314 THE VOYAGE OF THE 'DISCOVERY' 



It is evident that when the Southern glaciation was at a 

 maximum, when the glacier valleys were filled to overflowing, 

 and when the great reservoir of the interior stood perhaps 400 

 or 500 feet above its present level and was pouring vast masses 

 of ice into the Ross Sea, the Great Barrier was a very different 

 formation from what it is at present. There are abundant 

 evidences of its great enlargement ; granite boulders were 

 found on Cape Royds and high on every volcanic island in 

 our neighbourhood ; on the slopes of Terror, Dr. Wilson 

 found morainic terraces 800 feet above the present surface of 

 the ice ; Mr. Ferrar showed that nearly the whole of the Cape 

 Armitage Peninsula was once submerged ; and, in fact, on all 

 sides of us and everywhere were signs of the vastly greater 

 extent of the ancient ice-sheet. 



It is not until one has grasped the extent of the former 

 glaciation and the comparatively rapid recession of the present 

 that one can hope to explain the many extraordinary ice forma- 

 tions that now remain in the Ross Sea, but armed with this 

 knowledge one is at least able to advance a theory concerning 

 their origin. 



My opinion is that at or near the time of maximum glacia- 

 tion the huge glaciers, no longer able to float in a sea of 400 

 fathoms, joined hands and spread out over the Ross Sea, 

 completely filling it with an immense sheet of ice. At that 

 time the edge of the sheet and the first place at which it could 

 be water-borne bordered on the ocean depths to the north of 

 Cape Adare. Then followed the receding ice conditions, when 

 the ice-sheet as a whole grew thinner, and at length a time 

 came when it was curiously circumstanced. The Ross Sea is 

 comparatively uniform in depth north and south ; the ice-sheet 

 pressing out over this level floor would consequently have been 

 more or less uniform in thickness, and finally the wastage 

 would have been more or less uniform over the whole area. 

 As a result of these conditions there came a time when the 

 whole ice-sheet became buoyant, and when it had either to 

 break away with great rapidity or to float whilst remaining fast. 

 I imagine that it floated and broke away gradually, and that 



