The Oologists' Record, September i, 1922. 69 



" surface. Wejiave, therefore, a vast store of ' cold ' to neutralize 

 " the terrific downpour of the summer sun's heat, and it is probable 

 " that the air ten feet above the middle of the Polar ocean is seldom 

 " warmer, even in July, than 50° or 55° Fahr. above zero. • Higher 

 " up it would be somewhat warmer. 



" This means that conditions of flying, ^so far as temperature 

 " is concerned, would be about the same over thfe Polar ocean in 

 " July as they would be in France or England in late winter or early 

 " spring. 



" Greenland is peculiar among the Polar lands, in that its great 

 " altitude enables it to store up a large amount of ' cold.' In a few 

 " other northerly islands there are glaciers of moderate size (Franz 

 " Josef Island, Spitzbergen, North Devon) and glaciers of inter- 

 " mediate size (as in Ellesmere Island and Heiberg Island), but 

 " there are vast areas of Polar lowlands where the little snow that 

 " falls in winter (commonly much less than the snowfall of Vermont 

 ", or Scotland) disappears like magic in the early spring, and where 

 " the sun beats down for month after month upon a soil clad with 

 " vegetation. 



" We can take it for certain that there is far less permanent 

 " ice and snow in the lowland of North Siberia than there is in the 

 " mountains of Mexico. It is 'even possible that tropical Africa, 

 " with its one or two snow-clad mountains, contains more permanent 

 " snow than do all the lowlands of Arctic Siberia. 



" In Arctic Canada we have ice-free lowland everywhere except 

 " in the Yukon. 



" In Siberia and Canada there is, therefore, an aggregate area 

 '• much larger than the whole of the United States, where there is 

 " no stored-up ' cold ' to moderate the heat of the Arctic daylight, 

 " except the slight chill of the frozen sub-soil. This is kept from 

 " havirig much effect on the air by the insulation over it of the cloak 

 " of vegetation. 



" Accordingly we find that at Fort Yukon, in Alaska, north 

 " of the Arctic Circle, the United States Weather Bureau has 

 " recorded the temperature of 100° in the shade. No thoughtful 

 " person will, therefore, suppose that transpolar air journeys will 

 ' in summer be interfered with by low temperatures. Neither will 

 " it be uncomfortable because of extreme heat, for that can be 

 ' regulated by the airship's rising high enough into a cooler air. 



" It is true that parts of the Polar regions are given to summer 



