126 THE FLIGHT OF BIRDS 
just at the moment of,a terrific gust, when the gale 
was outdoing itself, Me might possibly be unable 
to move backward as they should. Certainly this is 
imaginable, though I cannot help thinking that the 
bird, though flustered for a moment, would cope with 
the difficulty. It must be remembered that it is 
only at slight altitudes above the earth’s surface 
that the wind is so capricious and irregular; the 
obstructions it meets with there make it a broken, 
boisterous torrent. The migrant bird flying high 
above us is in a calmer stream, however rapid its’ 
onward sweep may be. What we want is positive 
evidence. Being in difficulties some years ago about 
this question, I was delighted when I came across a 
paper read before a learned society in Germany on 
this subject. The writer maintained that birds did 
often fly with a gale blowing from behind them, but 
that under these circumstances their flight is so rapid 
that we do not see them! And the learned society 
printed his paper ! Commander Lynes has recorded 
an interesting observation that might seem to throw 
light upon the matter. A migrating Swallow was 
flying in the wrong direction, northward, when he 
should have been flying southward.* Apparently 
a gale sprang up, a gale from behind, and the Swallow 
in consequence, as it appeared, turned and was flying 
against the wind, as if intending to return to the place 
from which it had set out. It must not be forgotten, 
however, that migration, as a rule, proceeds at a 
great height, and that there the wind may not be 
blowing from the same quarter as it is at our lower 
level. At Alderney some years back I saw what I 
* British Birds, Vol. 111, p. 141. 
