FLYING-MACHINES, ETC. 459 



tail, and which can be inclined upward, or downward, or to one side, 

 and be loaded witli wax so that the centre of gravity of the machine 

 can be brought to the proper position. 



The warj)ing of the wings, X, is obtained by the mobility ot 

 the wing and of the little fingers, M N^ supporting them on the large 

 rods, J/Z, which do not partake of this rotation, A little liga- 

 ment of caoutchouc, D JB, connects the posterior interior angles ot 

 the wings with the middle of the central rod of the machine. This 

 ligament, whose function is similar to that of the posterior paws of the 

 bat, plays the part of an elastic sheet to our wing, so closely resem- 

 bling the topsail of a schooner. The torsions of the wing are thus 

 automatically regulated, as required, by the combined action of the 

 pressure of the air and of this elastic ligament. The interior third 

 of the surface of the wing acts like a kite during the elevation as well 

 as during the depression of the wing. The external two-thirds, cor- 

 responding to the primary and secondary quills of birds, propel and 

 sustain the machine during the downward motions of its wings. The 

 little drawing in the corner shows the wings just about to begin their 

 downward beat. During the elevation of the wing the terminal 

 feathers conform to the sinusoidal track along which they progress in 

 the air ; it thus only cuts the atmosphere without acting against it. 

 To start the machine, we simply abandon it to itself in the air. 



This machine was exhibited before the Society of Aerial Naviga- 

 tion on the 2d of June, 18V2, and flew several times more than seven 

 metres the length of the public hall raising itself in a continuous 

 manner, with an accelerated velocity, along a line of flight inclined 

 15 to 20. In an open space, the artificial bird fl.ew over twelve to 

 fifteen metres, elevating itself during this flight to about two metres. 

 Another model, exhibited before the same society in October, 1874, 

 flew in an horizontal line, vertically upwai'd, and also ascended ob- 

 liquely. 



On the 27th of last November, at a public exhibition, this model 

 flew from one end to the other of the hall of the Horticultural Society 

 {see Aeronaute, February, 1875). On the 2d of July, 1875, it per- 

 formed with success before the French Physical Society. The ve- 

 locity of its flight is from five to seven metres per second. 



The birds of twisted caoutchouc have been a great success. 



M. Hureau de Villeneuve, whose zeal in the study of aerial navi- 

 gation is well known, and who in his many contributions to the theory 

 of flight since 1868 has discussed the inclination to the horizon of the 

 axes of the scapulo-humeral articulations and their posterior conver- 

 gence, exhibited, on the 20th of June, 1872, a bird moved by twisted 

 caoutchouc, which, he states, elevated itself vertically to a height of 

 nearly one metre. Continuing his researches with perseverance, he 

 again exhibited his apparatus before the Society of Aerial Navigation 

 on the 13th of January, 1875, after having supplied it with wings 



