Aeroplanes and Dirigibles of War | Page 5

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 act of flying. It is simply a question of power. This is a broad assertion, and its meaning may be better understood by examining the question of flight in a broad sense.
A STONE AS A FLYING MACHINE.--When a stone is propelled through space, shape is of no importance. If it has rough and jagged sides its speed or its distance may be limited, as compared with a perfectly rounded form. It may be made in such a shape as will offer less resistance to the air in flight, but its actual propulsion through space does not depend on how it is made, but on the power which propelled it, and such a missile is a true heavier-than-air machine.
A flying object of this kind may be so constructed that it will go a greater distance, or require less power, or maintain itself in space at less speed; but it is a flying machine, nevertheless, in the sense that it moves horizontally through the air.
POWER THE GREAT ELEMENT.--Now, let us examine the question of this power which is able to set gravity at naught. The quality called energy resides in material itself. It is something within matter, and does not come from without. The power derived from the explosion of a charge of powder comes from within the substance; and so with falling water, or the expansive force of steam.
GRAVITY AS POWER.--Indeed, the very act of the ball gradually moving toward the earth, by the force of gravity, is an illustration of a power within the object itself. Long after Galileo firmly established the law of falling bodies it began to dawn on scientists