Steven Solomon

by Power;Civilization Water: The Epic Struggle for Wealth

  For a dynasty whose own rule lasted only fifteen years, the Chin’s legacy was remarkable. Their new political structure of all-powerful emperor with a centralized bureaucracy replaced the old feudal system. Uprooted aristocrats were compelled to move to the emperor’s capital, while their local estates were superseded by a system of provinces and counties ruled by governors loyal to the emperor. Standardization was applied to weights and measures, writing systems and currencies, census-taking was begun, and taxation ruthlessly levied.

  Like many great founding or restoring dynasties, the Ch’in were prodigious builders. Their accomplishments included building a vast road network and early segments of the Great Wall against marauding northern nomads. Of critical importance to their rise and legacy was the construction of large-scale, sophisticated irrigation and transport waterworks. Three in particular stood out. In their home state near the middle Yellow River they completed the Cheng-kuo Canal in 246 BC. By diverting water from two tributaries of the Yellow, it irrigated vast acreage in the Wei river valley north of its capital of Xi’an, site of the famous life-sized terra-cotta army of 8,000 soldiers, horses, and chariots that guarded the original Ch’in emperor’s tomb. Although heavy silting limited the irrigation canal’s productive life to a century and a half, the great increase in food and population it yielded played a vital role in providing the wealth, weaponry, and manpower the Ch’in needed to complete their conquest of China during the Warring States period.

  Even grander and more impressive were the irrigation works of western Sichuan, north of the upper Yangtze, undertaken by a water engineer so accomplished he seems almost to have been an avatar of Yu the Great. Li Bing had been appointed provincial governor in 272 BC, nearly half a century after the region’s conquest by Ch’in generals. To enrich the province and win loyalty from the local population, he embarked upon an ambitious hydraulic engineering scheme intended to provide at once flood protection and reliable irrigation from the rapidly flowing, unpredictable waters of the Min River to the surrounding farming floodplain. Li Bing’s celebrated waterworks—still flowing today—were constructed chiefly along Taoist precepts. Rather than directly block the river’s forceful flow with a dam, a series of diversion weirs were built from flexible bamboo cages filled with rocks that were situated at a juncture where the natural contours of the river facilitated its division into an outer and an inner channel. The weirs could be adjusted to direct more of the water to one channel or the other depending upon conditions—to the outer channel to divert water against flooding or to the inner channel when irrigation water was needed. Li Bing emplaced three upright stone figures in the water as signal gauges. When their feet grew visible, the weir’s gates were to be opened to water the fields; when their shoulders became covered, the gates were closed. To complete the irrigation diversion so it could reach the farmland in the Chengdu plain below, Li Bing’s workers laboriously cut a channel through the mountainside by heating the rock by bonfire, then dousing it with water until it cracked and could be chipped away. Li Bing’s waterworks transformed the plains of eastern Sichuan into one of China’s most affluent irrigated farming zones. Covering some 2,000 square miles it sustained a population of 5 million—the maximum supported by the Egyptian Nile from ancient times until the nineteenth century. The outer channel also provided navigability. Later, in medieval times, Li Bing’s flowing Min River canals in the plains found additional employment turning thousands of waterwheels to hull and grind rice, and to power textile spinning and weaving machinery.

  Li Bing also improved Sichuan’s production of precious salt by drilling early brine wells, some more than 300 feet deep, that drew salt directly from its underground sources rather than relying upon traditional salt harvesting from briny pools that had seeped up from the earth. His successors learned to use long, bamboo tubes with leather flap valves to create suction to draw the saltiest water from the deepest recesses. Bamboo plumbing became the mainstay not only of salt works, but eventually was applied ubiquitously throughout south China’s rice paddies by farmers as conduits for pump-lifted and relocated water and also in cities as rudimentary water mains.

  The Ch’in’s third extraordinary water project was the Ling Chu, or Magic Canal, the world’s first transport contour canal, which was dug by following the natural topography of the surrounding landscape to avert complex tunneling and water-level management problems. By controlling and joining two rivers that flowed near each other in opposite directions, the 20-mile-long Magic Canal created a waterway link through the mountain ranges dividing northern and southern China. Built on the orders of the Ch’in emperor to support the conquering armies he had sent south in 219 BC, the Magic Canal made it possible to travel by boat through natural waterways and earlier channel cuts all the way from the lower Yellow River, south to the Yangtze, and beyond to the port of Canton—an astonishing distance covering 1,250 miles. Nothing like it had ever existed before in history.

  The greatest beneficiary of this unprecedented precursor of the Grand Canal was not the Ch’in, however, but their immediate successors, the Han. Under the four centuries of Han rule, from 206 BC to AD 220, China’s powerful centralized state and high civilization flourished as one of the two greatest on Earth. Historians frequently have noted the many historical parallels between the Han and Roman empires. Their periods of greatest power, wealth, and influence were contemporaneous, their empires were of comparable geographic size, they flourished at the extreme edges of the civilized world at the time, and the proximate causes of the demise of each were barbarians attacking from the northern frontiers. Of course their political economies, cultures, and hydrological underpinnings were quite dissimilar. Rome did little intensive irrigation, relied for its wealth upon its Mediterranean sea-linked network of colonies, encompassed many cultures, and honored individualism. The Han Empire, by contrast, was the epitome of a hydraulic state: inward-looking and land-oriented, based upon intensively irrigated agriculture, and governed top-down by a despotic emperor and a cadre of expert technocrats overseeing mass peasant laborers.

  The Han wasted little time in marshaling forced labor to add and improve canal segments to the great transport waterway they’d inherited, along with so many other remarkable, nation-building achievements, from the Ch’in. Much of their success was also owed to the extensive construction of irrigation and flood control canals, dams, and dikes, including some forty major water projects to control the Yellow River. Under the Han’s centralized administration, the patchwork of cropland in the Yellow River valley was organized into a single, intensively irrigated continuum that created China’s classic landscape and served as the economic and political heartland of the empire. Treadle chain pumps, a simple but extraordinarily useful small-scale technology for lifting water operated by the simple stepping motion of as few as one or two individuals, invented in the first century AD, was widely applied across China for drainage and irrigation and to supply drinking water. Eventually all water planning was centralized in a national office, establishing a tradition that has endured to the present day.

  By 100 BC the Han state had become the largest landowner, with government monopolies also instituted over vital goods like iron, salt, and wine. Private merchants and the nascent profit-driven market system that had begun to develop under the Ch’in but conflicted with Confucian precepts of governance were suppressed by regulation. Sovereign taxing power was used to weaken disfavored classes and accrue authority to the Han state. In time, all urban markets became government controlled, with officially set commodity prices and taxation on commerce that filled the treasury.

  The Han’s bid for state domination over economic life was made easier by the fact that wealth creation remained predominantly based on intensively irrigated agriculture at inland locations along mostly navigable, relatively easily governed arterial rivers. Despite China’s long coastline, sea trade—always problematic for sovereign states to control—remained underdeveloped due to the geographical fact that there we
re simply few enticing, easily reached Far Eastern civilizations with whom to profitably trade. Although some unregistered itinerant merchants survived and even flourished trading between cities and at the peripheries of society, mainstream Chinese civilization developed a strongly inward-looking orientation that tended to accrue great power to the central state.

  The Han emperors encouraged the expansion of industry, some using water as a vital input. Most importantly this included its precocious iron casting industry. A process for casting iron into molds, one of history’s key inventions, had been discovered in China as early as the fifth century BC, nearly 1,800 years before cast iron became widespread in Europe. In the third century BC, the Chinese iron masters discovered a heating and cooling process that produced a malleable cast iron with the strength and solidity that rendered it nearly as good as steel. The Han employed it in important applications, such as making cast-iron plowshares for agriculture and pans in which brine could be evaporated for the mass production of salt. Within two years of nationalizing all cast-iron manufacturing in 119 BC, Han leaders had established 48 state foundries that employed thousands of workers. To achieve the high temperatures necessary for casting iron, the Chinese employed efficient bellows to stoke the blast furnaces. An early innovation that greatly increased cast-iron production was the application of waterwheel power to the bellows. In AD 31, noted Chinese engineer Tu Shih invented a powerful, widely imitated, water-driven bellows used to produce cast-iron agricultural implements.

  Unlike the Romans, who used waterwheels chiefly to grind grain and for mining, the Chinese also pioneered the large-scale application of waterpower for industrial production. Indeed, for well over a millennium, China was the human civilization’s leader in harnessing water as energy to do useful work. Powerful vertical waterwheels, with gearing to turn several shafts, were used to operate trip-hammers to pound iron into shapes, hull rice, and crush metallic ores, as well as for other applications, by the AD 200s and 300s, many centuries before they appeared in Europe. By AD 530 Buddhist monasteries in the northeastern city of Loyang were even operating waterwheel-powered flour-sifting and -shaking machines based on the same essential design as that used by the steam engine—albeit with the crucial absence of steam power itself—that would galvanize England’s eighteenth-century Industrial Revolution.

  Not surprisingly, the Chinese would become world pioneers in ensuing centuries in applying waterpower to the ancient art of silk making—one of trade history’s great monopolies that enriched imperial China for centuries. The art of producing silk filament from the cocoons of the mulberry silkworm and weaving it into textiles was first discovered as far back as the Stone Age. Hot water played a critical role in the silk-making process, in what was perhaps history’s earliest example of water use in industrial production. To net one pound of raw silk, silkworms had to eat 100 pounds of mulberry leaves and produce about 15 pounds of cocoons. Great skill was required to unwind the silk filament from the delicate cocoons. It was accomplished by first soaking the cocoons in boiling water to kill the chrysalis; the strands were drawn out, then joined together and finally woven to produce the soft fabrics desired worldwide.

  The Romans first encountered silk in 53 BC when fighting the Parthians in modern Iran. By the first century AD, Roman demand for popular Chinese silk became such a burden on Rome’s balance of trade that Emperor Tiberius tried to forbid the importation of silk garments. China’s monopoly advantage in the silk trade with the Roman world endured for another 500 years. It was finally broken by a famous case of industrial espionage when two Christian Byzantine monks traveling in China stashed silkworm cocoons in the hollow of their staffs and returned with them to Constantinople, which promptly established its own lucrative silk industry by the end of the sixth century.

  The Han began shipping large quantities of silk to Persia and the Levant on taxed and protected camel caravans across the famed 4,000-mile-long Silk Roads of arid central Asia in 106 BC shortly after discovering, to their surprise, the existence of a fairly advanced civilization in the far West—Rome. The availability of freshwater sources dictated the trade routes and the scale of the camel trains. The several Silk Roads started at the huge city of Chang’an (the former and later X’ian) in the Yellow River valley, skirted inside the Great Wall to the Jade Gate and then went beyond China’s borders to follow a string of oases across the harsh wind- and sand-blown high deserts of central Asia at the foot the Himalayan, Altai, and Tien Shan mountains. Oases formed wherever mountain streams rushed down, sometimes flooded by snowmelt or violent storms. A northern and a southern route came together between the Jaxartes and Oxus rivers and crossed through Samarkand and Bukkara in modern Uzbekistan, before following various roads through Persia and Mesopotamia to Roman Syria on the Mediterranean; another branch route headed south to India.

  The entire trek was made possible only by the astonishing strength and water-storing capacity of the two-humped Bactrian camel, which unlike its one-humped Arabian cousin was able to tolerate the freezing temperatures of the high Asian deserts. Caravans of sturdy, woolly Bactrian camels plodded 30 miles per day carrying 400 pounds of goods on their backs. Although larger trains offered greater safety, most of the caravans were no larger than 50 men and their beasts since that was all the scarce water resources en route could support at any one time.

  Many of the oasis outposts thrived as important entrepôts of civilization, where both high-value luxury goods and new ideas were exchanged free from government control. In addition to silk, China shipped iron goods, ceramics, jade, and lacquer; the West sent back gold, ivory, precious stones, coins, glass, Persian sesame seeds and nuts, and, from India, spices and perfumes. Buddhism entered China and the Far East from India along the Silk Roads, its teachings spread by two Buddhist monks in the first century AD, overlapping the simultaneous early spread of Christianity in the Roman Empire.

  Trade on the Silk Roads reached its apex in the seventh and eighth centuries. Then, suddenly, after the annihilation of a Chinese expeditionary force by a Muslim army at the Talas River near Samarkand in 751 helped trigger the collapse of Chinese power across central Asia, the Silk Roads closed for over four centuries. It was one of history’s obscure skirmishes that in retrospect had outsized consequences. The silk trade was redirected to the Indian Ocean spice routes that were increasingly dominated by Muslim shipping, accelerating the rapid rise and global reach of Islamic civilization. The Silk Roads were finally reopened for travel by the Mongol Empire, whose thirteenth-century conquests under Genghis Khan and his heirs spanned from China to Persia. It was at the end of the thirteenth century that Venetian Marco Polo, a jewel merchant, made his famous trading expeditions from Venice to the Mongol overlords of Cathay (China). But by that time the Muslim-controlled, two-way seasonal monsoonal Indian Ocean sea route had established itself as the most reliable and economical way to transport goods between East and West and retained the predominant share of the traffic.

  With the fall of the Mongols, the glory days of the Silk Roads ended forever. But the combination of these two overland and sea routes succeeded in establishing an enduring, unregulated, long-distance, Old World trading network based on market economic exchange that competed with and would eventually supplant the traditional authoritarian command organization of centralized states. International trade had reached a peak at the contemporaneous high point of the Roman and Han Empires in the early Christian era. It then eroded with their declines. But gradually, with the restoration of civilized order in the Orient and Occident it built up again. By about AD 1000 the web of international exchange had achieved a critical mass of sufficient density and volume to propel its expansion throughout the second millennium and ultimately evolve into the integrated global market economy of the twenty-first century.

  The Han empire finally collapsed in AD 220, like Rome, under pressure from barbarian raiders from its northern frontiers and internal depopulation and weakening from exposure to unfamiliar infectious disease
s inadvertently imported on trading ships and Silk Road caravans. Indeed, the Han imperial state had never fully recovered from the combination of a short-lived usurpation and a disastrous course change of hundreds of miles in the flooded Yellow River in AD 11. The delay of several decades in repairing the river’s damaged irrigation and protective infrastructure led to inadequate food supplies, famine, disorder, and massive emigration along China’s vital northern defensive frontier. Manpower shortages, in turn, weakened the size of the Han’s military presence. But the essential underlying reason for the Han’s eroding northern strength was its inadequate supply and control of irrigation water to grow enough food to maintain a sufficiently large army there—north China’s relative shortage of water resources. A third-century Chinese report highlighted that “there was insufficiency of water for the fullest use to be made of the productive power of the soil.” Nor was there yet in place any efficient network to transport compensatory southern food supplies to the northern borders.