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the size and shape of the aeroplane, having the threads of the fabric arranged-diagonally to the transverse spars and longitudinal ribs, as indicated at 6 in Fig. 2. Thus the diagonal threads of the cloth form truss systems with the spars and ribs, the threads constituting the diagonal members. A hem is formed at the rear edge of the cloth to receive a wire 7, which is connected to the-ends of the rear spar and supported by the rearwardly-extending ends of the longitudinal ribs 5, thus forming a rearwardly-extending flap-or portion of the aeroplane. This construction of the aeroplanes gives a surface which has very great strength to withstand lateral and longitudinal strains, at the same time being capable of being bent or twisted in the manner hereinafter described.

When two aeroplanes are employed, as in the construction illustrated, they are con- nected together by upright standards 8. These standards are, substantially rigid, be- ing preferably constructed of wood and of equal length, equally spaced along the front, and rear edges of the aeroplane, to which they are connected at their top and bottom ends by hinged joints or universal joints of any, suitable description. We have shown one form of connection which may be-used for this purpose in Figs. 4 and 5 of the draw- ings. In this construction each end of the standard 8 has secured to it an eye 9, Which engages with a hook 10, secured to a bracket-plate 11, which latter plate is in turn fastened to the spar 3. Diagonal braces or stay wires 12 extend from each end of each standard to the opposite ends of the adjacent standards, and as a convenient-mode of attaching these parts I have shown a hook 13 made integral with the hook 10 to receive the end-of one of the stay-wires, the other stay-wire being- mounted on the hook 10. The hook 13 is shown as bent down to retain the stay—wire in connection to it, while the hook 10 is shown as provided with a pin 14 to hold the stay-wire 12 and eye 9 in position thereon. It will be seen that this construction forms a truss system which gives the whole machine great transverse rigidity and strength, while at the same time the jointed connections of the parts permit the aeroplanes to be bent or twisted in-the manner which we will now proceed to describe.

15 indicates a rope or other flexible con- nection extending lengthwise of the front of the machine above the lower aeroplane, pass- ing under pulleys or other suitable guides 16 at the front corners 'e and f of lower aero- plane, and extending thence upward and rearward to the upper rear corners c and d of the upper aeroplane, where they are attached, as indicated at 17. To the central portion of this rope there is connected a laterally-movable cradle 18, which forms a means for moving the rope lengthwise in one direction or the other, the cradle being movable toward either side of-the machine. We have devised cradle as a convenient means for operating the rope 15, and the machine is intended to be generally used with the-operator lying face downward on the lower aeroplane, with his head to the front, so that the operator’s body rests on the cradle, and the cradle can be moved laterally by the movements of the operator's body. It will be understood, however, that the rope may be manipulated in any suitable manner.

19 indicates a second rope extending transversely of the machine along the rear edge of the body portion of the lower aeroplane, passing under suitable pulleys or guides 20 at the rear corners g and h of the lower aeroplane, and extending thence diagonally upward to the front corners a and b of the upper aeroplane, where its ends are secured in any suitable manner, as indicated at 21.

Considering the structure so far as we have now described it and assuming that the cradle 18 be moved to the right in Figs. 1 and Fig. 2, as indicated by the arrows applied to the cradle in Fig. 1 and by the dotted lines in Fig. 2, it will be seen that that portion of the rope 15 passing under the guide-pulley at the corner e and secured to the corner d will be under tension, while slack is paid out throughout the other side or half of the rope 15. The part of the rope 15 under tension exercises a downward pull upon the rear upper corner d of the structure and an upward pull upon the front lower corner e as indicated by the arrows. This causes the corner d to move downward and the corner e to move upward. As the corner e moves upward it carries the corner a upward with it, since the intermediate standard 8 is substantially rigid and maintains an-equal distance between the corners a and e at all times. Similarly the standard 8, connecting the corners d and h, causes the corner h to move downward in unison with the corner d. Since the corner a thus moves upward and the corner h moves downward, that portion of the rope 19 connected to the corner a will be pulled upward through the pulley 20 at' the corner h, and the pull thus exerted on the rope. 19 will pull the corner b on the other side of the machine downward and at the same time pull the corner g at said other side of the machine upward. This results in a downward movement of the corner b and an upward movement of the corner c. Thus it results from a lateral movement of the cradle 18 to the right in Fig. 1 that the lateral margins a d and e h at one side of the machine are moved from their normal positions, in which they lie in the normal planes of their respective aeroplanes, into angular relations with said normal planes, each lateral margin on this side of the machine being raised above said normal plane at its forward end and depressed below said nor-