To begin with, what does your geography say about deserts--about how they are made? How do mountains help make deserts? In and near what zone does your geography locate the great deserts of the world? How does the Sahara desert compare in size with the United States? (You see, the Sahara is practically a whole United States gone dry!) Yet, the soil of much of the Sahara is very fertile and with water would yield wonderful crops. But where is the water to come from? Where do we get the water that has made our deserts bloom? Has the Sahara any such sources of supply? Is it true that the Libyan desert was once covered by the sea, as it was in that story of Phaeton, the boy who set the world afire? And speaking of that story, was there a Jupiter and a Jupiter Pluvius, too?[33] [Footnote 33: "That was a good deal like asking if there was a George Washington and a President Washington too," said the High School Boy, after he had looked it up.] Wouldn't you say the addition of "Pluvius" to the name of their chief god meant the ancients recognized rain-making as a very important and difficult business to manage? But what is it, really, that brings our rains? What has the sea to do with it? And the winds? And the mountains? Your geography answers all these questions briefly. You will find a full treatment of the whole subject of the weather and of how the weather man, "the man with a hundred eyes," manages to be so clever, in "Pictured Knowledge."[34] [Footnote 34: In the article in the Nature Department, "What is the It that Rains?"] From what general direction do the winds come that bring the rains in North America? In South America? Why the difference? How many inches of rainfall are enough for raising good crops? Nevertheless, they raise fine crops in many parts of the United States where they have hardly any rain at all. How do they manage it? I mean how do they store up the water and distribute it, and everything? (Irrigation.) In reading up on deserts in the encyclopedias alone you will find many such interesting things as the following, and in other books--particularly books of travel--much more: How long the commercial caravans are (such great freight trains as those that cross the Sahara between Morocco and Timbuctoo); how many camels one driver takes care of; how fast the camels travel; how many days they can go without a drink. If you're going to cross with one of these caravans (or just pretend to cross) I must tell you one thing: _You've got to look out for lions!_ From what you have learned in your geography about African lions, where would you say you were likely to come across them?[35] [Footnote 35: Have you read Roosevelt's "African Game Trails"? or his "Life Histories of African Game Animals"?] What do these caravans bring back from Central Africa? (What is produced in Central Africa that the civilized world wants?)