The proportions of the head, and a standing nude
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.
Leonardo's early proportional studies distinguish between the face (from the chin to the hairline) and the head as units of measurement. Here Leonardo placed the eye at the mid-point of the head, and divided the face into three equal sections, with divisions at the brow and the base of the nose. The drawing also demonstrates the belief that the head from front to back is equal to the height of the face, and thus a square is drawn over the profile.
Text adapted from 'Leonardo da Vinci: the Divine and the Grotesque'