13. Why should a man not rise upward? He cannot, because he is too heavy. 14. He is heavy towards what? He is heavy towards the Earth, because of the Earth’s attraction. 15. Is he as heavy in Australia as in the United States? Exactly the same. 16. In what direction is he pulled there? Towards the Earth. All round our whole world the pull is towards the centre of the Earth. 17. Can our Earth be called “a bright world?” Quite as much so as other planets. If we were far enough off she would be seen by us to shine with reflected sunlight, like the Moon. CHAPTER III. BY DAY AND BY NIGHT. Let us take a good look up into the sky, and see what is to be found there. First, by day. Beginning in the early morning, just before sunrise, we have perhaps a clear sky, grayish rather than blue, and towards the east a brightening glow shows that the Sun is about to appear. That glow grows stronger and stronger, and soon a tiny glimmer creeps up over the rounded surface of our earth. Then the broad golden face follows, till the sun is visible, and full daylight has arrived. But the Sun does not stand still there, low down on the horizon. He goes on rising higher and higher, “climbing the heavens” steadily, one hour after another. At mid-day--twelve o’clock--he has reached his very highest point. Then he begins to descend, moving downward towards the west till he reaches the western horizon and vanishes from our sight. The Sun always rises in the East; never in the West. He always sets in the West; never in the East. By this I mean that he always rises to _the_ _east of our world_ and sets to _the west of our world_. He rises on the eastern side of the Earth and sets on the western side. You must not suppose that he always rises due east and sets due west of all countries in the world at once. On two days only he does so--that is at the Spring Equinox, on March 21st, and at the Autumn Equinox, on Sept. 21st. “Equinox” means “Equal Nights.” At those two dates days and nights are of the same length, twelve hours each, throughout the whole world; and everywhere the Sun rises exactly in the east, and sets exactly in the west. Everywhere except at the north and south poles. There the Sun is seen to circle round the sky in twenty-four hours, just above the horizon, neither rising nor setting. A man standing on the equator at one of the equinoxes sees the Sun rise just in the east; climb high in the sky just over his head; and set just in the west. People living in the northern parts of Europe and of America do not see precisely the same thing. With them the Sun does not circle round the sky, just over the horizon, as at the poles. And though he rises in the east and sets in the west, as at the equator, he does not reach the highest point in the sky, but only a point somewhat lower down, towards the south.