STOUY OF EXPERIMENTS IN MECHANICAL FLIGHT. 171 



possessed in the steam engine, as then constructed or in other heat 

 engines, more than the indispensable power, though it was added that 

 this was not asserting that a system of supporting surfaces could be 

 securely guided through the air or safely brought to the ground, 

 and that these and like considerations were of quite another order, 

 and belonged to some inchoate art which I might provisionally call 

 aerdromics. 



These important conclusions were reached before the actual publica- 

 tion of the volume, and a little later others on the nature of the move- 

 ments of air, which were published under the title of " The internal 

 work of the wind" (Smithsonian Contributions to Knowledge, Volume 

 XXVII, 1893, No. 884). The latter were founded on experiments inde- 

 pendent of the former, and which led to certain theoretical conclusions 

 unverified in practice. Among the most striking, and perhaps para- 

 doxical of these, was that a suitably disposed free body might, under 

 certain conditions, be sustained in an ordinary wind, and even advance 

 against it without the expenditure of any energy from within. 



The first stage of the investigation was now over, so far as that I 

 had satisfied myself that mechanical flight was possible with the power 

 we could hope to command, if only the art of directing that power 

 could be acquired. 



The second stage (that of the acquisition of this art) I now decided 

 to take up. It may not be out of place to recall that at this time, only 

 six years ago, a great many scientific men treated the whole subject 

 with entire indifierence, as unworthy of attention, or as outside of legiti- 

 mate research, the proper field of the charlatan, and one on which it 

 was scarcely prudent for a man with a reputation to lose to enter. 



The record of my attempts to acquire the art of flight may commence 

 with the year 1889, when I procured a stuffed frigate bird, a California 

 condor, and an albatross, and attempted to move them upon the whirl- 

 ing table at Allegheny. The experiments were very imperfect and the 

 records are unfortunately lost, but the important conclusion to which 

 they led was that a stuffed bird could not be made to soar except at 

 speeds which were unquestionably very much greater than what served 

 to sustain the living one, and the earliest experiments and all subse- 

 quent ones with actually flying models have shown that thus far we 

 can not carry nearly the weights which Nature does to a given sustain- 

 ing surface without a power much greater than she employs. At the 

 time these experiments were begun, Penaud's ingenious but toy-like 

 model was the only thing which could sustain itself in the air for even 

 a few seconds, and calculations founded upon its performance sustained 

 the conclusion that the amount of power required in actual free flight 

 was far greater than that demanded by the theoretical enunciation. 

 In order to learn under what conditions the aerodrome should be bal- 

 anced for horizontal flight, I constructed over thirty modifications of 

 the rubber-driven model, and spent many months in endeavoring from 



