204 AMONGST THE SOUTHERN ICE. 



the level of the wash-line, along which they lie for a long period. 

 The remains of the upper part of the crevasse which has 

 assisted in the development of a cave, are often to be seen 

 stretching up from its roof. Often by change of line of flota- 

 tion a line of caves is carried up far above sea level, and 

 three or four caves disposed along an old wash-line are thus 

 often to be seen on the surface of a berg, the line being some- 

 times horizontal, sometimes tilted. In a berg which has 

 undergone extreme denudation, or on a narrow spur of a young 

 berg, a cave may be excavated right through the cliff and give 

 rise to a natural arch. A further degeneration of the arch gives 

 rise to an isolated pinnacle. 



The base of the berg under water beneath the wash-line 

 being supported by the water, does not split off at once like 

 the cliff above when cut into. Hence the waves constantly 

 deepening the wash-line as the cliffs fall, and eating their way 



BI-TABULAR ICEBERG. 



At the base of the upper cliff is seen the old wash-line. (From a sketch by the 

 Author.) 



into the berg at the water-line, a platform of ice is left behind 

 under water, projecting at the base of the cliffs above it. After 

 a time the part above water losing weight, the berg rises and 

 becomes two-storied or bi-tabular, through the platform being 

 raised above the water. 



A fresh wash-line is cut below the margin of the platform 

 now raised, and low perpendicular cliffs are formed round it. 

 A third platform may be formed in the same manner and raised, 

 and the berg may become three-storied. 



At the base of the older cliffs in each case, the old wash-line 

 is usually to be seen where the cliffs are joined by the platform 

 succeeding them, but in some instances it is obscured by the 

 subsequent formation of a debris slope from the falling of the 

 cliff; for the cliff, as on land, when no longer cut into by the 

 waves at its base, tends to degenerate into a slope of natural 

 inclination. 



The resemblance in the weathering of a berg by the action 

 of waves to that undergone by a rocky coast under the same 



