200 years the ice edge remained in one position, forming
a great moraine. Brooks suggests that this pause about
8000 B. C. was due to the closing of the connection be-
tween the Atlantic Ocean and the Baltic Sea and the
synchronous opening of a connection between the Baltic
and the White Seas, whereby cold Arctic waters replaced
the warmer Atlantic waters. He notes, however, that
about 7500 B. C. the obliquity of the ecliptic was probably
nearly 1° greater than at present. This he calculates to
have caused the climate of Germany and Sweden to be
1°F. colder than at present in winter and 1°F. warmer in
summer.

The next climatic stage was marked by a rise of tem-
perature till about 6000 B. C. During this period the ice
at first retreated, presumably because the climate was
ameliorating, although no cause of such amelioration is
assigned. At length the ice lay far enough north to allow
a connection between the Baltic and the Atlantic by way
of Lakes Wener and Wetter in southern Sweden. This is
supposed to have warmed the Baltic Sea and to have
caused the climate to become distinctly milder. Next the
land rose once more so that the Baltic was separated
from the Atlantic and was converted into the Ancylus
lake of fresh water. The southwest Baltic region then
stood 400 feet higher than now. The result was the Daun
stage, about 5000 B. C., when the ice halted or perhaps
readvanced a little, its front being then near Ragunda
in about latitude 63°. Why such an elevation did not
cause renewed glaciation instead of merely the slight
Daun pause, Brooks does not explain, although his calcu-
lations as to the effect of a slight elevation of the land
during the main period of glaciation from 30,000 to
18,000 B. C. would seem to demand a marked readvance.

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