He fastened a small piece of paper to the tip of a crow’s wing, 
and as the bird flew in front of a perfectly black screen he 
took a photograph of this moving speck of white, while, of 
course, no image of the crow appeared on the plate. The 
resultant picture gave a series of “ figure of 8 loops” as one 
would make this figure with a pen, contriving to make the 
lower loop very small, and the upper loop very large. But as 
the wing-beat increased in speed the lower loop gradually 
faded out. 
These movements of the wing, however, are descriptive 
rather of what takes place during very vigorous flight, as 
when the bird is getting up ‘steam.’ When he is well 
under way there is no need for these long and very tiring 
strokes, except in the case of birds like the pheasant or the 
duck. A gull, when in full career, does not, apparently, raise 
the wings very high, nor depresses them very low, nor does 
it flex the wings at the wrist-joints. 
Stopping and turning movements are generally extremely 
difficult to follow, because they are performed so quickly. 
They can be seen fairly easily in the case of some of the larger 
birds. Ducks, as is well shown in one of our coloured Plates, 
draw the head backwards, tilt the body upward, thrust the 
feet forward, and spread the tail, at the same time turning 
it forwards. Gulls and pigeons too may be watched with 
profit. 
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