POLAR ICE. MAGNITUDE OF ICE-BERGS. 253 



Ice-bergs commonly float on a base which is larger 

 in extent than the upper surface. Hence the pro- 

 portion of ice appearing above water, is seldom less 

 in elevation than one-seventh of the whole thick- 

 ness ; and when the summit is conical, or of the 

 steeple form, the elevation above water is frequently 

 one-fourth of the whole depth of the berg. 



Perhaps the most general form of ice-bergs, is 

 with one high perpendicular side, the opposite side 

 very low, and the intermediate surface forming a 

 gradual slope. When of such a form. Captain Ross 

 found that the higher end was generally to wind- 

 ward. Some ice-bergs have regular flat surfaces ; 

 but most usually they have different acute summits, 

 and occasionally exhibit the most fantastic shapes. 

 Some have been seen that were completely perfo- 

 rated, or containing prodigious caverns, or having 

 many clefts and cracks in the most elevated parts, 

 so as to give the appearance of several distinct 

 spires. 



On some ice-bergs, where there are hollows, a 

 great quantity of snow accumulates ; others are 

 smooth and naked. The naked sides are often fill- 

 ed with conchoidal excavations of various magni- 

 tudes ; sometimes with hollows the size of the finger, 

 and as regular as if formed by art. On some bergs 

 pools of water occur stagnant : on others, large 

 streams are seen oozing through crevices into the 

 sea. In a high sea, the waves break against them 



