Steven Solomon

by Power;Civilization Water: The Epic Struggle for Wealth

  Rome vigorously exploited another of history’s seminal water technologies to help it produce the daily bread for so many hungry soldiers and citizens—waterpower. To grind grain into flour to make bread, Rome built vast numbers of waterwheel-powered gristmills on streams and artificial conduits fed by aqueducts that transmitted the energy captured from the flowing current to turn the wheel and the millstone attached to it. As early as the first century BC, Roman engineers had made the ingenious breakthrough of moving the traditional horizontal waterwheel to a position vertical to the water, and to multiply the power it generated through the use of gearing. Many of the water mills built by Rome to feed army garrisons and cities were impressively large and powerful. The famous fourth century AD Roman water mills at Barbegal near Arles, France, used water forced along a six-mile-long aqueduct to drive eight pairs of wheels. It could grind 10 tons of grain daily. It was in imperial Rome that water-powered mills were transformed from small, household and local community devices into tools of large-scale, centralized bread production. As such, they became key instruments of state power.

  Why the Romans never fully exploited the enormous work potential of their own advanced waterwheel techniques beyond grinding bread flour is one of the vexing questions of its history. They possessed sufficient know-how to apply waterwheels to industrial uses, such as driving mechanical saws, fullers’ beaters, tilt hammers, or bellows to heat iron furnaces. But what they may have lacked, given their surplus of expendable slave labor, was the economic incentive to invest in labor-saving mechanization.

  One new water engineering technology that Romans did profitably employ was hydraulicking for mining. Hydraulicking used powerful jets of water that were far more productive than manual digging in the hills of Spain to extract the gold used for its coinage and financial system. Roman engineers released water from large tanks erected 400 to 800 feet over the mining site to generate waterpower sufficient to shear away hillsides and break up rock formations that exposed the valuable gold veins. In the mid-nineteenth century, hydraulicking would have its most famous, intensive modern application at the height of the California gold rush.

  Although not famed for their technological originality, Romans did use water to make one transformational innovation—concrete—around 200 BC that helped galvanize their rise as a great power. Light, strong, and waterproof, concrete was derived from a process that exploited water’s catalytic properties at several stages by adding it to highly heated limestone. When skillfully produced, the end process yielded a putty adhesive strong enough to bind sand, stone chips, brick dust, and volcanic ash. Before hardening, inexpensive concrete could be poured into molds to produce Rome’s hallmark giant construction projects. One peerless application was the extensive network of aqueducts that enabled Rome to access, convey, and manage prodigious supplies of wholesome freshwater for drinking, bathing, cleaning, and sanitation on a scale exceeding anything realized before in history and without which its giant metropolis would not have been possible. That it amply served the poor as well as the rich was likewise a notable development in the history of civic society. Throughout its empire, Rome’s aqueducts supported the robust health of towns and frontier garrisons whose soldiers’ fitness for battle was a critical element of its army’s superiority. Its mobilization of public water that served all classes established a landmark civic standard embraced later by industrial democratic Western societies.

  Freshwater conduits had been in use for centuries before censor Appius Claudius built Rome’s first aqueduct, the 10-mile-long subterranean Aqua Appia, beneath its first major paved roadway, the Appian Way, in 312 BC. Some four hundred years earlier the Assyrians had built their aqueducts augmenting Nineveh’s water supply and Hezekiah had excavated Jerusalem’s secret water tunnel. In 530 BC the Greek island of Samos likewise cut a water tunnel two-thirds of a mile long, while classical Athens had several aqueducts. The technical high point of Hellenist water engineering was the Ionian city of Pergamum’s early second century BC 25-mile-long aqueduct with double and triple terra-cotta piping and a pressurized section that enabled water to cross a low valley and then rise again on the other side against the natural force of gravity.

  What distinguished Rome’s public water supply infrastructure was not its originality, but rather its precision, organizational complexity, and grand scale. Spectacular ruins of the famous three-tiered, 160-foot-high arches of southern France’s Pont du Gard, the still partly functioning, narrow-arched aqueduct bridge at Segovia, Spain, and the celebrated Roman baths at Bath in England offer glimpses of Rome’s widespread hydraulic accomplishments. Roman water systems underpinned the empire in southwestern Europe, Germany, North Africa, and Asia Minor, including at Constantinople, the “New Rome” established by Emperor Constantine at Byzantium on the Bosporus in AD 330.

  Yet nowhere was Rome’s public water system more influential than in Rome itself. Indeed, Rome’s rapid growth to a grand, astonishingly clean imperial metropolis corresponded closely with its building its 11 aqueducts over five centuries to AD 226, extending 306 miles in total length and delivering a continuous, abundant flow of fresh countryside water from as far away as 57 miles. The aqueducts funneled their mostly spring-fed water through purifying settling and distribution tanks to sustain an urban water network that included 1,352 fountains and basins for drinking, cooking and cleaning, 11 huge imperial baths, 856 free or inexpensive public baths plus numerous, variously priced private ones, and ultimately to underground sewers that constantly flushed the wastewater into the Tiber.

  As in all ages from antiquity to the present, the pattern of water distribution read like a map of the society’s underlying power and class structures. Nearly one-fifth of total aqueduct water during the empire’s heyday went to meet the watering needs of patricians’ suburban villas and farms. Inside the city walls, paying private consumers and industries and those granted water rights by the emperor were water-Haves who received another two-fifths of Rome’s freshwater. Public basins and fountains used freely by ordinary people, by contrast, received only 10 percent of total aqueduct water. Nevertheless, like the bread dole, provision of a minimum amount of free water was an essential pillar of the state’s political legitimacy that Roman officials were careful to maintain. The remainder of aqueduct water was allocated to the emperor’s ever-growing demands for public monuments, baths, nautical spectacles, and sundry other public purposes. Rome’s patrician families enjoyed hot and cold indoor running water, sanitary bathrooms, and water closets that were unsurpassed in comfort until modern times. Unlike today’s highly pressurized, enclosed pipe systems, Rome’s aqueducts flowed from their source by natural gravity through precisely sloping gradients maintained over long distances; only in the city was pressurized plumbing employed to raise water to elevated locations. Most of the aqueducts were subterranean. But about 15 percent of the system was above ground and ran along its famous arched structures to maintain its gradient over uneven terrain.

  Sustaining and housing a population of 1 million may not seem like much of an accomplishment from the vantage point of the twenty-first century with its megacities. Yet for most of human history cities were unsanitary human death traps of inadequate sewerage and fetid water that bred germs and disease-carrying insects. Athens at its peak was only about one-fifth the size of Rome, and heaped with filth and refuse at its perimeter. In 1800, only six cities in the world had more than half a million people—London, Paris, Beijing, Tokyo, Istanbul, Canton. Despite Rome’s hygienic shortcomings—incomplete urban waste disposal, overcrowded and unsanitary tenements, malaria-infested, surrounding lowlands—the city’s provision of copious amounts of fresh, clean public water washed away so much filth and disease as to constitute an urban sanitary breakthrough unsurpassed until the nineteenth century’s great sanitary awakening in the industrialized West.

  Although there are no precise figures in ancient records on how much freshwater was delivered daily, it is widely believed that Roman water availab
ility was stunning by ancient standards and even compared favorably with leading urban centers until modern times—perhaps as much as an average of 150 to 200 gallons per day for each Roman. Moreover, the high quality of the water—the Roman countryside offered some of the best water quality in all Europe, and still does so today—was an easily overlooked historical factor in explaining Rome’s rise and endurance.

  Yet it was a universal testimony to water’s perennial economic and human value that even in conditions of relative plenty man constantly desired to have more of it. In an amusing reminder of unchanging human nature, Senator Julius Frontinus, who became Rome’s Water Commissioner in AD 97, in his famous short treatise On the Water Supply of the City of Rome urged harsh punishment for the many water thieves who “have laid hands upon the conduits themselves by penetrating the side walls.”

  Frontinus modeled himself, almost reverentially, upon the single most illustrious creator of Rome’s public waterworks—Augustus’s loyal military commander, schoolmate, and virtual coemperor for much of his reign, Marcus Agrippa. In AD 33 Agrippa, acceding to Augustus’s request, assumed the office of aedile and with it responsibility for Rome’s municipal works and services. Actium was two years in the future and Augustus—still known as Octavian—faced waning public support at home with the outcome of the civil war with Mark Antony very much in doubt. A famously self-effacing, plebeian-born protégé of Julius Caesar, Agrippa enjoyed wide popularity with commoners that Augustus lacked. His year-long aedileship would become the most lauded and influential in Roman history. At its start, Rome’s public infrastructure, following years of civil discord and war, lay in a crumbling, neglected state. It ended with revolutionary improvements—on a scale often associated with historic dynastic restorations and renewals of civilization—that not only resurrected Rome’s municipal infrastructure and services but also Augustus’s popularity and much of the political support he needed to overcome Antony, then far removed in Egypt with Cleopatra.

  Waterworks were the centerpiece of Agrippa’s urban renewal program. In only one year, largely at his own personal expense, he repaired three old aqueducts, built a new one, and greatly expanded the capacity and distribution reach of the entire system. Some 700 cisterns, 500 fountains, and 130 ornately decorated distribution tanks were also constructed, and 170 free public baths were opened for both men and women. He cleaned out the sewers, famously rowing through the Etruscan-built Cloaca Maxima on an inspection tour. In addition, he put on splendid games, distributed a dole of oil and salt, and on festive occasions offered free barbers.

  Rome’s municipal water system became Agrippa’s lifelong passion. In the years after his aedileship, even as he ruled over the eastern half of Augustus’s growing empire, led important military campaigns and was considered a leading successor to the emperor when Augustus fell gravely ill, he acted as the city’s unofficial, permanent water commissioner and spent lavishly from his own funds for the purpose. In 19 BC he built a sixth new voluminous aqueduct, the Virgo, whose water was acclaimed for its purity and coldness, which he used partly to supply Rome’s first large public bath near today’s Pantheon.

  The Virgo aqueduct, much of which lay underground, had the historical distinction of being the only line never to completely stop flowing through Rome’s subsequent dark centuries; today, Virgo water flows in Bernini’s famous Quattro Fiumi (Four Rivers) fountain in Piazza Navona and terminates at the Trevi Fountain, where the relief in the left panel shows Agrippa himself supervising the construction of the Virgo with the design plans unscrolled before him. Upon his death in 12 BC, at age fifty-one, he bequeathed his slaves to Rome’s water system maintenance crew. His master water system plan was adopted as the basis of the official imperial water administration created a year after his death by Augustus. It guided Rome’s water management thereafter, including the major new aqueducts built until the early second century. Longer term, Agrippa’s civil works set a standard and concept of public municipal service for all classes, a democratic legitimacy, and tool of exercising political power that is influential in modern liberal Western democracies.

  Agrippa’s innovation of the first large public bath—soon magnified in scale, vanity, and variety of activities by the 11 monumental imperial baths erected by succeeding emperors—became the model central institution of social and cultural life in ancient Rome. The traditional Republican era bath was transformed from a simple “sheltered place where the sweaty farmer made himself clean” into a multifaceted, sometimes luxurious “community center and a daily ritual that defined what it meant to be Roman,” writes historian Lewis Mumford. “The Roman bath compares with the modern American shopping center.” A typical Roman’s day at the baths started after a day’s work and lasted several hours. A large facility consisted of a cluster of activity rooms and big bathing chambers surrounding an open, central garden. The richest baths were adorned with statues, floor mosaics, and marble or stucco reliefs on the walls. Bathers generally would first get an oil rubdown in the unctuarium before exercising in one of the gymnasiums. Bathing started in the hot caldarium and steam room or sudatorium, much like a modern Turkish bath, heated by furnaces from below; Romans didn’t use soap, but instead scraped the dirt off their perspiring skin with a curved metal instrument, the strigil. Next, they lounged at length with friends in the tepidarium or warm baths, often conversing and carousing together. Then they dipped in the cold bath, or frigidarium, and swam in the pool. Lastly came a rubdown with oils and perfumes. Along the way they ate snacks and sipped wine served to them by attendants, read books from the bath’s library, got massages, relieved themselves in multiseated latrines along the walls of the baths, and sometimes indulged in drunken carousing and lovemaking. A full range of bathhouses, from free to costly, were available for all classes. At some, men and women bathed naked together, a practice whose repeated banning by emperors testified to its persistence. From one outpost of the empire to the other, Romans reinforced their Roman identity by practicing the daily social and hygienic rituals of the bath.

  Just as the high and low floods of the Nile tracked the prosperous and low periods of civilization in Egypt, Rome’s great eras of achievement and population growth corresponded to its periods of aqueduct building and expanding water supply. The early aqueducts were built during Rome’s Italian peninsular expansion as rising population levels overtaxed the city’s resources of local freshwater springs and wells and potable Tiber River water. The transformative victory in the Second Punic War in AD 201 was followed by an intensive burst of Republican era aqueduct building featuring Rome’s third aqueduct, the voluminous, 57-mile-long Aqua Marcia in 144 BC, which for the first time distributed ample good water across the social spectrum. Agrippa’s aqueduct constructions sufficed until the mid-first century AD, when Emperor Claudius increased the water supply by about 60 percent with two new aqueducts, and Trajan added a third in AD 103 to keep pace with the doubling of Rome’s population in the early imperial period. The end of aqueduct construction in the early third century, by contrast, reflected the plague-ridden fall in the city’s population and the early decline of the Western Roman Empire; indeed, the last aqueduct was built in AD 226 mainly to serve the decadent luxury of refurbishing the emperor’s baths rather than the needs of the citizenry.

  Other water-related depredations also marked Rome’s decline. Rome’s heavily fortified European frontier river barriers were breeched by Germanic barbarians: In AD 251 the Goths crossed the Danube; in AD 256 the Franks broke through the Rhine. Both pillaged deep into the empire. In the same period Rome began to lose control of the seas and the security of its food and raw material lifelines to its provinces came under steady assault by pirates, Goths, and other barbarian tribes. Rome’s underfinanced and diminished navy increasingly retreated. Hyperinflation, heavy taxation, recession, and severe pestilential disease debilitated the empire’s economy from within. Without, new defensive walls were erected around the capital by Emperor Aurelian in AD 271.


  Although the empire earned a temporary, century-long reprieve through the administrative reforms, reassertion of military power, and authoritarian economic command of several resourceful soldier-emperors, notably among them Diocletian and Constantine, its command of the sea-lanes and defenses that underpinned its control of vital supplies from its provinces was irreparably breaking down. This was importantly illustrated in its Egyptian breadbasket. In response to onerous taxation payable in grain—tax “rates” were calculated by Roman governors according to the Nile’s annual flood level—cultivated cropland in Egypt by the third century had shrunk by half as its farmers grew weary of working for overlords and abandoned their fields. Draconian new grain taxes imposed in AD 313 worsened the long-term situation. Finally, in AD 330 Emperor Constantine transferred the capital itself to a new, more defensible and economically strategic location at the ancient Greek city of Byzantium overlooking the Bosporus Strait gateway to the Black Sea. The regular Rome-bound Egyptian grain shuttles were redirected to the “New Rome,” renamed Constantinople. Rome’s remaining population was left to fend for itself. As often in history, the change in main water transport routes signaled the shift in destinies among leading powers and civilizations.