vi! FLIGHT 239 



and thirty yards' distance the wind came in wild gusts, 

 as often upward as downward. Twelve yards to 

 windward of a bank only rising eight feet above the 

 level the vane was not quite steady, but on the whole 

 horizontal. At a distance of six yards there were 

 occasional upward swings ; at four yards' distance 

 there was a decided upward tendency, and this though 

 the bank itself presented only a very gentle incline. 

 These facts go far to explain the soaring of birds over 

 hill-tops or cliffs. 



Rising with the help of the Wind. 



One way to catch Condors is " to place a carcass 

 on a level piece of ground within an enclosure of sticks 

 with an opening, and, when the condors are gorged, to 

 gallop up on horseback to the entrance and thus enclose 

 them ; for when the bird has not space to run, it cannot 

 give its body sufficient momentum to rise from the 

 ground." 1 A Cormorant, wishing to lift himself from 

 the water, faces the wind, and flaps along the surface 

 for some distance and at considerable speed, before he 

 is able to mount upward. The Red-throated Diver is 

 said to be so powerless to begin his flight without a head 

 wind to help him that if you sail down upon him with 

 the wind he must cither fly towards you or remain upon 

 the water, the third alternative of diving often not 

 occurring to his mind. I have never seen a Lark rise 

 facing any way but head to the wind. In fact, all birds 

 seem to derive great assistance from this. 



1 Darwin's Journal of Researches, chap. ix. p. 133 (Minerva 

 Library). 



