Young Robert Adam encountered Giovani Piranesi when he studied aechitecture in Rome in 1754. It is said he found Piranesi's etchings "singular and clever". Adam was particularly drawn to the dark architectural images in Piranesi's fantasy prison series, the Carceri , which influenced his own later neo-classical architectural projects. When he and his brother were ready to publish their study, Works on Architecture (1778), they engaged several outside engravers to complete the project. Piranesi was commissioned to do two of the illustrations for the book.