samue;i. pierpont langley. o-, 



opened the way to others who have since achieved success with man- 

 carrying flying-machines. 



Meanwhile, in 1893, he pubHshed his celebrated paper upon "The 

 Internal Work of the Wind," based on quite another series of ex- 

 periments. He showed in this that the irregularities of the wind 

 were very nutch greater than theretofore supposed ; that they could 

 be utilized as a source of power, and might account for the soaring 

 upon outstretched, unflapping wings of certain species of birds. It 

 is believed that further reflections and computations convinced him 

 that these irregularities of the wind were probably not sufficient to 

 account fully for soaring flight. They doubtless are utilized on 

 occasion, but the main source of the power to soar and to overcome 

 the wind more probably comes from the rising trends which exist in 

 the air. 



It would have been far better for Mr. Langley's happiness and 

 reputation if he had terminated his experimenting with the demon- 

 stration, in 1896, that artificial flight was possible. He had made 

 a steam-engine fly nearly a mile, he had elucidated the general prin- 

 ciples, had given some data for computing the resistance and the 

 power required, rescued the subject from general disbelief in possi- 

 ble success, and placed the inchoate art upon firm ground. Here it 

 would have been preferable for him to stop, merely publishing such 

 additional data as he had gathered, so that they might be used by 

 others ; for few scientists possess the double faculty of investigating 

 the basic principles and of then applying them to produce practical 

 results. 



In 1898, however, a board of United States Army and Navy 

 officers recommended that a full-sized man-carrying machine should 

 be developed for war purposes. The Board of Ordnance and Forti- 

 fication of the United States Army made an allotment of $50,000 for 

 that purpose, and Mr. Langley agreed to supervise the work without 

 any remuneration to himself. He has given an account of the build- 

 ing of that machine, which occupied five years, in his paper of 1905, 

 entitled "Experiments with the Langley Aerodrome." As might 

 have been expected, there were endless delays and mishaps, more 

 particularly in developing the motor, which, after the failure of pri- 

 vate parties to furnish what they had contracted to deliver, was 

 finally built in the Smithsonian shops under the design and direction 

 of Mr. C. M. Manly. As finally completed, it was a marvel, being 

 a gasoline motor of 52 brake horse-power, weighing with cooling 

 Avater, carburetter, battery, etc., somewhat less than five pounds to 

 the horse-power — an achievement which now, five years later, has 



