Motion.
But when you slant the AB lines they suggest motion (Figs. 224, 225, and 226).
Fig. 244.
Although the pyramid is the emblem of stability, when resting upon its base—with the AB line dividing it in the centre—if you take the same form and point the apex in any other direction it immediately suggests motion, as in Figs. 227, 228, and 229.
Fig. 245.
Not only does it suggest motion, but it tells the direction of the movement suggested. Any child can tell in which direction the arrow and the ducks are flying.
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