Figure 6. Leonardo da Vinci, Sketches of the Moon, detail Codex Atlanticus, fol. 310r, 1505–1508, brown ink on paper. Biblioteca Ambrosiana, Milan. Veneranda Biblioteca Ambrosiana, Milan, Italy © Veneranda Biblioteca Ambrosiana/Metis e Mida Informatica/Mondadori Portfolio/Bridgman Images.