'On the Divine Proportion' (1509), title page. This work on mathematics was by Italian mathematician Luca Pacioli (c.1447-1517). The title describes the subjects covered: philosophy, perspective, painting, sculpture, architecture, music and mathematics. This book was about mathematical proportions in these subjects such as the 'golden ratio', the divine proportion referred to in the title. The text also mentions the book's editor (Antonio Capella) and the Venetian printer and publisher Paganino Paganini. The book popularised geometry. It included artworks and diagrams by Pacioli's friend the artist and architect Leonardo da Vinci.