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torsional strain； being located at the forward
portion of the wing surface。 Torsion has
reference to a twisting motion。
In some cases； as in the bat； this primary bone
has an attachment to the rear of the main joint；
where the rear margin of the wing is attached to
the leg of the animal； thus giving it a support
and the main bone is； therefore； relieved of this
torsional stress。
THE BAT'S WING。An examination of the bat's
wing shows that the pectoral bone is very small
and thin； thus proving that when the entire wing
support is thrown upon the primary bone it must
be large enough to enable it to carry out its functions。
It is certainly not so made because it is a
necessary shape which best adapts it for flying。
If such were the case then nature erred in the
case of the bat； and it made a mistake in the
housefly's wing which has no such anterior enlargement
to assist （？） it in flying。
AN ABNORMAL SHAPE。Another illustration is
shown in Fig。 30； which has a deep concave directly
behind the forward margin； as at A； so
that when the plane is at an angle of about 22
degrees； a horizontal line； as B； passing back from
the nose； touches the incurved surface of the plane
at a point about one…third of its measurement
back across the plane。
_Fig。 30。 One of the Monstrosities_
This form is an exact copy of the wing of an
actual bird； but it belongs； not to the soaring；
but to the class which depends on flapping wings；
and as such it cannot be understood why it should
be used for soaring machines； as all aeroplanes
are。
The foregoing instances of construction are
cited to show how wildly the imagination will
roam when it follows wrong ideals。
THE TAIL AS A MONITOR。The tendency of the
center of pressure to change necessitates a correctional
means； which is supplied in the tail of
the machine； just as the tail of a kite serves to
hold it at a correct angle with respect to the wind
and the pull of the supporting string。
CHAPTER VII
ABNORMAL FLYING STUNTS AND SPEEDS
〃PEQUOD； a Frenchman； yesterday repeatedly
performed the remarkable feat of flying with the
machine upside down。 This exhibition shows
that the age of perfection has arrived in flying
machines； and that stability is an accomplished
fact。〃News item。
This is quoted to show how little the general
public knows of the subject of aviation。 It correctly
represents the achievement of the aviator；
and it probably voiced the sentiment of many
scientific men； as well as of the great majority of
aviators。
A few days afterwards； the same newspaper
published the following：
〃Lieutenant ； while experimenting yesterday
morning； met his death by the overturning
of his machine at an altitude of 300 meters。
Death was instantaneous； and the machine was
completely destroyed。〃
The machines used by the two men were of the
same manufacture； as Pequod used a stock machine
which was strongly braced to support the
inverted weight； but otherwise it was not unlike
the well known type of monoplane。
Beachy has since repeated the experiment with
a bi…plane； and it is a feat which has many imitators；
and while those remarkable exhibitions
are going on； one catastrophe follows the other
with the same regularity as in the past。
Let us consider this phase of flying。 Are they
of any value； and wherein do they teach anything
that may be utilized；
LACK OF IMPROVEMENTS IN MACHINES。It is remarkable
that not one single forward step has
been taken to improve the type of flying machines
for the past five years。 They possess the same
shape； their stabilizing qualities and mechanism
for assuring stability are still the same。
MEN EXPEDITED； AND NOT THE MACHINE。The
fact is； that during this period the man has been
exploited and not the machine。 Men have learned；
some few of them； to perform peculiar stunts；
such as looping the loop； the side glide； the drop；
and other features； which look； and are； hazardous；
all of which pander to the sentiments of the spectators。
ABNORMAL FLYING OF NO VALUE。It would be
too broad an assertion to say that it has absolutely
no value； because everything has its use
in a certain sense； but if we are to judge from
the progress of inventions in other directions；
such exhibitions will not improve the art of building
the device； or make a fool…proof machine。
Indeed； it is the very thing which serves as a
deterrent； rather than an incentive。 If machines
can be handled in such a remarkable manner； they
must be； indeed； perfect！ Nothing more is
needed！ They must represent the highest structural
type of mechanism！
That is the idea sought to be conveyed in the
first paragraph quoted。 It is pernicious； instead
of praiseworthy； because it gives a false impression；
and it is remarkable that even certain scientific
journals have gravely discussed the perfected
（？） type of flying machine as demonstrated
by the experiments alluded to。
THE ART OF JUGGLING。We may； occasionally；
see a cyclist who understands the art of balancing
so well that he can； with ease； ride a machine
which has only a single wheel； or he can； with a
stock bicycle； ride it in every conceivable attitude；
and make it perform all sorts of feats。
It merely shows that man has become an
expert at juggling with a machine； the same as he
manipulates balls； and wheels； and other artifices；
by his dexterity。
PRACTICAL USES THE BEST TEST。The bicycle
did not require such displays to bring it to perfection。
It has been the history of every invention
that improvements were brought about； not
by abnormal experiments； but by practical uses
and by normal developments。
The ability of an aviator to fly with the machine
in an inverted position is no test of the machine's
stability； nor does it in any manner prove that
it is correctly built。 It is simply and solely a
juggling featsomething in the capacity of a certain
man to perform； and attract attention because
they are out of the ordinary。
CONCAVED AND COXVEX PLANES：They were performed
as exhibition features； and intended as
such； and none of the exponents of that kind of
flying have the effrontery to claim that they prove
anything of value in the machine itself； except
that it incidentally has destroyed the largely
vaunted claim that concaved wings for supporting
surfaces are necessary。
HOW MOMENTUM IS A FACTOR IN INVERTED FLYING。
When flying 〃upside down；〃 the convex
side of the plane takes the pressure of the air；
and maintains； so it is asserted； the weight of the
machine。 This is true during that period when
the loop is being made。 The evolution is made
by first darting down； as shown in Fig。 31； from
the horizontal position； 1； to the position 2； where
the turn begins。
_Fig。 31。 Flying upside down。_
TURNING MOVEMENT。Now