13. Does the Earth’s surface really rise to meet the sky? No: it really drops away, so that beyond a certain line we can no longer see it. CHAPTER II. WHY MEN DO NOT FALL OFF. We come now to a curious thought. The world is a round ball; and people live on all parts of it. Therefore, a man on the opposite side from us stands with his feet turned upwards towards our feet and his head pointing in the other direction--“hanging downwards, in short,” you might say. This seems extremely odd. Suppose you hold a big ball, and place a pea on the top of it. The pea will stay where you put it, if you keep your hand steady. But if you place the pea at the side or bottom of the ball it will instantly drop away. Try for yourself, and you will see. To be sure, a fly or a spider might stand with equal ease on the top or the bottom of the ball. The feet of a fly and a spider are made for clinging and walking in such a position. Man is not formed to stand or walk upside down, like a fly on the ceiling. Now, why don’t the people on the other side of the world, in Australia for instance, drop off the earth, and fall away into the sky? Of course there is a sky under our feet, just as much as over our heads. The entire world is surrounded on all sides by sky; not only over our heads, but down under our feet, beyond the solid Earth on which we stand, and in all directions. If you were to travel round the world, and were to reach Australia--then, as you stood on the ground, your feet would point upwards to the feet of people in the United States; just as two flies, standing on two opposite sides of a ball, have their feet pointed, those of one fly towards those of the other. It cannot help being so, because of the shape of our Earth. How do you think you would feel there? Do you think you would be in danger of dropping off the Earth into the blue sky? Not in the least. No more danger of such an accident in Australia than in America. Nothing indeed would astonish you more! Instead of being disposed to fall from the Earth, you would find it every inch as hard there as here to get away from the Earth. Your own weight would hold you fast to the ground in Australia just the same as in America. Try to jump up into the air, with all your strength. Try your very utmost; get as far away as you can from the ground, and stay up in the air as long as possible. Not much good; is it? Do what you will, you do not find that you can rise more than a foot or two, and you instantly drop back again. The most powerful leaper can manage at most only a few feet. A man is quite unable to stay up in the air at all, unless something holds him there: far less is he able to drop or float away into the sky.