The text discusses the geometric proportions of the face and head, using four outlined skull diagrams to illustrate consistency in structure. It explains the use of ovals and lines to achieve these proportions, emphasizing symmetry in drawing facial features. Techniques are offered for maintaining consistent proportions across different views.
The First Part
XIII
Having already spoken quite a bit about the youth's measurement, and proportion of the face and head, you will see represented here four skulls, fully revealed, which I described earlier, regarding the eyes, so you may see the root of the nose, maintaining the same proportion of my fifth problem, indicated by the letter B. Therefore, to create the first head, you must draw an oval divided into two equal parts by a line A B, and then into three by the letters C, A, D, E, A, F, G for the chin. If you wish to find the opening of the mouth, and the place of the teeth, and also the hollow of the eyes, draw a line from K to H, and from I to K, which lines form a proper triangle, for understanding that the skulls hold the same proportion, and vary only in view and appearance, and by the number A you will find such a face backwards, as I have demonstrated in my fifth problem.
Furthermore, we will go on to explain the previous proportions and positions in detail. This involves understanding the exact shapes and contours of the human head as observed from different angles, maintaining symmetry and balance in the facial features. Each head demonstrates consistency in structural proportions as shown in the fifth problem, and the techniques described provide the necessary geometric guidelines for achieving this.
Translation Notes: The text discusses measuring and drawing human heads with geometric precision, using ovals and triangles as guidelines. It places emphasis on understanding and maintaining proportions across different perspectives.