THE LANGLEY AERODROME 463 



take up the work and to use in connection with it such facilities of the 

 institution as were available. 



Before consenting to undertake the construction of this large 

 machine, I had fully appreciated that, owing to theoretical considera- 

 tions, into which I do not enter, it would need to be relatively lighter 

 than the smaller one; and later it was so constructed, each foot of 

 sustaining surface in the large machine carrying nearly the same 

 weight as each foot in the model. The difficulties subsequently ex- 

 perienced with the larger machine were, then, due not to this cause, 

 but to practical obstacles connected with the launching, and the like. 



I had also fully appreciated the fact that one of the chief difficulties 

 in its construction would lie in the procuring of a suitable engine 

 of sufficient power and, at the same time, one which was light enough. 

 (The models had been driven by steam engines whose water supply 

 weighed too much for very long flights.) The construction of the 

 steam engine is well understood, but now it would become necessary 

 to replace this by gas engines, which for this purpose involve novel 

 difficulties. I resolved not to attempt the task of constructing the 

 engine myself, and had accordingly entered into negotiations with 

 the best engine builders in this country, and after long delay had finally 

 secured a contract with a builder who, of all persons engaged in such 

 work, seemed most likely to achieve success. It was only after this 

 contract for the engine had been signed that I felt willing to formally 

 undertake the work of building the aerodrome. 



The contract with the engine builder called for an engine develop- 

 ing 12 brake horsepower, and weighing not more than 100 pounds, 

 including cooling water and all other accessories, and with the proviso 

 that a second engine, exactly like this first one, would be furnished 

 on the same terms. The first engine was to be delivered before the 

 close of February, 1899, and the frame of the aerodrome with sus- 

 taining surfaces, propellers, shafting, rudders, etc., was immediately 

 planned, and now that the engine was believed to be secured, their 

 actual construction was pushed with the utmost speed. The previous 

 experiments with steam-driven models, which had been so successful, 

 had been conducted over the water, using a small house-boat having 

 a cabin for storing the machine, appliances and tools, on top of which 

 was mounted a track and car for use in launching. As full success 

 in launching these working models had been achieved after several 

 years spent in devising, testing and improving this plan, I decided 

 to follow the same method with the large machine, and accordingly 

 designed and had built a house-boat, in which the machine could not 

 only be stored, but which would also furnish space for workshops, 

 and on the top of which was mounted a turntable and track for use 

 in launching from whatever direction the wind might come. 



