Prepared in connection with his lectures as Professor of Perspective at the Royal Academy, Turner’s diagram is based on an illustration from Samuel Cunn’s Euclid’s Elements of Geometry (London 1759, Book 12, Plate 2). It illustrates Proposition 17, Book 12: ‘Problem. To describe a solid polyhedron, in the greater of two spheres, having the same centre, which shall not touch the superficies of the lesser sphere’.1 There are sketches of the Proposition in Turner’s lecture notes.2
Blank, save for an inscription by an unknown hand in pencil ‘11’ bottom left.
Supported by The Samuel H. Kress Foundation