Perhaps Piranesi’s greatest work, in both size and importance, is _Le Antichità Romane_, in four volumes, containing a varying number of plates from 216–224. This was first issued in 1756. In 1761, he etched four plates for Robert Adam illustrating the latter’s design for Sion House, and in 1769 he published his _Diverse Maniere d’Adornare_, in which appear the ornate but very stimulating designs for chimneypieces, referred to above. Of his remaining works, perhaps the most important to architects is the _Vasi Candelabri Cippi Sarcofagi Tripodi Lucerne ed ornamenti Antichi_, to give it its full title, which was published in Rome in 1778--the year of his death. This contains a series of magnificent drawings of antiques, largely from his own collection. A great number of these drawings are dedicated to various English gentlemen, each described as “a lover of the fine arts,” which is proof of the interest Englishmen were already taking in Piranesi and his work. In addition to the foregoing, Piranesi published a number of monographs on special subjects illustrated with etchings. Among these are the volumes on Trajan’s Column, the Theatre at Herculaneum, Hadrian’s Villa, and the Temples at Pæstum, all of which are more noticeable for the boldness of the draughtsmanship than for the archæological views they set forth. It must not be imagined, however, because Piranesi was the interpreter of the romance of the Roman ruins, and through this very romance fired the imagination of Europe, that he was not when he liked an exact draughtsman. The cracks on the obelisk shown in the foreground of his etching of Santa Maria Maggiore tally with those shown in a photograph taken one hundred and fifty years later. In April, 1757, Piranesi was elected an honorary Fellow of the Society of Antiquaries, which is another proof of the esteem in which he was held in England. He was knighted by Pope Clement XIII. in 1767. He died in 1778, and is buried in the church of Santa Maria Aventina.