46 



THE POLAR WORLD. 



wliicli are the cause of so much delay and danger. They are icebergs when they 

 tower to a considerable height above the waters, and ice-Jields when they have a 

 vast horizontal extension. A floe is a detached portion of a lield ; pacA--ice, a 

 large area of lioes or smaller fragments closely driven together so as to oppose a 

 firm barrier to the progress of a sliij) ; and drift-ice,\oofiQ ice in motion, but not 

 so firmly packed as to prevent a vessel from making her way through its yield- 

 ing Tnasses. 



Tlie lariie ice-fields whieli the whaler encounters in Baffin's Bav, or on tl:.e 

 seas between Spitzbergen and Greenland, constitute one of the marvels of the 

 deep. There is a sulenni grandeur in the slow majestic motion with which 

 they are drifted by the currents to the soutli ; and their enormous masses, as 

 jnile after mile comes floating by, impress the spectator Avith the idea of a 

 boundless extent and an irresistible power. But, vast and mighty as tiiey are, 

 they are imable to withstand the elements combined for their destruction, and 

 their aj)parently triumphal march leads them only to their ruin. 



When tliey first descend from their northern strongholds, the ice of which 

 they are composed is of the average tliickness of from ten to fifteen feet, and 

 their surface is sometimes tolerably smooth and even, but in general it is cov- 

 ered with numberless ice-blocks or hummocks piled upon each other in wild con. 



fusion to a height of forty or fifty feet, the result of repeated collisions before 

 flakes and floos were soldered into fields. Before the end of June they are cov- 

 ered with snow, sometimes six feet deep, which melting during the summer 

 forms small ponds or lakes upon their surface. 



