Of course, in old times the sun was thought to be really taking this journey among the stars, and men talked of “the sun’s path” in the heavens. This path was named “the Ecliptic,” and we use the word still, though we know well that the movements are not really his, but ours. As the earth’s daily movement causes day and night, so the earth’s yearly movement causes spring, summer, autumn, and winter. A few pages back I mentioned, in passing, one slight yet important fact which lies at the root of this matter about the seasons. The earth, journeying round the sun, travels with her axis _slanting_. Put your candle in the middle of the table, and stand at one end, holding your orange. Now let the knitting-needle, with the orange upon it, so slant that one end shall point straight over the candle, towards the upper part of the wall at the farther end of the room. Call the upper end so pointing the North Pole of your orange. You will see that the candle-light falls chiefly upon the upper half of the orange; and as you turn it slowly, to picture day and night, you will find that the North Pole has no night, and the South Pole has no day. That is summer in the northern hemisphere, and winter in the southern. Walk round next to one side of the table, towards the right hand, taking care to let the knitting-needle point steadily still in exactly the same direction, not towards the same _spot_, for that would alter its direction as you move, but towards the same _wall_. Stop, and you will find the candle lighting up one-half of your orange, from the North to the South Poles. Turn it slowly, never altering the slope of the axis, and you will see that every part of the orange comes by turns under the light. This is the Autumnal Equinox, when days and nights all over the world are equal in length. Walk on to the other end of the table, still letting the needle slope and point steadily as before. Now the candle-light will shine upon the lower or South Pole, and the North Pole will be entirely in the shade. This is summer in the southern hemisphere, and winter in the northern. Pass on to the fourth side of the table, and once more you will find it, as at the second side, equal light from North Pole to South Pole. This will be the Spring Equinox. It is an illustration that may be easily practiced. But everything depends upon keeping the slant of the needle or axis unchanged throughout. If it be allowed to point first to right, and then to left, first towards the ceiling, and then towards the wall, the attempt will prove a failure. CHAPTER IV. THE LEADING MEMBERS OF OUR FAMILY--FIRST GROUP. The chief distinction between stars and planets is, as before said, that the stars shine entirely by their own light, while the planets shine chiefly, if not entirely, by reflected light. The stars are suns; mighty globes of glowing flame. The planets simply receive the light of the sun, and shine with a brightness not their own.