2 24 The Smithsonian Institution 



began serious work. Many of these investigations have been 

 carried on at the Smithsonian Institution, although some of 

 the earHer elaborate experiments with the whirling table were 

 carried on at the Allegheny Observatory. 



V. 



In 1 89 1 he published his now famous paper entitled "Experi- 

 ments in Aerodynamics," in which he first made public the 

 results of his studies upon this subject. This paper threw 

 new light on the motion of certain forms of bodies through 

 the atmosphere, and resulted in a practical revolution in the 

 conclusions drawn from the study of aerodynamics. His 

 paper on "The Internal Work of the Wind," presented to the 

 International Conference on Aerial Navigation, held in Chi- 

 cago, in 1893, made even a greater impression, especially 

 upon the minds of those engaged practically upon the prob- 

 lem of artificial flight. The importance of the views then 

 for the first time advanced was universally admitted, as is 

 evident from two recent authoritative general works on the 

 subject of aerial navigation, those of Mr. Octave Chanute, of 

 Chicago, and Doctor von Salverda, of Holland. In March, 

 1894, Lieutenant- Colonel Elsdale, of the Royal Engineers, 

 in an article in the Cotitempora^y Revieiv, wrote : 



" Professor Langley may fairly be said to have laid down, 

 for the first time, a really sound and reliable scientific basis 

 for the study of aerial locomotion, by a series of careful ex- 

 periments and well-reasoned deductions from them. What- 

 ever its ultimate measure of success is, new experiments with 

 it cannot fail to advance the cause of aerial navigation another 

 stage." 



To a letter of inquiry in regard to the significance of these 

 contributions to the science of aerodynamics, Mr. Octave 



