Fig. 222
It is not necessary that the changes in the width of the line be abrupt, as in the examples just given. The width of the line may increase or diminish gradually, in which case we may have, not only accents in the line, but movements due to gradations of dimension, to convergences, or to an increase or gradual crowding together of attractions in a series of visual angles.
Fig. 223
In this case we have a gradual increase followed by a diminution of the width of the line in certain parts, and these changes occur at equal intervals. A certain amount of rhythmic movement is given to the progression by such accents, provided the direction of movement is unmistakable, which it is not in this case. It is not at all clear whether the movement is down-to-the-right or up-to-the-left. It seems to me about as easy to move in one direction as in the other.
Fig. 224
In this case there is less doubt about the movement. It seems to be down-to-the-right. The eye is pulled through an increase of width-measures toward a greater extension and crowding together of contrasting edges.
Fig. 225