Science may explore the truth and mysteries that lay behind the visible world, but technology makes everything work and our lives easier. In spite of this practical advantage, people through most of the past have seen technology as a poor cousin to the favored science. Aristotle favored a life of the mind in which people contemplated abstract truths—essentially science—over those who practiced what he called “banausic arts,” manual labor in creating things.

As medieval thinkers venerated everything Aristotelian, they transmitted the devaluation of banausic arts. However, the situation in the Middle Ages was different from that in the classical world in some ways that contributed to the growth of technology. Most significant was the end of slave labor. No longer was there an abundance of labor to produce all that was necessary. Instead, medieval people were remarkably quick to adopt labor-saving devices, which led to a technological revolution that changed the face of European society. By the ninth century, some medieval thinkers saw the need to dignify technology above the disparaging position it held with Aristotle. John Scotus Erigena in the ninth century invented the term artes mechanicae (mechanical arts) to supplement the liberal arts in a well-rounded education. In the twelfth century, another scholar—Honorius of Autun—developed this idea further by adding mechanics to the liberal arts curriculum He wrote: “Concerning mechanics . . . it teaches . . . every work in metals, wood, or marble, in addition to painting, sculpture, and all arts which are done with the hands” (Gies, 11). Thus, from the twelfth century onward, thinkers—and scientists—had recognized the importance of technology in the spectacular growth of European medieval society.

To study the history of medieval technology is to review the many inventions that changed society rather than to consider individual inventors. This is largely because virtually all the great innovations that changed the West were invented in the East. Chinese inventions spread slowly to India, the Muslim world, and then into the West. Sometimes we can trace direct and sudden transmissions—silk worms, for example—but other times we just know that items that had been used in China for centuries slowly appeared in the West. The success of the medieval West was in its ability to adapt the inventions that came from older societies of the East. The easiest way to consider these technological innovations is to look at various industries that benefitted from new technology.

At the heart of most of the change was a revolution in power. Early medieval Europe suffered from a shortage of labor. This caused people to rely more on animal power and, more importantly for the history of technology, on new sources of power: water and wind. Waterwheels in particular offered reliable sources of energy all along rivers and even in the tidal areas of northern Europe where the difference between low and high tide was extreme.

For water mills to work, builders had to solve a specific problem: converting the rotary, horizontal, motion (of a wheel being turned by running water) to vertical motion. This was accomplished by using a cam, projecting from the axle of the waterwheel. Once this technological problem was resolved, builders could harness waterpower to accomplish many tasks. The most common watermills were used to grind grain, freeing people from the essential, but labor-intensive task of converting hard grain into useable flour to make bread. The watermill would power two large horizontal grindstones that made short work of the grain. But this was just the beginning.

Watermills were adapted to power triphammers to stimulate the constant food kneading that was necessary to break down fibers in other occupations. Waterwheel-powered triphammers greatly facilitated the difficult process of making thickened (also called “fulled”) wool fabrics, like felt. This had previously involved hard and disagreeable work as people had to pound the wet wool that was soaking in various solvents. Triphammer mills also pounded hemp stalks to make linen and broke oak bark into small pieces for tanning. Other agricultural products needed milling as well: Mustard and poppy seeds were turned into paste, and vegetable products were made into dyes and pigments. The numbers of watermills that proliferated in the early Middle Ages were astonishing. The Domesday Book, a survey prepared in England in 1086, records 5,624 mills in England: This is a remarkable three mills for every mile of river. Comparable figures exist for other areas of Europe, including the Byzantine Empire in the East. One analysis suggests that there was a mill for every forty-six peasant households (Gies, 113). This meant that peasants ate more baked bread instead of boiled, unground porridge, which allowed for a more portable food supply. Bread travels better than oatmeal.

Once builders had the concept of watermills, they applied it to all kinds of conditions. There were floating mills that could be moved so they wouldn’t obstruct river traffic, and mills that were permanently attached to bridges. Some mills harnessed water flowing over the top, but others were undershot mills, harnessing waterpower from a low river fl owing beneath. Modern calculations reveal the impressive advantages in power that constantly improved waterwheels offered medieval peasants: The Roman donkey or slave-powered grinding stone produced about one-half horsepower. The undershot (water flowing beneath) medieval wheel produced about three horsepower, and the medieval overshot wheel could generate as much as 40 to 60 horsepower (Gies, 115).

Waterwheels depended upon access to rapidly flowing rivers, so all regions could not be served by this technological wonder. Medieval engineers, however, took the principles of water-driven power and applied it to other sources of energy. Tidal mills were recorded in Ireland as early as the seventh century and in the Venetian lagoon before 1050. However, by the end of the twelfth century, windmills began to appear in the English Channel and the North Sea. Windmills were probably developed in Persia and spread through Muslim lands, but the Europeans modified the design to make it extremely useful.

They reversed the waterwheel’s design by placing the horizontal axle at the top of the mill to be turned by sails. The power would then be geared to stones below. Wind now joined water a power that was available to medieval people. I should note that this technological revolution in harnessing power was not universally praised. It required a substantial investment to build these mills, and lords of the land recouped the investment by charging peasants fees to use the mills. Local peasants were required to grind their grain (or press their oil and wine) at the local mill, and pay the required costs. This led to some boycotts in the fourteenth century, but the future lay with technology. In the long run, people will pay for labor-saving devices, and the mills of medieval Europe represented the first major innovation in labor saving in the West. Beyond power, the basis of medieval technology all over the world was iron. From the beginnings of the Iron Age in about 1200 B.C.E ., metallurgists heated iron repeatedly in a hot charcoal furnace to combine carbon molecules with iron. Then the iron had to be pounded to become strong. Smiths were valued craftsmen who could work the metal. Throughout the Middle Ages more and more iron came into circulation, allowing for use of horse shoes, metal plowshares, and cast iron cooking pots. However, in the fourteenth century European engineers (probably inspired by Chinese models) applied the technology of the waterwheel to forging iron and created the water-powered blast furnace.

A waterwheel could pump pairs of bellows continuously into a furnace, substantially raising the temperature. The higher heat increased the carbon uptake rapidly, producing an alloy that had a higher carbon content. Thus, iron was improved. Not only that, but the blast furnaces could run continuously for weeks or months at a time producing more iron than ever before. The molten metal flowed into several large, shallow depressions that reminded smiths of a sow with suckling pigs, so they called this “pig iron,” a term that remained long after ironsmiths forgot their rural roots (Gies, 202). The new mechanized forges produced much more iron cheaply, so Europe entered a newly invigorated iron age.

Although iron was useful in tools and cooking, it is best remembered for its application in warfare . In the late eighth century, French forces under Charles Martel, fielded horsemen on saddles equipped with stirrups, an innovation that had spread from India. Stirrups gave horsemen enough balance that a mounted soldier could directly engage an enemy (instead of riding by shooting arrows or throwing spears). The mounted knight was born and became the basis of medieval armies under feudal law . These knights, often called “men of iron,” depended upon defensive armor of increasing thickness and complexity—chain mail, developed by Vikings, was worn over thick padding, and in the fourteenth century, plate mail was placed on top of the chain. In the fourteenth century, changes in the technology of warfare appeared in the West that transformed feudal society. In the Hundred Years’ War , the English made use of the Welsh longbow, which offered substantial advantage in range and firepower over the crossbow. Furthermore, in Switzerland, foot soldiers armed with long pikes successfully held off mounted knights. The final transformation in warfare, however, came when gunpowder, developed in China, began to spread. The fi rst European mention of gunpowder occurs in 1268, but by the late fourteenth century, the use of guns and cannons began to change the defensive posture of knights in armor in favor of foot soldiers armed with the new weapons. The future lay with large armies of foot soldiers with guns rather than mounted knights with iron swords.

Through most of the Middle Ages, the Byzantine Empire held the lead in the technology of warfare. Their most dreaded weapon was “Greek fire,” believed to be an  incendiary mixture of crude oil, bitumen, resin, and sulfur. The secret of this recipe was carefully guarded, and Byzantine forces could pour or pump the deadly mixture on wooden ships in the harbor or on armored knights in the battlefield. The other military technological advance enjoyed by the Byzantines was systems of torches and mirrors for rapid communication. However, the coming of unpowder eveled the advantage of Byzantine technology: The great walls of Constantinople that had withstood invading armies fell to the cannons of the Turks in 1453, a date that signals the end of the Middle Ages. In agriculture , too, medieval technology created a small agricultural revolution. By the eleventh century, a new padded horse collar that had been developed in China appeared in western Europe, allowing more rapid horses to plow alongside (or in place of) slower oxen. A new, heavy wheeled plow came into service that efficiently turned the heavy clay soils of northern Europe bringing more land into cultivation.

By the twelfth century, many manors moved to a three-field system of cultivation in which one-third of the land was planted in the spring, another in the fall, and the remaining third was left fallow to improve its fertility. This replaced an old Roman system of two-fi eld cultivation in which half the land was left fallow each year and immediately brought more land into cultivation. In addition, the three-field system stimulated the growth of new crops that boosted production. Villagers began to plant legumes, such as peas and beans, which add nitrogen to the soil, thus fertilizing the subsequent grain crop. Legumes also provided an excellent source of protein, which vastly improved the villagers’ diets.

These major agricultural innovations were further aided by other laborsaving devices that spread from the East. For example, wheelbarrows appeared in Europe speeding peasant labor. In western Europe, peasants also began to harvest using a sickle, instead of bending over with a scythe. Of course, the increased availability of iron helped produce all these tools. The agricultural revolution in the West allowed the population to double between the eleventh and the fourteenth centuries.

The Byzantine Empire, which always boasted a larger population of workers, was not as quick to adopt these labor-saving tools. Instead, through most of the Middle Ages, the Eastern empire continued agricultural techniques that had served the Roman Empire.

The most labor-intensive occupation for women of the ancient and medieval worlds was making cloth. There was a constant desire to improve ways to prepare the raw materials—mostly wool, but later cotton—to make clothing. It is perhaps not surprising that the nineteenth-century industrial revolution first mechanized the fabric industry. The Middle Ages saw its own improvements in the production of fabric and in acquiring new fabrics. We have seen that watermills were put to use to make felt, but that was only one innovation.

The Byzantine Empire achieved a great advance in fabrics in the sixth century, for at that time, some monks smuggled silk worms and white mulberries to feed them back to Byzantium. This began a silk industry in the Byzantine Empire that finally broke the age-old monopoly held by China. In the thirteenth century, after the Fourth Crusade , the secret of silk was brought to Italy. In most of Europe, however, the main fabric was wool, which had to be washed, combed, then spun into thread. The traditional instrument for spinning was the drop spindle, a stick with a weighted disk at the bottom. The spinner spun the spindle, which twisted the attached fibers into threads. Women spun wool like this constantly, even while doing other tasks. In the thirteenth century, Europeans acquired spinning wheels that had probably originated in the Near East, making the process much more rapid. Once thread was spun, it could be woven into cloth on a loom. The earliest medieval looms were vertical, but by the late Middle Ages, these were replaced by horizontal looms, further speeding a weaver’s work. Knitting was introduced into Europe some time in the twelfth century.

A final major revolution in medieval technology came in navigation, which culminated in the explorations of the Renaissance that marked the end of the medieval age. The greatest ships of the early Middle Ages were the Viking longships, astonishingly seaworthy oak vessels propelled by a square sail and banks of oars. Vikings navigated by the position of the sun and of the North Star at night, but their ability to navigate the treacherous waters of the stormy north remains a wonder to modern sailors.

Improvements in sails stimulated shipping so much that by the thirteenth century shipping in the Mediterranean doubled in volume. The first improvement was the development of the “lanteen” sail, a triangular sail that allowed ships to sail closer to the wind, which means they can sail almost into a head wind, instead of waiting for a tailwind. In addition, more masts were rigged allowing ships with two and three masts to capture even more wind.

There remained the problem of how to know where you are going when out of sight of land. In the twelfth century, Christian Europe had acquired the astrolabe from Muslim Spain. The astrolabe essentially projected a map of the heavens on a plate that the navigator could rotate to show the local coordinates. The twelfth-century philosopher Abelard and his wife Heloise were so enamored of this new instrument that they named their son “Astrolabe,” which shows the enthusiasm that these new technological wonders stimulated in Europe. The astrolabe allowed ships to sail at night using the stars.

A magnetic compass had been invented in China and improved by the eighth century C.E. This was created by rubbing an iron needle with a magnet, then floating the needle on water on a bit of wood. The needle would then point roughly north (varying with the meridian where the reading is taken). The compass was improved by mountings that allowed it to float independent of the ship’s motion. By the thirteenth century, medieval European navigators had access to the improved compass and had begun to make sophisticated use of it in conjunction with navigational charts to find their way when moving out of the sight of land. The technological improvements were in place to allow Europeans to begin to explore outside the Mediterranean, a marker of the end of the Middle Ages.

In " The Greenwood Encyclopedia of Global Medieval Life and Culture", Joyce E. Salisbury general editor, Greenwood Press, USA/UK, 2009 vol.1 excerpts p. 64-69. Adapted and illustrated to be posted by Leopoldo Costa.