Piranesi’s print recreates, and possibly commemorates, a situation that was not visible when he created this work and, as such, poses questions about his use of evidence. The Aqua Virgo was constructed in the late first century BC under the supervision of Marcus Vipsanius Agrippa (63-12 BC), during the reign of Emperor Augustus (63 BC-14 CE). It was and still is known for its pure drinking water. After the renovation of its main channels under Pope Nicholas V (1397-1455), the name was altered to Acqua Vergine.  

Piranesi chose to depict the part of the aqueduct where an arch, an integral feature of an aqueduct’s structure, was altered to a triumphal arch, crossing the Via del Corso near the Trevi Fountain. He mentions in the alphabetic key that it was built by Emperor Claudius (10 BC-54 CE), whose successful invasion of Britain in 43 CE is commemorated by its construction (A). The arch was no longer intact in Piranesi’s day, which he indicated in the key: today this water channel remains buried up to the level of the monument’s capitals (D). Although Piranesi was not able to see the arch, he must have had access to visual or verbal sources that indicated its appearance. However, it was recorded on coins such as Aureus of 46-47 CE, which shows a triumphal arch with an equestrian statue of the emperor flanked by two trophies. Only these coins predate the final construction of the arch (Roman Imperial Coinage I 33). Based on his rendering of the inscription of the Arch of Claudius, it also does not seem plausible that he was aware of the fragment of the partial inscription found in 1641 that remains in the Capitoline Museums. 

[Insert close-up] 

Other details show his strategies for relating scale. He indicates in the key when the different parts were added, the tevolozza layers during Claudius’ restoration (B) and the upper part of the aqueduct “innalzata dai moderni cinque palmi dallo speco antico” (C). The inclusion of the measurement of five palmi indicates that Piranesi was also knowledgeable about the arches’ construction and later alterations to it. On the left, in one of his common practices, he offers insight into the incorporation of the aqueduct’s arches into the wall by using a cross-section. The four pairs of figures in the foreground appear to be in conversation; two others approach the arch in the distance. Their role seems limited to showing the use of the gateway and indicating a sense of scale; although they are relatively small compared to the architecture, the figures seem unfazed by it. 

At this point in the volume, Piranesi has moved around the Aurealian Wall and depicted a number of aqueducts connected to the city of Rome. This image of the Acqua Vergine shows a literal gateway to the city but is also used by Piranesi to introduce his new subject, since hereafter he continues with views of monuments in the city. One such structure, perhaps the Santa Maria in Via, can already be seen towering over this immense wall. (ML)