no. 3 \iTK\m\ 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 '•enter of pressure on the (rings, it 

 would add very gi eat ly to the value of your memoranda, and I think M r. Bolt 

 takes so full and intelligent an interest in the subject, that he might be pleased 

 to give his help. 



Very truly yours, 



S. P. Lan<;u.\ . 

 Secretary. 

 Mr. Robert Ridgway, 



Smithsonian Institution, 



Curator, Division of Ornithology, U. 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. 



Prof. S. P. Langley, 



Secretary, Smithsonian Institution. 

 Sib: 



I have the honor of submitting herewith the data obtained by Mr. Rolla 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, 



P. Ridgway, 

 Curator, Division of Birds. 



Memoranda in Regard to the Turkey Buzzard (Second Specimen) 



1. Weight. — 1850 grammes. 



2. Area of outstretched wings.— Ml square inches. (Computed from three 

 sheets of tracings, A x and A 2 comprising the entire area oi both wings; B, a 

 single wing.) . 



Note.— As the bird was in process of moult, one of the large wing ; quills, as 

 shown bv the tracings and compod.oard patterns, is but partially developed, 

 thus slightly modifying the results obtained. Its length, if lull grown, would be 

 nearly the same as that of the quill just above it. 



3. Distance between the lips of these wings.-5 feet, 8.7 niches. 



4. Distance between the lips of the same wings when the Inn ism ko™ordal 

 soar i n a /^.-Estimating the dihedral angle ot the wings to be 150 and 

 elevating the wings st> as to make this angle, the distance between then- tips 



33 



