114 EXPERIMENTS WITH THE LANGLEY AERODROME. 



to use in coiiiu'ctioii with it such fiu-ilities of the Institution as were 

 iivaihihle. 



Before consent in<,^ 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 Avas 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 Avith 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 chi(>f 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 wdiose water supply 

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

 steam engine is w-ell understood, but now- it Avould become necessary 

 to replace this by gas engines, Avhich 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 achicA^e success. It Avas only 

 after this contract for the engine had been signed that I felt Avilling 

 to formally undertake the Avork of building the aerodrome. 



The contract Avith the engine builder called for an engine dcA-eloping 

 12 brake horsepoAver, and Aveighing not more than 100 pounds, includ- 

 ing cooling A\^ater and all other accessories, and Avith the proviso that 

 a second engine, exactly like this first one, w-ould be furnished on the 

 same terms. The first engine w^as to be delivered before the close 

 of February, 1890, and the frame of the aerodrome with sustaining- 

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

 and noAv that the engine Avas believed to be secured, their actual con- 

 struction Avas pushed Avith the utmost speed. The previous experi- 

 ments with steam-driven models, Avhich had been so successful, had 

 been conducted oA^er the Avater, using a small house-boat having a cabin 

 for storing the machine, appliances and tools, on toj) of Avhich Avas 

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

 hiunching 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 machine, and accordingly 

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

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

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

 in launching from Avhatever direction the Avind migrht come. 



