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Determining the Pressure From the Speed。
Calculating Pressure From Speed。 How the Figures
are Determined。 Converting Hours Into Minutes。
Changing Speed Hours to Seconds。 Pressure as the
Square of the Speed。 Gyroscopic：Balance。 The Principles
Involved。 The Application of the Gyroscope。
Fore and Aft Gyroscopic Control。 Angle Indicator。
Pendulum Stabilizer。 Steering and Controlling
Wheel。 Automatic Stabilizing Wings。 Barometers。
Aneroid Barometer。 Hydroplanes。 Sustaining Weight
of Pontoons。 Shape of the Pontoon。
CHAPTER XII。 EXPERIMENTAL WORK IN FLYING
Certain Conditions in Flying。 Heat in Air。 Motion
When in Flight。 Changing Atmosphere。 〃Ascending
Currents。〃 〃Aspirate Currents。〃 Outstretched Wings。
The Starting Point。 The Vital Part of the Machine。
Studying the Action of the Machine。 Elevating the
Machine。 How to Practice。 The First Stage。 Patience
the Most Difficult Thing。 The Second Stage。
The Third Stage。 Observations While in Flight。 Flying
in a Wind。 First Trials in a Quiet Atmosphere。
Making Turns。 The Fourth Stage。 The Figure 8。
The Vol Plane。 The Landing。 Flying Altitudes。
CHAPTER XIII。 THE PROPELLER
Propeller Changes。 Propeller Shape。 The Diameter。
Pitch。 Laying Out the Pitch。 Pitch Rule。 Laminated
Construction。 Laying up a Propeller Form。
Making Wide Blades。 Propeller Outline。 For High
Speeds。 Increasing Propeller Efficiency。
CHAPTER XIV。 EXPERIMENTAL GLIDERS AND MODEL AEROPLANES
The Relation of Models to Flying Machines。 Lessons
From Models。 Flying Model Aeroplanes。 An
Efficient Glider。 The Deltoid Formation。 Racing
Models。 The Power for Model Aeroplanes。 Making
the Propeller。 Material for the Propeller。 Rubber。
Propeller Shape and Size。 Supporting Surfaces。
CHAPTER XV。 THE AEROPLANE IN THE GREAT WAR
Balloon Observations。 Changed Conditions in Warfare。
The Effort to Conceal Combatants。 Smokeless
Powder。 Inventions to Attack Aerial Craft。 Functions
of the Aeroplane in War。 Bomb…throwing Tests。
Method for Determining the Movement of a Bomb。
The Great Extent of Modern Battle Lines。 The Aeroplane
Detecting the Movements of Armies。 The Effective
Height for Scouting。 Sizes of Objects at Great
Distances。 Some Daring Feats in War。 The German
Taube。 How Aeroplanes Report Observations。 Signal
Flags。 How Used。 Casualties Due to Bombs
From Aeroplanes。
GLOSSARY
INTRODUCTORY
In preparing this volume on Flying Machines
the aim has been to present the subject in such a
manner as will appeal to boys； or beginners； in
this field of human activity。
The art of aviation is in a most primitive state。
So many curious theories have been brought out
that； while they furnish food for thought； do not；
in any way； advance or improve the structure of
the machine itself； nor are they of any service
in teaching the novice how to fly。
The author considers it of far more importance
to teach right principles； and correct reasoning
than to furnish complete diagrams of the details
of a machine。 The former teach the art； whereas
the latter merely point out the mechanical
arrangements； independently of the reasons for
making the structures in that particular way。
Relating the history of an art； while it may be
interesting reading； does not even lay the foundations
of a knowledge of the subject； hence that
field has been left to others。
The boy is naturally inquisitive； and he is interested
in knowing WHY certain things are
necessary； and the reasons for making structures in
particular ways。 That is the void into which
these pages are placed。
The author knows from practical experience；
while experimenting with and building aeroplanes；
how eagerly every boy inquires into details。
They want the reasons for things。
One such instance is related to evidence this
spirit of inquiry。 Some boys were discussing the
curved plane structure。 One of them ventured
the opinion that birds' wings were concaved on the
lower side。 〃But；〃 retorted another； 〃why are
birds' wings hollowed？〃
This was going back to first principles at one
leap。 It was not satisfying enough to know that
man was copying nature。 It was more important
to know why nature originated that type of formation；
because； it is obvious； that if such structures
are universal in the kingdom of flying creatures；
there must be some underlying principle
which accounted for it。
It is not the aim of the book to teach the art
of flying； but rather to show how and why the
present machines fly。 The making and the using
are separate and independent functions； and of
the two the more important is the knowledge how
to make a correct machine。
Hundreds of workmen may contribute to the
building of a locomotive； but one man； not a
builder； knows better how to handle it。 To
manipulate a flying machine is more difficult to
navigate than such a ponderous machine； because
it requires peculiar talents； and the building is
still more important and complicated； and requires
the exercise of a kind of skill not necessary
in the locomotive。
The art is still very young； so much is done
which arises from speculation and theories； too
much dependence is placed on the aviator； the
desire in the present condition of the art is to exploit
the man and not the machine； dare…devil exhibitions
seem to be more important than perfecting
the mechanism； and such useless attempts as
flying upside down； looping the loop； and characteristic
displays of that kind； are of no value to
the art。
THE AUTHOR。
AEROPLANES
CHAPTER I
THEORIES AND FACTS ABOUT FLYING
THE 〃SCIENCE〃 OF AVIATION。It may be
doubted whether there is such a thing as a 〃science
of aviation。〃 Since Langley； on May 6；
1896； flew a motor…propelled tandem monoplane
for a minute and an half； without a pilot； and the
Wright Brothers in 1903 succeeded in flying a
bi…plane with a pilot aboard； the universal opinion
has been； that flying machines； to be successful；
must follow the structural form of birds； and
that shape has everything to do with flying。
We may be able to learn something by carefully
examining the different views presented by
those interested in the art； and then see how they
conform to the facts as brought out by the actual
experiments。
MACHINE TYPES。There is really but one type
of plane machine。 While technically two forms
are known； namely； the monoplane and the
bi…plane； they are both dependent on outstretched
wings； longer transversely than fore and aft； so
far as the supporting surfaces are concerned； and
with the main weight high in the structure； thus；
in every particular； conforming to the form
pointed out by nature as the apparently correct
type of a flying structure。
SHAPE OR FORM NOT ESSENTIAL。It may be
stated with perfect confidence； that shape or form
has nothing to do with the mere