02 The World Is Round, for I've Been Round It

Did you ever run away from home?

I did—once upon a time—when I was younger than you are.

I wanted to see the World.

My Mother had told me the World was a huge ball and that if I kept on, straight ahead, following my nose, I would go round the ball and come back to where I started.

So early one morning, without telling any one, I set out to go around the World.

But I didn't get very far before night came on, and a big kind policeman brought me back home.

When I was grown up and had no home, I started out once again to go around the World. This time I got on a train headed toward the setting sun. Night came on, but no big, kind policeman brought me back home; so I kept on and on, day after day, week after week, month after month—sometimes on trains, sometimes on boats, sometimes in automobiles, sometimes on the backs of animals—but always toward the side of the World where the sun sets, the side which the people call “the west.”

I passed broad fields and thick forests, small towns and big cities—I went over bridges, round hills, and through holes in mountains—I reached a great ocean and sailed across it on a big ship to another continent—I came to strange lands where people dressed in strange clothes, lived in strange houses, and spoke strange languages; I saw strange animals, trees, and flowers; I crossed another great ocean and at last, after many, many months, always going in the same direction, I came back here to the exact spot from which I had started. So I knew the World was round, for I had been round it—but it was not round and smooth like a tennis ball, but humpety and bumpety, and so huge that it didn't seem like a ball at all.

It took me nearly half a year to go round the World—that seems like a long time, but then it was a long way—over twenty-five times a thousand miles. But others have been around the World in much faster time.The airship Graf Zeppelin flew around the World in three weeks. Two flyers took less than nine days to circle the globe in their airplane and return to their starting point, New York. An American Air Force plane flew around the World without stopping in less than four days.

If a man could start out when the sun rose in the morning and keep up with it all day long, go over the side of the World when the sun set, and keep up with it on the other side of the World, he would be back again where he started the next morning. He then would have gone round the World in one day. But to do that he would have to travel over 1, 000 miles an hour to keep up with the sun for each of the twenty-four hours in a day and night.

All around the outside of the World—as you probably know—is an ocean of air that covers everything on the World as the ocean of water covers everything in the sea. What you probably don't know is that this ocean of air is wrapped only round the World—it does not fill the sky. Men and animals live in this ocean of air as fish live in the ocean of water, and if a huge giant picked you out of the air you would die just as quickly as a fish does when taken out of the sea. The air is thick near the ground but gets thin and thinner the higher up you go off the ground. That's why airplanes can go up but a few miles high—there is not enough air to hold up the plane, for the plane must have air to rest on and for its propeller to push against, just as a boat in the water must have water to rest on and water for its propeller to push against. Or if it's a jet plane, it must have air to feed its jet motors. An airplane could not rise beyond the ocean of air and sail off into the sky where there is no air any more than a steamship on the sea could rise out of the water and sail off up into the air.

There is only one thing that men can send up high enough to travel above the ocean of air. That is a rocket, which doesn't depend on air for its motor or to hold it up. Someday rocket ships will probably carry men on trips to the Moon or even to the planet Mars. How would you like to go exploring in a rocket ship beyond the World's atmosphere out through empty, airless space? How would you like to be the first Man in the Moon? You wouldn't find any living thing on the Moon, for the Moon is a dead, lifeless ball without any air on it at all. But if your rocket got to Mars you would almost certainly find some living plants—and perhaps, who knows? —even some living animals.

Some mountains are so high that their tops almost stick out of the ocean of air; at least, there is so little air covering their tops that people can't go all the way to the top unless they take along canned air to breathe.

You can't see air—you may think you can, but what you see is smoke or clouds, not air. When air is moving, we call it wind. Then you can feel it when it blows your hat off, you can hear it when it bangs the shutters and whistles round the house; but no one has ever seen air itself.

The World wasn't always as it is now. It was once a ball of fire—a huge burning ball. That was millions of years ago, and of course long before there were any people or animals or plants on the World. But the fiery ball got cooler and cooler until it was no longer burning but a hot ball of rock. There were then no oceans, no water on the World, for water won't stay on anything very hot—it won't stay on a hot stove—it turns to steam when there is fire under it; so there were only clouds of steam, an ocean of steam, around the World. But the World kept getting cooler and cooler until at last the steam turned to water and fell on the World—rain, rain, rain, until there perhaps was one big ocean covering the whole World.

But the World still kept on cooling and cooling, and as it cooled it shrank and shriveled and wrinkled and crinkled and puckered like the outside of a prune. You know a prune was once smooth and round when it was a plum. These little wrinkles and crinkles rose up out of the ocean and were the continents and mountains, so you see how big the wrinkles and crinkles really are. The earth is still wrinkling a bit even now, and when it does so it shivers and shakes and we say there has been an earthquake. But the earthquakes nowadays are as nothing to what may have been the tremendous shudder when the continents rose out of the first single ocean. The thunderous roar of that quake may have reached the stars with a stupendous and appalling boom of a bursting, cracking, rending, groaning World, as if the last day had come. Don't you know what stupendous and appalling boom means? Why, it means “stupendous and appalling boom.” But that's all guess-for the continents may have risen out of the sea as softly, slowly, silently as a blade of grass grows out of the ground. No one knows. We only know the continents did rise out of the water-we can find seashells on the tops of high mountains, and we know they could only have been made under the water when the mountain was under the water.