CHAPTER VII 



HISTORY OF CONSTRUCTION OF FRAME AND ENGINES OF 



AERODROMES 



During the years 1892 and 1893, it will be recalled, four aerodromes, known 

 as Nos. 0, 1, 2, and 3, had been built, which were of two general types of construc- 

 tion. First, that represented by No. 0, in which a radically weak hull was made 

 to support rods at the front and rear, to which the wings and tail were attached. 

 This aerodrome was abandoned on account of the inability to provide it with 

 sufficient power, as well as because of its constructional weakness. Second, that 

 type represented by Nos. 1, 2, and 3, in which a midrod was carried through 

 from front to rear, around which the hull supporting the machinery was built. 

 These models were much lighter than No. 0, but were all abandoned because 

 it was found impossible to propel even the lightest of them. While all these 

 machines were in the strictest sense failures, inasmuch as none of them was 

 ever equipped with supporting surfaces, yet the experience gained in the con- 

 struction of them was of the very greatest value in determining the points at 

 which strength was needed, and in indicating the mode of construction by which 

 strength and rigidity could be obtained. 1 



1893 



Another aerodrome, known as No. 4 (shown in Plate 11), was designed in 

 the latter part of 1892, and by the end of March, 1893, its construction was well 

 under way. It was of the second type, in that the midrod was continuous, but 

 it differed from the preceding forms in having the machinery (boilers, burners, 

 and tanks) attached directly to the midrod, the hull now taking the form of a 

 mere protective sheathing. As in Nos. 2 and 3, two engines were used, which 

 were mounted on a cross-frame of light tubing attached to the midrod at right 

 angles. It had, as at first constructed, no provision for the generation of steam, 

 but only for carrying a reservoir of carbonic acid to supply gas for the engines. 



The whole, including wings, tail, and engines, but without the carbonic acid 

 reservoir, weighed 1898 grammes (4.18 lbs.). A cylindrical reservoir, weighing 

 521 grammes (1.14 lbs.) and capable of holding 1506 eu. cm. (92 en. in.) was 

 constructed for this purpose, and tested for 30 minutes witli a pressure of 100 



1 It. is to be remembered that these aerodromes were under incessant modifications. No. 4 for 

 instance, presenting successive changes which made of it in reality a number of different machines, 

 one merging by constant alterations into the other, though it still went under the same name. After 

 1895 the type of the models remained relatively constant, but during the first five years of the work, 

 constructions equal to the original building of at least eight or ten independent aerodromes were 

 made. 



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