ork in
one quarter or another, so that ultimate stagnation be comes impossible.
It is true that no such return of radiant energy has been detected in
our corner of the world; but we have not yet so far disentangled all the
force-relations of the universe that we are entitled to regard such a
return as impossible. This is one way of escape from the consummation
of things depicted by our authors. Another way of escape is equally
available, if we suppose that while the ether is without bounds
the stellar universe also extends to infinity. For in this case the
reproduction of nebulous masses fit for generating new systems of worlds
must go on through space that is endless, and consequently the process
can never come to an end and can never have had a beginning. We have,
therefore, three alternatives: either the visible universe is finite,
while the ether is infinite; or both are finite; or both are infinite.
Only on the first supposition, I think, do we get a universe which began
in time and must end in time. Between such stupendous alternatives we
have no grounds for choosing. But it would seem that the third, whether
strictly true or not, best represents the state of the case relatively
to our feeble capacity of comprehension. Whether absolutely infinite
or not, the dimensions of the universe must be taken as practically
infinite, so far as human thought is concerned. They immeasurably
transcend the capabilities of any gauge we can bring to bear on them.
Accordingly all that we are really entitled to hold, as the outcome of
sound speculation, is the conception of innumerable systems of worlds
concentrating out of nebulous masses, and then rushing together and
dissolving into similar masses, as bubbles unite and break up--now
here, now there--in their play on the surface of a pool, and to this
tremendous series of events we can assign neither a beginning nor an
end.

[3] Fortnightly Review, April, 1875.

We must now make some more explicit mention of the ether which carries
through space the rays of heat and light. In closest connection with
the visible stellar universe, the vicissitudes of which we have briefly
traced, the all-pervading ether constitutes a sort of unseen world
remarkable enough from any point of view, but to which the theory of our
authors ascribes capacities hitherto unsuspected by science. The very
existence of an ocean of ether enveloping the molecules of material
bodies has been doubted or denied