SCIENTILIC ADVANTAGES OF AN ANTARCTIC EXPEDITION. 431 



north of latitude 43° K.; and in Juue and July, also higher than it is 

 anywhere north of latitude 55° N. Now the higher pressure in these 

 four mouths necessitates the existence of upper currents in order to 

 maintain this high jDressure about the North Pole. These upper cur- 

 rents toward the pole are exactly opposed to the requirements of the 

 theory which intimates that the upper currents in the region of the pole 

 must necessarily blow, not toward but from, the pole. 



The actual center in this hemisphere, north of the tropics, toward 

 which the winds on or near the surface of the earth blow, is not the 

 North Pole; but, in the winter mouths the low barometric depressions 

 in the north of the Atlantic and Pacific, respectively, and in the summer 

 months the low barometric depressions in the Eurasian and North Ameri- 

 can continents; and the sources out of which the prevailing winds blow, 

 in the winter months, the high pressure regions in Siberia and North 

 America; and in the summer months the high pressure regions lying 

 northward of these continents, which, as already explained, are virtu- 

 ally the polar region itself. These are the facts in all regions where 

 the winds, according to the theory, become winds blowing over the 

 earth's surface. 



As regards the southern hemisphere. Professor Davis states that — 



"In the southern hemisphere the circumpolar eddy is much more 

 symmetrically developed." Again, "the high pressure that should 

 result from the low polar temperatures is therefore reversed into low 

 pressure by the excessive equatorward centrifugal force of the great 

 circumpolar whirl; and the air thus held away from the polar regions 

 is seen in the tropical belts of high pressure" (pp. 110, 111.) 



The interpretation of this is that the remarkable low-pressure region 

 of the southern hemisphere is continued southward to the South Pole 

 itself, the pressure diminishing all the way; and that in the region of 

 the South Pole the air currents poured thitherwards along the surface 

 of the earth ascend, and thence proceed northward as upper currents 

 of such enormous intensity and volume that they pile up in the tropi- 

 cal region of the southern hemisphere a mean sea-level atmospheric 

 pressure about an inch and a half more than the sea-level pressure near 

 the South Pole whence it starts. Now, to bring the matter to the busi- 

 ness which this meeting of the Eoyal Society has taken in hand — if 

 this theory be true and suiDported by the facts of observation, it is 

 plain that no meteorologist could signify his approval of any scheme 

 that could be proposed for exploring the Antarctic regions, it being 

 obvious that these strong west-northwesterly Avmds, if they blow vorti- 

 cally round and in upon the pole, heavily laden as they necessarily 

 would be with the aqueous vapor they have licked up from the Southern 

 Ocean, would oversi3read Antarctica with a climate of all but continu- 

 ous rain, sleet, and snow, which no explorer, however intrepid and 

 enthusiastic, could possibly face. 



But is this the state of things'? Let it be at once conceded that, as 

 far south as about latitude 55° S., the prevailing winds and the steadily 



