In this case the movement is more rapid again, the measures being measures of an arithmetical progression. There is a crowding together of attractions in the direction of the convergence, and the movement is easier than it is in [Fig. 183], in spite of the fact that the lines of convergence are more broken in [Fig. 184]. There is an arithmetical diminution of horizontal as well as of vertical lines in [Fig. 184].
Fig. 185
In this case the measures of the rhythm are in the terms of a geometrical progression. The crowding together of attractions is still more rapid in this case and the distance to be traversed by the eye is shorter. The convergence, however, is less compelling, the lines of the convergence being so much broken—unnecessarily.
The movement will be very much retarded, if not prevented, by having the movement of the crowding and the movement of the convergence opposed.
Fig. 186
There is no doubt that in this example, which is to be compared with that of [Fig. 184], the upward movement is almost prevented. There are here two opposed movements: that of the convergence upward and that of a crowding together of attractions downward. The convergence is stronger, I think, though it must be remembered that it is probably easier for the eye to move up than down, other things being equal.
111. The movements in all of these cases may be enhanced by substituting for the straight lines shapes which are in themselves shapes of movement.
