32 SMITHSONIAN MISCELLANEOUS COLLECTIONS. 



Most important of all, this publication gave the sanction of Ijigh 

 scientific authority to a line of investigation theretofore despised and 

 left to "cranks." The brothers Wright, in a private letter, say : 

 ''The knowledge that the head of the most prominent scientific insti- 

 tution of America believed in the possibility of human flight was one 

 of the influences that led us to undertake the preliminary investiga- 

 tion that preceded our active work. He recommended to us the 

 books which enabled us to form sane ideas at the outset. It was a 

 helping hand at a critical time, and we shall always be grateful." 



In a truly scientific spirit, Mr. Langley gave to others the data and 

 information which he had secured, and it may be well here to quote 

 the closing words of his memoir on "Experiments in Aerodyna- 

 mics" : "I wish, however, to put on record my belief that the time 

 has come for these questions to engage the serious attention, not 

 only of engineers, but of all interested in the possibly near practical 

 solution of a problem, one of the most important in its consequences 

 of any which has ever presented itself in mechanics ; for this solu- 

 tion, it is here shown, cannot longer be considered beyond our capac- 

 ity to reach." And now, fifteen years after, those words were 

 published, we are in possession of a solution of a problem which had 

 bafified the ingenuity of man since the dawn of history. 



When Mr. Langley became Secretary of the Smithsonian Institu- 

 tion, in 18S7, he resumed and extended his experiments in aero- 

 dynamics, and the results led him to take up the second stage of the 

 investigation, by endeavoring to show hoiv the facts ascertained 

 might be practically applied to artificial flight for man. For this 

 purpose he built from 1891 to 1895 four model flying-machines — 

 one driven by carbonic acid gas and three by steam-engines. W^ith 

 these he encountered, of course, a series of disappointments and fail- 

 ures, of which he has given a most interesting account in the "Aero- 

 nautical Annual" for 1897, and thus put others on their guard against 

 the same difficulties. 



At last, on the 6th of >May, 1896, he had the very great satisfaction 

 of seeing his faith and perseverance rewarded by the celebrated 

 flights of his "Aerodrome No. 5" for a distance of about 3,000 feet. 

 An account of this flight, by Dr. Alexander Graham Bell, will also 

 be found in the Aeronautical Annual for 1897. This was followed 

 on the 28th of November, 1896, by a successful flight of "Aerodrome 

 No. 6," and these performances have been repeated many times 

 since on occasions of which no public accounts have been given. 

 Langley was undoubtedly the first man to produce successful flights 

 of convincins: lengths of models with an artificial motor, and he thus 



