radiance we receive is less than a two-billionth part of what is
sent flying through the desert regions of space. Some of the
immense residue of course hits other planets stationed in the way
of it, and is utilized upon their surfaces; but the planets, all
put together, stop so little of the total quantity that our
startling illustration is not materially altered by taking them
into the account. Now this two-billionth part of the solar
radiance poured out from moment to moment suffices to blow every
wind, to raise every cloud, to drive every engine, to build up
the tissue of every plant, to sustain the activity of every
animal, including man, upon the surface of our vast and stately
globe. Considering the wondrous richness and variety of the
terrestrial life wrought out by the few sunbeams which we catch
in our career through space, we may well pause overwhelmed and
stupefied at the thought of the incalculable possibilities of
existence which are thrown away with the potent actinism that
darts unceasingly into the unfathomed abysms of immensity. Where
it goes to or what becomes of it, no one of us can surmise.

Now when, in the remote future, our sun is reduced to vapour by
the impact of the several planets upon his surface, the resulting
nebulous mass must be a very insignificant affair compared with
the nebulous mass with which we started. In order to make a
second nebula equal in size and potential energy to the first
one, all the energy of position at first existing should have
been retained in some form or other. But nearly all of it has
been lost, and only an insignificant fraction remains with which
to endow a new system. In order to reproduce, in future ages,
anything like that cosmical development which is now going on in
the solar system, aid must be sought from without. We must