The ruins of the eighth Roman aqueduct, completed in 50-52 A.D. under the Emperor Claudius I. The Romans constructed aqueducts to bring a constant flow of water from distant sources into cities and towns, supplying public baths, latrines, fountains and private households. Aqueducts moved water through gravity alone, along a slight downward gradient within conduits of stone, brick or concrete. Most were buried beneath the ground, and followed its contours; obstructing peaks were circumvented or less often, tunneled through. Where valleys or lowlands intervened, the conduit was carried on bridgework, or its contents fed into high-pressure lead, ceramic or stone pipes and siphoned across. Two aqueducts were completed by Claudius I; the Aqua Claudia and the Anio Novus. The print gives no indication which is depicted.