WIND AND FLIGHT 141 



extremity of Man. The wind blowing from the west 

 struck against the cliffs and was deflected upward. 

 The Gulls, as they always do, saw their chance ; 

 here was a fine, effort-saving up-draught. Flying 

 to the base of the cliff, they were lifted to the top 

 and far above it. They would then turn and face 

 the wind, and, with the left wing leading, return to 

 their night quarters, their heads being inclined just 

 a little towards the south. Occasionally Gulls adopt 

 this method of travelling when the wind blows 

 almost at right angles to the course of a steamer. 

 They will hang over it and keep pace with it, their 

 wings pointing to bows and stern. The slight adjust- 

 ments that they have to make for balancing purposes 

 are unceasing, but they are easily distinguishable 

 from the strong wing-strokes of ordinary flight. 



The two methods — advance in the teeth of the 

 wind and advance with one wing leading — pass into 

 one another. Obviously so, since, to get support 

 from an upward trending wind, the Gull either 

 faces it or much less often turns his tail towards 

 it. Hence the necessity of progression sideways 

 when he wishes to travel in a straight line at a 

 right angle to the wind. When he travels at a half 

 right angle to it, the line of advance will bisect the 

 angle between the axis of his body and his wing. 

 To put it less mathematically, he will be half-side 

 face towards his line of advance. 



Soaring. 



Perhaps a definition of soaring may be useful. 

 The word is used to describe the spiral ascent of a 

 bird in the air, effected without taking any strokes 



