THE ROSS BARRIER 131 



spectively In Western Inlet and the Bay of Whales. It will be noticed that the 

 Barrier between the Bay of Whales and Western Inlet is higher than its general 

 altitude between Western Inlet, on the meridian of 169° W., and the meridian of 

 175° E. This large lobe is probably due to the glacier ice coming from glaciers like 

 the Devil's Glacier, Axel Heiberg Glacier, Liv's Glacier, possibly also the Beardmore 

 Glacier, combined with the ice derived from Carmen Land and the areas between 

 the latter and King Edward VII. Land. 



The ancestor of the Bay of Whales, like its modern descendant, originated, no 

 doubt, in the stemming action of the high ice-covered island to the south of 

 Amundsen's winter quarters at Framheim. Possibly the lobe was nourished almost 

 entirely by glacier ice coming from between Carmen Land and King Edward VII. 

 Land, as well as by drift and new falling snow on the actual surface of the Barrier. 

 Possibly Western Inlet owes its origin to the stemming action of some other, as yet 

 undiscovered, ice-covered island to the south. 



The fact that since Boss' time this eastern lobe has retreated no less than 50 

 miles southwards, shows probably that the .ice supplies, on this eastern side of the 

 Barrier, have diminished to an even greater extent than the supplies to its western 

 side. 



The absence of high ranges in the direction of King Edward VII. Land and the 

 land farther to its south accounts, no doubt, for the comparative calm of the weather 

 in this region, as well as for its consequent low precipitation. 



Some observations may now be given on the internal structure of the material 

 of the Barrier. Plate XXXVII. Fig. 1 shows the appearance of the northern 

 edge of the Barrier, about 2 miles south of Cape Armytage, on March 1, 1909. 



The material here ajjpeared to be entirely formed of well stratified old drift 

 snow. It probably rested on a foundation of old sea ice of certainly more than one 

 winter's growth. It was doubtful whether it should be considered as the edge of 

 the Bai-rier proper. On the short sledge expedition by Shackleton, Armitage, and 

 one of us, it was noticed that there was a gradual slope, about 8 feet high, where the 

 sea ice joined the Barrier, and, between this spot and Pram Point, there was strong 

 evidence of pressure ridges on the Barrier surface. It is usually very difiicult to 

 determine the exact limit northwards of the edge of the Barrier proper at this part 

 of McMurdo Sound, as heavy snow-drifts, formed by the blizzards, tend to build up 

 an "apron" of hard snow over the sea ice lying to the north of the Barrier edge. 

 It is probable that the Nimrod, in the position shown in the photograph, was still 

 within the area of this snow and sea ice apron. 



The cliff of Boss Barrier, between long. 165° to 170° W., shown on Plate XXXVII. 

 Fig. 2, has a height of about 150 feet. This is near about half-way between long. 

 170° W. and the Bay of Whales. The cliff here was higher than the crow's nest 

 of the Nimrod, and was probably about 150 feet above sea-level. The photo- 

 graph shows that the cliff is composed, apparently down to the water's edge, of 



