‘The Portico of the Pantheon’, 1750s and early 1760s, National Gallery of Art, Washington, D.C.
Overall: 21 x 30 cm (8 1/4 x 11 13/16 in.)  left section: 21.1 x 8.4 cm (8 5/16 x 3 5/16 in.)  center section: 21 x 18.6 cm (8 1/4 x 7 5/16 in.)  right section: 21 x 7.4 cm (8 1/4 x 2 15/16 in.)