to
the actual passage of years. To say that man lived in the Glacial Age,
and that we have some faint traces of his presence in still earlier
periods, after all conveys to our minds only vague ideas of a far-away
time. The more a geologist studies the structure of the earth, the more
impressed is he with the magnitude of the time that must have passed
since "The Beginning." At present, however, there are no means known of
accurately measuring the time that has passed. It is just as well
that it is so, since, were it known, the human mind would be utterly
incapable of comprehending it. But as to the antiquity of man, it is but
natural that we should seek more particularly to solve the problem and
express our answer in some term of years.

Now, we have seen that the question of the antiquity of man is
intimately connected with that of the Glacial Age. That is to say, the
relics of man as far as we know them in Europe, are found under such
circumstances that we feel confident they are not far removed from the
period of cold. For it will be found that those conservative scholars
who do not think that man preceded the Glacial Age, or inhabited Europe
during the long course of years included in that period, do think he
came into Europe as soon as it passed away. So, in any case, if we
can determine the date of the Glacial Age, we shall have made a most
important step in advance in solving the problem of the antiquity of man
himself. So it seems to us best to go over the subject of the Glacial
Age again, and see what conclusions some of our best thinkers have come
to as to its cause, when it occurred, and other matters in relation to
it.

It is best to state frankly at the outset that this topic is one of the
great battle-grounds of science to-day, and that there are as yet but
few points well settled in regard to it. One needs but attempt to read
the literature on this subject to become quickly impressed with the
necessity of making haste slowly in forming any conclusions. He must
invoke the aid of the astronomer, geologist, physical-geographer,
and physicist. Yet we must not suppose that questions relating to
the Glacial Age are so abstruse that they are of interest only to the
scholar. On the contrary, all ought to be interested in them. They open
up one of the most wonderful chapters in the history of the world.
They recall from the past a picture of ice-bound coasts and countries
groaning under icy loads, where now are