Rams' heads were the sort of motif, derived from the natural world but easily stylized, that Piranesi loved, and they are found everywhere throughout his work. He had included similar examples in plate 17 of the Della Magnificenza and at left in his Catalogo delle Opere (first printed around 1761), and on the title page of the Lapides Capitolini of 1762; they would also be used in many of the fireplaces, pedestals, and candelabra that Piranesi would later design, including his own funerary candelabrum.
Drawing is on verso of a proof state of Plate 4, figure 2 from Piranesi's "Le rovine del Castello dell'Acqua Giulia," 1761 (f. 405), showing a brick stamp. Piranesi would reuse this brick stamp on the title page of his "Lapides Capitolini" published in 1762.
Mrs. J.P. Morgan, New York; by descent to her sons Junius S. Morgan, Princeton and Paris (no mark, see Lugt 1536) and Henry S. Morgan, New York.
Morgan, Jane Norton, 1868-1925, former owner.
Morgan, Junius Spencer, 1892-1960, former owner.
Morgan, Henry S. (Henry Sturgis), 1900-1982 former owner.
Stampfle, Felice. Giovanni Battista Piranesi, Drawings in the Pierpont Morgan Library. New York : Dover, 1978, no. 29, repr.