SYNTHESIS OF MOVEMENT 



311 



in all the successive phases of its wing increment. 

 The illusion was complete, and a flying bird could be 

 seen flying round and round the apparatus ; sometimes 

 flying away from the observer, sometimes across, and 

 sometimes towards him.* 



Scientific Applications of Plateau's Method. — All these' 

 applications would be simply childish if they were 



Fig. 2U3.— Zoutrope, with figures of a gull in relief, and in the successive attitudes 

 of flight. 



limited to the reproduction of phenomena which could 

 be observed by the eye in the case of living creatures. 

 They would be attended, in fact, by all the uncertainties 

 and difficulties which embarrass the observation of the 

 actual movement. In a bird, for instance, the wings 

 could only be distinguished as an indistinct mass, just 



* This zootrope with solid figures is still preserved at the Physio- 

 logical Station. 



