WIND AND FLIGHT 137 
majestic performance, but this time at a higher 
level. It is not often, I believe, that there is a 
steady upward-trending wind extending over so 
long a reach. In the Alps I recently saw an Eagle 
perform a similar feat, but not on so grand a scale. 
It is clearly possible for a bird to advance in this 
way facing with the wind instead of against it. The 
wind acts at right angles to the bird’s expanse of 
wing and body, and, except for friction, it will not 
matter whether it blows from in front or behind. 
If it has a sufficient upward incline, it will not get 
between the feathers and ruffle them. But, as a 
fact, one very seldom sees a bird advancing in this 
way. Still I have occasionally met with examples, 
though I doubt whether the wind comes quite 
directly from behind ; the bird turns himself just a 
little sideways. Circumstances are favourable when 
the wind blowing at a very slight angle against a cliff 
is deflected upward. The Gull then advances with 
the wind, head leading, wings motionless. But as 
I have said, there is, probably, always a very slight 
sideways turn made, so that the body from back to 
tail is not quite in line with the course of the wind. 
Is this to avoid a disarrangement of feathers—that 
bothersome question ? Whatever the explanation 
of this very slight deflection, and though this method 
of utilising an up-current is not so common as others, 
yet it is important that it should obtain recognition. 
It will help us to understand soaring when we come 
to investigate that difficult subject. 
The wonderful flight of the |Albatross, his wings 
with their spread of twelve feet or more held motion- 
less, I cannot undertake to describe, as I have never 
