PLATE XLVIL THE OLD GLACIER ICE OF ROSS ISLAND. 



FIG. 1 (Map B). From a photograph by E. A. WILSON (W. 9, ^-plate), Oct. 20, 

 1903 ; looking N. to Ross Sea from the pressure ridges at Cape Crozier. 



FIG. 2 (Map B). From a photograph by R. W. SKELTON (S. 17, 5" x 4" plate), 

 Jan. 1904 ; a cliff of old ice on the S. side of Winter- quarters peninsula. 



The ice-cliffs here shown are remnants of an older and far heavier ice-cap 

 than that which exists in the Antarctic at the present time. The " ice-slabs," of 

 which these figures show the section, with compressed and concentrated layers of 

 grit and clear black ice, are now completely severed from their original sources. 

 In the case of Fig. 1, this source must have been high on the slopes of Mount 

 Terror, and in Fig. 2 must have formed an ice-cap completely covering the greater 

 part of Winter-quarters peninsula. The summer disintegration of such old ice has 

 been well described by Mr Skelton : 



" During the hot days of the latter part of December and early in January, an 

 immense amount of melting goes on in the valley. On the glacier surface there is 

 quite a loud " buzzing " sound, caused by the air-bubbles confined in the ice being 

 freed and coming to the surface through water . . . every boulder in the moraines 

 stands in a large pool of water, often 3 or 4 feet deep . . . and in one of many 

 streams I calculated the flow of water to be about 53 tons per minute." From 

 a Report by R. W. Skelton, quoted by Capt. Scott. (See Voyage of the 'Discovery,' 

 vol. ii., p. 142.) 



Although this description applies really to the land-ice on the western side of 

 M'Murdo Sound, it is applicable, as the icicles in Fig. 2 show, wherever the sun 

 strikes dirty ice. 



See also Plate XXX. 



