600 inventions: Greece had not been cultivated previously, European farmers had to devise a heavier plow that turned over heavy clods of turf rather than merely scratching the top of the soil Animal power could also be applied to transportation The earliest wheeled vehicles appeared around 3000 b.c.e in central Europe They were probably wagons used for hauling agricultural products and firewood from fields and forests into the settlements Such vehicles were then improved with further inventions The Celts of central Europe, for example, produced extremely high-quality carriages and wagons, many of which archaeologists have found in such places as Germany and Austria An important innovation was the use of iron on wheels Rather than relying on purely wooden wheels, which deteriorated rapidly and often broke if the driver hit a stone, the skilled metalworkers of central Europe learned to create an iron hoop that served as a kind of tire for wagon wheels The hoop was heated and then rapidly cooled around the wooden portions of the wheel, shrinking it and thus binding it firmly to the wheel These wheels were far more durable than anything that had been produced before Further inventions in transportation technology took place late in prehistoric times One was the bearing, created by the ancient Scandinavians By the first century b.c.e the Vandals and Goths of northern Europe had invented a wooden roller bearing they used on wagons This bearing was durable and provided a more reliable and comfortable ride than anything the more technically proficient Romans produced To fill some of their wagons, the Europeans invented the wine barrel (as opposed to such containers as jars) to transport wine, a prestigious commodity, from the Mediterranean region To go along with their wheels and carriages, the ancient Europeans also developed engineered roads The ancient Romans are often credited with the earliest and best roadbuilding technology, but in fact the oldest known engineered road in the world—that is, a road that was built rather than simply cut through the forest—is the so-called Sweet Track, a causeway in Somerset, England, named after its discover, Ray Sweet It was built in about the 3800s b.c.e and was constructed with crossed poles of hardwood, along with lime, that were sunk in the spongy, wet soil to support a walkway Subsequently, roads made from timbers laid side by side across the direction of the road were built across many of the wetlands of northern Europe and the British Isles, especially as trade flourished during the Iron Age The ancient Europeans, like people the world over, looked for ways to improve their physical conditions In domestic architecture they developed new techniques of timber construction and joinery that enabled them to build warm and durable houses and barns The cold northern climates of Europe created the need for heavy, durable, and warm clothing, so a precursor of knitting called nålebinding, or “binding with the needle,” emerged from the Danes The Danes used this technique, which involved passing a needle through a loose loop to create a chain of loops, to make what may have been the world’s first true socks and mittens GREECE BY J EFFREY S CARNES The technological contributions of the Greeks are somewhat difficult to measure, owing in part to the nature of our sources, in part to political and social circumstances, and in part to the Greeks’ own attitudes toward science and technology There is, for example, little scientific literature—and essentially no technical literature—for the first four centuries for which we have historical records Only in the Hellenistic Period (323–31 b.c.e.) we find scientists discussing inventions, so there is only indirect evidence for the technical contributions Greeks may have made in the eighth through fourth centuries b.c.e To some extent this is due to a certain disdain for practical matters among members of the upper classes: Typical is the contempt shown by Plato and Aristotle for the “banausic” (mechanical) professions for their negative effect on the soul Theorists of science were generally drawn from the elite classes (there were no “pure science” occupations at which to make a living) and therefore tended to be ignorant of or unconcerned with technological developments Political and social conditions played a further role in slowing the progress of Greek technology Necessity truly is the mother of invention, and in many cases the Greeks lacked the necessity that might spur technological innovation There was little large-scale manufacturing of the sort in which costs might be reduced and profits increased by the invention of new machinery or processes Further, Greece was a slave-owning society on a large scale—perhaps one-third of the population of Athens was made up of slaves—and with so much forced labor there would have been little incentive for labor-saving devices Given the lack of records for all but the Hellenistic Period, we must content ourselves with noting aspects of Greek technology that not appear previously elsewhere and speculating that these may be inventions In agriculture the main improvements probably attributable to the Greeks were in the area of processing Various minor innovations in milling technology are known, mostly designed to mill more grain at once and allow more animal power to be applied to the mill Presses for wine and olives show steady improvement, starting with primitive lever presses using stone weights and progressing to a variety of screw and lever-and-screw presses in the Hellenistic Period The screw itself seems to have been developed in the third century b.c.e., making it the only one of the basic machines to have been invented in the historical period The screw was also used in devices for lifting water, which had applications in both agriculture and mining The remains of the Athenian silver mines at Laurium include washing devices that represent an improvement on earlier washing techniques, allowing for more efficient separation of the metal from its ore These machines also allowed the water to be recycled, a serious consideration in the semiarid climate of Greece Ironworking became more efficient with the development of the shaft furnace in about 500 b.c.e