Our wonderful, beautiful world is very large and very full; with more people and places and things in it than you can ever know about. The strange thing is, that our world must come to an end somewhere. Have you ever thought of that?

It was a great puzzle to learned men who lived long ago, and who did not know so much about some things as you may learn before the end of this lesson. They knew the world was not everywhere; that the sun and moon which shine above us are not part of the world, but are a great way off. So they said, Why do we never come to the end of the world? If we journey on over land and sea for years, surely we should come to the end then? And what is the end like? Should we fall off the edge, just as a cup might fall off the edge of a table?

At last it was discovered that people never came to the end of the world on account of its shape. There are certain things we use which you might run your finger along all day without ever coming to an edge.

Round things, such as balls or oranges have no edge, no end. And our world is round. It is more the shape of an orange than of a ball, because it is a little bit flat at what we may call the top and bottom.

Long before we traveled into space and could see the world from a distance, people were able to prove the world was round. The captain of a ship found out, that, by sailing on and on, and never turning back, he came at last to the very place he had started from. Try that plan on a straight table, and you will find that the farther you go, the farther you will be from your starting place. Try on a ball which you have first stuck a pin into for a mark. After you have moved your finger half way around the ball, the farther you go, the nearer you get to the pin, until at last you touch it, and have reached again the point you started from. As people now very often sail around the world in this way, we know that the world is round in one direction.

If you are on a hill or tower, so high that you can see over all the buildings near, and beyond them as far as the eye can reach, you will find that you are in the middle of a great circle or ring. Everywhere, all around you, the world and the sky seem to touch one another. It is not that they really do so; but the eye can see no farther, because the world, everywhere beyond this circle, dips down out of sight, as the sides of an orange might to a fly on the top. The place where the earth and sky seem to meet is called the horizon.

All over the world, wherever anybody stands so that he can have an unbroken view, he finds himself standing in the middle of such a circle.

That the surface of the world is every where rounded in this way is one proof that the world is round; or rather, that it is a sphere, a name given to objects which are round in every direction like a ball. Globe is another name given to objects of this shape.

As the world is rounded everywhere, this roundness hides very distant objects from view, as a hill might. Thus you may some times see the top of an object when its lower part is hidden by the round swell. The dome of Saint Paul's may be seen from a great distance; while the doors would be hidden by this rounding of the earth, even if there were no buildings between you and them. The best way to understand this is to stand on the sea-shore and watch a ship just coming into sight from below the horizon. The sea looks so flat, it is hard to believe there is any roundness there, and yet, something rises between you and the ship. Instead of seeing the whole of her, you see only the slight masts. The large heavy hull, the part which you would expect to show most clearly in the distance, is quite hidden from view. What hides it? The rounding of the waters. The sea, which covers part of the world's surface, has everywhere just the same curve or roundness as the land.

Notebook Work: Write the answers to the questions.

1. What is the shape of the world?

2. Give one reason for supposing that the world is round?

3. Does your reason prove that the world is round in every direction like a ball?

4. Why do we say the world is a sphere or globe?

5. List two ways that it is proved that the world is a sphere or a globe.

6. When nothing hides the view to a great distance, the land sinks out of sight all around us. We stand in the middle of a circle, where the world and sky seem to meet all around. What is this circle called?