Curator, Division of Birds.
MEMORANDA IN REGARD TO THE TURKEY BUZZARD (SECOND SPECIMEN)
1. Weight.—1850 grammes.
2. Area of outstretched wings.—641 square inches. (Computed from three sheets of tracings, A1 and A2 comprising the entire area of both wings; B, a single wing.)
Note.—As the bird was in process of moult, one of the large wing quills, as shown by the tracings and compo-board patterns, is but partially developed, thus slightly modifying the results obtained. Its length, if full grown, would be nearly the same as that of the quill just above it.
3. Distance between the tips of these wings.—5 feet, 8.7 inches.
4. Distance between the tips of the same wings when the bird is in horizontal soaring flight.—Estimating the dihedral angle of the wings to be 150°, and elevating the wings so as to make this angle, the distance between their tips [p290] measures 5 feet, 5.7 inches, or 3 inches less than when fully extended in the horizontal plane.
5. The position of the center of pressure of the wing.—This is indicated on two compo-board patterns, C and D. C was made from a fully extended wing, while D was made from the wing in the soaring position. The centers of pressure of the wings are about 2 feet, 0.5 inches apart, or 1 foot, 0.25 inches from the central point of the bird’s body.
6. The position of the center of gravity of the soaring bird.—(Length of buzzard, 26 inches.) The center of gravity of the soaring buzzard in the horizontal plane, CG1, was found to lie 912 inches behind the tip of the beak and 1612 inches in front of the tip of the tail.
The center of gravity of the soaring bird in the vertical plane, CG2, was found to lie 2.8 inches above the ventral point of the body and 1.6 inches below the dorsal point, the depth of the bird’s body at CG1, being 4.4 inches.