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 represents Proposition 16 from Book 12: ‘Problem. Two circles being about the same centre, to inscribe in the greater a polygon of equal sides, even in number, that shall not touch the lesser circle’.1 There are sketches of the Proposition in Turner’s lecture notes.2
Blank, save for an inscription by an unknown hand in pencil ‘27’ bottom left.
Supported by The Samuel H. Kress Foundation