Examine the Nautical Almanac, published by the British Government, a chart found on every sea-going vessel. On the trackless ocean it is the mariner's guide, his trusted friend and counsellor. He may embark upon a long voyage over the trackless ocean, to be absent for years, yet through all this time, and in any part of the world he has his truthful friend to consult, who will warn him of dangers, and direct his ship in safety in every changeful clime. He left his native land years ago, yet now far out amid ocean's waves, in a different hemisphere, he consults this little chart of astronomers. He knows in any and every latitude the time of eclipses of the Sun and Moon, and of Jupiter's satellites, their sidereal positions, distances, etc. It seems charged with messages from the skies for his guidance and safety. "When we consider the acquisition of such rare and precious knowledge--this mapping out beforehand, almost to a hair's-breadth, the exact order and track in which the heavenly bodies will run their course through space, and the precise relative position they will occupy at any given moment, when they can be seen in any part of the world--is not this convincing evidence of the correctness and truthfulness of the science of astronomy?" But we have on record a more startling demonstration of its correctness--we say "startling" because of its magnitude and importance, and because when we come to examine suns, planets, and worlds, through the lights of this science, when we contemplate their distances, magnitudes, and numbers, we shall be startled by their immensity, and exclaim: "How wonderful are Thy works, O Lord of Hosts!"