up, and pressed and heaped together so as to form the most irregular-shaped masses: severe, indeed, must have been the pressure at some period, as not a single level floe could be seen amongst it, and it seldom happened that we met with any piece exceeding a quarter of a mile in circumference, thus presenting a striking difference of character in the pack of the Antarctic from that of the Arctic Sea, where floes of several miles in diameter are of common occurrence, and sometimes "fields" as they are termed, whose boundary is beyond the reach of vision from a ship's mast head. The cause of this is explained by the circumstance of the ice of the southern regions being so much more exposed to violent agitations of the ocean, whereas the northern sea is one of comparative tranquillity.
