WIND AND FLIGHT 139 



seem to do, in open-mouthed astonishment. There 

 is one question that, I believe, has been but little 

 investigated. In tropical seas there may be up- 

 currents rising from the heated surface, just as there 

 are from sun-scorched plains even in much higher 

 latitudes, up-currents sufficient to serve the turn 

 of the Albatross. But his evolutions are to be seen 

 in Antipodean regions where no such heating is 

 likely to take place. Myself I have little doubt that 

 the Albatross's art is only that of the Shearwater, 

 though, owing to the great artist's enormous spread 

 of wing, the effect produced is much grander. A 

 writer quoted in Flight (Feb. 3rd, 1912) describes 

 it thus : " The flight is generally near the water, 

 often close to it. You lose sight of the bird as he 

 disappears between the waves and catch him again 

 as he rises over the crest. ... He alters merely the 

 angle at which his wings are inclined." Why, it is 

 just in this style that a Shearwater sweeps down- 

 ward, and then, by the help of a wave and the 

 resultant up -current of air, regains all the altitude 

 he has lost ! 



Advance Sideways in a Direct Line. 



To return to the Gull, a more commonplace, yet 

 intensely interesting subject. Often, when he wishes 

 to advance at right angles to the wind, he faces it 

 and travels with motionless wings sideways, or, 

 more correctly, almost sideways. As if thinking of 

 his objective, he inclines head and body very slightly 

 towards it. We are, of course, presupposing an 

 upward-trending wind ; the Gull is poised upon it. 

 If the left wing leads, then the wind must be blowing 



