Richmond Whig. [volume] (Richmond, Va.) 1862-1865, 1864-03-19


of the bird has nothing DO with his capscity for fight
that bird large even the Of Eastern fable If
formed on the model of the eagle with wings bones
and muscles in proportion would be able like the eagle
to Ay This is great mistake. The supporting power
10 the pressure Of the air against the under surface
the surface merely the square Of the length, while
the weight is as the cube Il follows that the larger the
bird the less the supporting surface compared with the
weight and consequently the more intense the pressure
required TO supply the deficiency Thetusainng force
results either from the upward impulse produced by the
wiz stroke from the prof con Of the body against
the air, which passes otLquey on the under surface
or from combination Of the two. But in either case
greater pfoporonate force OF wing is required as the
bird Is larger and consequently heavier bone anq mus
Gle Take two birds constructed alike, Of the same
specific gravity, but one double the others eugh-the
larger would require power OF Wing not as ., which
represents bis weight but as ii Sl2, the weight and
force in the OF the smaller bird being each l. To
that extent then must the larger wing be strengthened
or proporonate loss Of the surplus power, which the
smaller bird possesses be the consequence. Bat to
give the requisite additional strength, the muscles and
bones of the wing and breast must Increase in weight
In still greater ratio. We NAV hence easily under
sand why the largest birds that A such as the condor
and sociable vulture of Africa, have such great diff
Guilty in rsng from plain; and why, when once fairly
launched they can for such length of time with-
out tapping since the difficulty of rsng inversely as
the loss of velocity by atmospheric resistance.
But another principle operates quite as unfavorably
To take again the two birds mentioned above II formed
alike the wing-bone OF the lsrger would have twice
ne diameter Of the other But to give the due pro-
poronate strength the diameter should be about 2S3
and its weight instead Of g. should be l6. The other
wirg bones and the muscles Of the wing aud breast
must undergo a like enlargement. This requires
respond ng increase of the vital organs and by the in
crease OF weight the carrying power is in the came
degree diminished The larger the bird is the greater
will be the disadvantage from this source II the esgle
Is assumed to be feet long, and TO have WiDg-bone
half an inch thick, then machine 100 times as long
and of preportonate weight instead of bone beam
OF feet inches, which would have If built on the
same model would require one about AZ feet in dame
ter. Tnis enormous mass OF course puts. any large
machine quite cut of the question: but doubt may still
arise whether one large enough 10 carry man and
ty pound shot may not have strength Of material and
motive power sufficient. few considerations may
assist in removing L.
The wing beam of the machine If OF no stronger ma
teral than the bone, muH be larger than in the pro-
portion stated above Toe muscles OF the breast which
are those which the power OF the wng-stroke de-
pend are attached to the upper bone little below its
junction with the body, while the muscles that bend the
wing Joints distributed along the bones thus giving
them the support Ct elastic cords, which tightening
most when the strain is greatest, tesd to prevent
transverse xure boWsIring does to prevent the
bow from bending backwards. But this arrangement
can only very partially be inflated in machine Then
the powerful adverse leverage with which the muscle
has TO contend be encountered In the machine alta
still greater disadvantage.
have no doubt that machine With banded wings,
substituting in part the tensile for the transverse
strength OF material might be made 20 descend along
the track of inclined railway with acceleratng
speed TIL with the aid Of some light additional impul
son, which would be indispensable, 1t might be fairly
launched into the air, where il might long remain soar
ing about at the engineers will But Ii must descend
at length and how il could reach tLe earth without
fatal crash do not perceive As soon as 1t falls below
the velocity required 10 sustain its'ght IL would glide
rppdly downward; aud unless the wings had power 10
arrest ts course and to poise It Ia the air. the eng
neer by means of his rudder, should cause it to
cend destructive collision you'd seem inevitable II
we remember the conclusion caued by the small resid
uary motion of canal boat within ock, We can easily
imagine the shock With which heavy body moving
with 100 times the velocity and 10000 tines the force
Of collision would strike the earth.
There IL little hope imagine, Of combining lshness
with strength of material in greater degree than Ma
ture has done in the mechanism OF birds TIE transverse
strength Of STEEL in proportion to its weight, IS less
than that of many woods AID bone Is doubtless superior
10 both Animal muscle considering the force il dis
plays under the disadvantage Of enormous adverse
leverage will be found, apprehend, Of greater power
than any machinery man can deVise OF the same weight
But even # he could rival natural productions in these
respects, yet We have what may be caledA practical
exhibition OF all that Nature do by the aid Of bone
and muscle in raising heavy bodies into the air. aud tbs
eems quite inadequate to the object Mr. Davidson has
In view.
1t may possibly be supposed that a combination Of
the buoyancy Of gas with the propulsve force OF the
wings, might render the problem possible But 1t must
be remembered that to tighten the machine by the
weight OF ore cubic foot Of Vaer about 900 cubic
feet Of gas win be required. TIE quantity that could
be contained in tie Vaultcd root If sufficiently compact
in shape would be too uncomfortable to be of any pac
teal use II The receptacle Is enlarged them besides
the additional weight there will be increased atmos
pberc ssance necessitang greater propulsive force
70 give the requisite velocity besides which, the in
creased volume sugmentug the pressure of the air
above would act as depressing force counterActing
in measure the supporting tendency ofthe pressure
below.
viewed In any possible aspect, the undertaking az.
peas absolutely impraooa able unless some material
combining the properties OF ghtness and strength in
far higher degree than any yet known should hereafter
be discovered. t. q. d.
On mr. ON