146 THE REIGN OF LAW. 



foremost. A bird can, of course, allow itself to fall 

 backwards by merely slowing the action of its 

 wings so as to allow its weight to overcome their 

 sustaining power ; and this motion may sometimes 

 give the appearance of flying backwards, — as when 

 a Swift drops backwards from the eaves of a house, 

 or when a Humming Bird allows itself to drop in 

 like manner from out of the large tubular petals of 

 a flower. But this backward motion is due to the 

 action of gravity, and not to the action of the bird's 

 wing. In short, it is falling downwards, not flying 

 backwards. Nay, more, if the theory of flight here 

 given be correct, it must equally follow that even 

 standing still, which is the easiest of all things to 

 other animals, must be very difficult, if not alto- 

 gether impossible, to a bird when flying. This 

 also is true in fact. To stand still in the air is not 

 indeed impossible to a flying bird, for reasons to 

 be presently explained, but it is one of the most 

 difficult feats of wingmanship, a feat which many 

 birds, not otherwise clumsy, can never perform at 

 all, and which is performed only by special exer- 

 tion, and generally for a very short time, by those 



