454 Climate of the Glacial Period. (October, 
movement of elevation had commenced when the waters were 
much colder than now.* ‘This movement appears to be 
continued eastward round the Arétic sea, for, according to 
Wrangel, the land is slowly rising around the northern 
extremity of Siberia. He notices the occurrence of marine 
beds containing sea-shells of existing species along with the 
remains of the mammoth several feet above the sea-level. 
There is some evidence that the coasts of Scandinavia are still 
rising. 
Another line of elevation runs north from near New 
York. At Brooklyn the sea-beaches with marine shells 
occur 100 feet above the sea. ‘This elevation also increases 
northwards. At Quebec and Montreal it reaches between 
400 and 500 feet, and much farther to the north within the 
artic circle, on the shores of Barrow’s Straits, it has carried 
up sea-shells of existing species to a height of 1000 feet above 
the ocean. The movement clearly increases towards the 
pole. How far it extends westward I do not know, but it 
decreases eastward from Montreal, and in Nova Scotia I 
could find no traces of any elevation having taken place. 
Against these numerous instances of upheaval we have in 
northern regions the solitary instance of a depression of 
part of the coast of Greenland believed to be still in progress; 
and it is avery suggestive fact that that country is at present 
enduring intense glaciation and buried in snow and ice piled 
up mountains high upon it. Seeing, then, that towards 
both poles, with a single exception, there has been a rise 
of land, in some parts still going on, in all evidently ac- 
complished since the Glacial period, it is an important 
enquiry whether the land so raised was above or below the 
level of the sea in pre-glacial times. Within the arétic 
circle the evidence is clear that it was not, for nowhere have 
Tertiary marine shells been found. Nor can it be argued 
that they may have existed, but have been destroyed by the 
ice of the Glacial period, for Tertiary land-surfaces and land- 
plants are abundant and well preserved. ‘This points to the 
conclusion that like Greenland at present the land around 
the poles sank down after it was covered by ice, and has 
been slowly rising since it melted away. It is a legitimate 
speculation, and one fully warranted by the facts of the 
case, that the cause of the depression was the piling up of 
a vast weight of ice around the poles, and the cause of the 
elevation the removal of that vast weight by the melting of 
the ice. That the movement of elevation continues in some 
* The Terraces of Norway. ‘Translated from the Norsk by Dr. MARSHALL 
HALL. 
~~ 
