52 
Geology, 
this along and sometimes slides over it. At the end of the glac- 
ier the debris within the ice is freed by melting and accumulates 
as a talus slope. This sometimes protects the basal layers from 
melting and they become at length buried in the growing ac- 
cumulation. Their subsequent melting gives rise to one form of 
kettle-holes, but only one form. It appeared from the stages 
presented by the several glaciers that where a lobe is slowly ad- 
vancing the talus-slope gradually grows forward and constitutes 
an embankment upon which the glacier advances. It thereby 
grades up its own pathway in advance. On seeing this process 
one is at no loss to understand how ice can advance over fields of 
sand or soil without in any way disrupting them. It buries them 
before it advances upon them. A large number of the glaciers 
of the Inglefield region rest upon embankments or pedestals of 
this kind. Some that have recently retreated have left these 
causeways exposed to observation. 
When the frontal material accumulates in a large mass, it 
opposes such a degree of resistance to the ice that its layers are 
curved upward on the inner slope, and if the glacier subsequently 
advances, the ice rides up over the moraine. Several such in- 
stances were observed, but none were seen where the ice showed 
any competency to push even its own debris, in notable quantity, 
in front of it. The ice is weaker than its moraines, as a whole. 
WIND-DRIFT BORDER. There is a very notable wind- 
drift phenomenon connected witK the border of the great ice-field 
of north Greenland, to which Lieutenant Peary was the first, I 
think, to call attention. The winds of the great ice-cap flow 
chiefly down its slopes as though by direct control of gravity. 
They carry great quantities of snow, and this lodges in the lee 
of the terminal moraine. The breadth of the fringing-drift thus 
formed reaches 2000 or 3000 feet in some cases and its slope 
rises from 100 to 250 feet, though a portion of this elevation is 
doubtless due to a slope of the earth's surface below. This snow 
remains from year to year and becomes solidified after the fash- 
ion of a glacier; indeed, it is little short of a peripheral ribbon- 
like glacier skirting the border of the great ice-cap. Between 
this and the ice-cap, as a narrow line of division, lies the termi- 
