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From: Flying Machines Construction Operation

Changes, many of them extremely radical in their nature,
are continually being made by prominent aviators,
and particularly those who have won the greatest amount
of success. Wonderful as the results have been few of
the aviators are really satisfied. Their successes have
merely spurred them on to new endeavors, the ultimate
end being the development of an absolutely perfect aircraft.

Among the men who have been thus experimenting
are the Wright Brothers, who last year (1909) brought
out a craft totally different as regards proportions and
weight from the one used the preceding year. One
marked result was a gain of about 3 1/2 miles an hour in

Dimensions of 1908 Machine.

The 1908 model aeroplane was 40 by 29 feet over all.
The carrying surfaces, that is, the two aerocurves, were
40 by 6 feet, having a parabolical curve of one in twelve.
With about 70 square feet of surface in the rudders, the
total surface given was about 550 square feet. The
engine, which is the invention of the Wright brothers,
weighed, approximately, 200 pounds, and gave about 25
horsepower at 1,400 revolutions per minute. The total
weight of the aeroplane, exclusive of passenger, but
inclusive of engine, was about 1,150 pounds. This result
showed a lift of a fraction over 2 1/4 pounds to the square
foot of carrying surface. The speed desired was 40
miles an hour, but the machine was found to make only
a scant 39 miles an hour. The upright struts were
about 7/8-inch thick, the skids, 2 1/2 by 1 1/4 inches thick.

Dimensions of 1909 Machine.

The 1909 aeroplane was built primarily for greater
speed, and relatively heavier; to be less at the mercy
of the wind. This result was obtained as follows: The
aerocurves, or carrying surfaces, were reduced in dimensions
from 40 by 6 feet to 36 by 5 1/2 feet, the curve
remaining the same, one in twelve. The upright struts
were cut from seven-eighths inch to five-eighths inch, and
the skids from two and one-half by one and one-quarter
to two and one-quarter by one and three-eighths inches.
This result shows that there were some 81 square feet
of carrying surface missing over that of last year's
model. and some 25 pounds loss of weight. Relatively,
though, the 1909 model aeroplane, while actually 25
pounds lighter, is really some 150 pounds heavier in the
air than the 1908 model, owing to the lesser square
feet of carrying surface.

Some of the Results Obtained.

Reducing the carrying surfaces from 6 to 5 1/2 feet
gave two results--first, less carrying capacity; and, second,
less head-on resistance, owing to the fact that the
extent of the parabolic curve in the carrying surfaces
was shortened. The "head-on" resistance is the retardance
the aeroplane meets in passing through the air,
and is counted in square feet. In the 1908 model the
curve being one in twelve and 6 feet deep, gave 6 inches
of head-on resistance. The plane being 40 feet spread,
gave 6 inches by 40 feet, or 20 square feet of head-on
resistance. Increasing this figure by a like amount for
each plane, and adding approximately 10 square feet for
struts, skids and wiring, we have a total of approximately,
50 square feet of surface for "head-on" resistance.

In the 1909 aeroplane, shortening the curve 6 inches
at the parabolic end of the curve took off 1 inch of
head-on resistance. Shortening the spread of the planes
took off between 3 and 4 square feet of head-on resistance.
Add to this the total of 7 square feet, less curve
surface and about 1 square foot, less wire and woodwork
resistance, and we have a grand total of, approximately,
12 square feet of less "head-on" resistance over
the 1908 model.

Changes in Engine Action.

The engine used in 1909 was the same one used in
1908, though some minor changes were made as
improvements; for instance, a make and break spark was
used, and a nine-tooth, instead of a ten-tooth magneto
gear-wheel was used. This increased the engine revolutions
per minute from 1,200 to 1,400, and the propeller
revolutions per minute from 350 to 371, giving a propeller
thrust of, approximately, 170 foot pounds instead
of 153, as was had last year.

More Speed and Same Capacity.

One unsatisfactory feature of the 1909 model over
that of 1908, apparently, was the lack of inherent lateral
stability. This was caused by the lesser surface and
lesser extent of curvatures at the portions of the
aeroplane which were warped. This defect did not show so
plainly after Mr. Orville Wright had become fully
proficient in the handling of the new machine, and with
skillful management, the 1909 model aeroplane will be
just as safe and secure as the other though it will take
a little more practice to get that same degree of skill.

To sum up: The aeroplane used in 1909 was 25
pounds lighter, but really about 150 pounds heavier in
the air, had less head-on resistance, and greater
propeller thrust. The speed was increased from about 39
miles per hour to 42 1/2 miles per hour. The lifting
capacity remained about the same, about 450 pounds
capacity passenger-weight, with the 1908 machine. In this
respect, the loss of carrying surface was compensated for
by the increased speed.

During the first few flights it was plainly demonstrated
that it would need the highest skill to properly
handle the aeroplane, as first one end and then the other
would dip and strike the ground, and either tear the canvas
or slew the aeroplane around and break a skid.

Wrights Adopt Wheeled Gears.

In still another important respect the Wrights, so far
as the output of one of their companies goes, have made
a radical change. All the aeroplanes turned out by the
Deutsch Wright Gesellschaft, according to the German
publication, _Automobil-Welt_, will hereafter be equipped
with wheeled running gears and tails. The plan of this
new machine is shown in the illustration on page 145.
The wheels are three in number, and are attached one
to each of the two skids, just under the front edge of
the planes, and one forward of these, attached to a cross-
member. It is asserted that with these wheels the
teaching of purchasers to operate the machines is much
simplified, as the beginners can make short flights on
their own account without using the starting derrick.

This is a big concession for the Wrights to make, as
they have hitherto adhered stoutly to the skid gear.
While it is true they do not control the German company
producing their aeroplanes, yet the nature of their
connection with the enterprise is such that it may be
taken for granted no radical changes in construction
would be made without their approval and consent.

Only Three Dangerous Rivals.

Official trials with the 1909 model smashed many records
and leave the Wright brothers with only three dangerous
rivals in the field, and with basic patents which
cover the curve, warp and wing-tip devices found on
all the other makes of aeroplanes. These three rivals
are the Curtiss and Voisin biplane type and the Bleriot
monoplane pattern.

The Bleriot monoplane is probably the most dangerous
rival, as this make of machine has a record of 54
miles per hour, has crossed the English channel, and
has lifted two passengers besides the operator. The latest type
of this machine only weighs 771.61 pounds complete,
without passengers, and will lift a total passenger
weight of 462.97 pounds, which is a lift of 5.21 pounds
to the square foot. This is a better result than those
published by the Wright brothers, the best noted being
4.25 pounds per square foot.

Other Aviators at Work.

The Wrights, however, are not alone in their efforts
to promote the efficiency of the flying machine. Other
competent inventive aviators, notably Curtiss, Voisin,
Bleriot and Farman, are close after them. The Wrights,
as stated, have a marked advantage in the possession of
patents covering surface plane devices which have thus
far been found indispensable in flying machine construction.
Numerous law suits growing out of alleged infringements
of these patents have been started, and
others are threatened. What effect these actions will
have in deterring aviators in general from proceeding
with their experiments remains to be seen.

In the meantime the four men named--Curtiss, Voisin,
Bleriot and Farman--are going ahead regardless of
consequences, and the inventive genius of each is so strong
that it is reasonable to expect some remarkable developments
in the near future.

Smallest of Flying Machines.

To Santos Dumont must be given the credit of producing
the smallest practical flying machine yet constructed.
True, he has done nothing remarkable with it
in the line of speed, but he has demonstrated the fact
that a large supporting surface is not an essential feature.

This machine is named "La Demoiselle." It is a monoplane
of the dihedral type, with a main plane on each
side of the center. These main planes are of 18 foot
spread, and nearly 6 1/2 feet in depth, giving approximately
115 feet of surface area. The total weight is 242 pounds,
which is 358 pounds less than any other machine which
has been successfully used. The total depth from front
to rear is 26 feet.

The framework is of bamboo, strengthened and held
taut with wire guys.

Have One Rule in Mind.

In this struggle for mastery in flying machine efficiency
all the contestants keep one rule in mind, and this

"The carrying capacity of an aeroplane is governed
by the peripheral curve of its carrying surfaces, plus the
speed; and the speed is governed by the thrust of the
propellers, less the 'head-on' resistance."

Their ideas as to the proper means of approaching
the proposition may, and undoubtedly are, at variance,
but the one rule in solving the problem of obtaining the
greatest carrying capacity combined with the greatest
speed, obtains in all instances.



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