4 ANIMAL MECHANISM. 



solved? Ingenious constructors have already attempted to 

 imitate the natural propellers ; they have fitted up small boats 

 with machinery which works like the tail of a fish, oscillating 

 with an alternate motion. And it has been found that this 

 apparatus, although still imperfect, already constitutes a 

 powerful propeller, which will perhaps be preferred hereafter 

 to all those which have hitherto been used. 



Aerial locomotion has always excited the strongest curiosity 

 among mankind. How frequently has the question been 

 raised, whether man must always continue to envy the bird 

 and the insect their wings ; whether he, too, may not one day 

 travel through the air, as he now sails across the ocean. 

 Authorities in science have declared at different periods, as 

 the result of lengthy calculations, that this is a chimerical 

 dream, but how many inventions have we seen realised which 

 have also been pronounced impossible. The truth is, that all 

 intervention by mathematics is premature, so long as the 

 study of nature and experiment have not furnished the precise 

 data which alone can serve as a sound starting point for 

 calculations of this kind. 



We shall then attempt to analyse the rapid acts which are 

 produced in the flight of insects and of birds ; afterwards we 

 shall endeavour to imitate nature, and we shall see, once 

 more, that by seeking inspiration from her we have the 

 best chance of solving the problems which she has solved. 



We may even now affirm, that in the mechanical actions of 

 terrestrial, aquatic, and aerial locomotion, there is nothing 

 which can escape the methods of anaLysis at our disposal. 

 Would it be impossible for us to reproduce a phenomenon 

 which we understand ? We will not carry our scepticism 

 BO far. 



It was considered for a long time that chemistry, all- 

 powerful when it was a question of decomposing organic 

 substances, would always remain incapable of reproducing 

 them. What has become of this disheartening prediction ? 



We hope that the reader who follows the experimental 

 researches detailed in this book will draw from them this 

 conviction, that many of the impossibilities of the present, 

 need only a little time and much effort to become realities. 



