TKANSACTIONS OF SECTION G. 869 



The condor vulture, which measures sometimes 15 feet across the wings, will 

 fly upwards till quite out of sight. 



A flock of cranes have been seen migrating at a height of three miles, and pro- 

 . ceeding apparently without any movement of the wings. 



The peregrine falcon will swoop down upon a partridge, and, missing it by a 

 doubling movement of the latter, will slide upwards, thus converting his kinetic 

 into new potential energy. He will then turn and descend again, this time securing 

 his prey. 



Mr. J. E. Harting, one of the principal British ornithological authorities, has, 

 after careful investigation, arrived at the conclusion that the speed of falcons in 

 full flight is about 60 miles per hour.^ 



Mr. W. B. Tegetmeier, another well-known authority, gives ^ the results of a 

 number of experiments on the speed of homing pigeons, made under the auspices 

 of the United Counties Flying Club in 1883. The average speed of Ihe winner in 

 eighteen races was 36 miles, and the maximum 65 miles per hour. The greatest 

 distance flown was 309 miles. 



The albatross, the largest web-footed bird, measuring sometimes 17 feet from 

 tip to tip of wing, and weighing up to 20 lb., frequently accompanies ocean steamers 

 from the Cape to Melbourne, a distance of 5,500 knots, without being seen to rest 

 on the way. 



An American naturalist, Mr. J. Lancaster, who spent no less than five years on 

 the west coast of Florida,^ in order to study the habits of aquatic and other birds 

 which frequent these shores, arrived at the following conclusions, viz. — 



Though all birds move their wings sometimes, many can remain indefinitely in 

 the air, with wings extended and motionless, and either with or without forward 

 movement. This he calls ' soaring.' 



The wing-area of soaring birds varies from 1 to above 2 square feet per lb. of 

 weight. 



The larger the wings per lb. of weight, the greater the power to soar. 



The heavier the bird, the steadier his movements. 



Soaring birds always face the wind, which, if they do not move forward or 

 downward, must not blow at a less speed than 2 to 5 miles per hour. 



Mr. Lancaster specially watched a flock of buzzards about 30 feet above his 

 head, waiting for him to leave the body of a dead porpoise. Their wings were 

 about 8 feet from tip to tip, and their average weight about 6 lb. During three 

 hours at mid- day, when the wind which they faced was very strong, they flapped 

 Their wings about twenty times each. Later, during two hours, when the wind 

 had subsided, they never moved them at all. 



Mr. Lancaster timed frigate birds, and found them able to go at the rate of 100 

 miles per hour, and that on fixed wings ; he is of opinion that at all events up to 

 that speed they can fly just as fast as they please. He says, further, that the 

 same birds can live in the air a week at a time, night and day, without touching 

 a roost, and that buzzards, cranes, and gannets can do the same for several hours 

 at a time. 



The observed facts relating to the phenomena of flight are still but very imper- 

 fectly understood. That a bird should be able to maintain a downward pressure 

 on the air sufiicient to counteract the efl'ect of its own weight, and a backward 

 pressure sufiicient to force itself forward at such speeds as I have named, seems 

 wonderful enough when it is known that it continuously operates its wings. But 

 that it should be able to do the same without any muscular movement at all is 

 almost incomprehensible. It seems to be an instance of the suspension of the laws 

 of gravity and of the existence of cause without effect, and of efl'ect without cause. It 

 is not a case of flotation, like a balloon, for any bird falls to the earth like a stone 

 when shot. Mr. Lancaster .suggests that the bird's own weight is the force which 

 enables him to counteract the effect thereof, but this explanation is, I confess, 

 beyond my comprehension. 



' Field, December 5, 1891, p. 8.56. « 7J(U, January 22, 1887, p. 114. 



' ' Problem of the Soaring Bird,' American Naturalist, 1885, pp. 1055-1162. 



