The sun, the great central globe, is so vast as to overcome the attraction of all the planets, and compel them to circle around him; next we come to the planets, each turning on its axis while it flies around the sun in an elliptical orbit; then accompanying them are the satellites or moons, each revolving about its own planet, while all whirl in a dizzy waltz about the central orb; next the comets, rushing across the planetary orbits at irregular intervals of time and space; and finally shooting-stars or meteors, darting hither and thither, interweaving all in apparently inextricable confusion. To make the picture more wonderful still, every member is flying with an inconceivable velocity, and yet with such accuracy that the solar system is the most perfect timepiece known. The moon's distance from the earth is 239,000 miles; and it has a diameter of 2,160 miles. The above gives some idea of the immensity of the solar system. And it is but one of the myriads of systems, and our earth a speck amidst it. If on a clear night we cast our eyes upwards, we behold a belt of closely dotted stars extending across the sky--the Milky Way. This galaxy, a luminous, cloudlike band, stretches across the heavens in a great circle, and contains myriads of stars, densely crowded together. Herschel remarks that 288,000 stars once passed across the field of his great reflector in forty-one minutes, and says: "Thus we are to think of our own sun as a star of the second or third magnitude, and of our little solar system as plunged far into the midst of the vortex of worlds, a mere atom along that "'Broad and ample road Whose dust is gold and pavement stars.'" CHAPTER II. THE EARTH. This earth we live on is a planet, and belongs to the solar system of planets. It shines brightly, and appears to other worlds as other planets do to us. It is nearly 25,000 miles in circumference, and has a diameter of a little over 8,000 miles. It is five and a half times denser than water, and weighs about 6,096,000,000,000,000,000,000 tons.