466 ^'HE PHYSICAL GEOGRAPHY OF THE SEz\. 



sensible by precipitation on the other. Much of it is set free in 

 the equatorial calm belt, and it is this heat which assists mightily 

 to maintain the thermal equator in its northern position. 



872. So, in like manner, the vapor that is borne to the ant- 

 I'omiation of south- ^"^^<^tic rcgious by the polar-bound winds transports 

 crn iceberg:^. immcnsc volumcs 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 vapor 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 cli- 

 mate 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 Channel is cooler in summer 

 and warmer in winter than the Canadian, so is winter at the south 

 pole much less severe than that of the north. The difference be- 

 tween the two polar climates is, as the barometer indicates, even 

 greater than is the difference between a Canadian and an English 

 winter. 



873. As tending to confirm these views touching the mildness 

 Mild climate in 63° s. of uukuown autarctic climatcs, 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."'^ 



874. The low barometer and the implied heavy precipitation in 

 Antarctic ice-drift, the autarctic rcgious are not the only witnesses that 



may be called up in favor of bluffs and bold shores to the antarc- 

 tic continent. The icebergs, in their mute way, tell that the phys- 

 ical features of that unexplored land are such, in its northern 



♦ Maury's Sailing Directions. 



