The Fulton County news. [volume] (McConnellsburg, Pa.) 1899-current, 1900-04-12
THE FACULTY OF FLIGHT
A PROBLEM THAT MAY Be SOLVED
PY THE BlRD.kNkroMlST.

There is no faculty or power In crea-
! lures which can rightly perform It's func-
| tions without the perpetual aid Of tile Su-
| preme Being. ."--Hookcr.
Tho problem of bird flight has its
humors and it's absurdities. Recently
there has been revival of the gas.
eous theory to account for the appar-
emily impossible, yet every day-vis
ible, performances of tho hawks and
buzzards, the swifts and indeed all of
the best flyers. 1t is said that birds
have pneumatic system, in addition
to the osseous, muscular, vascular,
nervous and other systems common to
all higher animals, and that by the
functioning of this particular system
they render themselves 50 buoyant
that their alar operations are compar-
atively easy, requiring far less muscu I.
lar exertion and nervous expense than
would appear to be necessary.
This theory seems to me pre-
posterous, being based in fat con-
tradiction of an axiom Of natural
philosophy. A balloon, when collapsed,
will not rise in the air; but when
expanded With IA gas lighter than our
atmosphere it scars. The same prin
ciple causes hull TO font on water
when solid OF the same size would
sink plump TO the bottom. II the
bird has system Of pneumatic cavi-
ties, the birds body is at its lightest
when those cavities are absolutely
empty; for no gas is lighter than
vacuum. Then clearly the only
method by which the bird can increase
its buoyancy in this connection is by
expanding its substance, and at the
same time filling the spaces with
gas extremely light and yet able to
resist the increased pressure of the
external air. But does bird expand
its bones, or even it's softer parts, to
any practical extent while flying?
No theorist claims that it does. If
such expansion were possible the
only service a gas could perform
would be TO resist the atmos-
pheric pressure; for, as have said,
the bird would be lighter without the
gas than with it. No substance is
lighter than nothing!
1t is II perfectly manageable problem
to calculate just how much buzzard
would have to expand the "cavities of
its pneumatic system" inForder to in
crease the buoyancy of it's body
given number of ounces. But sup
posing the bird can at will expel from
it's bone-cavities aud other pneumatic
reservoirs oil gaseous contents, there
would not be All appreciable lessening
OF weight in the problem of fight.
In fact, if buzzard could at will dis
card its entire abdominal viscera, the
loss of substance would not be sufli-
cient to make any great change in our
problem; for the wild goose is twice
as heavy i'll the body as turkey
vulture, and just as good a flyer, with
out any advantage in wing force. The
difference in sailing ability in favor of
the vulture is easily accounted for on
the score of natural bodily lightness;
but this comparison does not in any
way assist in settling the main ques-
ton. OF course if two birds have
equal wing force and greatly unequal
bodily weight, the heavier will have
to work the harder in flying. Still,
under the most favorable co-ordina-
tion of weight and wing power IN
bird. the problem Of fight is far from
solution.
1t is easy to catch buzzard, q vul-
ture or goose and accurately meas
ure the muscular force of its wings.
! 1t has been done. This force has not
been found very remarkable. A boy
twelve years old can hold both wings
of twenty pound goose in one hand
without great exertioD. The wing
muscles are strong, but not marvel
ously strong; abou. equal to those Of
strong mans thumb. Well, a very
strong man can lift his own weight
with his two thumbs; wherefore it
should be easy enough for goose to
lift twenty pounds with tho same
muscular power. Here, however,
comes in the the immense counter
leverage of the birds long wings as
| troublesome element of our calcula-
ton. Let strong man take in his
hand van, the full size of vulture's
wing, and attempt to sweep it swiftly
through the air; the realization of
what the bird overcomes with such
apparent ease and with such marvellous
grace will Immediately arrive. 1t may
be said that in any event the vulture
has but to sustain the weight of its
own body; but remember that this
must be with outstretched wings
Were the wings mere thumbs and the
extreme leverage only three or four
inches, all would be we'll; but the air
pressure on the entire wing is at last
borne by the muscles where they pass
the wing-ioint, next to the body, and
the strain is kept up for many hours
without a moments rest. The strong
est mans arms could not bear it for
two hours, as experiment would easily
disclose.
The fight problem, therefore, sug-
gests deeper examination into bird
anatomy than has yet been made. The
whole physiological structure must be
restudied with a view to accounting for
the immense nervous resources of the
avian physique. Long continued
muscular exertion uses up nervous
force, with a corresponding exhaus-
ton OF heart-power. lung power and
will-power. Are birds not subject to
the laws of physical waste and recup-
eration2 Some OF them fly for forty
eight hours. or longer, without rest
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