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 nebulæ, 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 nebulæ 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