1995.12.16, Aicher, Guide to the Aqueducts of Ancient Rome

Peter Aicher has chosen an opportune time to produce a guide to Rome’s aqueducts. His book not only offers timely recognition of the growth of interest in aqueducts within the field of Roman studies, it is an overdue acknowledgement that ancient water delivery systems have always fascinated legions of nonspecialists. Until now, the amateur enthusiast was hard-pressed to find a suitably detailed guide, even in Italian, to the often elusive ruins of the eleven aqueducts that supplied ancient Rome. The aqueducts are strangely underrepresented in Filippo Coarelli’s Laterza guides to Rome, Rome’s environs, and Lazio, and are usually treated perfunctorily in single-volume travel guides to Rome. Thomas Ashby’s and Esther Van Deman’s exhaustive studies from the 1930s can rarely be found outside of research libraries, and they are not designed to serve as field guides. ¹ Moreover, as A. poignantly demonstrates, the Roman campagna is not the sleepy rustic retreat that it was 60 years ago. Large areas in the valleys and plains have given way to development, while the more mountainous regions have become overgrown due to the decline in grazing over recent decades.

Part One, entitled “The Roman Aqueduct,” is a brief introduction to ancient Roman hydraulic systems. It explains in straightforward terms the technology of ancient water delivery systems, from surveying to distribution and drainage. This section relies extensively on the work of Trevor Hodge; ² for instance, it accepts Hodge’s contention that, whenever possible, the Romans preferred aqueduct bridges over inverted siphons because of the prohibitive cost of lead production and transport (p. 17)—a defensible hypothesis, but one that still excites disagreement among specialists. The administration, law, and financing of the aqueducts of Rome also receive brief treatment here (pp. 23-28)—perhaps too brief, given that almost everything we know about Roman water commissions relates to the capital city. On this subject, Olivia Robinson’s work could have been consulted with profit. ³ Part Two, “The Eleven Aqueducts of Ancient Rome,” gives a historical and geographical survey of each of the ancient aqueducts in chronological order. Although the treatment is necessarily concise, here A. turns to the more specialized literature for his source material. ⁴

Part Three, “Guide to the Ruins,” is the heart of the book. It offers a detailed survey of the remains of Rome’s aqueducts starting from the city and progressing to the sources in the upper Anio Valley. (Since there is little to be seen of the city’s two ancient western aqueducts apart from a few sections of the Aqua Traiana’s specus along the Via Aurelia Antica, A. concentrates his efforts on the eastern conduits. He does not mention the recent investigations of the water mill, apparently powered by the Aqua Traiana, that lies today under a street just outside the American Academy. ⁵) A. gives detailed and up-to-the-minute instructions for finding the many remains that are far off the beaten track. For example, he explains that one section of the Aqua Alexandrina “has recently been made less accessible by the location of an archery range on its north side; an old farmhouse shares the south side with a Hare Krishna compound” (p. 109). But sometimes a precise description is impossible; occasionally, he concedes, only an exhausting search through the underbrush in the general vicinity of some landmark will yield results.

Once the ruin has been sought out, be it monumental like the Ponte Lupo (pp. 118-22) or humble like the exposed well-shaft to the Aqua Claudia along the modern Via Prenestina (pp. 114-15), the reader is treated to a full discussion of its construction and purposes. A. does not try to second-guess Ashby and Van Deman, from whose books he distills most of his material. When the two are in disagreement (as in their understanding of the dam at Subiaco), or when the physical condition of the remains has changed since they described them, A. duly reports the fact. In some cases the disintegration of the physical remains is distressing; the clearest instance of neglect in recent decades was the collapse in 1965 of several arches of the Ponte S. Gregorio, a Hadrianic rerouting of the Anio Vetus across the Valle della Mola.

Speaking as one who must constantly consult maps in his research and who too often finds them lacking the information sought or promised, I must express my satisfaction with the simple but well-conceived series of maps drawn for this guide. Several maps of the entire aqueduct system are included; sites of particular complexity, such as Romavecchia and the ravine crossings south of Tivoli, are given schematic plans with modern landmarks, many of them not featured on ordinary regional maps.

This book will remain the vade mecum of specialists and nonspecialists alike for some time to come. In the full expectation that it will be kept up to date, I offer the following minor corrections to A.’s introductory material: Armenia is in eastern, not western Turkey (p. 2); Nero’s branch was part of the Aqua Claudia, not the Aqua Marcia (p. 14) and extends southwest, not southeast from the Porta Maggiore (p. 61); Diocletian came at the end of the third, not the fourth century (p. 28); the Salinae of Rome were probably saltworks, not salt flats (p. 34); Lucullianus should be Lucullus (p. 71); Salvi was a sculptor, not a sculpture (p. 72). On page 35, A. follows Ashby’s hypothesis that the terminus of the Aqua Appia was 15 m above sea level (only 2 to 3 m above ground level at the riverbank), whereas on p. 165 he suggests the more plausible 20 m.

Somewhat more troubling is the claim on p. 18 that no traces of inverted siphons exist in Rome. While it is true that there were no siphons in the delivery system outside the city, the bulk of the intramural distribution system necessarily comprised inverted siphons made of pressure pipes, as in any other Roman city supplied by aqueducts. In 1880 Rodolfo Lanciani exhaustively catalogued the pipes found in Rome, and Christer Bruun has recently reexamined them along with more recent finds. Since Rome’s urban water distribution system was undoubtedly the most complex in the ancient world (all of the hundreds of fountains under Frontinus’ tutelage had at least two alternative water sources), surely the many surviving pipes, found all over Rome and at many levels, provide a persuasive document of its extent. Rome may have had no mighty siphons like those outside Lyon or Aspendos, but its dazzling web of smaller distribution siphons constitutes the greater achievement.

The foregoing, I must note, is a scholarly quibble with a book that consciously tries to avoid scholarly pretensions. In general, A. presents the state of our knowledge accurately and in due proportion, while focusing his efforts on producing a useful field guide; and in this he succeeds admirably. For those who wish to investigate the aqueducts further, he provides a full bibliography.