BRANCH CHORD AT A; CLASS 



THE BIRDS 365 



'his soaring has been the subject of much observation 

 nd study but is still imperfectly understood. The soaring 

 ird evidently takes advantage of horizontal air-currents, 

 nd some observers maintain that upward currents also 

 lust be present. The principal hopes for the invention 

 f a successful flying-machine rest on the power of soaring 

 ossessed by birds. The speed of flight of some birds is 

 normous, the passenger-pigeon having been estimated 



% IG. 144. Oriole's nest with skeleton of blue jay suspended from it; the 

 blue jay probably came to the nest to eat the eggs, became entangled 

 in the strings composing the nest, and died by hanging. (Photograph 

 by S. J. Hunter.) 



o attain a speed of one hundred miles an hour. The 

 ong distances covered in a single continuous flight by 

 ertain birds are also extraordinary, as is also the total 

 listance covered by some of the migrants. "It is said 

 hat some plovers that nest in Labrador winter in Pata- 

 gonia, their long wings easily carrying them this great 

 listance." 



