The wind moves over the land. It sways the tops of tall grass in meadows and sets leaves a-rustle in the woods. It scatters the smoke from chimneys. It lifts up limp flags and makes them flap. It touches your cheek with cool, quick fingers and impishly ruffles your hair. Wind is moving air. And it is the sun that makes air move.
The earth spins around like a big top. As it spins, each part of the earth, in turn, comes into the sunlight. The sun's light warms the earth. The heat makes the molecules of gas in the air move faster and spread apart. This warm air rises up, in a kind of big, invisible cloud. As the warm air rises, cooler air from other places flows in to replace the warm air. This moving, cooler air is the wind. When you feel the wind blow, you are feeling the movement of the cooler air pushing in to take the place of the warm air.
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