Now for the Planets, or Worlds, which journey as our Earth journeys, round and round the Sun, each in its own particular pathway. And--to begin with--a few words as to what keeps them in their pathways. Two things working together do this. There is an inward pull, and there is also an outward pull. The inward pull is the pull of Attraction, known also as Gravitation. You have heard a little about Attraction before. You know how the Earth pulls, with a steady downward drag, everything upon her surface. And in just the very same manner the Sun pulls towards himself all the worlds, little or big, which float around him in the sky. When you try to jump up from the Earth you drop back. It is impossible for you to get right away, merely by jumping, because of the Earth’s strong pull. And if our Earth tries to get away from the Sun, she cannot do so either; because of the Sun’s strong pull. In fact she is always trying and never succeeds. She is always trying to get away because she is always on the rush; always hastening at a great speed, and struggling to go straight forward in her rush, while the pull of the Sun keeps drawing her out of a straight line and making her travel in a bent path round the Sun. If it were not for the Earth’s rapid onward movement she would soon fall down upon the Sun; and if it were not for the Sun’s pull she would soon wander away from him. These two things--the inward pull of the Sun’s attraction and the outward pull of our Earth’s own quick rush--keep her at her present distance from the Sun. It is the same with the other Planets. They too journey round the Sun in oval pathways. Those worlds which are nearer to him are pulled more strongly; and they have to fly along at a great speed, to escape from falling down upon his fiery surface. Those which are farther off are pulled more feebly; and they move at a much slower pace. When “attraction” is spoken of, remember that it is always a pull on both sides. The Earth attracts the Sun, as well as the Sun attracting the Earth; and all the Planets attract one another. But the pull of the Sun is so powerful that other pullings seem small by comparison. Our world is only one little planet in the great Kingdom of the Sun. That kingdom is commonly called “THE SOLAR SYSTEM.” A “system” means something which is arranged, or which is made up of different parts put together in an orderly manner. The word “solar” is from the Latin for “Sun.” So, by the Solar System we mean that great System or Arrangement of Worlds which is governed by the Sun. No two worlds are at the same distance from the Sun; but all the larger planets travel on very much the same _plane_--that is, on the same level, or the same _flat_, in the sky. Also, they all go the same way. They journey round the Sun from west to east; not from east to west.