20 LIFE AND SPORT IN HAMPSHIRE 



every full up-and-down stroke cutting simultaneously 

 the double loop or figure-of-eight, the tail is going 

 through a less complex figure. Whether this tail 

 exercise, or quiver, is so simple as it might seem 

 merely a series of quick, short up-and-down strokes 

 is another thing. Probably some curve is even 

 here made in each tiny stroke, so that, as with the 

 wings, the up-and-down movements glide into each 

 other without jerk or stop. But, however this may 

 be, the tail, I imagine, need not be going through 

 that double figure by which the wings uphold 

 the bird and keep it fixed in the same point in 

 space. 



The beautiful discovery that the wings of bird and 

 insect cut a figure-of-eight in space seems to have 

 been made, independently, by both Pettigrew and 

 Marey, an Englishman and a Frenchman. The com- 

 plete figure-of-eight is only cut by the bird or insect 

 when the body is stationary a kestrel hovering over 

 a point in the field, or one of the little sphinx moths 

 whirring at its honey flower. One loop equalises as 

 it were defeats the other, and hence the body of the 

 flier is prevented from darting forward and onward. 

 The eight is the anchor of the bird or insect hanging 

 stationary in the air. 



No sooner is motion forward and onward made 

 than the figure-of-eight begins to lose its shape, 

 and the bird henceforth progresses in what has been 

 called the "waved track." As Pettigrew put it with 



