I remember that our astronomer, one day, spoke of the nature and magnitude of the sun. The manner that he chose to render clear to the imagination of his hearers some just notions of its size, though so familiar to astronomers, produced a deep and unexpected impression on me. "Our instruments," he said, "are now so perfect and powerful, as to enable us to ascertain many facts of the deepest interest, with near approaches to positive accuracy. The moon being the heavenly body much the nearest to us, of course we see farther into its secrets than into those of any other planet. We have calculated its distance from us at 237,000 miles. Of course by doubling this distance, and adding to it the diameter of the earth, we get the diameter of the circle, or orbit, in which the moon moves around the earth. In other words the diameter of this orbit is about 480,000 miles. Now could the sun be brought in contact with this orbit, and had the latter solidity to mark its circumference, it would be found that this circumference would include but a little more than half the surface of one side of the sun, the diameter of which orb is calculated to be 882,000 miles! The sun is one million three hundred and eighty-four thousand four hundred and seventy-two times larger than the earth. Of the substance of the sun it is not so easy to speak. Still it is thought, though it is not certain, that we occasionally see the actual surface of this orb, an advantage we do not possess as respects any other of the heavenly bodies, with the exception of the moon and Mars. The light and warmth of the sun probably exist in its atmosphere, and the spots which are so often seen on this bright orb, are supposed to be glimpses of the solid mass of the sun itself, that are occasionally obtained through openings in this atmosphere. At all events, this is the more consistent way of accounting for the appearance of these spots. You will get a better idea of the magnitude of the sidereal system, however, by remembering that, in comparison with it, the distances of our entire solar system are as mere specks. Thus, while our own change of positions is known to embrace an orbit of about 200,000,000 of miles, it is nevertheless so trifling as to produce no apparent change of position in thousands of the fixed stars that are believed to be the suns of other systems. Some conjecture even that all these suns, with their several systems, our own included, revolve around a common centre that is invisible to us, but which is the actual throne of God; the comets that we note and measure being heavenly messengers, as it might be, constantly passing from one of these families of worlds to another."