Mass Violence, and Regional War
The earliest Europeans to visit Rwanda observed intense pride in cultivating skills. A mother would give a crying baby a toy hoe to play with and a range of techniques often superior to those of eastern European peasants, notably the use of manure, terracing, and artificial irrigation.[143]
The Chaga people have long practiced an advanced form of agriculture which allowed them to maintain a high population density involving the control and distribution of water. Europeans wrote of their admirably constructed irrigation works and the care they witnessed in the maintenance of them and their powerfully centralized social organization.[144] Sir Harry Johnston, writing in 1894, echoed this praise of Chagga industry and skill:
They mostly excel in their husbandry, the skill with which they irrigate their terraced hillsides with tiny runnels of eater shows considerable advancement in agriculture. Their time is constantly spent in tilling the soil, manuring it with ashes, raking it and hoeing it with wooden hoes
— William Allan, The African Husbandman
The earliest evidence for the domestication of plants for agricultural purposes in Africa occurred in the Sahel region c. 5000 BCE, when sorghum and African rice (Oryza glaberrima) began to be cultivated. Around this time, and in the same region, the small guineafowl was domesticated. Other African domesticated plants were oil palm, raffia palm, African yam, black-eyed peas, Bambara groundnut, Cowpea, Fonio, Pearl millet, and kola nuts.
Investigations in the Upper Guinea forest region by found connections between palm oil processing, "sacred agroforests", and anthropogenic soil, or "dark earths". They identified "palm oil production pits" as central loci for the formation of dark earths, where charred palm kernels and other organic materials enriched soils for use in fields of vegetables and trees. Once left fallow those fields gradually morphed into biodiverse groves of palms and other forest species. These anthropogenic landscapes, patches of AfDES (African dark earths) and anthropogenic vegetation are permeated with symbolic significance because they are the ongoing outcome of inhabitation trajectories begun by ancestors, continuing to the present day. They are not simply areas of improved soils and anthropogenic agroforests, but the relics of old towns, villages, kitchens, graveyards, and initiation society areas, many of which were inhabited by direct ancestors of current inhabitants.[145]
African oil palms were most abundant as part of the oil palm-yam complex beginning just south and east of the rice belt running from Lower Guinea across the derived savannas of the Dahomey Gap and through the Niger Delta. From there oil palm cultivation extended deep into the Central African rainforests where swidden farmers spared and managed palms within their plots of yams, cocoyams, plantains, legumes, and other crops, and where dense rainforest alternated with emergent oil palm groves. Long disparaged by some Western scientists and environmentalists as "slash-and-burn", ecological research since the mid-twentieth century has demonstrated the efficacy of such ancestral systems, linking traditional swidden-fallow landscapes with enhanced floral and faunal biodiversity, higher returns on labor investment, food security, nutritional balance, and overall resilience and reliability, especially when compared to monocultures. Throughout western Africa, oil palm agroforests helped to nourish human communities by contributing to food security and balanced diets, complementing carbohydrate-rich tubers and grains with fats, provitamin A carotenoids (mainly a-and B-carotenes), and vitamin E. The source of fats is particularly important within the broad swath of sub-Saharan Africa where the voracious tsetse fly and the trypanosomiasis pathogens it carries make livestock husbandry virtually impossible.[145]
African methods of cultivating rice, introduced by enslaved Africans, may have been used in North Carolina. This may have been a factor in the prosperity of the North Carolina colony.[146] Portuguese observers between the half of the 15th century and the 16th century witnessed the cultivation of rice in the Upper Guinea Coast, and admired the local rice-growing technology, as it involved intensive agricultural practices such as diking and transplanting.[147]
Yams were domesticated 8000 BCE in West Africa. Between 7000 and 5000 BCE, pearl millet, gourds, watermelons, and beans also spread westward across the southern Sahara.
Between 6500 and 3500 BCE knowledge of domesticated sorghum, castor beans, and two species of gourd spread from Africa to Asia. Pearl millet, black-eyed peas, watermelon, and okra later spread to the rest of the world.[148]
In the lack of more detailed historical and archaeological studies on the chronology of terracing, intensive terrace farming is believed to have been practiced before the early 15th century CE in West Africa.[149][150] Terraces were used by many groups, notably the Mafa,[151] Ngas, Gwoza,[152] and the Dogon.[153]
In order to prevent erosion, southern africans built dry-stone terraces on steep hillsides.[154]
Randall MacIver describes the irrigation technology used in Nyanga, Zimbabwe:[155]
The country about Inyanga is well watered, but it would seem that the old inhabitants
required a more general distribution of the supply than was afforded by the numerous
streams running down from the hills. Accordingly, they adopted a practice which has been prevalent under similar conditions in several other countries, Algeria being one instancewhich has come under the waiter's own observation. The stream was tapped at a point near its source, and part of the water deflected by a stone dam. This gave them a high-level conduit, by which the water could be carried along the side of a hill and allowed to descend more gradually than the parent stream. There are very many such conduits in the Inyanga region, and they often run for several miles. The gradients are admirably calculated, with a skill which is not always equalled by modern engineers with their elaborate instruments. The dams are well and strongly built of unworked stones without mortar; the conduits themselves are simple trenches about one metre in depth. The earth taken out of the trench is piled on its lower side and supported by boulders imbedded in ito.
Cattle features as a primary source of sustenance and political and economic power in many parts of southern Africa. Sotho, Tswana and Nguni kingdoms rose to prominence on the back of successful cattle keeping, supplemented by cultivation.[156]
Cattle (and possibly goats) played a central role in Nguni culture. Nguni-speaking South Africans in KwaZulu-Natal revered the Nguni cattle. By 1824, Shaka Zulu's royal cattle pen contained 7,000 pure white Nguni cattle. Similarly, when the original pioneers arrived in Zimbabwe (then Rhodesia), they reported that the country was 'teeming with cattle that were, apparently, in good health and were immune to local diseases'.[157]
Before 1850, there were an estimated four to five million Nguni cattle in what is now KwaZulu-Natal. Indeed it could have been said that, so immense was the number of cattle, idaka liye lahlaba ezulwini (the kraal-mud was splashed up to heaven), but war, disease, political unrest and the introduction by whites of their own cattle, led to a decline in numbers so that a decade ago only about 100,000 pure Ngunis remained. In 1879, at the close of the Anglo-Zulu War, in which the power of the Zulu Kingdom was broken, Sir Garnet Wolseley ensured the end of the Zulu royal herds by slaughtering and confiscating what remained.
— Marguerite Poland, The Abundant Herds
South africans were known for being experts in finding lost cattle. A single Zulu was able to locate 10 cattle that were lost during conflict two years ago over a large area.[158]
Like many traditional societies, the Himba have astonishingly sharp vision and focus, believed to come from their cattle rearing and need to identify each cow's markings.[159]
For many years, scientists argued that Africa's first agriculturalists hacked and burned their way through a primeval "Guineo-Congolian rainforest" stretching from Sierra Leone to Congo and beyond. In this telling, oil palms were the survivors of forests destroyed by African farmers, leaving "derived savannah" behind. New research has overturned that interpretation, however. An "aridification event" about 4,000–5,000 years ago wiped out forests and encouraged the spread of grassland across western Africa. Oil palms probably expanded into these gaps ahead of human settlers, the seeds spread by animals. Humans helped the palm along, though, protecting it from grassland fires and voracious elephants. Linguistic evidence shows a close link between oil palm dispersion and the arrival of Bantu-speaking agriculturalists in the Congo basin beginning around 1,000 BCE. Few central and southern African languages use non-Bantu terms for the oil palm, suggesting that the tree came with migrants, either carried by them or sharing the same ecological openings in the forest. As a tradition among Mfumte-speakers of northern Cameroon tells us, oil palms "follow men", growing in the wake of human activity. The interplay of climate and agriculture pushed the oil palm's frontier to the south and east, but progress was slow. Nineteenth century travelers reported only scattered groves around Lakes Kivu and Tanganyika, despite amenable environmental conditions. Tanzanians interviewed in the twentieth century clearly indicated that oil palms were recent arrivals, brought by people rather than by animals. Rather than serving as agents of deforestation-with oil palms the evidence of ecological vandalism-African farmers may in fact be responsible for afforestation in many places. Ethnographic research, coupled with historic aerial photography, showed that forests grew out of the moist, nutrient-rich soils left behind in the shade of abandoned village palm groves. Rejecting earlier classifications like "semi-wild" or "sub-spontaneous", geographer Case Watkins describes these palm groves as "emergent" phenomena. They are not purely human creations, but rather develop out of human interactions with a complex set of natural forces. These emergent groves often give way to other tree species, creating true forest where none had existed. As early as the 1920s, elders in Congo told a missionary that they and their ancestors were not "shifting cultivators" cutting out clearings in a forest: they had built the forest with their farming practices. At the time, few Europeans cared to listen. One colonial forester recalled how blinded he had been by stereotypes: "What I had in my inexperience looked upon as glorious virgin [forest] growth, dating from the Flood, quickly revealed itself to my better experienced and disappointed eye as nothing more than secondary growth of moderately good quality." With the help of local guides, seeing a landscape was "like reading a book", revealing human history in the environment. Across much of western and central Africa, forests have probably been advancing rather than retreating for the past 1,000 years or so, and this despite bouts of low rainfall. Far from marking humanity's destructive impact on forests, oil palms stand across Africa as a testament to the versatility, ingenuity, and sustainability of local farming practices.[145]
