Celebrating the Invisible: Aqueduct Display Fountains in Rome and America PETER AICHER Some of the most famous monuments in Rome are fountains that explicitly commemorate the construction of the aqueducts that supply them. The Italian term for these special fountains is mostra, the same word that designates an art exhibit. Key to the term as applied by the Romans to a type of fountain is that the fountain be conceived of and inaugurated as a celebration of the aqueduct behind it. While the tradition continued somewhat less grandly with Rome’s 20th century aqueducts, its most famous and rhetorically explicit examples are three papal showpieces that culminate in the Trevi Fountain. After a brief review of these fountains and the Fountain of the Naiads, I will discuss the legacy of this tradition, and departures from it, in commemorations of the monumental aqueducts of New York City and California. This comparative approach will not only reveal the role of Rome in presenting American waterworks to the public, but explore the social, political, and environmental differences that complicate the continuation of display traditions on American shores.1 I have argued elsewhere against the still prevalent conception that the tradition of the grand mostre began in ancient Rome.2 In the face of the abundant evidence for a host of monumental fountains in ancient Rome and the empire, my argument relies on the important distinction, made above, between a mostra and a monumental fountain, however grand the latter may be. To complicate matters, there is some evidence that papal builders of mostre indeed imagined they were continuing an ancient tradition, and many modern comarion 27.3 winter 2020 68 celebrating the invisible mentaries on ancient Roman fountains follow in their fallible footsteps. There are scattered examples throughout antiquity of a fountain commemorating its aqueduct and its builder, but the practice wasn’t common and certainly not frequent enough to warrant the assumption of a standard practice that the popes simply continued. In fact, the papal mostre, for all their splendor and contribution to the charm of Rome, would, at least in terms of resources, expense, and scale, all be side-shows in comparison to the aquatic extravaganzas of the ancient imperial baths and their wall fountains. A more substantial connection between Baroque Rome’s mostre with antiquity exists in the papal aqueducts themselves, which, in varying degrees, all reused or refurbished sections of ancient channels and re-tapped sources that had been lost to the city for centuries. Another connection between the papal aqueducts and their ancient Roman counterparts involves the rediscovery of Frontinus’s handbook on the city’s nine aqueducts of his day (c. 100 ce). A century after a lone manuscript of his text resurfaced at Monte Cassino in 1429, Frontinus’s description of aqueduct routes helped a papal librarian, guided in addition by the piles of deposits removed from the ancient channel in antiquity, rediscover the original sources of the Aqua Virgo.3 Though copious and only eight miles from center city, the low-lying nature of these springs made them difficult to find—a geographical feature that will be memorialized by Trevi Fountain sculpture. Earlier papal work on the aqueduct (called by then the Acqua Vergine, the city’s sole ancient aqueduct that never entirely ceased running) had occasioned a humble commemorative fountain in a small square where three streets met—hence Trevi. But the aqueduct’s 16th century renovation and reconnection to the ancient springs called for something grander. It would take another two centuries until that spectacular display was created. In the meantime, within fifty years of the Vergine’s restoration, two other papal aqueducts, the Acqua Felice of 1587 and the Ac- Peter Aicher 69 qua Paola of 1612, were completed, reconnecting the city to sources tapped by two other ancient aqueducts, the Aqua Alexandrina and the Aqua Traiana respectively. Sadly, the Acqua Felice’s gloomy arcade cannibalized many of the fine cut-stone arches of the ancient Fig. 1: The mostra of the Acqua Felice near the Baths of Diocletian . Note the central Moses statue, the inscription commemorating Sixtus V and his aqueduct, and the ornamental obelisks that figured so prominently in Sixtus V...