LANGLEY LEFFMANK. 165 



the engine which the American builder had made and in the latter 

 part of 1900 began his work. He was able in September of that year, 

 to construct an engine weighing 108 pounds which gave on the 

 Prony brake, 18.5 horsepower at 750 revolutions per minute. The 

 cylinder's were, however, without water jackets, being cooled with 

 wet cloths, which, of course, would permit only short runs. 



The details of the development of the engine, of the difficulties 

 with sparking apparatus, carburetors, pistons, packing, lubrication, 

 and all the other vexations that go to make up what are collectively 

 known as " engine troubles " are described vividly and fully in the 

 " Memoir," but space does not permit of even a brief summary here. 

 Not the least of the troubles in the history of the affair was the 

 weather, which was very often exceedingly unfavorable. 



Finally, however, an engine was built which recorded 52.4 horse- 

 power at the average speed of 950 revolutions per minute, with an 

 approximate weight for the engine proper of 124.17 pounds, or, in- 

 cluding the improved water jackets, fly-wheels, spark coil, batteries, 

 etc., complete, a total of 187.47 pounds. 



Mr. Manly volunteered to be the operator for the first trip of the 

 aerodrome. His chief consented to this, though with much reluc- 

 tance. Every possible precaution was taken to prevent serious acci- 

 dent, and on October 7, 1903, about 16 years after the work had be- 

 gun at the Allegheny observatory, the machine was launched with 

 Manly in the aviator's chair. It was a little after noon that the 

 machine glided down the launching track. The operator soon felt 

 the sensation of being free in the air, when he noted that he was plung- 

 ing downward at a very sharp angle, and instinctively grasped the 

 wheel which controlled the Penaud tail, intending to throw it up 

 so as to depress the rear, but the effort failed, the machine crashed 

 into the water and it was with some difficulty that the operator was 

 saved from drowning. The machine was recovered from the water 

 and certain slight defects discovered as the cause of the mishap. 

 Arrangements were made to remedy these and the party returned 

 to Washington, after giving out a brief statement to the press. For- 

 tunately, an excellent photograph had been secured just as the ma- 

 chine left the launching platform, and also another taken close to 

 the wings, from which certain important facts can be easily estab- 

 lished. 



Examination showed that the machine was not seriously injured 

 and it was decided to make another attempt, but for convenience a 

 spot much nearer to Washington was chosen. On account of the 

 lateness of the season, favorable weather was unusual, and it was 

 December 8 before conditions were satisfactory. Some delay oc- 

 curred in getting the machine taken to the place of trial, and dark- 



136650°— 20 12 



