398 POLAR PROBLEMS 



to see the ground and yet to have a sufficiently extended horizon of 

 visibiHty. 



The best months for aircraft exploration in the Arctic are March 

 and April. For flying in the Antarctic December and January would 

 probably be the most suitable, although during this period the explorer 

 might be subject to some delay because of the weather. In the 

 Antarctic the weather, with the possible exception of the region noted, 

 is always more or less erratic, but inland summer conditions are likely 

 to be dependable. 



During winter flights over the Arctic the difficulty experienced 

 because of darkness is the same sort "of difficulty experienced at night 

 in any other latitude and may be overcome in the same way. As to 

 temperature there is generally less diurnal change in the Polar Regions 

 than elsewhere, and it has been proved that polar flying is subject 

 to temperatures not lower than those met with at altitudes necessarily 

 maintained on several established air-mail routes and to temperature 

 ranges much smaller than those experienced by the planes on these 

 routes when the warmer temperatures they pass through in their 

 low-altitude flying are taken into account. The difficulties because of 

 temperature are therefore less in high Arctic latitudes than those 

 contended with daily on mail routes across various other parts of 

 the world. 



Type of Aircraft To Be Used in Polar Exploration 



The cruising radius of airplanes depends in a measure on the 

 fatigue of metals and men. The continuous daylight and exhilarating 

 atmosphere in high latitudes are advantages to the men, and the low 

 temperatures experienced have, so far as we know, no deteriorating 

 effect on the materials used in modern aircraft. Temperature may 

 effect one's comfort and convenience in serving the machines, but on 

 expeditions or established air routes, this service — filling with gasoline 

 and oil and minor adjustments — could be performed at base head- 

 quarters, where the necessary conveniences, such as warmed hangars, 

 oil-heating arrangements, etc., may be easily provided. 



In a cabin of correct design the pilot and navigator can be warm 

 and comfortable. Heat for warming any part of the plane can be 

 taken from around the. exhaust pipe of the engine without interfering 

 with its power or adding much to the weight. A well-lighted cabin 

 will enable the navigator to read his instruments without the eyestrain 

 that would be incurred by looking from points of observation on the 

 brilliant sunlit snow back into a dark cabin. 



In choosing the type of machine for work confined to reconnais- 

 sance, consideration must be given to the maximum non-stop distance 

 to be covered. If airplanes are to be used, a multiple-engine machine 



