2 28 The Smithsonian Institution 



The significance of these experiments is summed up by a 

 recent writer as follows : 



" In both its matter and manner, Professor Langley's in- 

 vention, or discovery, is of unique interest. His machine is 

 built upon exactly the opposite principle from that upon 

 which other flying machines have been built, and his inven- 

 tion represents a clear triumph for pure inductive science. 



"When Stephenson built his locomotive he proceeded in 

 his work upon certain definitely known facts ; that is, he was 

 perfectly sure that if he could find a way to push his wheels 

 around by steam, his engine could run over the ground just 

 as an ordinary wagon would. He was venturing into no un- 

 known field of physics. With Professor Langley it was just 

 the opposite. Although men of science for two centuries or 

 more have been studying the dynamics of the air, have 

 weighed it and determined its compressibility, its action un- 

 der heat, etc., yet up to the time Professor Langley took hold 

 of the matter there existed no definite data as to the plan or 

 principle upon which a flying machine, if it is to successfully 

 navigate the air, must be built. To find out these new data 

 was his first work. 



" Put in a less technical way, Professor Langley's problem 

 was this : He says, ' Did you ever think what a physical mir- 

 acle it is for such a bird as one of our common turkey buz- 

 zards to fly in the way it does ? You may see them any day 

 along the Potomac, floating in the air, with hardly a move- 

 ment of their feathers. These birds weigh from five to ten 

 pounds ; they are far heavier than the air they displace ; they 

 are absolutely heavier than so many flatirons. 



" ' I fancy if you saw cannon-balls floating through the air 

 like soap-bubbles you would look upon it as a sufficiently sur- 

 prising matter, if not as a miracle. The only reason that we 

 are not surprised at the soaring bird is that we have seen it 

 from childhood. Perhaps if we had seen cannon-balls float- 

 ing in the air from our childhood we would not stop to inquire 

 how they did it, any more than we now do how the turkey 

 buzzard does it. I am speaking now, of course, not of birds 



