Mr. Octave Chanute, Esq.
Chicago, Illinois
Dear Sir;
For some years I have been afflicted with the belief
that flight is possible to man. My disease has increased in severity and
I feel that it will soon cost me an increased amount of money if not my
life. I have been trying to arrange my affairs in such a way that I can
devote my entire time for a few months to experiment in this field.
My general ideas of the subject are similar to those
held by most practical experimenters, to wit: that what is chiefly
needed is skill rather than machinery. The flight of the buzzard and
similar sailors is a convincing demonstration of the value of skill, and
the partial needlessness of motors. It is possible to fly without
motors, but not without knowledge & skill. This I conceive to be
fortunate, for man, by reason of his greater intellect, can more
reasonably hope to equal birds in knowledge, than to equal nature in the
perfection of her machinery.
Assuming then that Lilienthal was correct in his ideas
of the principles on which man should proceed, I conceive that his
failure was due chiefly to the inadequacy of his method, and of his
apparatus. As to his method, the fact that in five years' time he spent
only about five hours, altogether, in actual flight is sufficient to
show that his method was inadequate. Even the simplest intellectual or
acrobatic feats could never be learned with so short practice, and even
Methuselah could never have become an expert stenographer with one hour per year for practice. I also conceive
Lilienthal's apparatus to be inadequate not only from the fact that he
failed, but my observations of the flight of birds convince me that
birds use more positive and energetic methods of regaining equilibrium
than that of shifting the center of gravity.
With this general statement of my principles and
belief I will proceed to describe the plan and apparatus it is my
intention to test. In explaining these, my object is to learn to what
extent similar plans have been tested and found to be failures, and also
to obtain such suggestions as your great knowledge and experience might
enable you to give me. I make no secret of my plans for the reason that
I believe no financial profit will accrue to the inventor of the first
flying machine, and that only those who are willing to give as well as
to receive suggestions can hope to link their names with the honor of
its discovery. The problem is too great for one man alone and unaided to
solve in secret.
My plan then is this. I shall in a suitable locality
erect a light tower about one hundred and fifty feet high. A rope
passing over a pulley at the top will serve as a sort of kite string. It
will be so counterbalanced that when the rope is drawn out one hundred
& fifty feet it will sustain a pull equal to the weight of the
operator and apparatus or nearly so. The wind will blow the machine out
from the base of the tower and the weight will be sustained partly by
the upward pull of the rope and partly by the lift of the wind. The
counterbalance will be so arranged that the pull decreases as the line
becomes shorter and ceases entirely when its length has been decreased
to one hundred feet. The aim will be to eventually practice in a wind
capable of sustaining the operator at a height equal to the top of the
tower. The pull of the rope will take the place of a motor in
counteracting drift. I see, of course, that the pull of the rope will
introduce complications which are not met in free flight, but if the
plan will only enable me to remain in the air for practice by the hour
instead of by the second, I hope to acquire skill sufficient to overcome
both these difficulties and those inherent to flight. Knowledge and
skill in handling the machine are absolute essentials to flight and it
is impossible to obtain them without extensive practice.
The method employed by Mr. Pilcher of towing with
horses in many respects is better than that I propose to employ, but
offers no guarantee that the experimenter will escape accident long
enough to acquire skill sufficient to prevent accident. In my plan I
rely on the rope and counterbalance to at least break the force of a
fall. My observation of the flight of buzzards leads me to believe that
they regain their lateral balance, when partly overturned by a gust of
wind, by a torsion of the tips of the wings. If the rear edge of the
right wing tip is twisted upward and the left downward the bird becomes
an animated windmill and instantly begins to turn, a line from its head
to its tail being the axis. It thus regains its level even if thrown on
its beam ends, so to speak, as I have frequently seen them. I think the
bird also in general retains its lateral equilibrium, partly by
presenting its two wings at different angles to the wind, and partly by
drawing in one wing, thus reducing its area. I incline to the belief
that the first is the more important and usual method.
In the apparatus I intend to employ I make use of the
torsion principle. In appearance it is very similar to the
"double-deck" machine with which the experiments of yourself
and Mr. Herring were conducted in 1896-7. The point on which it differs
in principle is that the cross-stays which prevent the upper plane from
moving forward and backward are removed, and each end of the upper plane
is independently moved forward or backward with respect to the lower
plane by a suitable lever or other arrangement. By this plan the whole
upper plane may be moved forward or backward, to attain longitudinal
equilibrium, by moving both hands forward or backward together. Lateral
equilibrium is gained by moving one end more than the other or by moving
them in opposite directions. If you will make a square cardboard tube
two inches in diameter and eight or ten long and choose two sides for
your planes you will at once see the torsional effect of moving one end
of the upper plane forward and the other backward, and how this effect
is attained without sacrificing lateral stiffness. My plan is to attach
the tail rigidly to the rear upright stays which connect the planes, the
effect of which will be that when the upper plane is thrown
forward the end of the tail is elevated, so that the tail assists
gravity in restoring longitudinal balance.
My experiments hitherto with this apparatus have been
confined to machines spreading about fifteen square feet Of surface, and
have been sufficiently encouraging to induce me to lay plans for a trial
with a full-sized machine. My business requires that my experimental
work be confined to the months between September and January and I would
be particularly thankful for advice as to a suitable locality where I
could depend on winds of about fifteen miles per hour without rain or
too inclement weather. I am certain that such localities are rare.
I have your Progress in Flying Machines and your
articles in the Annuals of '95,'96, & '97, as also your recent
articles in the Independent. If you can give me information as to where
an account of Pilcher's experiments can be obtained I would greatly
appreciate your kindness.
Yours truly,
Wilbur Wright
Afflicted with
Need
to 
n May 13, 1900, Wilbur Wright
wrote to Octave Chanute, beginning a long and fruitful exchange of ideas.
This correspondence extended through the Wright brothers' "experimental"
years and gives us a insight into the problems they were wrestling with
and the methods they considered to solve them. But it is more than
historical documentation. Wilbur's letters are an important key to the
brothers' final success. Writing forced Wilbur to organize the results
of his experiments, examine his ideas, draw conclusions, and consider
how best to proceed.
