The suspension bridge was first given durable form in the sixth century when Chinese engineers employed iron chains to suspend roadways, a technique copied in Tibet but one that appeared in Europe only at the end of the eighteenth century. The segmental arch bridge, built in China shortly after A.D. A.D. 600, was imitated in the West in the fourteenth century. 600, was imitated in the West in the fourteenth century.25 Lock gates built under the Sung dynasty (9601279) followed in Europe in the late fourteenth century. Lock gates built under the Sung dynasty (9601279) followed in Europe in the late fourteenth century.26

A Chinese art that the West tried vainly to copy in the Middle Ages was the production of porcelain, the vitrified (gla.s.slike), fine-grained, and usually translucent pottery in latter days a.s.sociated with the word "china." In the seventh century A.D. A.D., Chinese potters discovered that the mineral feldspar could be incorporated into stoneware, resulting in a primitive type of porcelain. The process was perfected in the thirteenth century under the Mongols by mixing china stone, a rock containing feldspar, with kaolin, white china clay, and firing it at extremely high temperatures (up to 1,450C). During the late Middle Ages, European potters attempted to imitate Chinese porcelain, their efforts eventually culminating in the sixteenth century in an inferior product, soft-paste or artificial porcelain, a mixture of clay and ground gla.s.s fired at a lower temperature. True hard-paste porcelain was not produced in Europe until the eighteenth century.27

One pattern that was repeated through antiquity and the Middle Ages was the appearance of a device in Greece and Rome, paralleled or closely followed in China, then forgotten in the West but continuing to develop in the East, and finally revived in Europe. One such device was the odometer, known to Vitruvius and Heron of Alexandria, then disappearing until the end of the fifteenth century, when it was depicted by Leonardo da Vinci. In China the mechanism seems to have originated sometime in the first century B.C. B.C. as a mechanical toy, a vehicle in imperial processions whose turning wheels activated drums and gongs. The device's value for surveying and mapmaking was soon recognized, and the wheels and gears were arranged to measure distance. An eleventh-century historian described an elaborate model: "It is painted red, with pictures of flowers and birds on the four sides, and constructed in two stories, handsomely adorned with carvings. At the completion of every as a mechanical toy, a vehicle in imperial processions whose turning wheels activated drums and gongs. The device's value for surveying and mapmaking was soon recognized, and the wheels and gears were arranged to measure distance. An eleventh-century historian described an elaborate model: "It is painted red, with pictures of flowers and birds on the four sides, and constructed in two stories, handsomely adorned with carvings. At the completion of every li li, the wooden figure of a man in the lower story strikes a drum; at the completion of every ten li li, the wooden figure in the upper story strikes a bell."28 The "south-pointing carriage," a celebrated vehicle peculiar to China dating from the third century A.D. A.D., was once erroneously believed to represent a step in the development of the magnetic compa.s.s. A two-wheeled horse-drawn chariot on which a figure was mounted with its arm preset to point due south, the vehicle had gears so arranged that whichever way it turned, the figure pivoted to hold its south-pointing posture. Although it was an invention without further application, whose secret was later forgotten in China, the carriage was not without significance in cybernetics, as a pioneer self-regulating mechanism employing negative feedback.29

The magnetic compa.s.s, however, did originate in China in the early Middle Ages. Both European and Chinese antiquity were aware of the ability of the lodestone (a variety of magnet.i.te) to attract and repel iron, and of its inductive property-the power to magnetize iron, to impart the same attraction and repulsion to it. Discovery of the directive possibilities of the magnet, however, belonged to China, as did the invention of the magnetic needle, to make readings more accurate.

The earliest certain reference to the magnetic compa.s.s goes back to A.D. A.D. 83, in the Han dynasty, when a scholar described the "south-controlling spoon" which when thrown on the geomancer's divining board came to rest pointing south (the arrow on a compa.s.s may be, and often was, made to point south rather than north). The board used by geomancers to detect the "winds and waters of the earth" consisted of two plates, the lower square, symbolizing the earth, the upper round, symbolizing the heavens. The upper plate, engraved with the compa.s.s points, revolved on a central pivot and bore in the middle a representation of the Great Bear. This plate was turned on its axis to follow the annual path of the bear's tail. The spoon, cut from lodestone, also represented the bear. Aside from its role in divination, some form of "south-pointer" was used by Chinese travelers; a reference from the Han dynasty states that "when the people of Cheng go out to collect jade, they carry a south-pointer with them so as not to lose their way." 83, in the Han dynasty, when a scholar described the "south-controlling spoon" which when thrown on the geomancer's divining board came to rest pointing south (the arrow on a compa.s.s may be, and often was, made to point south rather than north). The board used by geomancers to detect the "winds and waters of the earth" consisted of two plates, the lower square, symbolizing the earth, the upper round, symbolizing the heavens. The upper plate, engraved with the compa.s.s points, revolved on a central pivot and bore in the middle a representation of the Great Bear. This plate was turned on its axis to follow the annual path of the bear's tail. The spoon, cut from lodestone, also represented the bear. Aside from its role in divination, some form of "south-pointer" was used by Chinese travelers; a reference from the Han dynasty states that "when the people of Cheng go out to collect jade, they carry a south-pointer with them so as not to lose their way."30 The compa.s.s matured with the development of more accurate instruments, including the magnetized needle, introduced in China in the eighth century A.D. A.D. Created by rubbing an iron needle with a magnet, the device was floated on water on a bit of wood or suspended by a silken thread. Created by rubbing an iron needle with a magnet, the device was floated on water on a bit of wood or suspended by a silken thread.31 By at least the ninth century, the Chinese were aware of the principle of magnetic declination-the fact that the compa.s.s needle does not point true north (or south), the inclination varying with the meridian where the reading is taken. By at least the ninth century, the Chinese were aware of the principle of magnetic declination-the fact that the compa.s.s needle does not point true north (or south), the inclination varying with the meridian where the reading is taken.32 Probably because most of China's water travel took place on its network of ca.n.a.ls and rivers or along the coast, the compa.s.s was slow to be adopted for navigation. Sometime between 850 and 1050, it began to appear aboard ships, the first certain mention in a Chinese text occurring early in the twelfth century, in a reference to events of the late eleventh: "The [seagoing] ship's pilots are acquainted with the configuration of the coasts; at night they steer by the stars, and in the day-time by the sun. In dark weather they look at the south-pointing needle."33 Incidental to the final development of the mariner's compa.s.s was a device with a number of applications, an eventual one of which was to provide mounting to keep the compa.s.s in horizontal equilibrium, independent of the ship's motion. Called in the West the "Cardan suspension" because it was described, much later, by Italian scientist Jerome Cardan, it was known in China from the second century, when an account described an incense burner with "a contrivance of rings which could revolve...so that the body of the burner remained constantly level and could [safely] be placed among bedclothes and cushions." Similar portable stoves were known to the Arabs, who probably transmitted the invention to Europe.34

Gunpowder appeared in China as early as the ninth century, when the first reference to the mixing of saltpeter, sulfur, and carbonaceous material occurred in a Taoist alchemy book. The first reaction of the inventors was to warn others against it, lest they singe their beards and burn down their laboratories.35 Contrary to popular belief, however, the Chinese did not limit early use of the invention to fireworks but very quickly incorporated it into military weapons, evolving from about Contrary to popular belief, however, the Chinese did not limit early use of the invention to fireworks but very quickly incorporated it into military weapons, evolving from about A.D. A.D. 950 into sophisticated rockets and guns. 950 into sophisticated rockets and guns.36 It seems almost certain that the secret was transmitted westward, though the route of diffusion has baffled discovery. It seems almost certain that the secret was transmitted westward, though the route of diffusion has baffled discovery.

One Chinese invention whose pa.s.sage to Europe can be traced step by step is paper. A felted sheet of fibers formed from a water-suspension process using a sievelike screen as a mold, paper was first manufactured in China sometime before the Christian era and was widely used in the third century A.D. A.D., by which time it had already spread beyond Chinese borders.37 Paper may have been first produced accidentally during the process of felting-making nonwoven fabric by applying heat, water, and pounding to plant or animal fibers, or shrinking and matting woven rags by the same process. In the Chinese paper industry, rags were soon replaced in high-grade papers by the bark of the paper mulberry. Gradually the product was improved with sizing and dyes, and by the use of molds made of bamboo strips to replace the earlier screens of coa.r.s.e cloth.38 Cheap and light, paper was first used in China not for writing or printing but for applications such as wrapping. Only in the third century A.D. A.D. did it completely replace silk, bamboo, and wood as a writing medium. The two writing materials of the ancient West, animal hides (parchment and vellum) and plant leaves (papyrus), were never used for writing in China, where paper came to have a unique importance. Among its hundreds of uses besides writing were cut-out designs, fans, and umbrellas from the third century; clothing, household furnishings, visiting cards, kites, lanterns, napkins, and toilet paper by the fifth or sixth century, playing cards and money by the ninth. did it completely replace silk, bamboo, and wood as a writing medium. The two writing materials of the ancient West, animal hides (parchment and vellum) and plant leaves (papyrus), were never used for writing in China, where paper came to have a unique importance. Among its hundreds of uses besides writing were cut-out designs, fans, and umbrellas from the third century; clothing, household furnishings, visiting cards, kites, lanterns, napkins, and toilet paper by the fifth or sixth century, playing cards and money by the ninth.

The use of toilet paper was recorded by a sixth-century Chinese scholar who wrote, "Paper on which there are quotations or commentaries from the Five Cla.s.sics or the names of sages, I dare not use for toilet purposes." In 851 an Arab traveler commented unfavorably on the cleanliness of the Chinese, who did not "wash themselves with water when they have done their necessities; but they only wipe themselves with paper." Toilet paper was made from rice straw, cheap and soft. In 1393 the Bureau of Imperial Supplies recorded the manufacture of 720,000 large sheets for the use of the court and 15,000 sheets, three inches square, light yellow, thick but soft, and perfumed, for the use of the imperial family.39 Paper money seems to have originated in the early ninth century when increased business and government transactions encouraged the inst.i.tution of "flying money," a credit medium rather than a true money, as a way to avoid carrying the weight of metal coins. Originally a private arrangement of merchants, the system was taken over by the government in A.D. A.D. 812 and gradually evolved into a true paper currency. 812 and gradually evolved into a true paper currency.40 Two centuries before Ca.s.siodorus sang the praises of papyrus, a Chinese scholar wrote a panegyric to paper in rhymed prose: Lovely and precious is this material,Luxury but at a small price;Matter immaculate and pure in its natureEmbodied in beauty with elegance incarnate,Truly it pleases men of letters.It makes new substance out of rags,Open it stretches,Closed it rolls up,Contracting, expanding,Secreting, expounding.To kinship and friendship scattered afar,When you are lonely and no one is by,You take brush to write on paper...41 Transmission of paper westward occurred in two stages, the paper and paper products arriving first, followed a century or two later by the manufacturing technique. Neighboring Korea, j.a.pan, and Indo-China learned papermaking as soon as they began to have contact with China (c. second century A.D. A.D.). Moving westward over the Old Silk Road, paper arrived in eastern Turkestan, on the sh.o.r.es of the Caspian Sea, in the third century. Chinese paper craftsmen captured at the battle of Talas River in 751 were brought to Samarkand to found an industry that made "paper of Samarkand" an important article of commerce, leading to the establishment of a mill at Baghdad in about 794.42 Arab ma.n.u.scripts written on paper survive from the following century. Arab ma.n.u.scripts written on paper survive from the following century.43 Paper products finally entered Europe in the tenth century through Muslim Spain, which also became the first European country to develop a paper industry, followed a little later by Muslim Sicily and southern Italy. Waterpower was first applied to the pounding process in Baghdad about 950. Paper products finally entered Europe in the tenth century through Muslim Spain, which also became the first European country to develop a paper industry, followed a little later by Muslim Sicily and southern Italy. Waterpower was first applied to the pounding process in Baghdad about 950.44 In China paper had many advantages over its alternatives, clumsy bamboo and wood and expensive silk. In Europe it had only the advantage of cheapness over papyrus and parchment, and it was more fragile and perishable. Not until the advent of printing in Europe did paper fulfill its potential, replacing parchment for all but the most permanent records.

The course of transmission of printing is much less easily discerned than that of paper. After a long history of preprinting techniques-seals for stamping, stencils to duplicate designs, inked impressions from stone inscriptions-the Chinese began to use woodblock printing in the seventh century. More practical than movable type for written Chinese, with its thousands of ideograms rather than an alphabet, the woodblock dominated Chinese printing for several centuries. A Persian historian described the reproduction and distribution of woodblock-printed Chinese books: a skilled calligrapher copied the author's text onto wooden tablets; these were corrected by proofreaders before being carved on the tablet surface by expert engravers. The tablets (pages-to-be) were then consecutively numbered and placed in sealed bags. When a copy of the book was wanted, the customer paid a charge fixed by the government, and the tablets were taken out, inked, and imposed on sheets of paper.45 Since under the Chinese ideograph system the amount of movable type required a large capital investment and elaborate organization of labor, it was profitable only for large-scale production. In about 1045 an artisan named Pi Sheng formed clay characters "as thin as the edge of a coin," fired them; a.s.sembled the type on an iron plate coated with pine resin, wax, and ashes; warmed and cooled the plate to solidify the type; then inked it and made the impression. A contemporary, describing the process, explained, "If one were to print only two or three copies, this method would be neither simple nor easy. But for printing hundreds or thousands of copies, it was marvelously quick." Pi Sheng usually worked with two forms, taking the impression from one while type was being set on the other, enabling the printing to be done "with great rapidity." The type was arranged in wooden cases with paper labels, "one label for words of each rhyme-group."46 The first practical wooden movable type appeared late in the thirteenth century, when a magistrate named w.a.n.g Chen used characters cut out of wood blocks with a small, fine-toothed saw, then finished with a knife for exact uniformity and arranged for easier handling in compartmental wooden cases on revolving tables.47 Metal movable type was developed early in the fifteenth century in Korea, where three cast-bronze fonts were made before the appearance of metal type in Europe or China. Metal movable type was developed early in the fifteenth century in Korea, where three cast-bronze fonts were made before the appearance of metal type in Europe or China.

A reasonable conjecture is that printing followed the path of paper to Turkestan, whence it reached Persia during the thirteenth-century Mongol domination of central Asia, to appear in Europe, first in block form and then as movable type.48

One outstanding Chinese invention that did not migrate westward was the junk, one of the best sailing ships ever designed. Powered by square sails composed of linen panels that were raised and lowered like venetian blinds, the junk had a high stern and ma.s.sive stern rudder (an idea that did eventually reach the West) that on the junk doubled as a keel. Another notable feature was the watertight compartment.

The Technology of India and Persia The technological contributions of India and Persia, many of them fundamental inventions, belong mostly to prehistory and antiquity. Indian metallurgy was far ahead of European; the Romans imported Indian steel. Medieval India produced landmark scientific advances, notably in mathematics-algebra and the so-called Hindu-Arabic numerals, embodying the principle of place value and the zero. Of its technical innovations, one, the churka churka (cotton gin) had an enormous impact on the West. India may also have produced the original ancestor of the spinning wheel, for use with cotton. (cotton gin) had an enormous impact on the West. India may also have produced the original ancestor of the spinning wheel, for use with cotton.

Persia's chief medieval invention was the Eastern version of the windmill, mentioned for the first time in the seventh century. Like the Eastern waterwheel, it was horizontal, with enclosing walls admitting the wind on one side. Windmills of the Persian type spread to Turkestan and thence to China, where they took on a nautical form, with fore-and-aft sails mounted on masts around a drum. If a connection exists between these horizontal windmills and the vertically mounted windmill that began to appear in Europe in the twelfth century, it is probably that of stimulus diffusion.

The Arabs, Transmitters and Inventors In the immense transfer of science and technology that marked the Middle Ages in Europe, Africa, and Asia, the Arabs played a unique role. Along with the spices and silks they carried from China and India, they brought many of Asia's discoveries and inventions, and they provided the means by which Europe at last recovered its own lost heritage of Greek knowledge. The protracted conflict between Islam and Christian Europe has obscured the remarkable service performed by the former to the benefit of the latter, but the process occurred naturally enough. "Between the eighth and the twelfth centuries, the sophistication and culture of the Islamic world made it the suitable heir of cla.s.sical civilization" (Joel Mokyr),49 and as such it readily absorbed the science and philosophy of Greece. and as such it readily absorbed the science and philosophy of Greece.

The Arab Age of Translation began during the reign of Harun-al-Rashid (A.D. 786809), when scholar-physicians at a Nestorian Christian academy in Jundi-Shapur, in southwest Persia, were brought to Baghdad to translate Greek ma.n.u.scripts gathered by the caliph's agents, acting, in the words of a modern writer, as "buyers of culture." 786809), when scholar-physicians at a Nestorian Christian academy in Jundi-Shapur, in southwest Persia, were brought to Baghdad to translate Greek ma.n.u.scripts gathered by the caliph's agents, acting, in the words of a modern writer, as "buyers of culture."50 A young scholar from Jundi-Shapur, Hunayn ibn-Ishaq, became court physician to Harun's son, Caliph al-Mamun, and in 830 was named head of the "House of Wisdom," a library founded by the caliph to store and translate Greek ma.n.u.scripts. Hunayn and his colleagues translated Plato's Republic, many of Aristotle's works, and the medical writings of Hippocrates, Dioscorides, and Galen (some of whose works were later lost in the original Greek and preserved to the world solely in Hunayn's Arabic). A young scholar from Jundi-Shapur, Hunayn ibn-Ishaq, became court physician to Harun's son, Caliph al-Mamun, and in 830 was named head of the "House of Wisdom," a library founded by the caliph to store and translate Greek ma.n.u.scripts. Hunayn and his colleagues translated Plato's Republic, many of Aristotle's works, and the medical writings of Hippocrates, Dioscorides, and Galen (some of whose works were later lost in the original Greek and preserved to the world solely in Hunayn's Arabic).51 Most of the Greek works translated belonged to the h.e.l.lenistic period, and the culture they represented was not that of literary Athens but that of scientific Alexandria. Homer was never rendered into Arabic, nor were the works of Greek historians or dramatists. Aristotle's comments about Greek drama in the Poetics Poetics puzzled Arab readers; they had no theater of their own and were totally unacquainted with Sophocles and Euripides. Their interests were essentially those of Aristotle himself: the natural sciences, medicine, chemistry, astronomy, mathematics, geography, and the philosophy underlying them. They did not stop with preservation and translation; Arab scholars expounded and interpreted the Greek material, to the great benefit of later European intellectuals. The most famous of the Arab commentators were Avicenna (Ibn-Sina, 9801037) and Averroes (Ibn-Rushd, 11261198). The distinguished astronomer and mathematician al-Khwarizmi (c. 780c. 850) revised the geography of Ptolemy and wrote an original treatise expounding the Hindu numerals which, in Latin translation, introduced them to the Christian West. puzzled Arab readers; they had no theater of their own and were totally unacquainted with Sophocles and Euripides. Their interests were essentially those of Aristotle himself: the natural sciences, medicine, chemistry, astronomy, mathematics, geography, and the philosophy underlying them. They did not stop with preservation and translation; Arab scholars expounded and interpreted the Greek material, to the great benefit of later European intellectuals. The most famous of the Arab commentators were Avicenna (Ibn-Sina, 9801037) and Averroes (Ibn-Rushd, 11261198). The distinguished astronomer and mathematician al-Khwarizmi (c. 780c. 850) revised the geography of Ptolemy and wrote an original treatise expounding the Hindu numerals which, in Latin translation, introduced them to the Christian West.

Muslim philosopher Averroes (Ibn-Rushd). Detail of fresco The Triumph of St. Thomas Aquinas, The Triumph of St. Thomas Aquinas, by Andrea da Firenze, in Santa Maria Novella, Florence. [Alinari.] by Andrea da Firenze, in Santa Maria Novella, Florence. [Alinari.]

In other fields the Arabs made original contributions. Commerce was a respectable, even prestigious profession in the world of Islam. "The honest Muslim merchant will rank with the martyrs of the faith," said Muhammad, and "Merchants are the couriers of the world and the trusted servants of G.o.d upon earth."52 Islamic business techniques in banking, bookkeeping, and coinage were so far in advance of those of Europe that when the Normans conquered Sicily (10711091), their pragmatic Christian kings employed Muslims to handle their finances. Islamic business techniques in banking, bookkeeping, and coinage were so far in advance of those of Europe that when the Normans conquered Sicily (10711091), their pragmatic Christian kings employed Muslims to handle their finances.53 To the science of distillation, already centuries old, Muslim alchemists made many practical contributions. Muslim musicians introduced the first bowed instruments, the lute and rebec, ancestors of the violin. Following the First Crusade, European military engineers learned much of the art of castle building from their Muslim foes. The secrets of Syrian gla.s.smaking were sold to Venice (in 1277) and its techniques taught by Muslim artisans, founding a monopoly of the manufacture of fine gla.s.s long maintained by that city.54 Undergirding the transformation of the Muslim half of the Mediterranean world lay Islam's own revolution in agriculture. Like so much else, the crops and processes of the new system were borrowed from Asia, in this case mostly from India. Muslim enterprise, public as well as state-encouraged private, combined them into a fresh synthesis. A wide array of food and fiber plants was introduced, new patterns of cultivation were adopted, and extensive irrigation systems were built. The new crops included rice, sorghum, hard wheat, sugarcane, cotton, watermelons, eggplants, spinach, artichokes, sour oranges, lemons, limes, bananas, plantains, mangoes, and coconut palms. Most required intensive cultivation with application of fertilizer, heavy watering, and a flexible system of crop rotation that employed all the seasons of the year. New irrigation devices, also borrowed rather than invented by the Arabs, included dams, drainage tunnels, ca.n.a.ls, and water-lifting machines. The system with its wider variety of crops, more land under cultivation, and more intensive cropping, helped stabilize Islamic agriculture, stimulating denser rural settlement and the growth of cities.

Like other elements of Islamic civilization, the new agriculture migrated from Baghdad westward, by way of Egypt, Tunisia, and Morocco, to reach Europe via Muslim Spain. Some of the techniques, notably irrigation works, were quickly imitated in Christian Europe, whose southern regions also adopted the cultivation of cotton, rice, sugarcane, and citrus fruits. At the end of the Middle Ages, many of these were successfully transplanted to the Americas.55 In stock farming, Spanish Muslims bred the famous merino sheep, which made Spanish wool preeminent in the world. But it was in wool's great rival, cotton, that Islam made its most important textile contribution, transmitting to Europe the secrets of its cultivation and conversion into cloth. The Arabs were the first people in the Near East and Europe to adopt cotton for ordinary clothing. Muhammad himself set the style by wearing a white cotton shirt and trousers under a woolen cloak, a costume adopted by the first caliphs. In later times, rulers and the very wealthy wore silk and embroidered cloth, but everyone else, in both town and country, wore cotton, either white or black-cotton undergarments, cotton caftans and robes, cotton mantles for women, cotton veils and turbans. Cotton was used for shrouds and funeral clothes, and for bedclothes, tablecloths, curtains, towels, and rugs.

Housed in a network of textile workshops known as tiraz tiraz factories, royal textile manufacturing was closely regulated and workmanship and production were strictly controlled. Alongside the factories, royal textile manufacturing was closely regulated and workmanship and production were strictly controlled. Alongside the tiraz tiraz establishments in the great cities, a flourishing private industry was carried on in surrounding smaller towns. The most prized cotton fabrics produced for international commerce came from the establishments in the great cities, a flourishing private industry was carried on in surrounding smaller towns. The most prized cotton fabrics produced for international commerce came from the tiraz tiraz cities of Iraq, Persia, and Syria, while the lesser towns produced under private management textiles for local and regional markets. Arab conquest brought cotton manufacture and cultivation to North Africa, Spain, Sicily, and southern Italy. In Spain the Arab cotton industry disseminated technical knowledge via regions reconquered by the Christians. In Sicily and Italy, Europeans inherited the Arab textile systems intact. cities of Iraq, Persia, and Syria, while the lesser towns produced under private management textiles for local and regional markets. Arab conquest brought cotton manufacture and cultivation to North Africa, Spain, Sicily, and southern Italy. In Spain the Arab cotton industry disseminated technical knowledge via regions reconquered by the Christians. In Sicily and Italy, Europeans inherited the Arab textile systems intact.56

Well into the Middle Ages, Europe remained a poor relation of Asia, accepting hand-me-down technology from China and India, carried westward either in artifact or in idea by intermediaries of whom the most important were the Arabs. Up to the thirteenth century, there was scarcely any direct contact between the two regions; an English cleric, French knight, or Italian merchant knew hardly more of China than had Julius Caesar. Yet through these centuries, Asian technology was steadily infiltrating Europe, unheralded and unrecognized, but with growing impact on the European way of life and patterns of work.

5.

THE T TECHNOLOGY OF THE C COMMERCIAL R REVOLUTION.

9001200 AFTER 900 EUROPE'S DEFENSES AGAINST Viking and Saracen marauders gradually stiffened, containing, converting, and absorbing the Scandinavians, and pushing back the unconvertible Muslims by counteroffensive. In Spain, Christian kings slowly gained the upper hand over their Muslim rivals; a band of Norman French adventurers successfully invaded Arab-held Sicily in 1071; and in the last decade of the eleventh century, the religious outburst that fueled the First Crusade carried the European counteroffensive into Asia Minor, Syria, and Palestine.

Whether Christianity gained anything from the capture of Jerusalem is debatable, but the Italian maritime cities, in particular Pisa and Genoa, unquestionably profited from the seizure and colonization of the coastal towns of the Levant. The long-distance commerce in the luxury goods of the Orient carried on through these colonies played an important role in what Robert S. Lopez has called "the Commercial Revolution of the Middle Ages," the economic surge in which the Italian cities were the energetic leaders.

The other military victories over the Muslims brought dividends hardly noticed at the time but of immense future significance: access to Islamic learning and technical knowledge. Toledo, taken by Alfonso VI of Castile in 1105 and converted into his new capital, proved a tremendous cultural prize, the decline of Baghdad having made it the leading center of Islamic learning.1 Sicily and southern Italy bestowed another treasure of scientific and technical information. The princ.i.p.al European gain from military success was thus not the expulsion of the infidels but the opportunity to mix with them. In Spain the strengthening of Muslim defenses by reinforcements from North Africa prolonged the interface by stabilizing the military and political front for a century. Sicily and southern Italy bestowed another treasure of scientific and technical information. The princ.i.p.al European gain from military success was thus not the expulsion of the infidels but the opportunity to mix with them. In Spain the strengthening of Muslim defenses by reinforcements from North Africa prolonged the interface by stabilizing the military and political front for a century.2 The Vikings, meanwhile, turned their attention westward, where Irish missionaries had discovered Iceland. Reconnaissance was followed by settlement of the large island, up to then inhabited only by foxes. From Iceland's western sh.o.r.e another island could be discerned some 175 miles away. Eric the Red colonized Greenland in the 980s, and one of the first ships to sail for the new colony, commanded by Bjarni Herjulfson, missed its landfall in the fog and was blown across the Davis Strait to Labrador. Bjarni inspected the forested coast and without attempting to land became, in 986, the first known European discoverer of America. In the millennial year of 1000, Leif Ericsson undertook to follow up the discovery (using Bjarni's own ship) by planting a colony there.3 As an achievement, Leif's voyage was unimpressive, merely another crossing of the Davis Strait. As a historic event it also proved insignificant. The colony vanished almost without a trace, and though other Viking ships visited North America in the following two centuries (mainly in search of wood for unforested Greenland), they made little impact. As an achievement, Leif's voyage was unimpressive, merely another crossing of the Davis Strait. As a historic event it also proved insignificant. The colony vanished almost without a trace, and though other Viking ships visited North America in the following two centuries (mainly in search of wood for unforested Greenland), they made little impact.

Bjarni and Leif may not even have been Europe's first discoverers of America; they may have been preceded by Irish missionaries, sailing their toylike skin-covered boats via Greenland to Labrador or Newfoundland.4 As a practical enterprise, any such project was doomed; Europe was not ready to discover America, which it did not yet need. The missionary effort, however, has a certain symbolic significance, as a reminder of the early roots of one of the great motivations of explorers. As a practical enterprise, any such project was doomed; Europe was not ready to discover America, which it did not yet need. The missionary effort, however, has a certain symbolic significance, as a reminder of the early roots of one of the great motivations of explorers.

In the centuries after Eric, Bjarni, and Leif, Europe was at last getting ready to discover America and to do much more. "From 950 on," writes Robert Reynolds, "there was...growing manufacture of textiles, pottery, leather goods, and many other things. The list of articles manufactured gets longer and longer [as the tenth century gives way to the eleventh], the products get better and better. Prices go up in terms of money but down in terms of man hours because of more efficient management, the application of mechanical power, improvement in tools and machinery, and better transport and distribution."5 Where Europe had formerly exported "low-grade, backward-area" products such as slaves and furs, by Leif Ericsson's time it had begun shipping textiles and metal products to Africa and the Near East, and even to Asia. By 1200 it was sending high-grade woolens to Alexandria, Constantinople, and farther east, as well as bar iron, copper ingots, utensils, and arms and armor. Returning ships carried grain to Europe's cities from Sicily and North Africa. A notable import was chemicals, especially alum, used by dyers to fix colors in the ever-expanding wool cloth industry. Where Europe had formerly exported "low-grade, backward-area" products such as slaves and furs, by Leif Ericsson's time it had begun shipping textiles and metal products to Africa and the Near East, and even to Asia. By 1200 it was sending high-grade woolens to Alexandria, Constantinople, and farther east, as well as bar iron, copper ingots, utensils, and arms and armor. Returning ships carried grain to Europe's cities from Sicily and North Africa. A notable import was chemicals, especially alum, used by dyers to fix colors in the ever-expanding wool cloth industry.

In the north, several German towns situated on or with access to the North Sea-Cologne, Bremen, Hamburg-launched careers as major commercial carriers. By the year 1000 their merchants had won a privileged position in London for their "Hanse," or merchant guild, in time gaining virtual exemption from customs by lending money to Richard Lionheart.6 In a word, Europe was turning from a developing into a developed region. The growth of industry meant the growth of cities, which in the eleventh and twelfth centuries began to abandon their old roles of military headquarters and administrative centers as they filled with the life of commerce and industry. Some, like Genoa, once Roman villages, mushroomed, while others, like Venice, appeared out of nowhere. Still others, calling themselves simply "New City" (Villanova, Villeneuve, Neustadt), were founded by progressive rulers. Instead of growing haphazardly, they were built on a plan, typically a grid pattern with a central square, church, and market buildings.7 Beginning in tenth-century Italy, businessmen and craftsmen in many cities established what they called "communes," declaring themselves free men who owed allegiance only to a sovereign who collected taxes but otherwise left them alone. Astute lords granted charters exempting city dwellers from feudal obligations-"so that my friends and subjects, the inhabitants of my town of Binarville, stay more willingly there," sensibly explained one lord. Beginning in tenth-century Italy, businessmen and craftsmen in many cities established what they called "communes," declaring themselves free men who owed allegiance only to a sovereign who collected taxes but otherwise left them alone. Astute lords granted charters exempting city dwellers from feudal obligations-"so that my friends and subjects, the inhabitants of my town of Binarville, stay more willingly there," sensibly explained one lord.8 Under the rubric "Free air makes free men," even serfs were declared emanc.i.p.ated if they maintained themselves in a city for a year and a day. Under the rubric "Free air makes free men," even serfs were declared emanc.i.p.ated if they maintained themselves in a city for a year and a day.

A central feature of the Commercial Revolution was the trade fair. Dating back to Roman times, the fair was kept alive through the early Middle Ages by maritime centers where native and foreign merchants could conveniently meet. The practice spread to inland towns in Italy and southern France; in northern France, St. Denis, near Paris, opened a highly successful annual fair in about 635. In the ninth century, many more were inaugurated, spreading in the tenth to Flanders and northern Germany. But by far the most famous and significant were the Fairs of Champagne, the region east of Paris. In the eleventh and twelfth centuries, the counts of Champagne organized them into an annual cycle of six fairs occupying the entire year, with safe conduct guaranteed to foreign merchants. The Champagne Fairs forthwith became the established rendezvous for merchants from Italy and Flanders.

The Middle Ages had inherited no effective credit instruments from the ancient world, which had never developed any. Furthermore, the Christian Church, in accordance with the Bible, condemned usury and defined it as the charging of any interest whatsoever. The revival of commerce and the transactions of the Champagne Fairs stimulated the invention of novel forms of credit designed to circ.u.mvent the Church's ban. Italian merchants had already adopted one form, from Arabs, Jews, or Byzantines, the commenda commenda (also called the (also called the collegantia collegantia or or societas societas), by which one partner undertook a voyage, borrowing all or most of the capital from the other partner, with profits divided according to a prearranged formula-an insurance device as well as a loan and a temporary partnership. Another form of credit developed simultaneously was the cambium maritimum cambium maritimum, in which a merchant undertaking an ocean voyage borrowed capital in one place in one currency, to be repaid in another place in another currency, the interest concealed in the rate of exchange, repayment contingent on safe arrival of the ship. The Champagne Fairs converted this form of loan into a land arrangement, omitting the element of marine insurance and creating both a way to earn interest and a means of transferring funds abroad, thus making possible the transaction of business by remote control.9 Along with the cities, the farming regions that fed them grew. A European population between the Baltic and Mediterranean estimated at 27 million in A.D. A.D. 700 had reached 60 or 70 million by 1200. 700 had reached 60 or 70 million by 1200.10 In Carl Stephenson's words, the creation of "a bourgeois cla.s.s such as the Roman Empire had never seen" gradually brought with it "the emanc.i.p.ation of the rural ma.s.ses that made possible our modern nations." In Carl Stephenson's words, the creation of "a bourgeois cla.s.s such as the Roman Empire had never seen" gradually brought with it "the emanc.i.p.ation of the rural ma.s.ses that made possible our modern nations."11 Behind this demographic and economic surge lay technical innovations: a radically new system of organizing agricultural work, newly expanded power sources, dramatic new techniques in building construction, and other novelties undreamed of by Greeks and Romans.

Open Fields and Waterpower By the central Middle Ages, much of the countryside was dominated by two complementary systems: on the level of the village and its peasant inhabitants, the form of organization of work known as the "open-field system" on the level of the lord, the form of management called the "manorial system."

The manor, often not coincidental with the village (which might contain more than one manor, or be only a part of a manor), was an estate held by a lord. In its cla.s.sic form it consisted of land directly exploited by the lord (the demesne) and peasant holdings from which he collected rents and fees, usually including labor services. The combination of demesne and tenants probably dates from the early Middle Ages, but it had its first specific doc.u.mentary mention in the ninth century in northern France and in the tenth century in Italy and England. By the eleventh century it was well established in Europe.12 Snow highlights house sites, gardens behind them, and surrounding fields in aerial photograph of deserted open-field village of Wharram Percy, Yorkshire. [Cambridge University Collection of Air Photographs.]

The origins of open-field agriculture are lost in the obscurity of the tenth and eleventh centuries, whose scanty doc.u.mentation offers only scattered sc.r.a.ps of information. By the time the more abundant records of the twelfth century provide light, the system was already mature.

Several factors may have contributed to this second agricultural revolution. One was population growth, fragmenting family holdings through the custom of dividing inheritance among children or among sons. A second was "a.s.sarting," cultivating new land or reclaiming wasteland. When a group of peasants banded together to clear forest or drain swamp, they divided the resulting "a.s.sart" into strips convenient for plowing. A third factor was the heavy plow, which favored working long strips over square plots, to reduce the number of turnarounds, especially awkward with multiple-animal teams. In time, broad areas of Britain and continental Europe were occupied by villages surrounded by two or three large fields made up of cultivated strips cl.u.s.tered in "furlongs" fitted to the contours of the terrain. Each year one field was left fallow, the remaining land cultivated with spring and fall crops. Crop rotation was biennial in a two-field system, triennial in a three-field.

The strips were not apportioned equally; some peasants held several, some few, some none. The lord's demesne usually consisted of a large number of strips, cultivated by the serfs (villeins, in England) in payment for their holdings. Every tenant, free or serf, who held strips held them in both or all three fields, to ensure a crop every year.

Crop rotation and fallow were not new devices. What was new was the way they were organized and regulated. Plowing and planting, harvesting and opening the fields to grazing, all had to be done in concert. The necessary decisions were made not by the lord but by the peasants, whose cooperation became the hallmark of the system. While meeting their obligations of labor and money payments to the lord, the villagers created their own self-governing apparatus based on a set of bylaws that ruled their working lives. The system was neither free enterprise nor socialism; it was sui generis, one of the unique creations of the Middle Ages.13 The heavy plow and the new horse harness fitted well into the open-field system, even if the two devices probably did not, as was once believed, play the decisive role in its establishment. The plow heightened the need for cooperation, since not all peasants who held land owned plows or plow animals. Expanded use of the horse stimulated cultivation of oats, a spring crop appropriate to open-field rotation. The fact that the horse was fed in the barn made his manure easy to collect and thus increased the use of fertilizer, while the spring legumes (peas, beans, and vetches) restored nitrogen content to the soil. Another fortuitous benefit of the system emerged in the ridge-and-furrow pattern built up by strip plowing. In the wet but erratic climate of northern Europe, the ridge tended to stay dry in wet seasons and the furrow to stay moist in dry seasons, providing a kind of crop insurance.

Not all medieval agriculture was open-field. In some regions isolated homesteads were the rule. Other systems existed, notably the infield-outfield system, in which a small "infield" was worked intensively with the aid of fertilizer while the large "outfield" was held as a land reserve.

The population surge stimulated another response in the Low Countries, where an unending war against the sea had been carried on since the seventh century. The Frisians and other coastal dwellers depended for life and livelihood on precarious seawalls four or five feet high, which they maintained with great difficulty until the monks of the new Cistercian Order came to the rescue. An arrangement was worked out by which the land was deeded to the monasteries, then leased back to its cultivators while the monks took responsibility for upkeep of the dikes. Lay brothers performed the labor despite recurrent overwhelming floods. A chronicler of one such flood left an arresting image: a floating tree, to which clung a man, a wolf, a dog, and a rabbit.14 Another new monastic order, the Carthusians, dug the West's first deep-drilled well in 1126, at Lillers, in Artois (whence the name "artesian" well). A shaft only a few inches in diameter was sunk through impermeable strata to reach a stratum of water under pressure, producing a well that needed no pumping. The technique-percussion drilling, a succession of blows struck on a rod with a drilling tool on its end-had long been used in China. Whether it was borrowed or independently invented in Europe is conjectural.

The tenth and following centuries witnessed steady progress in reclamation of unproductive areas via drainage, irrigation, and land clearance. Northern and western Europe, once spa.r.s.ely inhabited, filled in. By the end of the twelfth century, the fields, meadows, and woodland of thousands of villages ab.u.t.ted one another. All of them cultivated grain, and most ground it by water mill. The rapidly multiplying written records supply a wealth of statistics, of which perhaps the most telling is the figure given in Domesday Book, the survey prepared in England in 1086 at the order of William the Conqueror. A century earlier, fewer than 100 mills are recorded in the country; Domesday Book lists 5,624 (low, since the book is incomplete). Georges Duby calculates that the figure indicates a mill for every forty-six peasant households and points out an implication: a substantial rise in consumption of baked bread in place of boiled, unground porridge.15 Continental records tell a similar story. In one district of France (Aube), 14 mills operated in the eleventh century, 60 in the twelfth, and nearly 200 in the thirteenth. Continental records tell a similar story. In one district of France (Aube), 14 mills operated in the eleventh century, 60 in the twelfth, and nearly 200 in the thirteenth.16 In Picardy, 40 mills in 1080 grew to 245 by 1175. In Picardy, 40 mills in 1080 grew to 245 by 1175.17 The boat mills invented by Belisarius, moored under the bridges of early medieval Paris and other cities, began in the twelfth century to give way to structures permanently joined to the bridges. The boat mills invented by Belisarius, moored under the bridges of early medieval Paris and other cities, began in the twelfth century to give way to structures permanently joined to the bridges.

Water mill with overshot wheel and eel trap in the millstream. [British Library, Luttrell Psalter, Ms. Add. 42130, f. 181.]

The waterwheel never played a major role in the Muslim world, not for lack of knowledgeability-Muslim hydraulic engineering was far ahead of European-but for want of fast-flowing streams. Large dams and intricate irrigation systems aided agriculture in Moorish Spain, but the waterwheel was used only for grinding grain and raising water.18 In Christian Europe, in contrast, the vertical wheel, including the powerful overshot type, was finding important new applications. Once more the monasteries led the way. The great Benedictine abbey of St. Gall in Switzerland pioneered the use of waterpower for pounding beer mash as early as 900. In Christian Europe, in contrast, the vertical wheel, including the powerful overshot type, was finding important new applications. Once more the monasteries led the way. The great Benedictine abbey of St. Gall in Switzerland pioneered the use of waterpower for pounding beer mash as early as 900.19 The new Cistercian reform movement launched in 1098 at Citeaux, in Burgundy, carried on the Benedictine tradition of promoting technology by founding waterpowered grain mills, cloth-fulling mills, cable-twisting machinery, iron forges and furnaces (where the wheels powered the bellows), winepresses, breweries, and gla.s.sworks. The edge-runner mill, long known to China, was adopted for more efficient pressing of olives, oak galls and bark for tannin, and other substances requiring crushing. The new Cistercian reform movement launched in 1098 at Citeaux, in Burgundy, carried on the Benedictine tradition of promoting technology by founding waterpowered grain mills, cloth-fulling mills, cable-twisting machinery, iron forges and furnaces (where the wheels powered the bellows), winepresses, breweries, and gla.s.sworks. The edge-runner mill, long known to China, was adopted for more efficient pressing of olives, oak galls and bark for tannin, and other substances requiring crushing.20 The contemporary biographer of St. Bernard, leader of the Cistercian movement, ill.u.s.trated the respect accorded the waterwheel; in describing the reconstruction of the saint's abbey of Clairvaux in 1136, he neglected the new church but included an enthusiastic account of the monastery's waterpowered machines.21 The first waterpowered iron mills in Germany, England, Denmark, and southern Italy were all Cistercian. The first waterpowered iron mills in Germany, England, Denmark, and southern Italy were all Cistercian.22 One of the earliest widespread industrial applications of the waterwheel was in fulling cloth; the trampling feet of the fullers were replaced by heavy wooden hammers lifted and dropped by the turning waterwheel. One effect was to draw the fullers into the countryside, where they further profited by freedom from the sometimes restrictive regulations of the towns. Another effect was the spread of the knowledge of gearing.23 Hemp production required a similar pummeling action to break up the woody tissues of the dried stalks and free the fibers for manufacture of ropes and cords. The existence of a waterpowered hemp mill is doc.u.mented in the Dauphine, in southeastern France, as early as 900.24 By the late eleventh century, waterpower was pounding, lifting, grinding, and pressing in locations from Spain to central Europe. In several applications of waterpower, notably in lifting and dropping hammers, the camshaft made its earliest Western appearance, diffused from China (as Joseph Needham believes) or independently invented, as seems not unlikely. The cam, a small projection on the horizontal shaft of a vertical waterwheel, caught and lifted the falling hammer, which dropped of its own weight. Usually a pair or more of cams on the same shaft operated alternately.25 The more abundant records of the twelfth century throw scarcely more light than the scanty ones of the eleventh on the types of waterwheel that were built, but increasingly the efficient vertical overshot wheel justified its initial cost when used to grind grain, and its superiority was persuasive in industrial applications. Modern calculations show that the ancient donkey-or slave-powered quern of Rome produced about one half horsepower, the horizontal wheel slightly more, the undershot vertical about three horsepower, and the medieval overshot wheel as much as forty to sixty.26 A continuing weakness of waterwheel installations was their reliance on fragile wooden parts, gears as well as camshafts. On the other hand, a broken wooden piece was easily replaced by a peasant craftsman. The cost of iron made metal gears a luxury even as late as the eighteenth century. A continuing weakness of waterwheel installations was their reliance on fragile wooden parts, gears as well as camshafts. On the other hand, a broken wooden piece was easily replaced by a peasant craftsman. The cost of iron made metal gears a luxury even as late as the eighteenth century.

The proliferation of gristmills may have owed as much to the role that they had come to play in the lord-peasant relationship as to their labor-saving value. An aspect of the "ban," the lord's local power, became one of the most resented of his privileges: the obligation of unfree peasants to have their grain ground at the lord's mill, at the cost of a multure, commonly one thirteenth of the grain or flour. Despite peasant protests, the profitable ban was gradually extended to oil and wine presses, bake ovens, and iron forges. The peasants' resentment was not only against the payment of multure but against the inconvenience of taking the grain to the mill and waiting in turn. The right to "jump the queue" was reserved to free tenants willing to pay a fine to grind "next after the grain which is in the hopper." Many peasants surrept.i.tiously operated illegal hand querns, while others went back to eating porridge.

The gristmill often represented the most visible symbol of a wider oppression, as in the rebellion of the inhabitants of St. Albans. Seeking to secure a charter of urban liberties from the lord abbot, the townspeople openly and defiantly milled their own grain with their hand querns. When the rising was suppressed, the abbey confiscated the querns and incorporated the millstones into the floor of the monks' parlor as a trophy of victory. Fifty years later, during the Peasants' Rebellion of 1381, the people of St. Albans dug up the monks' floor and distributed the fragments of the stones among themselves as tokens of solidarity, in the spirit, according to St. Albans chronicler Thomas Walsingham, of sharing the sacrament. Struggles over hand mills in other places likewise signaled deeper grievances about taxes, labor services, and legal status.

Some scholars have argued that the lord's gristmill was economically viable only because of the ban and that without the ban the tenants would have chosen to use their own cheaper and more convenient hand mills. Evidence to the contrary, however, is found in the existence of a special rate of multure charged to free tenants, who were not under obligation to use the lord's mill. This rate, typically one twenty-fourth, a little more than half that charged unfree tenants, seems to represent the true, free-market value of the service. Recent scholarship has also discovered the presence of independent water mills, outside the lord's control and competing with his mills, held by free tenants and even by villeins, who charged their own multure fees and kept the profits. Such mills seem sufficient proof that compulsion was not the only basis for the gristmill and that powered milling of grain made compelling economic sense even without the ban.27

Waterpower spurred construction of dams, at first on a small scale to create millponds and millraces but increasingly on a larger scale. The Arabs, who in their era of conquest had learned about dam building from India and the Near East, brought their knowledge to Spain, where a few Roman dams still operated. These they kept in repair, adding dams of their own, such as the great structure at Murcia, 425 feet long and 25 feet high, its rubble core faced with masonry blocks.28 By the twelfth century, dam building had crossed the Pyrenees in a spectacular form. At Toulouse, forty-five mills were driven by streams controlled by three dams in the Garonne. The princ.i.p.al one, mentioned in a doc.u.ment of 1177, was probably the largest dam then existing. Thirteen hundred feet long, it was built diagonally across the river by ramming thousands of giant oak piles into the riverbed to form palisades that were then filled with earth and stone. By the twelfth century, dam building had crossed the Pyrenees in a spectacular form. At Toulouse, forty-five mills were driven by streams controlled by three dams in the Garonne. The princ.i.p.al one, mentioned in a doc.u.ment of 1177, was probably the largest dam then existing. Thirteen hundred feet long, it was built diagonally across the river by ramming thousands of giant oak piles into the riverbed to form palisades that were then filled with earth and stone.29 Millraces similarly expanded into hydropower ca.n.a.ls in the twelfth century. The monastery of Clairvaux dug a 3.5-kilometer (2-mile) millrace ca.n.a.l from the river Aube to the abbey, while the Cistercians of Obazine chipped one 1.5 kilometers through solid rock.30 Medieval engineers were the first to exploit the waterpower supplied by ocean tides. Tidal mills are recorded in Ireland as early as the seventh century, in the Venetian lagoon before 1050, near Dover in Domesday Book, and a little later in Brittany and on the Bay of Biscay. The practical value of tidal mills was limited by their short operating periods (six to ten hours a day), the eccentric working hours imposed on the millers, and the vulnerability of the mills to storm damage.31 In the last twenty years of the twelfth century, an entirely new prime mover appeared simultaneously on both sides of the English Channel and the North Sea. Nothing like the windmill in its vertical European form had ever been seen. Though some scholars believe it to have derived from the horizontal windmill of Persia, perhaps diffused through Muslim Spain, the weight of evidence favors an independent origin, possibly in East Anglia, where it replaced unsatisfactory tidal mills and supplemented the scanty waterwheels. Reversing the waterwheel's arrangement, the windmill placed the horizontal axle at the top of the structure, to be turned by sails, gearing it to the millstones below. The immediate problem of keeping the sails faced into the wind (or out of it in a gale) was solved by balancing the mill on a stout upright post, on which it could be turned, none too easily, by several st.u.r.dy peasants gripping a large boom.

Crafts in Town and Country While agriculture still absorbed much the largest share of human labor, the number of handicraft workers and the volume and diversity of handicraft production increased significantly in the central Middle Ages. By far the most universal and widespread craft was that of cloth making, which experienced a major change in the organization of work. Throughout antiquity and the early Middle Ages it had been the province of women working in the gynaeceum; now, as slavery waned and the gynaeceum disappeared, the craft was decentralized to the family unit. The male head of the household was the weaver; the women prepared and spun the yarn for his loom.32 A fourteenth-century windmill. [British Library, Stowe Ms. 17, f. 89v.]

By the twelfth century, the loom the weaver operated was a new mechanized model, probably a descendant of the Chinese silk loom. Horizontal rather than vertical, it allowed the weaver to sit while he worked. In operating the old vertical warp-weighted loom, the weaver, standing, had advanced or r.e.t.a.r.ded sets of warp threads by moving the heddle bar forward or backward in its brackets; now this operation was performed by a pair of foot treadles, leaving the operator's hands free. To pa.s.s the weft yarn through the shed created by the heddles, he used another innovation, the boat-shaped shuttle, holding a bobbin wound with thread.33 Horizontal loom, c. 1250. The weaver "leans upon two stirrups" (the treadles, which control the heddles by means of an overhead pulley arrangement), while he pa.s.ses back and forth the newly invented boat-shaped shuttle. (The plane of the warp threads is parallel to the floor, despite the faulty perspective.) [Trinity College, Cambridge, Ms. 0.9.34, f. 34v.]

To the English scholar Alexander Neckam (11571217), the weaver at the horizontal loom was "a horseman on terra firma who leans upon two stirrups," the treadles, which were attached to a pulley arrangement above the loom called the "harness."34 The shuttle was weighted and contained "an iron or wooden bobbin," from which the weft thread was drawn as "the one hand of the weaver tosses the shuttle to the other, to be returned vice versa." As he completed a row, the weaver "beat down the work accomplished." Alexander pictured a woman, a The shuttle was weighted and contained "an iron or wooden bobbin," from which the weft thread was drawn as "the one hand of the weaver tosses the shuttle to the other, to be returned vice versa." As he completed a row, the weaver "beat down the work accomplished." Alexander pictured a woman, a textrix textrix, working alongside the weaver, combing the wool, spinning the yarn, smoothing the finished cloth, and helping the time pa.s.s by singing "sweet songs" to the man at the loom.35 From about 1000, wool cloth manufacture for the market had begun to concentrate in certain regions. Especially prominent was Flanders, where the favorable conditions included a soil congenial to dye plants, an abundance of the cleansing agent fuller's earth, and proximity to England, the prime source of fine fleece. As in Roman times, fulling and dyeing were specialized trades. Traditionally, the fuller trampled the cloth in a trough filled with water, fuller's earth, urine or wine dregs, lime, and sand, changing the water several times. The cloth was hung to dry on a wooden frame, the "tenter," fastened by hooks that could be adjusted to stretch the fabric to the right length and breadth and then teaseled to raise the nap.

Dyeing might be done at different stages in manufacture: before the yarn was woven ("dyed in the wool"), after fulling, or sometimes after the cloth was sold. Among the most demanding of cloth techniques, it required a knowledge of fabrics, dyes, and mordants (color fixatives) and by the twelfth century had been taken over almost completely by men.36 Cloth or yarn was soaked in a tub of hot water and turned at intervals with a pole. Red and blue were the predominant colors, produced respectively from the madder root and the woad leaf. Since woad leaves could be plucked several times a year, blue dye was cheaper. Cloth or yarn was soaked in a tub of hot water and turned at intervals with a pole. Red and blue were the predominant colors, produced respectively from the madder root and the woad leaf. Since woad leaves could be plucked several times a year, blue dye wa