'Dark Prison (Carcere Oscura)', 1790?99, Watercolor over graphite, Sheet: 14 3/16 x 9 1/4 in. (36 x 23.5 cm), Drawings, Joseph Mallord William Turner (British, London 1775?1851 London), After Giovanni Battista Piranesi (Italian, Mogliano Veneto 1720?