文档介绍：AEROPLANES
AEROPLANES
BY J. S. ZERBE
1
AEROPLANES
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 plete 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 mus