On the left is Leonardo's familiar Vitruvian man, drawn from the proportions specified by the Roman architect Vitruvius in his book on architecture. The image is endlessly reproduced, yet few people know what it means.
Vitruvius said that the proportions of a building should correspond to those of a person, and laid down what he considered to be the relative measurements of an ideal human. This is not just on the mundane level of the size of doors and the height of chairs, but has to do with the effect of the building on the human mind. Similarly in art, the proportions of the human body in a statue or painting have a direct effect on the mind.
We know nothing about the Greek canon of proportion except by guesswork from their surviving works of art and from Vitruvius, assuming the Roman canon was based on that of the Greeks.
I shall have some more to say about this later. For now, here is a sketch I have done relating the proportions of the second Egyptian canon to those of Vitruvius. The woman is drawn using the Vitruvian canon and the scale at the left shows how this varies from the Egyptian system which was based on the number 22. I believe other Egyptian systems were based on the numbers 9 and 18.
According to accepted artistic convention, dating from the Greek Classical period, the head of a god or goddess is represented as 1/8 of the total height, whereas the head of a man is 1/7 and the head of a woman is 1/6.5-1/7 of the total height.
To Human Proportions II: child proportions
Image of female proportions copyright 2002 Martin Dace