The hollow of the cheek bone occurs half way between the tip of the nose and the top of the jaw bone, which is the lower angle of the setting on of the ear, in the frame here represented.

From the angle of the eye-socket to the ear is as far as the length of the ear, or the third of the face.

[Footnote:  See Pl.  IX.  The text, in the original is written behind the head.  The handwriting would seem to indicate a date earlier than 1480.  On the same leaf there is a drawing in red chalk of two horsemen of which only a portion of the upper figure is here visible.  The whole leaf measures 22 1/2 centimetres wide by 29 long, and is numbered 127 in the top right-hand corner.]

316.

From a to b—­that is to say from the roots of the hair in front to the top of the head—­ought to be equal to c d;—­that is from the bottom of the nose to the meeting of the lips in the middle of the mouth.  From the inner corner of the eye m to the top of the head a is as far as from m down to the chin s. s c f b are all at equal distances from each other.

[Footnote:  The drawing in silver-point on bluish tinted paper—­Pl.  X—­which belongs to this chapter has been partly drawn over in ink by Leonardo himself.]

317.

From the top of the head to the bottom of the chin is 1/9, and from the roots of the hair to the chin is 1/9 of the distance from the roots of the hair to the ground.  The greatest width of the face is equal to the space between the mouth and the roots of the hair and is 1/12 of the whole height.  From the top of the ear to the top of the head is equal to the distance from the bottom of the chin to the lachrymatory duct of the eye; and also equal to the distance from the angle of the chin to that of the jaw; that is the 1/16 of the whole.  The small cartilage which projects over the opening of the ear towards the nose is half-way between the nape and the eyebrow; the thickness of the neck in profile is equal to the space between the chin and the eyes, and to the space between the chin and the jaw, and it is 1/18 of the height of the man.

318.

a b, c d, e f, g h, i k are equal to each other in size excepting that d f is accidental.

[Footnote:  See Pl.  XI.]

Proportions of the head seen in front (319-321).

319.

a n o f are equal to the mouth.

a c and a f are equal to the space between one eye and the other.

n m o f q r are equal to half the width of the eye lids, that is from the inner [lachrymatory] corner of the eye to its outer corner; and in like manner the division between the chin and the mouth; and in the same way the narrowest part of the nose between the eyes.  And these spaces, each in itself, is the 19th part of the head, n o is equal to the length of the eye or of the space between the eyes.