tlet through the
Mohawk Valley into the Hudson, which is now filled up with glacial
drift. The evidence is so conclusive that it is no longer doubted that
the Niagara River dates from the time that the ice receded from that
point. When the water first began to flow through this new channel it
plunged over the high rocky cliff at Queenstown, and from that time to
this it has been wearing its way back to the present position of
Niagara Falls, a distance of about seven miles. A vast amount of
interest centers about this river because it is the best evidence we
have of the time that has expired since the glacial period. A great deal
of study has been given to determine the amount of erosion at the Falls
during a year's time. If this could be accurately determined, then by
measuring the distance from the present falls to Queenstown, we could
easily determine the number of years since the ice period. It is
difficult to determine, for the conditions may have changed; for
instance, the rock at the Falls to-day is said to be harder than it is
further down toward Queenstown. The estimates vary from 35,000 years to
10,000 years--that is, from a rate of erosion of five feet to one foot,
per year.

Every science is, nearly or remotely, related to every other science. If
we could determine accurately the date of the ice period it would settle
a whole lot of other questions that are related to it, and one of them
is the antiquity of man. Many stone implements such as were made and
used by the aborigines have been found at various times buried deeply
under the glacial drift. These finds have occurred so often that there
no longer remains a doubt but that a race of men existed on this
continent in preglacial times. There are evidences that at a time long
ago the temperate zone extended far north of this, and it is not
impossible that what is now the continent of Asia and that of North
America were joined. In fact, they come very close together to-day at
Bering Strait. If such were the case this continent could have been
inhabited from the old world by an overland route. This, however, is
mere speculation. There are a number of factors that are taken into
account in determining the period of the ice age besides the Niagara
River and the Falls. The Falls of St. Anthony at Minneapolis (which like
the Niagara is a creature of the ice age), the wear of water on the
shores of the great lakes, the newness of the rocks that are piled up on
the