A drawing of a nude man seen to below the waist, turned in profile to the left. His head is more finished and squared for proportion. There is also a note on the proportions of the head. To the right is a full-length figure of a nude man standing in profile to the left, and in the lower left corner is a seated child, of which only the head is clearly visible. During the 1480s Leonardo became increasingly interested in the scientific basis of painting. He planned to write a treatise on the subject, and for the rest of his life he compiled material on the theory of light and colour, the principles of anatomy and so on. Here Leonardo attempts to codify the proportions of the face. The eye is at the mid-point of the head, and the face is divided into three equal sections, from the base of the chin to the base of the nose, thence to the brow, and thence to the hairline. But the practical difficulties that an artist would have encountered in making use of such principles cannot have been lost on Leonardo, and he soon abandoned his proportional studies. Text adapted from Leonardo da Vinci: A life in drawing, London, 2018