370 WINGS OP BIRDS. 



have large wings ; whilst those whose wings are short, or of a 

 medium size in comparison with the size of the body, fly with 

 much less speed, and are obliged to rest more frequently. 



332. Among the Birds remarkable for the speed of their 

 flight, we may mention the Condor, and the Frigate-Bird 

 (Fig. 304). The Condor, or great Vulture of the Andes, is 

 sometimes thirteen feet across the wings ; and rises higher than 

 any other Bird ; it is seen sometimes on the sea-shore, sometimes 

 hovering over Chimborazo, that is, at an elevation of nearly 

 22,000 feet above the first point. Its usual dwelling is on 

 the ridges of the Cordilleras of the Andes, immediately below 

 the limit of perpetual snow, at a level of from 10,000 to 15,000 

 feet above the level of the sea. It is from these pinnacles that 

 it descends into the valleys and plains to seek its food, which 

 consists principally of the corpses of large Mammalia ; it is even 

 said that several together can easily kill oxen, and that they are 

 strong enough to carry off in their claws Sheep and Llamas, and 

 thus transport them to the top of Chimborazo, and the other 

 loftiest mountains of the chain of the Andes. The Frigate-Birds, 

 whose wings are longer in proportion to their size, and which 

 dwell on the tropical seas, have so powerful a flight, that they 

 can venture to a distance of more than 400 leagues from land. 



333. To rise vertically in the air, it is necessary that the 

 wings of the Bird should be entirely horizontal ; but this is not 

 usually the case ; they are generally inclined from before back- 

 wards, so as to give the animal an obliquely- ascending movement; 

 sometimes this inclination is such, that to rise nearly vertically 

 in the air, the Bird must fly against the wind. The relative 

 length of the wing-feathers influences the facility with which it 

 can rise in calm air ; the Birds whose primaries are the longest 

 and most resisting at their extremity, have a more oblique flight 

 than those whose wing is rounded at the end. Thus the Falcons 

 which have pointed wings, can rise only in a zigzag, like a 

 tacking vessel, or by flying against the wind ; while Sparrow- 

 hawks, Eagles, and other Birds of prey termed ignoble, whose 

 wings are truncated (or abruptly cut short) at their extremity, 

 can rise vertically (Fig. 182). When the Bird wishes to rise 



