NO. 3 
APPENDIX 
289 
If you could get Mr. Holmes (who made most of the sketches and all of the 
photographs of the “ John Crow ”), to try and do something like this for your 
buzzard, especially getting such a photograph of it in flight , as will give the posi- 
tion of its center of gravity relative to the center of pressure on the wings, it 
would add very greatly to the value of your memoranda, and I think Mr. Holmes 
takes so full and intelligent an interest in the subject, that he might be pleased 
to give his help. 
Very truly yours, 
S. P. Langley, 
' Secretary. 
Me. Robeet Ridgway, 
Smithsonian Institution, 
Curator, Division of Ornithology, IT. S. National Museum, Washington, 
D. C. 
In response to this request, Mr. Ridgway submitted the following very inter- 
esting information : 
Smithsonian Institution, 
United States National Museum 
Washington, D. C., October 16, 1900. 
Peoe. S. P. Langley, 
Secretary, Smithsonian Institution. 
Sib: 
I have the honor of submitting herewith the data obtained by Mr. Rolia P. 
Currie concerning measurements, etc., of the common Turkey Buzzard ( Cathartes 
aura ) of the United States, as requested by you in your letter of March 29, last. 
The difficulties in the way of securing these data, already explained by me in 
previous communications, are responsible for the delay in submitting them. 
Hoping that this material may prove of use to you, I am, 
Very respectfully, 
R. Ridgway, 
Curator, Division of. Birds. 
Memoeanda in Regaed to the Tubkey Buzzaed (Second Specimen) 
1. Weight. — 1850 grammes. 
2. Area of outstretched wings. — 641 square inches. (Computed from three 
sheets of tracings, A t and A 2 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 icings 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 
33 
