For this is the difference between nature and the machine:  nature never produces two things alike, the machine never produces two things different.  Man could solve the social problem to-morrow if you could produce him equal units.  But if all men were alike and equal, where would be the life and fun of existence? it would depart with the variety.  And in proportion, as in life, variety is the secret of vitality, only to be suppressed where a static effect is wanted.  In architecture equality of proportion is more often met with, as the static qualities of repose are of more importance here than in painting.  One meets it on all fine buildings in such things as rows of columns and windows of equal size and distances apart, or the continual repetition of the same forms in mouldings, &c.  But even here, in the best work, some variety is allowed to keep the effect from being quite dead, the columns on the outside of a Greek pediment being nearer together and leaning slightly inwards, and the repeated forms of windows, columns, and mouldings being infinitely varied in themselves.  But although you often find repetitions of the same forms equidistant in architecture, it is seldom that equality of proportion is observable in the main distribution of the large masses.

Let us take our simple type of composition, and in Diagram XXVIII, A, put the horizon across the centre and an upright post cutting it in the middle of the picture.  And let us introduce two spots that may indicate the position of birds in the upper spaces on either side of this.

Here we have a maximum of equality and the deadest and most static of results.

To see these diagrams properly it is necessary to cover over with some pieces of notepaper all but the one being considered, as they affect each other when seen together, and the quality of their proportion is not so readily observed.

[Illustration:  Plate XLVIII.

THE ANSIDEI MADONNA.  BY RAPHAEL (NATIONAL GALLERY)

A typical example of static balance in composition.

Photo Hanfstaengl]

In many pictures of the Madonna, when a hush and reverence are desired rather than exuberant life, the figure is put in the centre of the canvas, equality of proportion existing between the spaces on either side of her.  But having got the repose this centralisation gives, everything is done to conceal this equality, and variety in the contours on either side, and in any figures there may be, is carefully sought.  Raphael’s “Ansidei Madonna,” in the National Gallery, is an instance of this (p. 230).  You have first the centralisation of the figure of the Madonna with the throne on which she sits, exactly in the middle of the picture.  Not only is the throne in the centre of the picture, but its width is exactly that of the spaces on either side of it, giving us three equal proportions across the picture.  Then you