License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Giovanni Battista Piranesi. Various Roman Ionic capitals compared with Greek examples from Le Roy [S. Maria in Trastevere, S. Paoplo fuori le Mura, S. Clemente, etc.], tab. 20 from "Della Magnificenza e d'Architettura de'Romani" (On the Grandeur and the Architecture of the Romans by Gio. Battista Piranesi, Fellow of the Royal Society of Antiquaries of London), mid-18th century. The Metropolitan Museum of Art.