These stupendous calculations, however, form but the first column of the inventory of the universe.  Faint white specks are visible, even to the naked eye of a practiced observer in different parts of the heavens.  Under high magnifying powers, several thousands of such spots are visible,—­no longer however, faint, white specks, but many of them resolved by powerful telescopes into vast aggregations of stars, each of which may, with propriety, be compared with the milky way.  Many of these nebulae, however, resisted the power of Sir Wm. Herschell’s great reflector, and were, accordingly, still regarded by him as masses of unformed matter, not yet condensed into suns.  This, till a few years since, was, perhaps, the prevailing opinion; and the nebular theory filled a large space in modern astronomical science.  But with the increase of instrumental power, especially under the mighty grasp of Lord Rosse’s gigantic reflector, and the great refractors at Pulkova and Cambridge, the most irresolvable of these nebulae have given way; and the better opinion now is, that every one of them is a galaxy, like our own milky way, composed of millions of suns.  In other words, we are brought to the bewildering conclusion that thousands of these misty specks, the greater part of them too faint to be seen with the naked eye, are, not each a universe like our solar system, but each a “swarm” of universes of unappreciable magnitude.[A] The mind sinks, overpowered by the contemplation.  We repeat the words, but they no longer convey distinct ideas to the understanding.

[Footnote A:  Humboldt’s Cosmos, iii. 41.]

CONCEPTIONS OF THE UNIVERSE.

But these conclusions, however vast their comprehension, carry us but another step forward in the realms of sidereal astronomy.  A proper motion in space of our sun, and of the fixed stars as we call them, has long been believed to exist.  Their vast distances only prevent its being more apparent.  The great improvement of instruments of measurement within the last generation has not only established the existence of this motion, but has pointed to the region in the starry vault around which our whole solar and stellar system, with its myriad of attendant planetary worlds, appears to be performing a mighty revolution.  If, then, we assume that outside of the system to which we belong and in which our sun is but a star like Aldebaran or Sirius, the different nebulae of which we have spoken,—­thousands of which spot the heavens—­constitute a distinct family of universes, we must, following the guide of analogy, attribute to each of them also, beyond all the revolutions of their individual attendant planetary systems, a great revolution, comprehending the whole; while the same course of analogical reasoning would lead us still further onward, and in the last analysis, require us to assume a transcendental connection between all these mighty systems—­a universe of universes, circling round in the infinity of space, and preserving its equilibrium by the same laws of mutual attraction which bind the lower worlds together.