irdle
Saturn. When, in the history of these wonderful processes of growth
which have taken place in our solar system, our earth parted from the
shrinking sun, the separate life of the sphere began. In the course of
ages it set off the mass of the moon, and after that process was
effected by further shrinking, it was reduced from a body several
hundred thousand miles in diameter to a relatively small sphere. Such
are the steps which led to the birth of our planet.

As the earth's matter gathered into a smaller bulk, its heat was greatly
increased, so that for a time it was a hot, shining star like the sun.
Gradually, however, it parted with so much of its heat that it, as we
may say, froze over or became covered with a solid crust which soon
became cool enough to permit the waters hitherto in the state of steam
to descend upon the surface of the sphere. With this descent of the
waters, which led to the formation of the seas, another stage of great
importance in the history of the earth began. In the earlier ages the
heat of the earth, which came from within its mass, was so great that
the temperature coming from the sun was of no consequence, but when the
earth acquired a crust of cold rocks, a new period began, that in which
the solar heat was thereafter to be the source of most of the movements
that occurred in this limited world. Thenceforward to the present day,
and yet on through the ages, the sun and earth are linked together in
their actions in a marvellously entangled way.

When the sun's heat began effectively to work on the earth in the manner
which we now behold, the winds began to blow, the ocean waters under
their influence to circulate currents, and the moisture to rise into the
air to be carried to and fro and to fall as rain. It seems likely that
these movements of air and water, which we know to be due to the action
of the sun's heat, took place at first upon the surface which was
everywhere covered by the ocean, a vast continuous sea through which the
lands had not yet pierced, and in which living creatures had not begun
to dwell. This universal field of waters could not have long continued,
and this for the reason that certain changes in the earth itself brought
about the creation of broad folds on the sea-bottom, which grew upward
until dry lands rose above the level of the waters. The way in which
this process took place can in general be easily understood.

After the earth had cooled to the point