NO. 3 DR. LANGLEY S PARADOX — PARKINSON 3 



Langley viewed the solution of an aeronautical problem, the answer 

 was to be found in the power-plant and the application of that power. 

 This factor of power is more than ever a part of scientific rocket re- 

 search. The development of flight had awaited the development of a 

 light-weight engine which could be harnessed to propellers and pull 

 or push sustaining surfaces or wings through the air to create lift 

 and, hence, flight. Langley designed and built his "aerodrome" using 

 sustaining wings. Then on September 25, 1902, while on a trip to 

 Boston, he again opened his mind to Manly. Langley acknowledged 

 a telegram from Manly and noted that Maxim ■' would not enter his 

 engine for the prize offered by the St. Louis Exposition of 1904. He 

 then concluded with this paragraph : ® 



I have been thinking of something so paradoxical that I hesitate to enunciate 

 it even as a mere possibility. The very idea of the aerodrome as we have always 

 conceive [sic] it, has been to obtain support from sustaining surfaces driven 

 against the air. I seem to see my way to dispensing with the surfaces absolutely 

 and altogether so long as the engine works. I do not mean that this is a hypo- 

 thetical possibility, but something apparently practical and perhaps within our 

 actual means, or very near it. It is one of the very simple things which we both 

 know are the last to be seen, but I will write to you or better talk to you about 

 this later. 



If Langley had any further thoughts on the possibility of wingless 

 aircraft he must only have spoken of them to Manly ; there is ap- 

 parently no further correspondence between them on this subject. 

 LJpon his return to Washington Langley did, however, pursue the 

 subject one step further. In a memorandum dated October 14, 1902, 

 he recorded the conversation in which : 



I submitted to Professor Newcomb "^ today the following question, using con- 

 crete values "to fix our ideas." 



A spherical rocket head, which weighs 20 pounds, is initially maintained in 

 place by a vertical pressure of 20 pounds caused by reaction and due to a force 

 which we may suppose, for illustration, to be i horsepower. 



Next, let us suppose the axis of the reactive jet still to be directed to the centre 

 of gravity of the head, but at some acute angle o with the horizon. 



I understand that the rocket will advance indefinitely in a horizontal line with 



accelerated velocity under the impulse of a constant force -^— o being 2 horse- 



sm 

 power producing 40 pounds.^ 



^ Sir Hiram Maxim, who had conducted aeronautical experiments in England 

 in 1894. 



♦5 Langley to Manly, Boston, Mass., September 25, 1902, op. cit., p. 152. 



'^ Prof. Simon Newcomb, mathematician and astronomer who for many years 

 was associated with the Nautical Almanac and the U. S. Naval Observatory. 



8 Added to the original copy, in handwriting believed to be Langley's, "in case 



