strata by the slow accumulation of materials, they alone would convince
us of the long and slow maturing of God's work on the earth but when we
add to these the successive populations of whose life this world has
been the theatre, and whose remains are hidden in the rocks into which
the mud or sand or soil of whatever kind on which they lived has
hardened in the course of time,--or the enormous chains of mountains
whose upheaval divided these periods of quiet accumulation by great
convulsions,--or the changes of a different nature in the configuration
of our globe, as the sinking of lands beneath the ocean, or the gradual
rising of continents and islands above it,--or the wearing of great
river-beds, or the filling of extensive water-basins, till marshes first
and then dry land succeeded to inland seas,--or the slow growth of coral
reefs, those wonderful sea-walls raised by the little ocean-architects
whose own bodies furnish both the building-stones and the cement that
binds them together, and who have worked so busily during the long
centuries, that there are extensive countries, mountain-chains, islands,
and long lines of coast consisting solely of their remains,--or the
countless forests that must have grown up, flourished, died, and
decayed, to fill the storehouses of coal that feed the fires of the
human race to-day,--if we consider all these records of the past, the
intellect fails to grasp a chronology for which our experience furnishes
no data, and the time that lies behind us seems as much an eternity to
our conception as the future that stretches indefinitely before us.

The physical as well as the human history of the world has its mythical
age, lying dim and vague in the morning mists of creation, like that of
the heroes and demigods in the early traditions of man, defying all
our ordinary dates and measures. But if the succession of periods that
prepared the earth for the coming of man, and the animals and plants
that accompany him on earth, baffles our finite attempts to estimate its