our sun that centre? Far from it.
Our sun is only a star like all the rest, circling on with its attendant
satellites--our giant sun a star, no different from myriad other stars,
not even so large as some; a mere insignificant spark of matter in an
infinite shower of sparks.

Nor is this all. Looking beyond the few thousand stars that are visible
to the naked eye, Herschel sees series after series of more distant
stars, marshalled in galaxies of millions; but at last he reaches a
distance beyond which the galaxies no longer increase. And yet--so he
thinks--he has not reached the limits of his vision. What then? He has
come to the bounds of the sidereal system--seen to the confines of the
universe. He believes that he can outline this system, this universe,
and prove that it has the shape of an irregular globe, oblately
flattened to almost disklike proportions, and divided at one edge--a
bifurcation that is revealed even to the naked eye in the forking of the
Milky Way.

This, then, is our universe as Herschel conceives it--a vast galaxy
of suns, held to one centre, revolving, poised in space. But even
here those marvellous telescopes do not pause. Far, far out beyond the
confines of our universe, so far that the awful span of our own system
might serve as a unit of measure, are revealed other systems, other
universes, like our own, each composed, as he thinks, of myriads of
suns, clustered like our galaxy into an isolated system--mere islands of
matter in an infinite ocean of space. So distant from our universe are
these now universes of Herschel's discovery that their light reaches
us only as a dim, nebulous glow, in most cases invisible to the unaided
eye. About a hundred of these nebulae were known when Herschel began
his studies. Before the close of the century he had discovered about
two thousand more of them, and many of these had been resolved by his
largest telescopes into clusters of stars. He believed that the farthest
of these nebulae that he could see was at least three hundred thousand
times as distant from us as the nearest fixed star. Yet that nearest
star--so more recent studies prove--is so remote that its light,
travelling one hundred and eighty thousand miles a second, requires
three and one-half years to reach our planet.

As if to give the finishing touches to this novel scheme of cosmology,
Herschel, though in the main very little given to unsustained
theorizing, allows himself the privilege of