Fig. 47
Comparing this Rhythm with the Rhythm of [Fig. 43], the reader will appreciate the force of a diminution of scale in connection with a diminution of intervals.
47. Seventh. Unstable groups may be repeated in progressions of intervals, in which case the movement in the group is conveyed to the whole series, in which there will be, also, the movement of a gradual increase of attractions from one angle of vision to another. In all such cases contrary motion should be avoided if the object is Rhythm. The several movements should have a harmony of direction.
Fig. 48
In this case the movement in the group is felt throughout the series, and the force of the movement is enhanced by the force of a gradual increase of attractions from one visual angle to another, in the same direction, to the right. By reversing the direction of increasing attractions and so getting the two movements into contrary motion, the feeling of rhythm would be much diminished. Such contrary motions are unsatisfactory unless Balance can be achieved. In that case all sense of movement and of rhythm disappears.
48. Eighth. Unstable groups may be repeated, not only in a gradation of intervals, but in a gradation of scale, in which case we have a combination of three causes of movement: lack of stability in the group repeated, a gradual increase in the number of attractions in the sequence of visual angles, and a crowding or convergence of the attractions. Rhythms of this type will not be satisfactory unless the three movements have the same direction.
Fig. 49
Here we have the repetition of an unstable group of attractions in a progression of scale and also of intervals. The arrangement gives us three elements of movement, all in the same direction.