a wonderful progress in the past half a century. The one, seeking for
the history and transformations of the physical earth, and the other,
aiming to discover the antiquity, differences of race, and social and
ethnical development of man, have obtained results which we cannot
regard without amazement and more or less incredulity. The two sciences
have been faithful handmaidens the one to the other; but geology has
always led the way, and archaeology has been competed to follow in its
path.

[Sidenote: Four Eras of Civilization.]

Though we may doubt as to the exactness of the detailed data established
by the archaeologists, there are certain broad facts which we must
accept from them as established beyond doubt. These facts are of the
highest value and interest. The antiquary has been able, from discovered
remains of extinct civilizations, to reconstruct societies and peoples,
and to trace the occupancy of countries to periods far anterior to that
of which history takes cognizance. The general fact seems to be settled
that, in prehistoric times, Europe passed through four distinct eras.
These were the Rude Stone Age, when man was the contemporary in Europe
of the extinct hairy elephant and the cave bear; the Polished Stone Age;
the Bronze Age, when bronze was used for arms and utensils; and the Iron
Age, in which iron superseded bronze in the making of useful articles.

[Sidenote: Ancient America.]

In the same way it has been established that, on our own continent, the
oldest discoverable civilization was one in which rude stone implements
were used, and man lived contemporaneously with the megatherium and the
mastodon. Then polished and worked stone implements came into use; and