DERELICTS AND ICEBERGS 55 



along the coasts of Baffin Land and Labrador 

 and flows at an average rate of from ten to 

 thirty-six miles a day; but even in this cur- 

 rent bergs at times drift northward without 

 any apparent reason, thus presenting another 

 mystery of the sea which is yet to be solved. 



As the bergs are formed from ice frozen 

 at a very low temperature their surfaces melt 

 very rapidly, when exposed to a thawing tem- 

 perature, and the difference in tension between 

 their exterior and interior often results in 

 their bursting apart with deafening sound. 



We are all familiar with the pictures of ice- 

 bergs in geographies and other school books, 

 but these lofty, overhanging, craggy, pinna- 

 cled forms are the most unusual of all and 

 no two bergs are really anything alike in 

 shape. Some are low, or squareish, others are 

 crowned with spires, domes, minarets and 

 peaks, and still others are pierced by great 

 caves and fissures. There are bergs with 

 round tops, flat tops, sloping tops and peaked 

 tops, and with sloping sides, sheer sides, and 

 craggy sides, and in size they vary as greatly 

 as in form. 



