ANTARCTIC EXPLORATION. 299 



sphere, and thus when there was no mobile current to steal northwards 

 with it, warmth could accumulate and modify the climate. 



Under the influences of such changes the icy mantle would be slowly 

 rolled back towards the South Pole, and thus many plants and aniii,als 

 were able to live and multiply in latitudes that to day are barren. 

 What has undoubtedly occurred in the extreme north is equally possi- 

 ble in the extreme south. But if it did occur — if South Polar lands, 

 now ice bound, were then as prolific of life as Disco and Spitzbergen 

 once were — then, like Spitzbergen and Disco, the unsubmerged rem- 

 nants of tbis continent may still retain organic evidences of the fact in 

 the shape of fossil-bearing beds, and tbe discovery of such deposits 

 would confirm or confute such speculations as these. The key to the 

 geological problem lies within the Antarctic Circle, and to find it would 

 be to recover some of the past history of the southern hemisphere. 

 There is no reason to despair of discovering su(;h evidence, as Dr. 

 McCormack, in his account of Ross's voyage, records that portions of 

 Victoria Land were free from snow, and therefore available for inves- 

 tigation; besides which their surface may still support some living 

 forms, for they can not be colder or bleaker than the peaks which rise 

 out of the continental ice of North G-reenland, and these, long held to 

 be sterile, have recently disclosed the existence upon them of a rich 

 though humble flora. 



We have now to consider some important meteorological questions. 

 If we look at the distribution of the atmosphere around the globe we 

 shall see that it is spread unequally. It forms a stratum which is 

 deeper within the tropics than about the poles and over the northern 

 than over the southern hemisphere, so that the barometer normals fall 

 more as we approach the Antarctic than they do when we near the 

 Arctic. Maury, taking the known isobars as his guide, has calculated 

 that the mean pressure at the North Pole is 29,1, but that it is only 28 

 at the South (Maury's Meteorology, 250). In other words, the Ant- 

 arctic Circle is permanently much barer of atmosphere than an}' other 

 part of the globe. Again, if we consult a wind chart we shall see that 

 both poles are marked as calm areas. Each is the dead center of a 

 perpetual wind vortex, but the South. Polar indraught is the stronger. 

 Polarward winds blow across the forty-fifth degree of north latitude for 

 IS!) days in the year, but across the forty-fifth degree of south latitude 

 for 209 days. And while they are drawn in to the North Pole from 

 over a disk-shaped area 5,500 miles in diameter, the South Polar in- 

 draught is felt throughout an area of 7,000 miles across. Lastly, the 

 winds which circulate about the South Pole are more heavily charged 

 with moisture than are the winds of corresponding parts of the other 

 hemisphere. Now, the extreme degree in which these three conditions, 

 of a pei-petual grand cyclone, a moist atmosphere, and a low barom- 

 eter, cooi)erate without the Antarctic ought to produce within it an 

 exceptional meteorological state, and the point to be determined is 



