"Marble, in the Vatican. Empreor of Rome, and celebrated for his virtuous reign, A.D. 138-161. The original was found by Gavin Hamiltdon, in Hadrian's Villa." [P. 10.]
Catalogue of the Paintings, Statuary, Casts, Bronzes, &c. of the Corcoran Gallery of Art. Prepared by the Curator. Gibson Brothers, Printers.