Now it is perfectly logical for us to infer that the canoe is already homeward bound, when we see it coming toward us in scene "c" immediately after the drum has sounded the alarm, and we can therefore only resent being caught in error and virtually told, two scenes later, "This time we won't fool you, now the canoe, as you see, is really turning about."
If one moving object can send our thoughts ahead to the goal of its travel, two or more objects moving toward the same point can send our thoughts there with greatly increased force. Thus a picture of two ships shown approaching each other on converging courses will surely make us think of that region of the sea where they are likely to come close aboard each other. If there is an enemy submarine at that point and if the two vessels are destroyers, the suspense and emphasis is complete.
A similar law of attention may be seen at work in cases where lines move along their length to a junction. Suppose we take as a setting a western landscape in which two swiftly flowing streams meet and form the figure of a "Y." Suppose now that we desire to place an Indian camp in this setting so carefully that it will attract attention as soon as the picture is flashed on the screen. We must place it at the junction of the two streams, because the eyes of the spectators will naturally be drawn to that point. Now suppose that a long white road crosses the main stream just below the place where the tributaries meet. The position would be emphasized more than ever because the road would virtually form two fixed lines leading toward the bridge; and fixed lines, as we saw
