THE OCEAN. 339 



evening of the 24th ; and on the 1st of June the indications of approaching summer were 

 unequivocal. Upon the return of the sun, and as the power of his beams increases, the 

 bonds which connect the masses of ice with the land are dissolved ; and the ice itself, 

 broken up into a thousand fragments of various size and thickness, is set afloat upon the 

 sea under the direction of the winds and currents. The general course of the north polar 

 current is at first south-south-west, passing through the narrow sea which separates 

 Iceland from Greenland, and after a deviation into Davis's Strait, descending upon the 

 shores of Labrador and Newfoundland. It then proceeds to the south-east, reaches the 

 centre of the Atlantic, and is lost in the gulf stream. It is by this current that the ice 

 of the northern regions is borne to the south, far away from the place of its birth, where 

 it is rapidly dissolved by the warmer temperature of the water and of the atmosphere. A 

 slight attention to the direction of this current will at once explain the non-appearance of 

 the polar ice off the northern shores of Europe, though at a much higher latitude than 

 that which it visits in the heart of the ocean. If its course at first was south, or south- 

 east, large masses would be impelled to the coasts of Norway and Scotland, and make 

 their appearance in the German Ocean ; but as it sets in to the south-west, these districts 

 are kept free from their presence, and they are conducted along the other side of the 

 Atlantic. 



The masses of ice by which the ocean is thus traversed assume a vast variety of shapes, 

 but may be comprehended in two general classes. The first consist of sheets of ice, 

 analogous to those which annually cover the lakes and rivers of northern lands. They 

 present a surface which is generally level, but here and there diversified by projections, 

 called hummocks, which arise from the ice having been thrown up by some pressure or 

 force to which it has been subject. Sheets of ice, which are so large that their whole 

 extent of surface cannot be seen from the mast-head of a vessel, are called fields. They 

 have sometimes an area of more than a hundred square miles, and rise above the level of 

 the sea from two to eight feet. When a piece of ice, though of a considerable size, can 

 be distinguished in its extent, it is termed a floe. A number of sheets, large or small, 

 joining each other, and stretching out in any particular direction, constitute a stream. 

 Captain Cook found a stream extending across Behring's Straits, connecting eastern 

 Asia with the western extremity of North America. Owing to the vast extent of some 

 fields of ice, they would undoubtedly be conducted to a lower latitude in the Atlantic 

 before their dissolution, under the influence of the warmer climate, but for the interven- 

 tion of other causes. It frequently happens that two masses are propelled against each 

 other, and are both shivered into fragments by the violence of the concussion. The ordinary 

 swell of the ocean also acts with tremendous power upon a large tract, especially when it 

 has been so thawed as to have become thin, and breaks it up into a thousand smaller 

 pieces in a very short period. The danger of being entrapped between two ice-fields 

 coming into contact with each other is one of the perils which the navigator has frequently 

 to encounter in the northern seas ; and fatal to his vessel and his life has the occurrence 

 often been, while in a vast number of instances escape has seemed almost miraculous. 



" At half-past six," says Captain Ross, relating his first voyage of discovery in the 

 Isabella to the arctic regions, with Parry in the Alexander, " the ice began to move, 

 and, the wind increasing to a gale, the only chance left for us was to endeavour to 

 force the ship through it to the north, where it partially opened ; but the channel was so 

 much obstructed by heavy fragments, that our utmost efforts were ineffectual ; the ice 

 closed in upon us, and at noon we felt its pressure most severely. A large floe, which 

 lay on one side of the Isabella, appeared to be fixed ; while, on the other side, another of 

 considerable bulk was passing along with a rapid motion, assuming a somewhat circular 



direction, in consequence of one side having struck on the fixed field. The pressure con- 



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