Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1900-04-03
elaD FLIGHT.
SOME INTERESTING sPEcULATIoNs ON
THE PROBLEM.


The problem of bird flight has III
humor and ia absurdities. Recently
there has been revival Of the gaseous
theory to account for tho apparently
impossible, yet every day visible per-
formauces OF the hawks and buzzsrds
the swifts, and indeed all Of the bes,
flyers. Il IA said that birds have pneu
matte system, In addition to the osseous
muscular, vascular, nervous and othel
systems common TO higher animals; ant
that by the functioning Of this peculial
system they render themselves 90 buoyan,
that their alar operations are compars
lively easy, requiring far less muscular
exertion and nervous expense thar
would appear TO be- necessary.
This theory seems to be prep0sterous
being based 10 q fat contradiction OF M
axiom Of natural philosophy. A balloon
when collapsed, will not rise In the air
but when expanded with q gas lighter
than our atmosphere It scars. The sam,
principle causes hull to float on wateI
when solid Of the same size would
sink plump TO the bottom. IL the bird
has system of pneumatic cavities the
birds body is at Its lightest when those
cavities are absolutely empty; for no
gas IL lighter than vacuum. Then clearly
the only method by which the bird car
increase les buoysncy In this connection
10 by expanding It's substance, and Ut the
same time 6lling the spaces with gas
extremely light, and. yet able to resist
the increased pressure Of the external
air. But does q bird expand It's bones
or even its softer parts to any practical
extent while Hyings No theorist claims
that II does. IL such expansion were
possible the only service a gas could
perform would be to resist the atmos.
pheric pressure; for, as l have said, the
bird would be lighter without the ga
than with it. No substance IL lighter
than nothing!
1t Is a perfectly manageable problem
10 calculate just how muci, buzz,rd
would have to expand the "csvities Of
It's pneumatic system" In order to In
crease the buoyancy OF Its body giver
number of ounces. But supposing that
the bird can at will expel from Its bone
cavities and other pneumatic reservoirs
sll gaseous contents, there would not b.
an sppreciable lessening OF weight In the
problem Of flight. In fact, II buzz ,rd
could at will discard It's entire abdominal
viscerx, the loss OF substance would no,
be sufficient to make any great chsnge In
our problem for the wild goose Is twice
In the body ss heavy "a n turkey vulture
and just as good y Ayer, without any ad.
vantage 10 wing force. The difference II
sailing ability In favor OF the vulture !.
easily accounted for on the score OF nat
ursl bodily lightness; but this compari
son does not In any wav assist In settling
the main question. OF course II two
birds have equal wing force and greatly
unequal bodily weight, the heavier vii
have TO work the harder 10 dying. still
under the most favorable coordination
" weight and wing power In bird, IN,
problem OF flight Is far from solution.
II Is easy to catch buzzsrd, a vultur'
or goose and accurately measure thu
muscular force OF Its wings. II has been
done. This force has not been found
very remarkable. A bow IL years ole
can hold both wings OF 20-pound goose
In one hand without great exertion. The
wing muscles are strong, but not marvel
ously strong, about equal TO those OF
strong mans thumb. Well, n very strong
man can lift his own weight with his two
thumbs; wherefore II should be easy
enough for goose to lift twenty pounds
with the same muscular power. Here
however, comes In the immense counter
leverage Of the birds long wings as s
troublesome element of our calculation
Let q strong man take In his hand fan
the fuli-size Of q vulture's wing, and NJ
tempt to sweep II swiftly through thu
air: the realization of what the birc
overcomes with such apparent ease ant
with such marvellous grace will imme
diately arrive. Ii may be said that IL
any event the vulture has but 10 sustain
the weight of his own body; but remem
Der that this must be with outstretchec
wings. Were the wings mere thumb:
and the extreme leverage only three Of
four inches, sll would be well, but thu
air pressure on the entire wing is n
last borne by the muscles where they
pass the wing joint next 10 the body
and the strain Is kept up many hours
without 4 moments rest. The strongest
mans arms could not bear II for two
hours, As experiment would easily dis
0 ose.
The fight problem, therefore, sug
gest deeper examination into bird
snstomy than has yet been made. The
whole physiological structure must be
restudied with view TO accounting foi
the immense nervous resources OF the
avian physique. Long continued mus
culsr exertion uses up nerve force, with
corresponding exhaustion OF heart
power, lung power and will power. Ar,
birds not subject to the law OF physical
waste and recuperationS Some OF then
Az for forty-eight hours, or longer
without rest or food; and IL they sleeT
IL Is while necessarily continuing theil
flight. have taken them, on their MI
grafton, when storm had driven then
70 earth, and found not trace OF fooc
in their stomachs But for the storm
they would have gone hundreds, perhaps
thousands Of miles farther without p
mouthful Of sustensuce. Does not this
point TO some physiological secret
some unknown factor 10 the birds phys
ical economy-which may or may not b'
undiscoverableg We do not yet know
what magnetism L.; we are but guess
Ing at electricity; We cannot even b'
sure what causes the difference 10 weight
between steel and platinum, or between
gold and aluminium. Why then should
we turn up our scientific" nose when Il
Is suggested that there may be prin
ciple, not vet even guessed at, upor
which 1t would be easy to base all the
conditions of flight a. We see 1t In birds
There Is not Psychologist living who
csn absolutely account for the correla'
ton Of horsepower aud muscular force
which brings about the voluntary crook
ing OF ones finger. Yet the ignoramu'
who does not, and never can, know how
ha u,inka hia ava Drafanda IN ser hon nds