27. Directions balance when they are opposite.

[Illustration: Fig. 20]

The opposite directions, right and left, balance on the point from

which they are taken.

28. Equal distances in opposite directions balance on the point from

which the directions are taken.

[Illustration: Fig. 21]

The equal distances AB and AC, taken in the directions AB and AC

respectively, balance on the point “A” from which the directions are

taken.

29. Two directions balance when, taken from any point, they diverge at

equal angles from any axis, vertical, horizontal, or diagonal.

[Illustration: Fig. 22]

The directions AB and AC balance on the vertical axis AD from which

they diverge equally, that is to say, at equal angles.

30. Equal distances balance in directions which diverge equally from a

given axis.

[Illustration: Fig. 23]

The equal distances AB and AC balance in the directions AB and AC which

diverge equally from the axis AD, making the equal angles CAD and DAB.

Both directions and distances balance on the vertical axis AD.

31. The positions B and C in Fig. 23, depending on balancing directions

and distances, balance on the same axis. We should feel this balance of

the positions A and B on the vertical axis even without any indication

of the axis. We have so definite an image of the vertical axis that

when it is not drawn we imagine it.

[Illustration: Fig. 24]

In this case the two positions C and B cannot be said to balance,

because there is no suggestion, no indication, and no visual image of

any axis. It is only the vertical axis which will be imagined when not

drawn.

32. Perfect verticality in relations of position suggests stability

and balance. The relation of positions C-B in Fig. 24 is one of

instability.

[Illustration: Fig. 25]

These two positions are felt to balance because they lie in a perfectly

vertical relation, which is a relation of stability. Horizontality in

relations, of position is also a relation of stability. See Fig. 28, p.

21.

33. All these considerations lead us to the definition of Symmetry.

By Symmetry I mean opposite directions or inclinations, opposite and

equal distances, opposite positions, and in those positions equal,

corresponding, and opposed attractions on a vertical axis. Briefly,

Symmetry is right and left balance on a vertical axis. This axis will

be imagined when not drawn. In Symmetry we have a balance which is

perfectly obvious and instinctively felt by everybody. All other forms

of Balance are comparatively obscure. Some of them may be described as

occult.

[Illustration: Fig. 26]

In this case we have a symmetry of positions which means opposite

directions, opposite and equal distances, and similar and opposite

attractions in those positions. The attractions are black dots

corresponding in tone, measure, and shape.

[Illustration: Fig. 27]

In this case we have a balance of positions (directions and distances)

and attractions in those positions, not only on the vertical axis

but on a center. That means Symmetry regarding the vertical axis,

Balance regarding the center. If we turn the figure, slightly, from

the vertical axis, we shall still have Balance upon a center and axial

Balance; but Symmetry, which depends upon the vertical axis, will be

lost.

34. The central vertical axis of the whole composition should

predominate in symmetrical balances.

[Illustration: Fig. 28]

In this case we do not feel the balance of attractions clearly or

satisfactorily, because the vertical axis of the whole arrangement

does not predominate sufficiently over the six axes of adjacent

attractions. It is necessary, in order that symmetrical balance shall

be instinctively felt, that the central vertical axis predominate.

[Illustration: Fig. 29]

The central vertical axis is clearly indicated in this case.

[Illustration: Fig. 30]

Here, also, the central vertical axis is clearly indicated.

35. All relations of position (directions, distances, intervals), as

indicated by dots or points, whether orderly or not, being inverted on

the vertical axis, give us an obvious symmetrical balance.

[Illustration: Fig. 31]

This is a relation of positions to be inverted.

[Illustration: Fig. 32]

Here the same relation is repeated, with its inversion to the right on

a vertical axis. The result is an obvious symmetrical balance. If this

inversion were made on any other than the vertical axis, the result

would be Balance but not Symmetry. The balance would still be axial,

but the axis, not being vertical, the balance would not be symmetrical.

36. In the case of any unsymmetrical arrangement of dots, the dots

become equal attractions in the field of vision, provided they are

near enough together to be seen together. To be satisfactorily seen

as a single composition or group they ought to lie, all of them,

within a visual angle of thirty degrees. We may, within these limits,

disregard the fact that visual attractions lose their force as

they are removed from the center of the field of vision. As equal

attractions in the field of vision, the dots in any unsymmetrical

arrangement may be brought into a balance by weighing the several

attractions and indicating what I might call the center of equilibrium.

This is best done by means of a symmetrical inclosure or frame. In

ascertaining just where the center is, in any case, we depend upon

visual sensitiveness or visual feeling, guided by an understanding

of the principle of balance: that equal attractions, tensions or

pulls, balance at equal distances from a given center, that unequal

attractions balance at distances inversely proportional to them. Given

certain attractions, to find the center, we weigh the attractions

together in the field of vision and observe the position of the

center. In simple cases we may be able to prove or disprove our visual

feeling by calculations and reasoning. In cases, however, where the

attractions vary in their tones, measures, and shapes, and where there

are qualities as well as quantities to be considered, calculations and

reasoning become difficult if not impossible, and we have to depend

upon visual sensitiveness. All balances of positions, as indicated by

dots corresponding in tone, measure, and shape, are balances of equal

attractions, and the calculation to find the center is a very simple

one.

[Illustration: Fig. 33]

Here, for example, the several attractions, corresponding and equal,

lie well within the field of vision. The method followed to balance

them is that which I have just described. The center of equilibrium

was found and then indicated by a symmetrical framing. Move the frame

up or down, right or left, and the center of the frame and the center

of the attractions within it will no longer coincide, and the balance

will be lost. We might say of this arrangement that it is a Harmony

of Positions due to the coincidence of two centers, the center of the

attractions and the center of the framing.

37. It will be observed that the force of the symmetrical inclosure

should be sufficient to overpower any suggestion of movement which may

lie in the attractions inclosed by it.

[Illustration: Fig. 34]

In this case the dots and the inclosure are about equally attractive.

[Illustration: Fig. 35]

In this case the force of attractions in the symmetrical outline is

sufficient to overpower any suggestion of instability and movement

which may lie in the attractions inclosed by it.

There is another form of Balance, the Balance of Inclinations, but I

will defer its consideration until I can illustrate the idea by lines.

A theory of pure design · 第 34 / 156 题