OCR Text |
Show Sahara's Immensity In Africa are natural wonders which almost challenge belief. The Sahara, a vast waste of rock, gravel and sand, is so big it would hold the entire continental United States. The reason it Is a desert at all Is. simply stated, that the wind blows In the wrong direction down from the dry heart of Central Asia Instead of from the moisture-giving ocean. The temperature changes so sharply at nightfall that travelers who have suffered In the blazing hent find themselves shivering under blankets. This Immense area of desolation served as a highly effective shield which long protected Central Africa from overland exploration from the north. Gilbert Grosvenor In the National Na-tional Geographic Magazine. |