lights.  We cannot see what those lights illuminate, we can only conjecture what untold wealth of non-luminous bodies may also lie in their vicinity; we may, however, feel certain that just as the few gleaming lights from a ship are utterly inadequate to give a notion of the nature and the contents of an Atlantic steamer, so are the twinkling stars utterly inadequate to give even the faintest conception of the extent and the interest of the universe.  We merely see self-luminous bodies, but of the multitudes of objects and the elaborate systems of which these bodies are only the conspicuous points we see nothing and we know very little.  We are, however, entitled to infer from an examination of our own star—­the sun—­and of the beautiful system by which it is surrounded, that these other suns may be also splendidly attended.  This is quite as reasonable a supposition as that a set of lights seen at night on the Atlantic Ocean indicates the existence of a fine ship.

The Clusters of Stars.

On a clear night you can often see, stretching across the sky, a track of faint light, which is known to astronomers as the “Milky Way.”  It extends below the horizon, and then round the earth to form a girdle about the heavens.  When we examine the Milky Way with a telescope we find, to our amazement, that it consists of myriads of stars, so small and so faint that we are not able to distinguish them individually; we merely see the glow produced from their collective rays.  Remembering that our sun is a star, and that the Milky Way surrounds us, it would almost seem as if our sun were but one of the host of stars which form this cluster.

There are also other clusters of stars, some of which are exquisitely beautiful telescopic spectacles.  I may mention a celebrated pair of these objects which lies in the constellation of Perseus.  The sight of them in a great telescope is so imposing that no one who is fit to look through a telescope could resist a shout of wonder and admiration when first they burst on his view.  But there are other clusters.  Here is a picture of one which is known as the “Globular Cluster in the Centaur” (Fig. 2).  It consists of a ball of stars, so far off that, however large these several suns may actually be, they have dwindled down to extremely small points of light.  A homely illustration may serve to show the appearance which a globular cluster presents in a good telescope.  I take a pepper-caster, and on a sheet of white paper I begin to shake out the pepper until there is a little heap at the centre and other grains are scattered loosely about.  Imagine that every one of those grains of pepper was to be transformed into a tiny electric light, and then you have some idea of what a cluster of stars would look like when viewed through a telescope of sufficient power.  There are multitudes of such groups scattered through the depths of space.  They require our biggest telescopes to show them adequately.  We have seen that our sun is a star, being only one of a magnificent cluster that forms the Milky Way.  We have also seen that there are other groups scattered through the length and depth of space.  It is thus we obtain a notion of the rank which our earth holds in the scheme of things celestial.