106 PEOCEEDINGS OF REGENTS. 



In this v/ork he laid the foundations for a science and art of aero- 

 dromics, and raised the whole subject of aerial flis^ht to a scientific 

 plane. 



The knowledge that this eminent man of science believed in the 

 practicability of human flight gave a great stimulus to the activities 

 of others and started the modern movement in favor of aviation that 

 is such a marked feature of to-day. 



Everyone now recognizes the influence exerted by Langley on the 

 development of this art. The Wright brothers, too, have laid their 

 tribute at his feet. 



"The knowledge," they say, "that the head of the most prominent 

 scientific institution of America believed in the possibility of human 

 flight was one of the influences that led us to undertake the preliminaiy 

 investigations that preceded our active v/ork. 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." 



CONTRIBUTIONS TO THE SCIENCE OP AERODROMICS. 



Langley's experiments in aerodynamics gave to physicists, perhaps 

 for the first time, firm ground on which to stand as to the long dis- 

 puted questions of air resistances and reactions. Chanute says: 



(a) They established a more reliable coefficient for rectangular pressures than that 

 of Smeaton. 



(6) They proved that upon inclined planes the air pressures were really normal to 

 the surface. 



(c) They disproved the "Newtonian law" that the normal pressure varied as the 

 square of the angle of incidence on inclined planes. 



(d) They showed that the empirical formula of Duchemin, proposed in 1836 and 

 ignored for fifty years, was approximately correct. 



(e) That the position of the center of pressure varied with the angle of inclination, 

 and that on planes its movements approximately followed the law formulated by 

 Joessel. 



(/) That oblong planes, presented with their longest dimension to the line of motion, 

 were more effective for support than when presented with their narrower side. 



(g) That planes might be superposed without loss of supporting power if spaced 

 apart certain distances which varied with the speed. 



(h) That thin planes consumed less power for support at high speeds than at low 

 speeds. 



The paradoxical result obtained by Langley that it takes less power 

 to support a plane at high speed than at low, opens up enormous pos- 

 sibilities for the aerodrome of the future. It results, as Chanute has 

 pointed out, from the fact that the higher the speed, the less need be 

 the angle of inclination to sustain a given weight, and the less there- 

 fore the horizontal component of the air pressure. 



It is true only, however, of the ])lane itself, and not of tlie struts 

 and framework that go to make up the rest of a flying machine. In 



