as Fig. 5, this pervades the whole record. Here the hand moves to and fro, keeping time—not accurately at all, but in a general way—with the strokes of the metronome.
To obtain similar results for a visual impression, a silently swinging pendulum is used, the subject watching the oscillations and counting them. The result is more frequently a movement toward the pendulum, Fig. 6, but occasionally there appear periodic movements
in maintaining a concentrated attention; moreover, the position of the subject may not be suited to a ready movement in the direction of the hidden object.
A further interesting mode of concentrating the attention con-