^1o 



NATURE 



[Feb. 1 6, 1888 



pn the wing do not give us correct ideas or the move- 

 ments of the wings ; we must photograph the bird under 

 several aspects in order thoroughly to comprehend this 



mechanism. We have made several arrangements in 

 order to procure this effect. One of these, placed at a 

 height of 12 metres (nearly 13^ yards), gave representa- 



FiG. 4. — Crested heron. Transverse flight. Ten images per second. 



J. 



Tf^ 



Fig. s- — Pelican. Transverse descending flight. Ten images per second. 



Fig. 6. — Sea-gull seen from above. Ten images per second. (Fac-simile of instantaneous photographs taken by the author.) 



lions of the bird as seen from above (Fig. 6) ; others, 

 variously placed, showed it from the side, or flying in 

 the direction of the photographic apparatus (Fig. 7). 



These representations, taken under different conditions, 

 complement each other. Thus, the birds seen from 

 above show a singular curvature in the flat surface of the 



