Aerodrome in the Air during its 

 Flight on May 6, 1896. 



would propel and sustain in horizontal 

 flight at a velocity of about forty 

 miles an hour a little over 200 pounds. 

 Langley's experiments were in the 

 main made with a whirling-table which 

 forces the model to move in horizontal 

 flight and at a fixed angle. In 1887, 

 however, he began experiments with 

 free-flying models at the Allegheny 

 Observatory, following Pinaud in 

 using twisted rubber as motive power. 

 Some forty models were made, but 

 while, as Pinaud had shown, a small 

 toy could be made to fly for a few 

 seconds, the motive power was inade- 

 quate for a larger machine or a longfir 

 flight. 



In 1891 Langley began the construc- 

 tion of a steam engine. Daimler had 

 invented the internal-combustion en- 

 gine in 1885, but its possibilities were 

 not at first realized, and it was neces- 

 sary to wait for the development of 

 , the automobile to demonstrate the re- 

 \ markable combination of power and 

 lightness in an engine which has made 

 possible the contemporary aeroplane. 

 After innumerable experiments a steam 

 engine was constructed weighing about 

 six pounds and of approximately one- 

 horse power. An aerodrome, chiefly of 

 steel, weighing, apart from fuel and 

 water, about twenty-four pounds, was 

 launched on the Potomac River on May 

 6, 1896, and flew for over half a mile. 

 It alighted with safety and performed 

 a second flight on the same day. This 

 was a performance of great historic 

 interest. The paths of the aerodrome 

 ' on May 6 and again on November 28 

 ■ are here reproduced, as also an instan- 

 taneous photograph of the aerodrome in 

 the air, which bears a remarkable re- 

 semblance to a contemporary picture. 

 In 1898 the board of ordnance and 

 fortifications of the war department 

 appropriated $50,000 for experiments 

 with a man-carrying aerodrome. Lang- 

 ley was at first indisposed to complete 

 the work which he had carried so far, 

 believing that might be left to com- 

 mercial enterprise. It was, however, 

 undertaken with the assistance of Mr. 

 Manly, who now describes the results 

 in this memoir. The great difficulty, 

 as before, was with the engine. A 

 New York builder could not supply the 



