The wonders of the heavens were among the primary subjects of human thought. The rising and setting of the sun, and his splendid way through the sky; the milder beauty of the moon; the marshalled hosts of the stars aroused the admiration, interest, even worship, of the earliest representatives of our race. Men concluded that the heavenly bodies were gods or men, who for great deeds had been taken to shine in deathless glory in the skies. With enlarging ideas they understood that the stars are worlds, but they had no means of determining how large or how distant they might be. The first students of the skies thought that the earth was the largest of the heavenly bodies, and stood still, while the others moved. They considered also that the earth was flat, and that the skies above it were a vast hemispherical dome. Such notions are instinctive even at the present time. How natural it is for us to believe that the earth is the lower half of the universe, and the skies the upper half! We speak as if the heavens and the earth were two separate creations. We are slow to recognize the fact that the earth is merely one little part of the heavens. The heavens are about us on every side. By the heavens we mean that part of space which seems to be star filled. In these heavens our world is as a globe suspended, and every star that we see is another globe suspended in space. Of these globes we can, with the unaided eye, see countless thousands; millions more are reached only by powerful telescopes; very likely myriads still exist which no glass is strong enough to bring into human sight. In ancient times people fancied that the stars ruled the lives of men, and from them came good or evil influences, wars, famines, plagues. They foretold the events of years by the stars that showed highest and brightest, and cast the horoscopes of individuals by dividing the sky into “houses” or sections, and considering the appearances of these houses at the hour when a child was born. This pursuit was called astrology, and it extended to the study of comets, eclipses, and all the appearances of the skies. This astrology was an elaborate science, and one of the most ancient studies of men, and by degrees led the way to the present noble science of astronomy. When we look at the skies they seem to be crowded with shining bodies sown thickly together without any particular order. Looking more carefully, we see that in parts of the sky the stars are thickly clustered, and that there seem to be empty spaces. We observe too that there are differences in the size, brightness, and color of the stars. Some stars are red, some white, some blue, some green or yellow: some shine with a clear, steady ray, some quiver, tremble, disappear, reappear. During the day we cannot see the stars, because of the greater brightness of the sunshine. When the moon is full and bright at night the stars seem dim, but on a cloudless, moonless night the stars are well displayed.