Copperplate engraving from the 1762 supplement to "Encyclopedie, ou Dictionaire Raisonne Des Sciences", 1751-1780 by Denis Diderot and Jean Lerond d'Alembert. The double page, folio size engraving on watermarked laid paper, titled 'Antiquites;, shows (fig. 1 and 2,) the Arch of Constantine, and (fig 3 and 4,). the Arch of Septimus Severus. The arches are shown on the right side as they would have looked when recently constructed, and on the left as ruins. Single fold, as issued. Excellent condition with very minor foxing. Plate size, approx. 13 7/8" x 17 1/2" Frame, approx 24" x 32 1/4".