114 EXPERIMENTS WITH THE LANGLEY AERODROME. 



to use ill rouiiec'lioii witli it such facilities of the Institution as were 

 avaihihle. 



Before consenting to uiulertake the construction of this hirge 

 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 

 experienced 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 difficul- 

 ties in its construction w'ould 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 

 Aveighed 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 Avork, 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 developing 

 12 brake horsepower, and weighing not more than 100 pounds, includ- 

 ing 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 Avas to be delivered before the close 

 of February, 1899, and the frame of the aerodrome with sustaining 

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

 and now that the engine was believed to be secured, their actual con- 

 struction was pushed with the utmost speed. The previous experi- 

 ments with steam-driven models, Avhich 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 Avorking models had been achieved after several 

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

 to folloAV the same method Avith the large madiine, and accordingly 

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

 only be stored, but Avhich Avould also furnish space for workshops, 

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

 in launching from whatever direction the Aviiicl might come. 



