248 THE HAUNTS OF LIFE 
see a marvellous thing, but the marvel in- 
creases when in front of us the bird tilts its 
body and turns, and comes towards us down 
the other side of the ship, and all, so far as 
we can see, without a stroke of its wings. This 
sailing is, we think, the most wonderful loco- 
motion in the world, and the puzzle of it does 
not seem to have been altogether solved. It is 
finely illustrated by vultures “soaring” in 
mid-air, describing circle after circle, ascend- 
ing in a magnificent spiral and sailing down 
again, and all, so far as the field-glass shows, 
without any stroke of the wings. The word 
“soaring” is often applied to this mysterious 
kind of flight, but “sailing” is a better word. 
It is better to keep “soaring” for the ascend- 
ing flight of the lark, where there is very 
rapid up-and-down movement of the wings, 
without any backward stroke. This leads on 
to the “hovering” of the kestrel, where the 
up-and-down movements of the wings are 
extraordinarily rapid, and to the “ fluttering” 
of a humming-bird, poised lke a moth before 
a flower. But sailing is a different matter. 
Sailing is seen in birds with a large wing- 
area or sail-area in proportion to the size and 
weight of the rest of the body, e.g. albatross, 
