88 Glaciers and GUicial Radianfy Claypole. 
n^v^s were a powerful radiant for the western part, of central' 
Europe. 
Such facts are enough alone to establish the existence of ^n 
ice-age b}'^ necess-iry implication without any consideration of 
the direct evidence found to the north of Switzerland. It is 
impossible that glaciers could have been formed of such size 
there and have descended so low without the occurrence of a 
climate that must have covered the northern mountains with a 
still larger ice-sheet. 
Of the condition of the northern isles at the date in question- 
we need now say nothing. Of their severe glaciation there can 
be no question, but that Novaya Zemlia and Spitzbergen, Jan 
Mayen and Iceland sent down glaciers that became confluent 
with those of the continent so as to form one continuous polar 
ice-sheet, there is no evidence suflBcient to prove. On the con- 
trary the greater extent of the polar sea on the eastern hemis- 
phere is directly opposed to any such belief. As we have already 
shown, the formation of glaciers is not possible on a marine area 
except under conditions so far from any now existing that the 
severest proof must be given of their past occurrence before the 
doctrine can be accepted. That the polar sea was covered with 
ice during the greater part of the ice-age may be readily ad- 
mitted even over the European area and that the ice was very 
thick admits of little doubt, but that the whole Arctic ocean was 
solid to the bottom with ice so thick that it flowed away all 
round the pole by the pressure of its own mass is an assertion 
transcending all the bounds of legitimate deduction. 
Passing now farther east we come to the Ural mountains. 
Were this range situated as are the Dovrefelds of Norway they 
must have formed another great gathering-ground for snow and 
ice. But in the drier inland climate of the great continent of 
Europe-Asia the rainfall is less and what is equally important 
in this connection the evaporati(»n is much greater than on the 
sea^coast. Antecedently therefore the same results can scarcely 
be expected. We accordingly find, though the glacial geology 
of the Ural mountains is yet very little known, that the evidence 
of extensive glaciation is wanting. 
The great ice-sheet which covered northern and central Kns- 
