But it is when we turn our observation and our thoughts from our own
system, to the systems which lie beyond it in the heavenly spaces, that
we approach a more adequate conception of the vastness of creation. All
analogy teaches us that the sun which gives light to us is but one of
those countless stellar fires which deck the firmament, and that every
glittering star in that shining host is the center of a system as vast
and as full of subordinate luminaries as our own. Of these suns--centers
of planetary systems--thousands are visible to the naked eye, millions
are discovered by the telescope. Sir John Herschell, in the account of
his operations at the Cape of Good Hope (p. 381) calculates that about
five and a half millions of stars are visible enough to be _distinctly
counted_ in a twenty-foot reflector, in both hemispheres. He adds, that
"the actual number is much greater, there can be little doubt." His
illustrious father, estimated on one occasion that 125,000 stars passed
through the field of his forty foot reflector in a quarter of an hour.
This would give 12,000,000 for the entire circuit of the heavens, in a
single telescopic zone; and this estimate was made under the assumption
that the nebulæ were masses of luminous matter not yet condensed into
suns.
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 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.]