I have observed particularly the following points with the Jamaica specimen (which I can only give, however, approximately), and I should like to have you give corresponding ones for our Washington buzzard if you can oblige me. [p286]
I note here that the measurements were made on a live bird and that it was impracticable to get the separate weight of the wings except by estimate, but the two wings may be estimated collectively as 114 lbs., the whole weight being 234 lbs. to 3 lbs.
Approximate values:
- Weight of the bird complete, 3 pounds.
- Length of bird, 23 inches.
- Spread of wings from tip to tip, 5 ft. 5 in.
- Complete curtate area of both wings (that is, the area of the shadow of the bird’s wings when these are fully extended under a vertical sun) is 600 square inches, or nearly 4 sq. ft., consequently each square foot of the bird’s sustaining surface carries 34 lbs. Diedral angle nearly 150°.
When the bird is soaring in a nearly calm atmosphere, which it inexplicably does,—soaring I mean nearly in line of the observer’s eyes and coming directly to of going directly away from him,—it presents nearly the following appearance:
FIG. 1—Jamaica, Mch. 22, 1900. “John Crow.” Sketch soaring horizontally, by W. H. Holmes. Weight 3 lbs. Total wings area = 546 in. Perpendicular distance c below a b = 3.3 in. =
√(546)7 = CP2−CG2.
FIG. 2—Another.