molluscs in their shells, by a belief that they occupied the
centre of a comparatively small disk--some ventured to say a
globe--which was poised in a mysterious way in the middle of a
small system of heavenly bodies. The general feeling was that
these heavenly bodies were lamps hung on a not too remote ceiling
for the purpose of lighting their ways. Then certain enterprising
sailors--Vasco da Gama, Maghalaes, Columbus--brought home the
news that the known world was only one side of an enormous globe,
and that there were vast lands and great peoples thousands of
miles across the ocean. The minds of men in Europe had hardly
strained their shells sufficiently to embrace this larger earth
when the second discovery was reported. The roof of the world,
with its useful little system of heavenly bodies, began to crack
and disclose a profound and mysterious universe surrounding them
on every side. One cannot understand the solidity of the modern
doctrine of the formation of the heavens and the earth until one
appreciates this revolution.

Before the law of gravitation had been discovered it was almost
impossible to regard the universe as other than a small and
compact system. We shall see that a few daring minds pierced the
veil, and peered out wonderingly into the real universe beyond,
but for the great mass of men it was quite impossible. To them
the modern idea of a universe consisting of hundreds of millions
of bodies, each weighing billions of tons, strewn over billions
of miles of space, would have seemed the dream of a child or a
savage. Material bodies were "heavy," and would "fall down" if
they were not supported. The universe, they said, was a sensible
scientific structure; things were supported in their respective
places. A great dome, of some unknown but compact material,