[Sidenote: Ruin of anthropocentric ideas.] What, therefore, now becomes of the doctrine authoritatively put forth, and made to hold its sway for so many centuries, that the earth is not only the central-body of the universe, but in reality, the most noble body in it; that the sun and other stars are mere ministers or attendants for human use? In the place of these utterly erroneous and unworthy views, far different conceptions must be substituted. Man, when he looks upon the countless multitude of stars--when he reflects that all he sees is only a little portion of those which exist, yet that each is a light and life-giving sun to multitudes of opaque, and therefore, invisible worlds--when he considers the enormous size of these various bodies and their immeasurable distance from one another, may form an estimate of the scale on which the world is constructed, and learn therefrom his own unspeakable insignificance. [Sidenote: Aids for measurements in the universe.] In one beat of a pendulum a ray of light would pass eight times round the circumference of the earth. Thus we may take the sunbeam as a carpenter does his measuring-rule; it serves as a gauge in our measurements of the universe. A sunbeam would require more than three years to reach us from alpha Centauri; nine and a quarter years from 61 Cygni; from alpha Lyræ twelve years. These are stars whose parallax has been determined, and which are therefore nearest to us. [Sidenote: Clusters of stars.] Of suns visible to the naked eye there are about 8000, but the telescope can discern in the Milky Way more than eighteen millions, the number visible increasing as more powerful instruments are used. Our cluster of stars is a disc divided into two branches at about one-third of its length. In the midst of innumerable compeers and superiors, the sun is not far from the place of bifurcation, and at about the middle of the thickness. Outside the plane of the Milky Way the appearance would be like a ring, and, still farther off, a nebulous disc. [Sidenote: Distribution of matter and force in space.] From the contemplation of isolated suns and congregated clusters we are led to the stupendous problem of the distribution of matter and force in space, and to the interpretation of those apparent phantoms of self-luminous vapour, circular and elliptic discs, spiral wreaths, rings and fans, whose edges fade doubtfully away, twins and triplets of phosphorescent haze connected together by threads of light and grotesque forms of indescribable complexity. Perhaps in some of these gleaming apparitions we see the genesis, in some the melting away of universes. There is nothing motionless in the sky. In every direction vast transformations are occurring, yet all things proclaim the eternity of matter and the undiminished perpetuity of force.