ANTARCTIC CRUISE. 351 



showed but little change above this latitude, and no doubt it was at 

 its maximum, as it was then the height of the summer season. 



During their drift to the northward, reaching lower latitudes, and 

 as their distance from the land increases, they are found in all stages 

 of decay ; some forming obelisks ; others towers and Gothic arches ; 

 and all more or less perforated ; some exhibit lofty columns, with a 

 natural bridge resting on them of a lightness and beauty incon- 

 ceivable in any other material. The annexed wood-cut and the tail- 

 pieces of the chapters are sketches of some of them. 



J- 



Vl will, TL—JfiiTZJ^T v 



ICEBERG. 



While in this state they rarely exhibit any signs of stratification, 

 and some appear to be formed of a soft and porous ice ; others are 

 quite blue ; others again show a green tint, and are of hard flinty ice. 

 Large ice-islands are seen that retain their tabular tops nearly entire 

 until they reach a low latitude, when their dissolution rapidly ensues ; 

 whilst some have lost all resemblance to their original formation, and 

 had evidently been overturned. The process of actually rending 

 asunder was not witnessed by any of the vessels, although in the 

 Flying-Fish, when during fogs they were in close proximity to large 

 ice-islands, they inferred from the loud crashing, and the sudden 

 splashing of the sea on her, that such occurrences had taken place. 

 As the bergs gradually become worn by the abrasion of the sea, they 

 in many cases form large overhanging shelves, about two or three 

 feet above the water, extending out ten or twelve feet ; the under part 

 of this projecting mass exhibits the appearance of a collection of 

 icicles hanging from it. The temperature of the water when among 

 the icebergs, was found below or about the freezing point. 



I have before spoken of the boulders embedded in the icebergs. 

 All those that I had an opportunity of observing apparently formed a 

 part of the nucleus, and were surrounded by extremely compact ice, 

 so that they appear to be connected with that portion of the ice that 



