STORY OF EXPERIMENTS IN MECHANICAL FLIGHT. 173 



an apparently familiar construction, promised best in practice, but in 

 taking- it up, I, to my cost, learned that in the special application to be 

 made of it, little was really familiar and everything had to be learned 

 by experiment. I had myself no previous knowledge of steam engi- 

 neering, nor any assistants other than the very capable workmen 

 employed. I well remember my difQculties over the first aerodrome 

 (1:^0. 0), when everything, not only the engine, but the boilers which 

 were to supply it, the furnaces which were to heat it, the i^ropellers 

 which were to advance it, the hull which was to hold all these — were 

 all things to be originated, in a construction which, as far as I knew, 

 had never yet been undertaken by anyone. 



It was necessary to make a beginning, however, and a compound 

 engine was planned which, when completed, weighed about 4 pounds, 

 and which could develop rather over a horsepower with 60 pounds of 

 steam, which it was expected could be furnished by a series of tubular 

 boilers arranged in "bee-hive" form and the whole was to be contained 

 in a hull about 5 feet in length and 10 inches in diameter. This hull 

 was, as in the construction of a ship, to carry all adjuncts. In front of 

 it projected a steel rod, or bowsprit, about its own length, and one still 

 longer behind. The engines rotated two propellers, each about 30 

 inches in diameter, which were on the end of long shafts disposed at 

 an acute angle to each other and actuated by a single gear driven from 

 the engine. A single pair of large wings contained about 50 square 

 feet, and a smaller one in the rear about half as much, or in all some 

 75 feet, of sustaining surface, for a weight which it was expected would 

 not exceed 25 pounds. 



Although this aerodrome was in every way a disappointment, its 

 failure taught a great many useful lessons. It had been built on the 

 large scale described, with very little knowledge of how it was to be 

 launched into the air, but the construction developed the fact that it 

 was not likely to be launched at all, since there was a constant gain in 

 weight over the estimate at each step, and when the boilers were com- 

 pleted it was found that they gave less than one-half the necessary 

 steam, owing chiefly to the inability to keep uj) a proi^er fire. The 

 wings yielded so as to be entirely deformed under a slight pressure of 

 the air, and it was impossible to make them stronger without making 

 them heavier, where the weight was already prohibitory. The engines 

 could not transmit even what feeble power they furnished, without 

 dangerous tremor in the long shafts, and there were other difficulties. 

 When the whole approached completion, it was found to weigh nearer 

 50 pounds than 25, to develop only about one-half the estimated horse- 

 power at the brake, to be radically weak in construction, owing to the 

 yielding of the hull, and to be, in short, clearly a hopeless case. 



The first steam-driven aerodrome had, then, proved a failure, and I 

 reverted during the remainder of the year to simpler plans, among them 

 one of an elementary gasoline engine. 



I may mention that I was favored with an invitation from Mr. Maxim 



