288 DISCOVERY en. 



a definite advance of knowledge secured by the methods 

 of exact science. The practical men who, in these 

 days of rapid locomotion, might have been expected to 

 investigate the laws of air resistance, left it to a man of 

 science to prove that a rule which had been accepted 

 for two hundred years was incorrect. His experiments 

 demonstrated that relatively little power was required 

 to sustain a given weight if the horizontal velocity 

 reached a certain rate. All that was needed in or.der to 

 make mechanical flight possible was a light motor 

 capable of forcing a plane or set of planes through the 

 air with sufficient velocity. 



Guided by his results, Langley had a model aeroplane 

 constructed, weighing about 25 Ib. ; and successful 

 flights, each about half a mile in length, were made 

 with it in 1896. His experiments were regarded, how- 

 ever, as the trivial amusements of a scientific man ; 

 and when, in 1903, his man-carrying aeroplane was 

 wrecked, owing to an accident in launching it, so much 

 ridicule was thrown upon the trials that he abandoned 

 the subject and devoted himself to other things. Eleven 

 years later, in 1914, the same machine was used for 

 flights with a pilot. Langley did not live to see this 

 success, but he never lost faith or confidence in the 

 ultimate possibility of aerial flight with heavier-than-air 

 machines. Concluding an account of his experiments in 

 1897, he said : 



I have brought to a close the portion of the work which seemed 

 to be specially mine the demonstration of the practicability of 

 mechanical flight and for the next stage, which is the com- 

 mercial and practical development of the idea, it is probable 

 that the world may look to others. The world, indeed, will be 

 supine if it does not realise that a new possibility has come to it, 

 and that the great universal highway overhead is now soon to 

 be opened. Prof. S. P. Langley. 



