268 THE STRUCTURE AND LIFE OF BIRDS chap. 



that their weight is insufficient to give them momentum. 

 This may be the true explanation. When we speak 

 of a soaring bird as a kite, the momentum is the 

 string, and the small bird with a spread of wing, for 

 him, so large, may be like a kite whose string is too 

 weak to hold it. Those who maintain the superiority of 

 the small to the big, would perhaps say that they do 

 not get the wind to help them, because they have no 

 need of its help. 



Velocity. 



Many and various are the methods by which 

 attempts have been made to measure the velocity of 

 birds' flight. Audubon found rice in the crops of 

 Pigeons which, judging by its condition, he estimated 

 had been eaten six hours before. This rice they could 

 only have obtained in Carolina, which was 300 — 400 

 miles distant. These data give at the lowest estimate 

 a velocity of fifty miles per hour. The Frigate Bird 

 is often seen flying over mid-ocean, and it is said that 

 he never travels at night, and never sleeps upon the 

 sea. Hence, a very rough calculation of the pace of 

 his flight may be made. 



Such methods, however ingenious and interesting, 

 are most unsatisfying. We want indisputable 

 measurements, and it is only in the case of one or 

 two species that they are obtainable. The racing of 

 Homing Pigeons is a popular amusement in England, 

 Belgium, and other countries, and " times " are 

 accurately taken. In 1892 a pigeon, according to 

 the published record, accomplished a flight of 114 

 miles at a rate of eighty miles per hour. This is so 



