Page:Physical Geography of the Sea and its Meteorology.djvu/492

466 winds transports immense volumes of heat from the more temperate latitudes of the south, and sets it free again in the polar regions there. And as for the southern icebergs, they are rather of fresh than of salt water; and they are the channels through which the water that the winds carry there as vapour finds its way back again. Being fresh water, and falling on the antarctic declivities of the land, it is by rills, and streams, and rains brought together, and by constant accretions formed into glaciers of a size and thickness that are almost impossible to be formed out of sea water unless it be dashed up as spray. Moreover, on the arctic ocean the rains are not so copious, and for that reason, though the climate be more severe, icebergs, or rather glaciers, are not formed on so grand a scale. Southern icebergs are true glaciers afloat. Arctic winds are dry enough to evaporate much of the ice and snow that fall and form in the north polar basin. As compared with arctic climates, antarctic are marine, arctic continental; and for the very reason that the English climate is cooler in summer and warmer in winter than the Canadian, so is winter at the south pole much less severe than winter at the north. The relative difference between the two polar climates is, as the barometer indicates, even greater than is the difference between a Canadian and an English winter.

875. Mild climate in 63° S.—As tending to confirm these views touching the mildness of unknown antarctic climates, the statement of Captain Smyley, an American sealer, may be mentioned. He planted a self-registering thermometer on the South Shetlands, lat. 63° S., and left it for several winters, during which time it went no lower than—5° Fahr.

876. Antarctic ice-drift.—The low barometer and the implied heavy precipitation in the antarctic regions are not the only witnesses that may be called up in favour of bluffs and bold shores to the antarctic continent. The icebergs, in their mute way, tell that the physical features of that unexplored land are such, in its northern slopes, as to favour the formation of glaciers on the shore, thence to be launched and become the huge icebergs that, on their journey to the milder climates of the north, are encountered far away at sea. After a somewhat attentive, but by no means a thorough, examination and study of antarctic icebergs as they endanger the routes of navigation, the idea suggested