Proportions of the Head in Profile.
The mass of the head being found, as seen in plate 10, fig. 2, what remains is to divide the head and locate the positions of the organs. We will proceed in the following manner:
We assume here, plate 11, fig. 1, an upright head. From point C, the lower end of the operation line, a horizontal line is drawn from right to left, and from point G, the upper end of the operation line, a second horizontal line, parallel to the first, is drawn. Between these two lines, from A to B, a vertical line is drawn that will serve as a scale of proportions for the entire head.
The height of the head is divided into four equal parts: namely, one part or a quarter, from the base of the chin to below the nose; a second part, a quarter, for the height of the nose; a third part, from the top of the nose to the beginning of the hair; then a fourth part, for the top of the head.
The greatest width of a head viewed in profile, taken above the eyebrow, is equal, as we have already seen, to the height minus an eighth. Here, (fig. 1st) the width MN is equal to seven-eighths (or three and a half quarters), of AB, or of CG.
Returning to the height. The vertical line, represented by AB, is divided into four equal parts; then, from each division represented here by 1, 2, 3, horizontal lines are drawn parallel to AB, until they meet the operation line CG, and on this line are the points dc, ef, gj which divide the head into four equal parts*. The other operation lines that indicate the position of the mouth, the underside of the nose, and the position of the ear, and finally the eye, must make a right angle across, parallel to the operation line. These lines are known as operation lines.
From the point represented here by d, a horizontal line is drawn, upon which the nose must be positioned. The width of a nose in profile is equal to half its height. The height of the nose represented here by de is divided into two equal parts, then this part being newly divided into two, half is placed on the line destined to receive the underside of the nose, half on either side of the point represented by e, fg, width of the nose, therefore, equals half of de, its height. It often happens that there are two smaller thirds of the nose's width beyond the operation line and the larger third within, that is to say, de would be the two smaller thirds of bg, and de the larger third, but altogether bg would always be half of de, height of the nose.
The line represented here by ah, which marks the opening of the mouth, is placed, starting from the nose, at the small third of the distance found from the nose to the chin. When the mouth is found at the exact third of the distance represented by Cd, the distance is too large and produces an unpleasant effect. When it is a quarter, the distance is too short.
The width of the mouth is equal to the distance found from the underside of the nose to the opening of the mouth. Thus it is equal to de. The height of the eye is usually on level with the top of the nose. You see here that the top of the eye comes to touch the operation line aF. There are heads, though unfortunately, whose eyes are placed higher or lower. The distance from the operation line to the eye equals three-quarters of the width of the nose: thus ej is equal to three-quarters of fg. The diameter of the eye globe is equal to half the width of the nose: thus j/l is equal to half of bg.
The ear is always located along the continuation of the line below the nose. The distance found from the tip of the nose to the start of the ear is equal to two parts or half the height of the head. The line represented by bg is extended, upon which a dimension equal to Ce is taken. The height of the ear is always the same as the height of the nose. The ear is tilted like the nose, so the line DF is parallel to de. The greatest width of the ear equals the larger half of its height. To draw the ear, it is supposed inscribed in a square. Thus, for example, on the extension of the line represented by eI, a dimension eD equal to ÐD is taken. The line DF equal to be is drawn, always on the extension of eF, and FK equal to the larger half of DF is given, making the square DFKM intended to receive the ear.
* When you are familiar with these proportions, you divide the operation line into four straight away, without establishing a scale.
Translation Notes:
- "Ligne d'opération" is translated as "operation line." It is a term used in drawing to refer to a guideline or structural line used to determine proportions and placements.