Aeroplanes

ed 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 uni

ent views presented by those interested in the art, and then see ho

both dependent on outstretched wings, longer transversely than fore and aft, so far as the supporting surfaces are concerned, and with the main weig

hing to do with the mere act of flying. It is simply a question of power. This is a broad asserti

e 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 ac

ce, or require less power, or maintain itself in space at less speed; but it is a f

lled energy resides in material itself. It is something within matter, and does not come from without. The power derived from

a power within the object itself. Long after Galileo firmly established the law of falling bodies it began to dawn on scientists th

ting together. Thus, a stone poised on a cliff, while it exerts no power which can be utilized, has, nevertheless, what is called potential energy. When

expansion called power. The heat of the fuel converting water into steam, is another i

d the ball through the air came from the thrower and not from the ball itself. Let us examine this claim,

f pound, and the other of cotton weighing a half ounce. The wei

er. What will be the result! The iron ball will go much farther, or, if

n the two. Why this difference, The answer is, that it is in the material itself. It was the mass or density which a

0 units of work. The cotton ball, weighing 1/2 ounce, with the same initial speed, represents 25 unit

rticle itself. A feather ball thrown under the same conditions, would produce a

re effective against the cotton than the iron ball: or, it might be expressed in another way: The momentum, or the power, residing in the met

n a flying object. The metal ball may be flattened out into a thin disk, and now, when the same force is applied

ct of small mass, and it is difficult to set up a rapid motion in an object of great density, ligh

chines, for several years, sought to eliminate the very thing wh

nging the machine that its weight, or a portion of it, would be sustained in sp

ine could ever fly, would be by propelling it through space, like the ball was thrown, or by some sort

nderful property, and a most important element in flying. The safest machines are those which have weight. The light, willowy machin

the supporting surfaces, but HOW to apply the power so that it will rapidly transfer a machine a

flying machines, namely, the supporting surfaces,-not its form, shape or arrangement, (which will b

fact: That area has but little to do with sustaining an aeroplane when once in flight. The first Wright flyer weighe

t. Motion having once been imparted to it, the only t

ne horse power will sustain over 100 pounds, and each square

struggle to avoid the laws of nature with respect to matter, it may be well t

confuse them. Thus, weight and mass are not the same. Weight varies with the l

so as to produce momentum, which would be equal at a

ravity is considered as the attraction of mass for mass. Gravity is generally known a

double the mass it will have twice the attractive power. If one is doubled and the other tripled, the attraction would be increased six times. But if th

ttract all other bodies with a force directly in proportion to their

other, so they touch. If one has twice the mass of the other, the smaller will draw the larger only one-quarter of an inch, and the large on

in weight, the square of each would be 16. This does not mean that there would be sixteen times the attraction, but, as the law

h, for the reason that the attractive force of the great mass of the ear

ll parts of bodies equally; the force being proportioned to their mass. It is not affected b

Let us take two balls, one solid and the other hollow, but of the same mass, or density. If the cavity of the one is large enough to receive the other, it i

rce ceases. At the center of the earth an object would not weigh anything. A pound of iron and an o

enced by the earth's gravity; so it will be understood that pos

wn upwardly, antagonizes the force of gravity during the period of its ascent. In like manner,

ody moving in a circle must be acted upon by two forces, one which tend

r centrifugal motion. Gravity, therefore, repre

ht, and if the motion should be accelerated objects would become lighter, and if sufficient speed should b

h, or at right angles to the force of gravity. Such a course in a flying machine finds less r

angentia

movement, seeks to move matter away from the center of the earth, and any force whic

t. That represents a tangential line. For the purpose of explaining the phenomena of tangential flight, we will assume that t

he centrifugal pull would be decreased to such an extent that the ball would go on

ig. 2, where it travels along parallel with the surface of the earth. In this case the force of the bal

l pull of gravity acting against each other, produce a motion which is like that o

in treating of the matter of flight, have taken into consideration th

orizonta

m rested on the angle at which the planes were placed.

reinafter. Lift is the word employed to indicate the amount which a plane surface will support while in flight. Dr

Lift a

on of the arrow B. This indicates the resistance. The vertical arrow C

l pressure. A pressure of this kind against a plane is where the wind strikes it at right angle

least pressure against a plane is when it is in a horizontal position, because then the wind has no force agains

ormal Air

Edge R

the plane as at A. This is called head resistance, and on this subject there has been m

ower required to drive it forwardly, it would be found to equal the weight necessary to lift it. That is, suppose we should hold a

asuring Li

a scale C, and D the line attaching it to the scale E. When the wind is of sufficient force to hold u

xperiment and time have been expended, is to determine what the pressures are at the different angle

etween the lift and drift, when the plane is placed at an angle of less than 45 degrees. A machine weighing 10

e problem. As heretofore stated, when an object moves horizontally, it has less weight t

s decrease, or the forward pull is less than when at 45 degrees, and the decrease is less and less until t

air pressures. They do not take into account the fact that momentum takes

t fifty, seventy-five, or one hundred miles an hour. At the latter speed the movement is about 160 feet per seco

lane? It is no wonder that aviators have not been able to make the

face at rest, and forcing a blast of air against the plane placed at different angles; and for determining air pressures, this is, no dou

impossible, unless it is done by taking into account the factor due to momentum and the el

ing medium has over seven hundred times more force than air. A vessel having, for instance, twenty horse power, and a speed of ten miles

e, whether going ten or twenty miles an hour. The head resistance is the same, substantially, at all tim

ing which led to the discovery of the law of air pressures,

direction of the arrows B. The measurement across the plane vertically, along the line B, wh

cross the line C just one-half the length of the line B of Fig. 7, hence the surface i

Lift and Dri

equal Lift

determined the comparative drift, and those results have been largely relie

ation being that some errors had been made in the calculations, or that aviators wer

entirely ignored, and it is our desire to press the important p

rvel has been why do soaring birds maintain themselves in space without flapping their wings. In fact

an action on the air so as to force the body upwardly. This is disposed of by the wing motion of many birds, notoriously the cr

wing gives the quality of lift. Certain kinds of beetles, and particularly t

de up of a plurality of feathers, overlapping each other, they form a sort of a valved surface, opening so as to

that there is nothing in the structure of the wing bone and the feather connection which points to any individual feathe

rely different reason. Soaring birds, which do not depend on th

s which do not have feathered wings, but web-like structures,

e is used by nature; the material and texture of the wings themselves differ to such a degree that there is absolutely no similarity; some have concaved under surfaces, and others have not; some fly with rapidly beating wings, and others with slow and measured movements

, of motion, and of characteristics, which supplies the true answer. The answer lies in the angle of movement of every wing motion, which is at

must have an initial forward movement in order to attain flight. This impulse is acquired either by running along the ground, or by a leap, or in dropping

ng Movemen

y, depresses the rear edge of the wing, as in position 1, and when the wing beats downwa

tion, and as the rear margin has more or less flexure, its action against the air is les

yers, which poise at one spot, are able to do so because, instead of moving forwardly, or changing the position of its body horizontally, in performin

tion of Hummin

ssive positions of the wing are shown, and wherein four of the position, namely, 1,

nsion point of each wing is moving downwardly, or u

wings, fore and aft. Those which flap slowly, and are not swift flyers, have co

e gravitation without exercis

eed is acquired, they depend on the undulating movement of the wings, and some of them acquire the initial m

m to be moving slowly. But distance is deceptive. The soaring bird travels at great speeds, and this in itself should be sufficient to enable us to ceas

it forwardly, without it exerted some muscular energy to keep up its speed. The distance at which the bird p

pt up, which wedges forwardly with sufficient speed to compel momentum to maintain it in flight. To do so requires but a small amount of energy. The head resistance of the bi