The Open Polar Sea. 



to this current of air ascending in a north-westerly direction, and even 

 cause it to gyrate in a certain stratum around the pole. To make this 

 more clear, let us call to mind the manner in which the well-known 

 trade-winds are produced. The atmosphere at the equator is being 

 carried round by the motion of the earth on its axis at the rate of a 

 little over 1,000 miles an hour. Forty-five degrees north of the equa- 

 tor the atmosphere adjacent to the earth is in like manner carried out 

 about five hundred miles in the same period of time. Suppose a sec- 

 tion of this atmosphere at forty-five degrees north of the equator be 

 started on its course southward to fill the vacuum made by an ascend- 

 ing column of air from the tropics. As it goes south it takes with it 

 its rotary velocity of only five hundred miles an hour, but it goes into 

 a region where the earth has a rotating velocity of from seven hundred 

 to a thousand miles per hour as it approaches the equator. The earth, 

 therefore, slips on ahead to the eastward, causing the wind to blow 

 west of a south direction. In other words the trade-wind north of 

 the equator blows from the north-east to the south-west. A similar 

 effect is produced, as it has been said, at the north pole, by the heat 

 brought there by the gulf -stream, causing a current of air to ascend in 

 a spiral direction. This current of air, after rising to a considerable 

 height above the earth, would return southwards as a cold, dry wind, 

 its moisture having been squeezed out of it in its ascent, still affected 

 by the rotary motion of the earth, but now in an opposite direction, 

 this time causing it to have a westward instead of an eastward deflec- 

 tion, and familiar to all in the north temperate zone as the cold, dry, 

 north-west wind of winter. Hence a balloou might take advantage of 

 this and sail over the circumpolar zone of hummock ice and reach the 

 pole, or eircumvolitate it at will ; or, indeed, approach or retreat from 

 the pole by taking the proper air current. 



This of course describes the wind system of that region in its general 

 tendencies. Storms and atmospheric disturbances would not unfre- 

 quently interrupt the regular course of the air currents, and are as 

 truly a part of nature's law as the trade-winds of the Pacific. 



Such are the logical results of what is known of the meteorological 

 conditions of the northern polar regions. So far as we know of the 

 Antarctic pole the conditions are widely different. Not only does the 

 southern hemisphere receive somewhat less heat from the sun than the 

 northern, but the greater amount of land in the vicinity of the south 

 pole makes the climate much more severe. Nor is there a warm equa- 

 torial ocean current sending its heat there as at the north. Indeed, 

 there is reason to believe that a large continent includes and surrounds 

 the southern pole, which must be loaded down with glaciers that no 

 summer's sun will ever melt. 



