290 DISCOVERY OH. 



of sustained flight with man-carrying aeroplanes, and 

 they have acknowledged that their confidence in the 

 practical solution of the problem was derived from 

 Langley and his work. 



The knowledge 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 preliminary 

 investigations that preceded our active work. 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. Wilbur and Orville Wright. 



In December, 1903, the Brothers Wright made the 

 first actual flight with an aeroplane driven by a petrol 

 motor. It is constantly stated that artificial flight 

 would have been accomplished long before if engines 

 light enough to drive them had been available, but that 

 is not the case. Flights with two, three, or more 

 passengers show that lightness of the motor is not the 

 only consideration, and motors with equivalent weights 

 were available ten years before the Wrights designed 

 their man-carrying aeroplanes. It was by following 

 the scientific guidance of Langley, and using mechanical 

 ingenuity to extend it, that they were able to give prac- 

 tical effect to the desire of man to rise above the clouds. 



Though the Wrights were the first aviators to make 

 successful flights with a heavier-than-air machine driven 

 by its own power, little was known of their work for 

 about two years after 1903. During this period they 

 were engaged in perfecting their aeroplane until, in 1905, 

 they were able to remain in the air for half an hour and 

 cover a distance of about twenty-four miles. They did 

 not give a public demonstration of their achievements 

 until 1908 two years after a young Brazilian, M. Santos 

 Dumont, had made a short public flight in France, using 



