ason that worlds die. They reach a stage in
which they are lifeless. They cool down until the waters and gases
that are on the surface and above the surface recede more and more
into the surface and then into the interior, until they wholly
disappear. Cold takes the throne of nature. Universal aridity
supervenes, and all forms of vegetable and animate existence go away
to return no more. They dwindle and expire. The conditions that have
come are virtually conditions of death.

Whether the universe contains within itself, under the Almighty
supervision, certain arrangements and laws by which the dead world can
be again cast into the crucible and regenerated by liberation through
the action of heat into its primordial state once more and go the same
tremendous round of planet life, we know not. The conception of such a
process, even the dream or vague possibility of it, is sufficiently
sublime and fills the mind with a great delight in contemplating the
possible cycles through which the material universe is passing.

At any rate, we may contemplate the three great stages of world-life
with which we are already acquainted--that is, the birth stage, the
epoch of life and the epoch of death. There is a birth, as also a life
and a death of planets. Richard A. Proctor, of great fame, on one of
his last tours of instructive lecturing among our people, had for his
subject the "Birth and Death of Worlds." The theme was not dissimilar
to that which has been here presented in outline. The birth, the life
and the death of worlds! Such is a summary of that almost infinite
history through which our earth is passing--the history which the
globe is _making_ on its way from its nebulous to its final state.

Such, if we mistake not, is the story epitomized--the life history in
brief--of all the worlds of space. They have each in its order and
kind, an epoch of the beginning, then an epoch of growth and
evolution, then an epoch of life--toward which all the preceding
planet history seems to tend--and finally an epoch of death which
must, in the course of infinite time, swallow from sight each planet
in its turn, or at least reduce each from that condition in which it
is an arena of animated existence into that state where it is a
frozen and desert clod, still following its wonted path through space,
still shining with a cold but cheerful face, _like our moon_, upon the
silent abysses of the universe.

WHAT THE WORLDS ARE MADE OF.