THE SOARING OF BIRDS 105 



writer in the playing fields at Eton in an autumn 

 gale. 



The strong wind struck the tall front of Windsor 

 Castle and the terrace scarp, and caused a strong up- 

 draught, carrying the dead leaves of the trees high up 

 above the battlements of the towers. On this up- 

 current the rooks were floating and sailing with 

 motionless wings, and up among and between the 

 black rooks floated the yellow leaves. In the same 

 way we have watched the sea-gulls soaring in the 

 strong upward current of air near the top of a cliff 

 against which a high wind was blowing. But these were 

 exceptional conditions ; and there are many birds, 

 such as the kite, the condor and the vultures, with 

 whom this wonderful and effortless soaring is the 

 normal way of flight. Darwin thus describes the 

 soaring of the condors : ' When the condors are 

 wheeling in a flock round and round any spot, their 

 flight is very beautiful. Except when rising from the 

 ground, I do not recollect ever having seen one of these 

 birds flap its wings. I watched several for nearly 

 half-an-hour without once taking off my eyes. They 

 moved in large curves, sweeping in circles' [as did the 

 kites at Mayence], ' descending and ascending without 

 giving a single flap. As they glided close over my 

 head, I intently watched from an oblique position the 

 outline of the separate and great terminal feathers of 



