80 
RAPIDITY OF FLIGHT. 
(at first sight) most improbable capacity, so as to render it 
no longer a matter of doubt or difficulty, but merely an ad- 
ditional instance of the beautiful arrangement adopted by 
the providence of God in all bis wondrous works. 
On examining it, we shall find just beneath the throat a 
large pouch communicating with the lungs, and with the 
hollow and particularly light bone-work of its skeleton. Sup- 
pose, then, that the bird wishes to rest in the air; — in the 
first place, it avails itself of its large wings, which it is enabled 
by constant habit to keep expanded, and which are in them- 
selves nearly sufficient to sustain its weight and float its 
light body in the air. But in addition to the wing, suppose 
the bird fills its large pouch with air, and from thence forces 
it into all its hones and cavities between the flesh and the 
skin, what will happen ? That the heat of its circulation 
(and it is well known that the heat of a bird’s circulation is 
considerably beyond that of other animals) will rarefy the 
internal air; which will therefore puff up, not only the pouch, 
hut every cavity, and thus give the bird a surprising addi- 
tional buoyancy or power of floating, even in the higher 
regions of the atmosphere. And that this is the case may 
he presumed from its habits; for when the lower currents of 
air are stormy and disagreeable, up goes the Frigate-Bird 
to a higher and calmer current, where, just as we see the 
light fleecy clouds in the sky, it remains, suspended with 
outspread wing, motionless, and at rest, till, roused by hunger, 
it expels the rarefied air, and emptying its pouch, descends 
towards the waves; hut as it never either dives or swims, on 
approaching within a few feet, it instantly stops, and changes 
its direction, so as to skim along and catch the flying-fish 
with its hawk-like bill or talons, or both together. So averse 
are they, in fact, to diving, or even touching the water, that, 
instead of dashing downwards head foremost, like the Gannet 
and other diving birds, the Frigate-Bird holds its neck and 
feet in a horizontal direction; striking the upper column of 
air with its wings, then raising and closing them one against 
the other above its back, it darts on the flying-fish with such 
skill and certainty, as almost invariably to insure success. 
