APPENDIX 



STUDY OF THE AMERICAN BUZZARD AND THE "JOHN CROW" 



In the preparation of this Memoir, the writer lias deemed it besl to generally 

 omit any mention of plans and ideas which were brought forth in the work, an] 

 constructions or tests in accordance with them were carried to a sufficient extent 

 to admit of some definite conclusion regarding them. However, owing to the im- 

 portant part played by the warping of the supporting surfaces, or the variation 

 in the angle of auxiliary surfaces, in the methods of preserving the equilibrium 

 of practically all flying machines of the present day, il may be of interest to here 

 add a short mention of the direction in which plans along this line were orig- 

 inally proposed in this work. Mention has already been made of the importance 

 which Mr. Langley attached to the study of the works of the great master 

 builder, Nature, though recognizing at the same time that owing both to the 

 difference in the forces and methods of construction possible to man, it was not 

 in general possible for him to produce the best results by attempting to too 

 closely imitate the methods or plans of Nature. 



Mr. Langley considered it not practicable or besl to attempt to imitate the 



details of construction of the flying mechanism of birds. At the same time, he' 



strongly believed that much was to be learned from them about the practical 



side of the art of balancing, and he therefore spent a great deal of time both in 



analyzing the methods practiced by the birds in preserving their equilibrium and 



in criticizing his own plans in this direction in (lie light of what Nature would 



seem likely to do if she had to construct a flying creature on such a Large scale. 



In carrying on his investigations in the ail as practiced by the birds, he made a 



trip to Jamaica during the early weeks of 1900, in order to study the species of 



buzzard which are so numerous and tame there ami are known locally as the 



"John Crow." After his return from this trip he wrote the following very 



interesting letter to Mr. Robert Ridgway, requesting certain data regarding the 



American buzzard, which he wished to compare with some data on the " John 



Crow " which he had obtained on this trip: 



Mahcii "J!). L900. 



Dear Mr. Ridgway : 



I have just returned from Jamaica, where among other occupations, 1 have 

 been studying the evolutions of the buzzard locally called the " John Crow," a 

 soaring bird which is almost as much superior in skill to our buzzard as that is 

 to a barn-yard fowl in its power of keeping itself in the air without flapping its 

 wines, in what is very nearly a calm. 



I have observed particularly the following points with the Jamaica specimen 

 (which I can only give, however, approximately), and I should like to have yon 

 give corresponding ones for our Washington buzzard if you can oblige me. 



