Why does snow stay can the mountain tops?
In Georgia, a deep winter snowfall is rare. But in Canada, and some Of our northern states, the ground is covered with snow all through the winter. Frost and new snowfalls build a crusty layer that does not melt until the spring warms the air. But even at the equator, lofty mountains keep their snowcaps all through the year. The earth, as we know, is warmed by the beaming sun, and the top of a mountain is nearer to the sun than a deep valley. It is logical to suppose that a mountain top gets more heat than a valley, and you would think that the snow that falls upon it would soon melt and. Come gushing down the slopes. But the facts contradict this reasonable idea. Imagine a journey westward across the prairies in summer time. The scorching sun beats down, dusty whirlwinds dance among the sage and the air feels as hot as an oven. Suddenly you see a fluffy cloud bank on the western horizon. Soon, you hope, there will be some sheltering shade in the sky. But not at all. Those distant clou
