254 ACCOUNT OF THE AllCTIC REGIONS. 



as against a rock ; and, in calm weather, where 

 there is a swell, the noise made hy their rising and 

 falling is tremendous. When ice-hergs are aground, 

 or when there is a superficial current running to 

 leeward, the motion of other ice past them is so 

 great, that they appear to he moving to windward. 

 Fields of ice of considerable thickness, meeting a 

 berg under such circumstances, are sometimes com- 

 pletely ripped up, and divided through the middle. 

 Ice-bergs, when acted on by the sun, or by a tem- 

 perate atmosphere, become hollow and fragile. Large 

 pieces are then liable to be broken off, and fall into 

 the sea with a terrible crash, which in some places 

 produces an extraordinary echo in the neighbouring 

 mountains. When this circumstance, called cal- 

 ving, takes place, the ice-berg loses its equilibrium, 

 sometimes turns on one side, and occasionally is in- 

 verted. The sea is thereby put into commotion ; 

 fields of ice in the vicinity are broken up ; the waves 

 extend, and the noise is heard to tlie distance of 

 several miles ; and sometimes the rolling motion of 

 the berg not ceasing, other pieces get loosened and 

 detached, until the whole mass falls asunder, like a 

 wreck *. 



Ice-bergs differ a little in colour, according to 

 their solidity and distance, or state of the atmos- 

 phere. A very general appearance is that of cliffs 



• FAnnicTus, Trriv.ilafion bv Sir Joseph Banks. 



