NO. 5 SMITHSONIAN INSTITUTION AND WRIGHT BROTHERS 23 



22. With reference to the second question, although there were 

 some changes in the supporting and guiding surfaces in the Ham- 

 mondsport machine as compared with those of the 1903 machme, 

 they were not, in our judgment, material, either as regards the 

 Hammondsport machine when fitted with the original Manly 

 engine, or subsequently when modified by a more powerful engme 

 with a tractor screw. Moreover, the machine as it stood was vir- 

 tually an exact copy of a quarter-size model which had shown itself 

 aerodynamically quite satisfactory. We conclude, accordingly, that 

 the answer to the second of the fundamental questions above is 

 also in the affirmative. 



23. When it comes to the question of strength, the case is not so 

 clear. There is no question that the changes made in 1914 provided 

 additional strength. Additional strength was obviously needed if 

 40 per cent additional weight was to be carried. However, the 

 fact that additional strength was provided renders it impossible to 

 remove the third question from the realm of controversy. This is 

 a question for technical experts. A complete wing, one-quarter of 

 the sustaining area, showed, by sand load test, ability to carry a 

 total weight of 260 pounds without damage, while one-quarter of 

 the weight of the original machine and pilot was 207^ pounds, 

 only. Subsequently, the Hammondsport machine with a much 

 more powerful engine (a Curtiss 80 horsepower engine) and with 

 only a moderate increase in strength, showed itself capable of 

 flight carrying 1,520 pounds, or 85 per cent more weight than the 

 original machine of 1903. These facts, in our opinion, establish 

 a strong presumption in favor of the adequacy of the structural 

 strength of the original machine. However, we have asked the 

 disinterested head of the Design Section of the Bureau of Aero- 

 nautics of the Navy Department, to study with his experts the 

 original machine and give us their opinion as to the adequacy of 

 the original structure They are of the opinion that structurally the 

 original Langley flying machine was capable of level and controlled 



flight. 



24. It should not be thought that the original Langley machine 

 ■ was, in any sense, a finished product. Langley himself regarded 

 his machine as only a beginning ; numerous problems had occurred 

 to him which needed solution before aviation could be considered 

 practicable. Since Langley and the Wright brothers looked at the 

 subject from such different angles it would have been an inesti- 

 mable advantage to the science and the art of aviation if Langley 

 had been able to continue his work. 



