AMONGST THE SOUTHERN ICE. 241 



one or two bergs I noticed a fine cleavage lamination like that 

 of slate or shale, the laminae being pa- 

 rallel to the face of the cliff, and breaking 

 up at their edges with zigzag fracture, 

 almost as in diamond cleavage of slate ; 

 this condition may have been produced 

 by peculiar exertion of pressure in this 

 particular berg. 



When the lower cliff of the two storied rEACTCRE OF ICE CLIFF ' 

 berg, described and figured in the text, had a shot fired into it, 

 large masses of ice fell, raising a considerable swell in the sea. 

 The pieces of the cliff split off in flat masses parallel with the 

 face of the cliff, just as I noticed to be the case in the splitting 

 of the glacier cliffs at Heard Island, and did not tumble forward 

 but slid down the face of the cliff, keeping their upper edges, 

 parts of the old plateau surface, horizontal. 



The ice floated round the ship in some quantity ; it was 

 opaque and white-looking, somewhat like white porcelain, and 

 the shattered fragments had remarkably sharp angular edges, 

 showing that the ice was very hard and compact, far more so 

 than its appearance in mass would lead one to suppose, since it 

 looks at a distance as if it were hardly consolidated, but merely 

 closely pressed snow. Its manner of cleavage only gives 

 evidence at a distance of its very compact nature. 



Many of the floating fragments were traversed by parallel 

 veins of transparent ice, which were those which, when seen on 

 a cliff surface, look blue. A shot fired at the top of the higher 

 cliff produced no effect, the ball apparently going in without 

 splitting off any ice at all. 



The greater approximation of the strata towards the base of 

 the bergs is no doubt due to the increasingly greater pressure 

 sustained by them. The blue lines seem to represent successive 

 slight surface thawings of superimposed falls of snow. In these 

 lines of clear transparent ice, a complete fusion of the snow 

 particles has taken place. The opaque white ice between them 

 though, as appears from its fracture, very compact, is less so than 

 these bands, as shown by its being melted sooner.* 



* See preceding page. 



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