{p. 25}

sea at a higher level than now, were the warm inter-glacial periods,
when the country was free of snow and ice, And a mild and equable
condition of climate prevailed. This is the conclusion toward which
we are being led by the more recent revelations of surface-geology,
and also by certain facts connected with the geographical
distribution of plants and animals during the Glacial epoch."[1]

H. B. Norton says:

"When we come to study the cause of these phenomena, we find many
perplexing and contradictory theories in the field. A favorite one is
that of vertical elevation. But it seems impossible to admit that the
circle inclosed within the parallel of 40°--some seven thousand miles
in diameter--could have been elevated to such a height as to produce
this remarkable result. This would be a supposition hard to reconcile
with the present proportion of land and water on the surface of the
globe and with the phenomena of terrestrial contraction and
gravitation."[2]

We have seen that the surface-rocks underneath the Drift are scored
and grooved by some external force. Now we find that these markings
do not all run in the same direction; on the contrary, they cross
each other in an extraordinary manner. The cut on the following page
illustrates this.

If the direction of the motion of the ice-sheets, which caused these
markings, was,--as the glacialists allege,--always from the elevated