510 THE ANTARCTIC MANUAL. 
in this wall, and it is very little water-worn, proving the rare occur- 
rence of gales from the north and the accompanying high seas, which 
would otherwise wear huge caves into it; its summit affords abso- 
lutely no obstacle for travelling with sledges and dogs, being smooth 
and level and but little crevassed. 
A theory has been advanced and very widely accepted that the 
great ice-barrier is the front of a huge polar ice-cap, which moves from 
the south pole northwards. It has even been calculated that the centre 
of this polar ice-cap must be 3 miles, and may be 12 miles deep, and that, 
the material of this ice-mass being viscous, its base must spread out 
under the crushing pressure of the weight of its centre, and the extrusive 
movement thus set up is supposed to thrust the ice-cliffs off the land at 
a considerable rate. The improbability of this theory is evident to any 
one who has carefully observed the barrier and the ice-caps of that part of 
B 
> 
1 
1 
Y 
1 
H 
i 
V 
A 
TEE 
t 
{ 
1 
1 
See esl C) 
CAPE CROZIER, LAT. 77° 25’ s., LONG. 169° 10’ £. 
A, iceberg; B, height nearly 200 feet ; C, Crozier and the great ice-barricr. 
the antarctic, none of which can possibly be more than 2000 feet in depth. 
The following theory with regard to the formation of the great ice- 
barrier I hope may bear logical scrutiny. 
In the first place, reasoning from analogy, all the ice-sheets of South 
Victoria Land, due to the north and south trend of the lofty mountain 
ranges, flow towards the east, and the glaciers extend for long distances 
into the sea in the form of huge tongues of ice, their length varying 
according to the extent of glaciation due to differences of latitude. 
Thus, in Robertson bay (lat. 71° 18’ 8.), some run out into the sea for 
a distance of 3 miles, and are half a mile in width; whilst near Cape 
Gauss (lat. 76° 8.) they extend as far out as 30 miles, and are 4 or 5 miles 
across. These tongues of ice are characteristic of every glacier. Why 
should the great ice-barrier be an exception? The huge Parry range 
of mountains runs parallel with the coast, and appears to be simply a 
continuation of the coast-line, for there is absolutely no land in sight 
to the east of them. It follows that the ice-sheet, which covers these 
mountains and where the glaciation attains its maximum dimensions, 
