While the through-measure of the Earth is eight thousand miles that of the Moon is only a little more than two thousand miles. And while the Earth is nearly twenty-five thousand miles round outside, the Moon is only about six thousand miles. So if we could put a knitting-needle straight through the Moon, with the ends just showing, one on each side, it would need to be only a quarter as long as a needle to go through the Earth. And a ribbon to fold round the Moon should be scarcely a quarter as long as a ribbon which could be folded just round the Earth. This makes a good deal of difference in the sizes of the two globes; perhaps more than you would suppose. I want you now to bring down the Moon, in your mind, to the size of a very small ball; only _one inch_ through or _three inches_ round outside. Picture her to yourself as getting smaller--and smaller--and smaller, till she is only the size of a very big grape. Then think of the Earth also, as getting smaller and smaller, just in the same way. Only the Earth must not get so small as the little Moon, in your mind. It must still be four times as long in its through-measure--four inches instead of one inch. And while a little piece of tape, only three inches long, would go just round the tiny Moon, a tape to go round the little Earth would have to be twelve inches long. Then, if the Moon is about the size of a big grape, or a small walnut, the Earth will be the size of a very large apple, or of a small cocoa-nut. It would be a good plan to get a walnut and cocoa-nut of the right sizes, or, if you like, to find two balls, and to place them side by side. The little one must be one inch through, the bigger one must be four inches through. Looking upon them, you will see in a moment how great is the difference between the Earth and the Moon. I shall often speak of these sizes, so it would be as well to fix them now in your mind, and have them there, ready for use. Now as to the distance of the Moon from the Earth: It is about _two hundred and forty thousand miles_! A rope twenty-five thousand miles long would reach once round the whole Earth, if laid down on the equator. But a rope to reach all the way from our Earth to the Moon would have to be more than nine times as long as the equator-rope. You have tried to picture the Earth in your mind as brought down to the size of a small cocoa-nut, and the Moon as brought down to a walnut. In doing this we make one little half-inch do duty for a thousand miles; so that one inch stands for two thousand miles, and four inches means eight thousand miles. The Moon is two thousand miles through; therefore a ball or walnut, to picture the Moon, must be one inch through. The Earth is eight thousand miles through; therefore a very big apple or small cocoa-nut, to picture the Earth, must be four inches through.