The Basis of Civilization - Water Science? (Proceedings o f lhe UNESCO/IAHS/IWHA symposium held in Rome. December 2003). IAHS I'ubl. 286. 2004 31

Water management: the central Italy model and its dissemination

PAOLO BUONORA Via Stamira 31, 1-00162 Rome, Italy bLionorafoiasrm .archivi.bcnicultiirali . i t

Abstract Water management in central Italy is characterized by a develop­ment model focused on producing energy from water, rather than on drainage and irrigation. Its history begins in the Middle Ages with the creation of the communal territories, and continues until the rise of the hydroelectric industry. As Italian towns developed, they did not simply restore Roman aqueducts, built mostly for celebrating the role of the Empire, but they adapted these sUuctures to fulfil the needs of a growing urban population. Apart from the literature celebrating the relevance of restoration politics and the role of the River Tiber, this model is the same in the small towns and in the capital of the Papal State, Rome. The damage caused by flooding mostly affected urban buildings, but not agriculture, which was kept away from the danger areas surrounding rivers. To face the hazard of floods in towns, the simple tech­niques of hydraulic engineering known at the time were employed to channel and divert the water away. Of course the early natural philosophers considered floods as a moment in the circulation of the waters within the internal body of the Earth. In reality, the catastrophic floods of the 16th and 17th centuries seemed to be the product of both human action and climatic change. While the importance of hydraulic energy in the ancient world has still to be demon­strated, it has been well established for the Middle Ages and for the Modern Era. The four basic elements for supplying water and energy for the growing urban systems were: a canal and reservoir for maintaining a regular flow of water, the building of walls for the city and its mills, a masonry-lined canal for moving water under pressure to a horizontal water wheel powering a grain mill, and a means of conveying the water used by the mill to another reservoir. In spite of the long accepted tradition in the history of hydraulic technology, these mills seem to have been the most effective and labour-saving machines within the confines of central Italy. These systems often included vertical wheels which were used for different purposes such as fulling mills, paper making and metal working. Irrigation is mainly a variant of the model: water from the mills was employed for specialized cultivation around and inside the city walls, when not employed for powering water wheels. The role of the rivers—the River Tiber was the only important one of the region—is quite different. They were used for transport and they were harnessed for power, as well as providing a receptacle for wastewater. Many questions have still to be defined by historical research. Among them, In the long term, is the centre of urban water supply to be placed on rivers or on artificial aqueducts? and Is the development of water technology generated by the planning of a central authority, or by the competition between the different entities? There is a real exchange of scientific and technological knowledge in the history of development, which allows us to consider "water science" as one of the "bases of civilization". K e y w o r d s a q u e d u c t s ; cent ra l I taly; h y d r a u l i c ene rgy ; Hoods ; hyd rau l i c s c i ence ; mi l l s ; R o m e ; T i b e r R ive r

32 Paolo Buonora

INTRODUCTION

For a long time, water, as a subject in Italian history, was approached mainly from the point of view of drainage and irrigation (Buonora, 1992). However, at the end of the 19th century the development of the newly emerged country as an agricultural producer motivated technicians and politicians to project an extension to the entire peninsula of the type of land use that was typical only of some parts of the Po plain in northern Italy, based on widespread use of irrigation. But the historical role of water in the central Italian region has instead been more complex, and more related to other uses, for instance to energy. However, at that time, this long tradition was finally swept aside by the growth of the hydroelectric industry. One of the aims of this paper is to alter views on this approach: the plains in central Italy are near the coast in areas for centuries affected by malaria, where the economic activities were limited and based on pasture, wood and fishing. The drainage of these areas was only completed in the 20th century, employing workers from other regions of Italy.

A second misunderstanding of the role of water, also connected to the politics of drainage which developed with the growth of the nation State after 1970, is the consideration of the continuity of the drainage tradition, starting in Roman times and continuing through the Middle Ages to the Modem Era with its contemporary experiences. This point of view, with its traditions based on the political choices of a centralized state, has an opposite "democratic" version in Carlo Cattaneo: it was not the Romans, but the ancient Italic people who discovered and practiced the drainage of the soil. The Romans, with their extensive cultivation of grains, arrived to destroy this landscape, but the growth of towns restored this landscape and took it to full development in the 19th century. This approach is an improvement: the models of water management, control and development we discussed here deal with the urban situation—every component of these hydraulic systems is a part, or a separate element, or a mirror of the urban structure. Here we try to consider separately each element of this model, although they are part of a system, i.e. none of them can exist alone in the real situation.

WATER SUPPLY

For a start, let us look at what the Roman tradition could mean in the central Italy context, of course first examining the aqueducts (Buonora, 2000) (Fig. 1). Hodge (1992) remarked that Roman aqueducts were not built for drinking and washing: these basic needs were met, and continue to be, from the system of springs and private cisterns. They were instead a sign of luxury and urban status that satisfied civic pride: the symbolic interest of Roman aqueducts is underlined by a series of monumental and artistic uses of their water. In other words, there were "two quite separate water systems operating in parallel and independently, fulfilling different purposes and observing different rules", the primary role of the aqueduct being to demonstrate civic prowess. What is really important is the public and civic relevance of the aqueduct as an enterprise, compared to the private character of the cisterns.

A difficult question to answer is: How can very different urban situations—some towns are on a hill, others on the plain—have a similar hydraulic model? Some years

Water management: the central Italy model and its dissemination 33

Fig. 1 Frontino's aqueducts in Ancient Rome (Evans, 1994).

ago research upon several cities and small towns of the Umbria region gave a reason­able impression that we were concerned with a long term, flexible and widespread model (Buonora, 1994). The employment of aqueduct techniques of Roman origin, gave good results in every urban centre, no matter where they were located.

In the case of Perugia, the main city of Umbria, which is located on a hill top, we find many ancient wells and tanks of Etruscan origin. These were employed to purify rainwater collected from the roofs of the houses and the big monastic buildings, the water having to pass through the sand contained in two concentric tanks to become drinkable. It is important to note that the difference between these tanks and the simple rectangular cisterns supplied by aqueducts is that in Roman cisterns the source water is only purified by gravity, depositing some mud and other material. In Perugia, as in Spoleto, Bevagna, Spello, Assisi, Terni and other towns, it is always difficult to say after the 13th century whether we are facing the "restoration" of an ancient Roman aqueduct or the "creation" of a new one. Many elements are the same as in the Roman original—arches, bridges, subterranean conduits, cisterns ("castella" or "bottini"), but we also find significant variations. First, the limited economic resources of the medieval community did not often allow the complete restoration of the arches and bridges, and forced the alteration of the original route to a new one, employing conduits of terracotta and much later iron. The second variation is an original solution to a basic drawback to the original Roman structure of the aqueduct: the presence of calcareous deposits that required very expensive maintenance and which finally degraded them (Fig. 2). By mixing rainwater from the tanks with the calcareous spring water, the aqueduct would last longer.

34 Paolo Buonora

* " ^ " _ ^ 5 s L j t • *"*^*^^^"*~'

Fig. 2 Calcareous deposits inside a Roman aqueduct (Riera, 1994).

In the towns of Umbria—and similarly in all the towns of central Italy—the hydraulic system parallels the properties of a blood circulation system: clean water is separated from dirty water, and passes from the "artery" to the "vein" only after performing several functions, that we will discuss later.

In the case of a city crossed by an important river, like Rome, this scheme seems to fail (Buonora & Pineiro, 2004). Rome appears to be much more dependent on the Tiber. But going deeper into research, we discover that the relevance of the river is more the effect of a literary tradition than of its real role in the urban economy. As in other towns, before the restoration and the rebuilding of aqueducts in the 16th and 17th centuries, people's basic needs were satisfied mainly by wells. Of the three aqueducts which were restored, the Vergine (Fig. 3) had never really stopped functioning, because it carried less calcareous water; the Felice (Fig. 4) can be considered a real restoration of the Roman "Aqua Alexandriana", but not reaching the main spring sources of the others in the Aniene valley, its flow remained much lower than the standard of supply in Imperial times. Finally the Aqua Paola is a quite different aqueduct from the original, bringing water which is not drinkable from Lake Bracciano. The real difference in the water supply of Rome compared to smaller towns is that the "arterial" parts of the system, in ancient as well as in modern times, are specialized: one aqueduct for drinking water, another supplying the monumental fountains, another for water mills, while the river takes the discharges of wastewater rather than providing a source of supply. Of course there is the role of the Renaissance movement in the restitutio of the ancient imperial capital, but also some of the architects were familiar with Vitruvius, but these works were made by simple men and family companies of masons coming from Lombardy and Canton Ticino: Fontana and

Water management: the central Italy model and its dissemination 35

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Castelli. These companies had experience both in erecting buildings and in constructing water supply systems since the 14th century, like the one that was

36 Paolo Buonora

developed in Milan Navigli (the urban canals), which can be considered as one of the main roots of Italian hydraulics. In other words, Rome can be considered another case of the model, typical of the communal Italian town.

FLOOD CONTROL

Flooding, a problem particularly important for the city of Rome, is in direct contrast to those of water supply. What the concern is here is the context of this problem in the Renaissance. Some of the "hydraulic architects" of the Pope, tried to measure flows during floods—the most destructive was in 1598. But they had no solution other than building "regolatori", bridges built for controlling the flow to a certain volume of water, and no more (Fig. 5). It must be considered that these were simply giant versions of the fixed "mouth" in stone or bronze, usually employed for delivering water. As for the excess water, it did not matter what happened outside the controlled area of the town: there was no cultivation of grain on the periphery of Rome, only pasture. The situation may have been a little different in country areas, but not by much. In Umbria the land in the floodplain was commonly used for pasture or for marginal farming, but never for grain. If towns were very close to each other, they may have marked the limits of flooding, but often the boundary of each urban area was unclear. Of course flooding in the open country had serious consequences too in marginal lands, but concern was more for the physical aspects of flooding rather than those due to polluted water. Cereal crops were cultivated on higher ground but nevertheless floods deposited mud and stones on the fields.

Fig. 5 Engraving in the first edition of Castelli's masterpiece (Benedetto Castelli, 1628).

Water management: the central Italy model and its dissemination 37

Fig. 6 The circulation of water in the Mundus subtervaneus by Athanasius Kircher, Amsterdam 1664-1665.

The efforts for protecting Rome from floods by building "regolatori" bridges was also undertaken upstream of the city (at the Marmore Falls near Terni, in the Chiane Valley near Arezzo and at the Ponte Felice at the beginning of Umbria region) but this did not mean there was an awareness of basin problems. Common sense never failed to perceive that the consequences of heavy rain and deforestation, in the 17th and 18th centuries, however we can see that, in both the popular and in the "scientific" context, theory was far removed from a realistic vision of the hydrological cycle. The leading hydrological theorists (Descartes and the Jesuit Kircher) conceived springs and floods as coming mainly from inside the Earth, through the internal circulation of seawater, like in a human body (Fig. 6). Floods were something unpredictable like earthquakes, out of human control and not connected with land use and its development (Buonora, 2003).

The dramatic increase in the flooding of the Tiber in Rome during the 16th and 17th centuries is possibly related to climate change—the Little Ice Age—and to demographic growth. Probably these worked together, creating a dangerous mix. Population pressure pushed the limit of cultivation higher, climate change augmented the rainfall, especially at altitudes where the forests had been replaced by arable crops. This mix of circumstances caused a series of well documented hydrological and hydrogeological disasters across the entire Apennine region in central Italy (Buonora, 2001).

Hydraulic energy

We have considered the floods in Rome, but there were floods elsewhere that produced a change in the courses of the River Topino near Bevagna, in Umbria, and the River

38 Paolo Buonora

Fig. 7 The Tiberine Island in the 18th century (Chiesa & Gambarini, 1746).

Reno near Bologna, both at the beginning of the 17th century. These examples show the relationships that exist between climatic change and human development, not only of the soil, but also in terms of hydraulic energy. In Rome, at the end of 16th century, the river was full of floating mills, while the dikes caused an increase of the level of the river bed (Fig. 7). Similar rises occurred in Bevagna and in Ferrara at the about same time. The only difference was that in Rome the river could not find another course, while in the other cases a new river bed was created naturally. We can date these disasters from the expansion of the urban hydraulic model outside the walls of the towns.

Up to that time, the energy produced by water had been used mostly inside the towns. Going back to ancient Romans, the differences with the medieval-modern situation are worth noting. In Hodge's opinion, water was largely employed by industry in ancient times, especially to power the waterwheels. It did not have a secondary role as historical tradition maintains: the Romans knew the structure and function of water powered mills very well; moreover, aqueducts were an ideal method of supplying the water for these mills. In other words: "the only reason that we think water-mills were rare is that we have not found many, and this may reflect simply a failure either of archeological evidence, or of our interpretation of it". In fact, the remains of a series of mills have been found in Barbegal, which were supplied by their own aqueduct, one different but parallel to the one used for the water supply of the city of Aries. In the archeological reconstruction, there seems to be a system of eight

Water management: the central Italy model and its dissemination 39

Fig. 8 A reconstruction of the ancient Roman mills on the Gianicolo Hill (Lanciani, 1990).

buildings with two wheels in each, a truly industrial system: "how many Barbegals are there awaiting discovery?" Hodge asks, affirming, "this may well be the largest and most important question raised by this book" (Hodge, 1992).

His thesis must be considered very carefully. In fact the discovery of millstones in 1990-1991 under the American Academy on the Gianicolo Hill confirms the existence and the importance of those mills (Fig. 8). Nevertheless the fact that few mills have been found does not exclude the possibility that they ever existed. Hodge's opinion seems to be restricted too much to the technological aspects of the problem: adopting a technology is not only a technical matter, it is also an economic problem. The main argument used by economic historians is that the presence of so many slaves made the labour saving potential of mills irrelevant and that the different conditions made water power an essential element of development in the medieval urban economy (Bloch, 1935). In fact, the same number of mills would have had a quite different relevance in imperial Rome with one million inhabitants, in contrast to the city of the Pope, which had a modest population.

The fact is that water mills in towns are completely different from the point of view of their structure and technology. The Roman (Vitruvius) mill has a vertical wheel, which is fed by an aqueduct and is moved by gravity; its efficiency depending on the dimensions of the wheel, the head of water, and the number of mills that are in the chan­nel, where each wheel is only a component of the complex system. In central Italy there are no vertical wheels for milling grain: if they ever existed in early medieval times, they were replaced by another type of mill, whose characteristics are (Fig. 9(a,b)):

40 Paolo Buonora

(a) A large reservoir feeding a small canal is built upstream of the mill: it is filled by a channel or a canal connected with the river, or from an aqueduct.

(b) The wall of the building is, in fact, a part of the dike: sometimes part of the city walls.

(c) Water from the reservoir flows down a masonry-lined canal inclined at about 45% to reach the horizontal wheel, moving it not by gravity, but by the pressure of the water: the wooden wheel has separate spoon-paddles that can be replaced.

(d) The water flowing from the mill is not used directly by another grain mill, but it flows eventually to another mill reservoir.

(a)

(b)

Fig. 9 (a) Cross section and (b) map of the modern mills on the Gianicolo, 1827. Rome State Archive, Collezione I disegni e mappe, 80/232.

Water management: the central Italy model and its dissemination 41

Fig. 10 The Marrana canal at Porta San Giovanni, end of 17th century. Rome State Archive, Catasto Alessandrino, 429/24.

This kind of mill has several advantages in the geographic and social context we are considering. Both the employment of pressure and the direct connection of the moving wheel to the heavy millstone produce an amount of power sufficient for milling at a fast speed, even with a small or discontinuous flow of water. The installation of others mills is conditioned by the fall of the water course, but it does not require the building of a complex aqueduct system. Mills can be added upstream or downstream as required by the community. At a certain point in time, no further mills can be added and the system can be considered complete: but in contrast to the systems with vertical wheels this one is long lasting, and can be thought of as a real component of the historical landscape.

This type of hydraulic settlement expanded outside the walls of the towns: demographic growth required not only new space, but also more energy. Expansion continued downstream on other watercourses in the valley, with mills built far from the urban centre. These buildings can be considered as separate parts of the town, commu­nal properties, whose functioning is ruled by communal "statuti" and defended by fortified towers. In Spoleto, for example, the communal mills are in the same towers, on the other side of the aqueduct bridge; in Rome the San Giovanni mills on the Marrana canal (Fig. 10) are just outside the city walls, within the Pope's sight under the Laterano Palace. In Perugia they are on several canals fed by the Tiber, at the end of the hill where the town is built, each of them was defended by a "door" or "quartiere".

When the State employed public money on an important drainage scheme in a plain (the Pontine marshes at the end of 18th century, for example and the Umbrian Valley in the 19th), the choice made seems to have been connected to the dynastic interest of the Pope. He wanted to ensure that his family possessed the main grain mill, where each harvest would produce a large and constant revenue (Rocci, 1995).

42 Paolo Buonora

At the end of 16th century a series of flood disasters connected to climate change, over-exploitation of the soil and over-development of water for energy, forced the communal and state authorities to look for a better method for water and energy management. The solution was the building of controlled canals carrying a clear and constant flow, completely separated from the natural water courses that continued to cany the runoff. This operation was undertaken with the agreement of the different communities and towns interested in the same watercourses, sometimes with the direct intervention of the State. Some examples are: the role of the Canalino of Cento after the Reno diversion; the relevance of the River Clitunno in the Umbrian Valley, powering the communal mills of five different towns, when the River Topino was diverted; and finally, the building of an aqueduct in Rome—the Aqua Paola from Lake Bracciano. The latter was projected for the new public mills on the Gianicolo Hill and to free the river from the dangers presented by the floating mills. This project was conceived at the end of the 16th century, carried out in the 17th, but the final effects were seen only at the end of the 18th century.

In fact, there are a few exceptions to this type of horizontal wheel grain mill, namely the floating mills in Rome (Fig. 11), although recent research shows that during the second half of 18th century they were replaced by other mills on urban canals. Another exception are the communal mills by large vertical wheeled mills in Bologna, more strictly with Barbegal-like machinery. The horizontal wheel standard for grain mills does not exclude the employment of vertical wheels for purposes when less energy and more precise movement is required. For fulling mills (Fig. 12), paper mills and metal drawing, we usually find vertical wheels are used, with the advantage over horizontal wheels that they can be installed on a canal without requiring new dams and new reservoirs, as they need less energy. So mills with vertical wheels can be added to a canal or removed as the market requires.

Fig. 11 A grain mill in the Tiber River. Rome State Archive, Congregazione dette Acque, b. 245.

Water management: the central Italy model and its dissemination 43

Fig. 12 A fuller in the country, near Rome, 1660. Rome State Archive, Catasto Alessandrino, 429/24.

A river or a canal offers savings in the transport of goods and materials by the use of boats and barges or through floating objects. In Milan, the "navigli" canals which carried wealth to the Italian cities remained a classical paradigm which was followed for a very long time in Europe and in America. At the beginning of the 20th century, an American engineer investigating "waterways versus railways" was surprised by the way that the "ideology of canals" had lasted, independent of an economic evaluation of the modes of transport and the politics involved (Multon, 1912).

In central Italy this aspect of the question had much less relevance than in the Po Valley or in Lombardy. However, we must not forget that the basic role in the development of Rome was played in the Renaissance by the transport of marble from the quarries near Tivoli along the rivers Aniene and Tiber, down to the port of Ripetta (Fig. 13). Saint Peter's Cathedral, and all the churches, fountains and buildings of the city in the 16th century were constructed with this marble. This case is similar to the Navigli of Milan, which were built to carry stone for the building of the Dome in the 15th century (Buonora, 2000).

In any case, the needs of the expanding towns and cities are not very different, compare Milan and Rome, for example. A city of 100 000 inhabitants needed 500-800 km 3 of woods, but as a large part of the territory was woodland, the only difficulty concerned transport. This indicates how strategically important were natural and artificial watercourses for navigation: for example, in the case of medieval Milan, the quantity of wood that carts and barges brought into the city was estimated at the remarkable amount of 150 000 carts a year (Malanima, 1990).

In the case of Rome, at the river port of Ripetta, which was the upstream entrance to the city, the percentage of barges that earned wood compared to other kinds of merchan­dise remained above 50% throughout the 18th century. At the end of the 17th century, the wood supply was located near the river, not more than 1.5 km from the river and 74 km from the city. This was not the only source of wood used in Rome, where in partic­ular years the climate or the increased number of pilgrims caused an abrupt rise in its consumption. The claims of the owners on the amount of wood cut show that it was taken from areas along the river in Sabina up to Orte according to a 9-year woodcut (Sansa, 2001).

44 Paolo Buonora

Fig. 13 River navigation along Aniene and Tiber Rivers (1661). Rome State Archive, Catasto Alessandrino, 433/41.

All this explains why projects for improving the river for navigation were considered over a period of more than two centuries by the popes. However, none of these projects were earned out except for some important maintenance work: this was little or nothing compared to the canals being built in the rest of Europe at that time.

The diffusion of the technology of canal building from Italy to the remainder of Europe is clear, and not only for the work undertaken by Leonardo da Vinci. For instance, all those responsible for the "Canal de Languedoc" undertaking were of Italian origin: namely Craponne and Andreossy, while the same applied to Riquet. Craponne was a descendent of the Pisan family of Crapone; and Riquet from Gerardo Arrighetti, exiled from Florence in 1268. They inherited not only an engineering culture, but also entrepreneurial expertise which spread across the whole of Europe, maintaining links with Italian traditions. Nevertheless, this tradition seems to have been lost in Rome; at the end of the 17th century the Pope called on a Dutch engineer, Cornelius Meyer, to improve the navigation of the Tiber.

IRRIGATION

It must be clear that irrigation practices connected to the urban hydraulic system had nothing in common with the canals built mainly for irrigation in other parts of Italy, for production of hay, or rice, or later for com. The irrigation that took place near the mills was for horticulture and connected with the needs of large monastic communities and

Water management: the central Italy model and its dissemination 45

of the entire town population, or of the small communities in hydraulic settlements developed at some distance from the town (Figs 14 and 15). Sometimes more specialized production took place—just an indication of a weak market-oriented economy: artichokes in Rome, or onions and celery in the little towns of Cannara and Trevi in Umbria. But the main, and more general role played by irrigation in these towns was concerned with hemp, perhaps the most market-oriented product in modern Italy. Water is required not only in the cultivation of hemp, but also in processing it: so the best fields around the town—sometimes inside it, as in the textile centre of Bevagna—were devoted to hemp cultivation, while the canals around the towns were employed for soaking hemp fibres.

The link with the urban hydraulic system is not only in the use of the same water. The fact is that the functioning of horizontal mills implies a waste of water, in terms of quantity and in terms of time. Since the building of the canals, rules were established for delivering water both to the mills and to users of irrigation water; these laws were generally confirmed by a public authority and often were the origins of private companies of users: for instance, the Consorzio of Mariana Water in Rome was founded in medieval times and ended only in 1974 when the canal was finally diverted.

Mills did not work all the days of the week: at least on Saturdays and Sundays the water could be used to irrigate the fields. If horticulture was more important, a day-by-day rotation was planned to satisfy the needs of the mills and the crops. Apart from these main uses of water, there were those industries needing water, which were located near urban canals: such as those involved with textiles, leather, and pottery. There was also fishing, which was mainly based on the breeding of fish in the controlled waters of mill canals.

Fig. 14 Horticulture in Trastevere, Rome, beginning of the 19th century. Rome State Archive, Catasto Urbano, Trastevere, mappa 6.

46 Paolo Buonora

Fig. 15 Horticulture outside the city walls of Porta San Giovanni, Rome, 19th century. Rome State Archive, Cessato Catasto Rustico, Agro Romano 161, mappa 1.

CONCLUSIONS

To conclude we must relate this urban hydraulic model, which concerns a part of Italy, one whose role in the history of Europe was very limited from the 16th century on­wards, to the broader historical context.

It is relatively simple to find the origins of modern water supply in ancient Rome, in its aqueducts and through the restoration work carried out during the Renaissance. Rome—both the ancient and the modern city—was an example for every capital city in Europe. The question is whether the water supply of towns based on aqueducts can be generalized to the development of large cities. At first sight the answer appears to be in the negative: the growth of Paris and London, for example, seemed to depend on a large river. But in the long run it is clear that basing an urban water supply system on river water was (and is) not easy, both from the health point of view, and the maintenance of the channels and conduits. So in modem times a water supply from a river seems to be an easy way of satisfying the basic needs of expanding capital cities, mainly for energy (London). However, sooner or later such as system may have to be replaced by installing better and larger aqueducts fed by spring sources, no matter how distant they are. This trend can be seen in towns in France and the USA in the 19th and 20th centuries. The New York water supply system is an extraordinary example. It consists of several aqueducts, coming from Delaware and delivering to the city about the same amount of water per person as in Imperial Rome. Furthermore, the system of monitoring and mixing different waters is very similar to the system described in Frontino's De aqueductibus urbis Romae.

A second topic is whether the control of water is exercised by a central power of some kind, i.e. the "hydraulic despotism" expounded by Wittfogel (1998). However,

Water management: the central Italy model and its dissemination 47

the impression gained from Italian history is that, on the contrary, only conflicts generated over the control of water produce a higher level of technology, science, public management, and regulatory law. Some conflicts last for years, others for centuries, as for example the Bologna-Ferrara conflict about the River Reno, but we must not only consider them as limits to the control of waters. In fact in the 16th-17th centuries, when the Papal State had great authority and was at its richest, the efforts in controlling rivers ended with several losses, hinging on the absence of a scientific theory on the movement of water and practical experience in river hydraulics. It was in order to find solutions to these problems that the municipal and state powers decided to pay lawyers and technicians, and to establish the teaching of related disciplines in the universities (Maffioli, 1994).

Finally there is a problem concerning the transfer of technology from and to Italy. Italy is well known as the birthplace of practical hydraulics and water science. This is of course a true story, not one generated in the literature. The real problem is to under­stand if the know-how on hydraulics is conveyed by people travelling (technicians, companies making water works), or by a scientific tradition (books, university teaching), or simply by exporting an economic structure (every town needs an aque­duct) (Glick, 1998). Sometimes two generations are enough to lose all knowledge about an ancient technique, left aside by the changing economic trends. From this point of view, the less a technique is related to market production, the longer it lasts. Although it is difficult to find documentary evidence of origins, several technologies seem to be have been conceived, or brought to fruition, in Italy. This is a reasonable assumption, as in the Mediterranean and in the European context Italy has, on several occasions, been the historical centre of streams of technology, the centre where experience deposited knowledge.

The connection between the Old and New Worlds is more difficult to judge where energy and industry are concerned. In the 19th century, while the small towns of central Italy maintained their ancient water mills, steam engines were spreading in other parts of Europe and in the New World, where later Italy exported many simple workers with apparently little technical knowledge. If we examine the evolution of hydraulic machines more closely, something interesting emerges. The horizontal wheel we described earlier appears to be an early example of a turbine; in other words, it represents the optimal mechanical solution—considering the level of technology at the time—for a particular geographical situation where flows are relatively constant, and where differences in height along water courses are important. So we can say that the hydroelectric industry is significantly in debt to those ancient mills of central Italy.

In addition, we must consider that the milling of grain has not only been something related to feeding the population. When economic conditions allowed and when the basic needs for making bread were exceeded, milling started to turn towards a real market-oriented industry. In Naples and Genoa and also in Rome during the second half of the 18th century, some mills began to produce hard wheat meal for pasta manufacturing. By the end of the 19th century, the highest concentration of water mills was not in northern Italy, but near Naples, for the pasta manufacturers. In other words, if new pasta factories were built in the New World employing steam engines, techniques of milling were strictly derived from a world where water energy had a decisive importance.

48 Paolo Buonora

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