NORTH POLE OF THE WINDS 



to subjugate the peoples supposed to reside in the 

 interior of Greenland. 



The explanation of the foehn, wherever it is 

 found, is very simple, and accustomed as we are 

 in these latter days to the use of pneumatic tires, 

 it is not difficult to make it clear The surface cur- 

 rents over the Greenland ice-cap are set in motion 

 by the cooling of the air in immediate contact with 

 the ice surface, so that it slides outward down the 

 marginal slopes through the influence of gravity. 

 Only when the velocity of these air currents is high 

 do they move downward fast enough to be heated 

 through compression of the air as it comes to lower 

 and lower levels. This is in every way similar in 

 its nature to the elevation of temperature of the 

 air which is being forced under pressure into a 

 pneumatic tire. 



Thus the storms from the "Great Ice" start 

 slowly because to cool the air by contact requires 

 considerable time, but they end suddenly because 

 the compression of the air is rapid when winds 

 move downward with hurricane force. When the 

 foehn winds blow on the margins of the Greenland 

 ice-cap, it is not uncommon for the temperature 

 of the air to rise 30 or 40 degrees Fahrenheit in a 

 very few hours. 



Dr. H. Rink, long the Governor of South Green- 



46 



