We must now draw the jaw; we will also pause a little to study it, in order to understand its particular construction, which is conditioned by the position and the foreshortening of the face. For this purpose, we will first try to study the simplified jaw, or better yet, this mobile bone called the lower maxilla (mandible). Let us return to the skeleton:

To continue with the general construction, immediately draw the perspective circle R, which will surround the curved shape of the jaw and will be parallel to the circle above it. If you recall, the position of these two circles determines the placement of the eyebrows and the length of the nose; at the same time, they also give us the height and position of the ears.

Note on this same figure the way the ear is framed by a rectangle drawn in perspective, whose verticals are parallel to the axis line A. At the same time, in the middle of the lower module, draw the small curve that indicates the position of the mouth. Remember that this curve is none other than the line mentioned in figure no. 8 when we studied the canon. Its placement gives us the profile of the lower lip (fig. 29).

All these elements give us the base structure, since we have placed the division lines of the canon in perspective and we are now ready to carefully draw the different parts of the face in their proper proportions: eyebrows, eyes, nose, mouth… and I won’t mention the ears, since we have already placed them.

The eyebrows: we place them on the central circle line of the sphere. There is no problem with this; we will see them in more detail later on the following pages that illustrate the drawings.

Let’s move on to the eyes, where the difficulties are certainly greater. Let’s see:

We know that the eyes are located at the exact center of the head (exactly at half its height); but we must now see their position in relation to the ears and the nose, when the head is looking up or down. Indeed, we must consider that because of foreshortening, and because the eyes lie on a different plane than the eyebrows… But let’s take things step by step.

Also remember that when the head is tilted downward, the depression or concavity where the eyes are located causes them to appear under the eyebrows, almost hidden by them; one can barely see, or only with difficulty, the upper orbital plane — that is, the distance that exists between the eyebrows and the eyelids (fig. 31, following page).

On the contrary, when the head is raised, for the same reasons of perspective and foreshortening, this orbital plane appears almost frontal and the eyes are clearly lower than the eyebrows (fig. 32, following page).

(Observe also, in these figures 31 and 32, the changes produced by the same cause on the shape of the nose, the mouth, the cheekbones and the cheeks, etc., whose dimensions vary noticeably depending on whether the head is looking more or less upward or downward.)

We can now move on to the construction of the nose, which is relatively easy to sketch, as the text and the following illustrations indicate:

Finally, there remains the placement of the mouth, the birth of the hair, the temples, the sideburns, etc. See the placement of these elements on the drawings on page 22, figure 33, which shows you the completed construction of several heads in different positions, summarizing everything that has been studied during the process.

Here we consider the study of the human head from the point of view of general construction to be complete, without having gone into the details. The second part of the book will be devoted to the study of these details.

Allow me beforehand to give you a final piece of advice on the construction of the human head, as we have studied it so far:

Always draw “thinking of the other ear.”

When you draw a head in profile, in three-quarters view, or in any case where you can only see one ear, draw while thinking of the other, invisible one. This other ear should be for you like the symbol of the entire part of the face that remains hidden from your view.

“Thinking of the other ear” means drawing at the same time the two ears, the two eyes, the two cheekbones, the entire shape of the lower jaw… as if you were drawing a transparent head. And, without going so far as to actually draw these elements on the other side, remember that they are there, “precisely there, at the same level as the other ear, the other eye, the other cheekbone”…