Indeed, even the roughest shepherd who looks at the dawn brightening in the east, or at evening, while driving his ?ock home, stops to contemplate the sky ablaze with the glow of the setting sun, and the sailor who watches from the deck the great vault of heaven and its countless stars mirrored in the water around him, can not but be moved by the great ness of such scenes. Yet their admiration, great as it is, can not even be compared with that of the student of astronomy, who knows what those stars are, and how many thousands of millions Of miles theirlight has traveled to reach us; who knows that nearly every one of those countless sparkling points is the centre of. A separate solar system, each system as great and wonderful as that in which we live.