Wright Brothers – Invention Of The Airplane

Articles relating to the Wright Brothers’ invention of the airplane.

The dedication of Wright Field in 1927 presented a 5,000-acre site to the government on behalf of the citizens of Dayton. Some 600 citizens and business donated to the fund.

Orville Wright was present for the ceremony and contributed an article he wrote for the publication, “Aviation Progress,” that described the early trials of inventing the airplane. “Aviation Progress” dated October 8, 1927, was a special edition covering the dedication. It was published by the National Cash Register Co. (NCR).

Here is Orville’s story:

Our interest in aeronautics dates back as far as 1899, at which time my brother, Wilbur, and I started work on the development of a heavier-than-air machine which would be sufficiently mobile to permit practical flying.

Some of our experiments were carried out in Dayton and others in Kitty Hawk, NC.

The first actual heavier-than-air machine was a glider, flown in the year 1900, at Kitty Hawk. The span of this plane was 18-feet with a chord of 5-feet.

Most of the experiments with this glider were made as a kite, operating the levers by chords from the ground.

In 1903, we developed a power machine having a span of 41-feet and a chord of 6 1/2-feet. Inasmuch as we had previously been unable to secure a satisfactory motor for this plane, we developed and made one which met the requirements and which developed from 10 to 12 horsepower. The motor was a horizontal type.

The weight of the machine with operator was 750 pounds. This machine made the first flight in the history of the world at Kitty Hawk on December 17, 1903.

The flights of 1902 glider had demonstrated the efficiency of our system of maintaining equilibrium, and also the accuracy of the laboratory work upon which the design of the glider was based.

We then felt we were prepared to calculate in advance the performance with a degree of accuracy that had never been possible with data and tables possessed by our predecessors. Before leaving camp in 1902, we were already at work on the general design of a new machine which we proposed to propel with a motor.

When the motor was completed and tested, we found that it would develop 16- horsepower for a few seconds, but that the power rapidly dropped till, at the end of a minute, it was 12-horsepower. Ignorant of what a motor of this size ought to develop, we were greatly pleased with the performance.

More experience showed us that we did get one-half of the power we should have had.

We left Dayton, September 23rd, and arrived at our camp at Kill Devil Hill on Friday, the 25th.

On November 28, while giving the motor a run indoors, we thought we again saw something wrong with one of the propeller shafts. On stopping the motor we discovered that one of the tubular shafts had cracked. Immediate preparation was made for returning to Dayton to build another set of shafts.

Wilbur remained in camp while I went to get new shafts. I did not get back to camp again till Friday the 11th of December.

Saturday afternoon the machine was again ready for trial, but the wind was so light a start could not be made from level ground with the run of 60-feet permitted by our monorail track. Nor was there enough time before dark to take the machine to one of the hills where, by placing the track on a steep incline, sufficient speed could be secured in calm air.

Monday, December 14, was a beautiful day, but there was not enough wind to enable a start to be made from the level ground around camp. We therefore decided to attempt a flight from the side of Kill Devil Hill.

We arranged with the members of the Kill Devil Hill life-saving station, which was located a little over a mile from our camp, to inform them when we were ready to make the first trial of the machine.

During the night of December 16, 1903, a strong wind blew from the north. When we arose on the morning of the 17th, the puddles of water, which had been standing about the camp since the recent rains, were covered with ice. The wind had a velocity of 10 to 12 meters per second (22 to 27-miles per hour). We thought it would die down before long and so remained indoors the early part of the morning.

But when ten o’clock arrived, and the wind was as brisk as ever, we decided that we had better get the machine out and attempt a flight.

We hung out the signal for the men of the life-saving station. We thought by facing the machine into a strong wind there ought to be no trouble in launching it from the level ground about the camp.

We realized the difficulties of flying in so high a wind, but estimated that the added dangers in flight would be partly compensated for by the slower speed in landing.

After running the motor a few minutes to heat it up, I released the wire that held the machine to the track, and the machine started forward into the wind. Wilbur ran at the side of the machine, holding the wing to balance it on the track. Unlike the start on the 14th, made in calm, the machine facing 27-mile an hour wind started very slowly. Wilbur was able to stay with it until it lifted from the track after a 40-foot run.

One of the life-saving men snapped the camera for us, taking a picture just as the machine reached the end of the track and had risen to a height of about 2-feet.

The course of the flight up and down was exceedingly erratic, partly due to the irregularity of the air, and partly to lack of experience in handling the machine.

The control of the front rudder was difficult on account of its being balanced too near the center. This gave it a tendency to turn itself when started, so that it turned too far on one side and then too far on the other. As a result, the machine would rise suddenly 10-feet and then as suddenly dart for the ground.

A sudden dart a little over 100-feet from the end of the track, or a little over 120-feet from the point at which it rose into the air, ended the flight.

As the velocity of the wind was over 35-feet per second and the speed of the machine over the ground against this wind 10-feet per second, the speed of the machine relative to the air was over 45-feet per second (30.7 mph), and the length of the flight was equivalent of a flight of 450-feet made in calm air.

This flight only lasted 12-seconds had but it was nevertheless the first time in history of the world in which a machine carrying a man raised itself by its own power into the air in full flight, had sailed forward without reduction of speed, and had finally landed as high as that from which it started.

At twenty minutes after eleven Wilbur started on the second flight. The course of this flight was much like that of the first flight, very much up and down. The speed over the ground was somewhat faster than of the first flight, due to the lesser wind. The duration of the flight was less than a second longer than the first, but the distance was about 75-feet greater.

Twenty minutes later the third flight started. This one was steadier than the first one an hour before. I was proceeding along pretty well when a sudden gust from the right lifted the machine up 12 to 15 feet and turned it up sidewise in an alarming manner. It began a lively sliding off to the left. I warped the wing to try to recover lateral balance, and at the same time pointed the machine down to reach the ground as quickly as possible.

The lateral control was more effective than I had imagined, and before I reached the ground the right wing was lower than the left and struck first.

The time of the flight was 15-seconds and the distance over the ground was a little over 200-feet.

Wilbur started the fourth and last flight at just twelve o’clock. The first few hundred feet were up and down as before, but by the time 300-feet had been covered, the machine was under much better control. The course for the next four or five hundred feet had but little undulation. However, when at about 800-feet the machine began pitching again, and on one of its starts downward struck the ground.

The distance over the ground was measured and found to be 852-feet. The time of the flight was 59-seconds.

The frame supporting the front rudder was badly broken, but the main part of the machine was not injured at all.

There are three people that can speak with authority about the flying qualities of the Wright 1903 Flyer. They are Orville Wright, Wilbur Wright and Ken Kochersberger.

Who is Ken Kochersberger? Ken is a professor at the Rochester Institute of Technology, Rochester, NY. But more important to this article is that Ken is the only other person that has successfully flown the Wright 1903 Flyer.

Ken flew a reproduction Flyer on Nov. 20, 2003 at the Wright Memorial in Kill Devil Hills. It was launched in a northerly direction into a 12-mph wind and flew 97 feet. This is the first time in 100 years that a Wright 1903 Flyer has been successfully flown and landed without damage, using an authentic engine.

Ken flew another flight of 115 feet and landed sustaining minor damage to the Flyer consisting of four broken ribs.

Two other flights were attempted. One resulted in a crash. The final flight was attempted on Dec. 17, 2003 during the Wright brothers centennial celebration at Kill Devil Hills. Unfortunately the weather was not suitable to sustain a successful flight.

This reproduction Flyer was researched and built by Ken Hyde’s Wright Experience, Warrenton, Va. They produced an exact reproduction of the original machine, including the engine, using artifacts and photographs. This plane is more faithful than the “original” Flyer hanging in the Air and Space Museum in Washington, D.C.

The Wright brothers never flew their 1903 Flyer again after their fourth successful flight in 1903. The machine was caught by a gust of wind while resting on the ground and sent tumbling over the sand, which resulted in severe damage. The Wrights dissembled and packed the parts of the airplane in crates and sent them back to Dayton.

There, it sat in storage enduring flood damage in 1913. It was taken out of storage and restored in 1916 and again in 1925. On both occasions the restoration was for display and not for flying. This resulted in some subtle but significant variations of the original structure.

Here are some observations from a pilot’s perspective on flying the Wright Experience Flyer.

The Flyer is not very comfortable to fly. Elbows must be placed to avoid the fuel mixture control and the fuel line, creating an awkward position. One must lie on the wing in an arched shape for forward visibility, not a comfortable position for long periods of time. To gain some relief, the pilot can shift around in the wingwarping cradle during the engine start prior to launch.

During takeoff it is necessary to keep the wings levels because they are only two feet off the ground. The famous picture of the first flight shows Wilbur running along side the Flyer. He had been holding the wings steady until takeoff.

The canard (front elevator) is kept neutral to reduce drag while running down the launching rail until ready for rotation. A positive canard deflection of at least 10 degrees is required to initiate flight.

The Flyer benefited by the wings being close to the ground by increased lift, “ground effect,” and a reduction of “induced drag.” The anhedral (curved down) shape of the wings also produced additional lift.

There was no speed indicator on the Flyer, so the pilot must estimate the speed for rotation by experience. Once takeoff speed is reached, the Flyer requires significant positive canard to rotate because of a nose-down moment caused by the thrust line.

Rotation is limited to 3.5 degrees by the physical clearance between the tail and the rail. At this rotation the target speed is 26-mph.

Complicating the process is that the flyer trims with more canard at higher speeds and less with lower speeds. This requires the pilot to continuously adjust trim reference as airspeed changes. If there is a crosswind on takeoff, the warp corrections held on the rail must be lessened immediately at rotation.

Wingwarping was found to be responsive. The hip cradle required about 14 pounds of force. This is about twice that required on the 1902 glider. A good grip is required on the canard actuator crossbar while moving the hips to prevent the body from moving instead of the cradle.

The Flyer is unstable in sideslip during takeoff because of the anhedral of the wing. The flight on Dec. 3, 2003 experienced a crosswind and upon rotation the right warp and the anhedral effect caused a right roll with the right wingtip grazing the ground. The plane recovered and continued to fly and landed with the left wing low after traveling 115-feet.

Once the Flyer is airborne, large pitch corrections are required frequently to maintain stability. The wood structure of the Flyer is flexible which makes all control inputs less responsive resulting in control lags. The machine is substantially unstable in pitch and never flies strictly at trim but operates over the full range of the canard travel.

Ken reports that the Flyer flies more like a powered kite than an aircraft, with a soft feel to the handling in part caused by the lag between the canard input and the pitch response.

The Wright Experience pilots found that they could handle the Flyer although it takes much practice to acquire the flying skills needed. They all found a new respect for the skills and talent of Orville and Wilbur.

References: Flying Qualities of the Wright Flyer: From Simulation to Flight Test, Kochersberger, K., Ken Hyde, et. al., 42nd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 5-8 Jan. 2004.

www.wrightexperience.com

Birdflight

by Dr. Richard Stimson

in Inventing The Airplane

Since ancient times mankind has looked up to view birds in flight, envied their freedom of travel, and dreamed of flying.

The Wright brothers were no different. They liked to ride their bicycles to a popular picnic area south of Dayton called the “Pinnacles.” There they would observe the soaring birds and their observations were crucial in convincing them that gaining lateral control of a flying machine would require actually changing the shape of the wing.

At first they didn’t learn anything of use to them by their observations. Later, after they had thought out certain principles, they observed the birds to see if they used the same principles.

Orville wrote many years later, “learning the secret of flight from a bird was a good deal like learning the secret of magic from a magician. After you once knew the trick and know what to look for, you see things that you did not notice when you did not know exactly what to look for.”

They would have found out even more about birds and flying if they had known about a prehistoric fossil that contained a feathered flying dinosaur, the Microraptor. It was discovered in China just two years ago.

Researchers found that the only way the animal could have remained airborne was if it had split wings like those of a biplane. With this configuration, the tree-dwelling animal could jump from a high branch and glide half the length of a football field without flapping. The theory is that flying dinosaurs evolved from tree dwellers that parachuted to the ground, which then gave rise to gliders and eventually to flappers who could perform powered flight.

Over 500 years ago Leonardo da Vinci conceptualized a man-powered flying machine that would achieve both lift and thrust with flapping wings and named it the “ornithopter.” Leonardo never flew his machine. Even to this day experimenters have tried this approach with limited success.

Orville wrote in the spring of 1899, “our interest in the subject (flight) was again aroused through the reading of a book on ornithology. We could not understand that there was anything about a bird that would enable it to fly that could not be built on a larger scale and used by man. At this time our thought pertained more to gliding flight and soaring. If the bird’s wings would sustain it in the air without the use of any muscular effort, we did not see why man could not be sustained by the same means.”

The surest way to discovery is choosing the right path to get there. The most frequent path taken by the early pioneers who wanted to discover the secret of flight wrongly attempted a design that imitated a flapping-wing bird. This was the approach of Icarus and da Vinci.

Those who studied the straight-outstretched, motionless wings of birds like the condor, hawk and vulture which that swoop and glide for hours were closest to the right solution.

This was the approach of Otto Lilienthal in Germany who heavily influenced the Wrights. Lilienthal learned what a bird does with its wing. He found that a bird alters dihedral to change stability, varies curvature to change lift and determined the superiority of a curved wing.

He didn’t find all the answers but did more than anyone else up until the Wright brothers. The Wrights would discuss what Lilienthal was doing and were impressed by his scientific approach to flying when others were using unscientific trial and error. Some of Lilienthal’s coefficients and equations had to be superseded later, but they were remarkable at he time. Lilienthal developed and established a foundation for the science of aerodynamics.

The idea of gliding appealed to Orville and Wilbur as a sport.

A tragic event occurred that would change the destiny of the Wrights. Lilienthal was killed in a gliding accident in 1896. Orville was in bed recovering from typhoid fever (an illness that would later claim Wilbur’s life) when Wilbur read the news to him. Their ensuing discussion about what caused Lilienthal’s death and the problem of flight led them to a commitment to prove the possibility of flight. As soon as Orville recovered, they embarked on what their neighbors liked to call their “crazy doings.”

Lilienthal had died because he attempted to maintain lateral balance of his glider in flight by swinging his body, an ineffective method. Wilbur and Orville reasoned that a mechanism could be designed so that a pilot with practice could maintain directional control of flight.

The Wrights had observed that gliding and soaring birds regained their lateral balance by torsion of the tips of their wings. Orville explained how that could work for a glider. “The basic idea was the adjustment of the wings to the right and left sides to different angles so as to secure different lifts on the opposite wings.”

They knew that turning an airplane had to do with changing wing surfaces, though not the way that the hawks did it. That’s a significant distinction. The Wrights drew inspiration form biology, but they didn’t exactly copy it. The problem was how to implement the concept mechanically.

Louis Pasteur once said: “Fortune favors the prepared mind.”

Wilbur was talking to a customer one day in the bicycle shop while at the same time toying with a cardboard box for a bicycle tire. He suddenly realized he had found the answer. He noticed that although the vertical end sides of the box remained rigid, the top and bottom sides could be twisted to form a new set of angles at opposite ends.

Wilbur tested his “wingwarping” idea in July 1899 using a 5-foot box kite with a fixed horizontal tail plane. Orville wrote, “According to Wilbur’s account of the tests, the model worked very successfully. It responded promptly to the warping of the surfaces, always lifting the wing that had the larger angle.”

The evolution of the airplane followed in many similar aspects nature’s evolution of the earliest animals that could fly.

Orville never lost his interest in birds. In September 1905, two years after the first powered flight at Kitty Hawk, he was flying over Huffman Prairie in Dayton when he reported hitting a bird. It seems he was doing circles, chasing birds and whacked one. According to his diary. It landed dead on the upper wing.

A few days after the first successful powered, sustained, controlled flight of the Wright Flyer at Kitty Hawk in 1903, it was disassembled and returned to Dayton, Ohio. Orville and Wilbur were pleased with its performance but knew that there was much work yet to be done to produce a practical flying machine. One of their important tasks would be to improve the stability of the machine.

1904 Machine, Wright Flyer II

The dimensions of the 1904 machine were similar to the 1903 machine but a large number of design changes were made. These included a new engine, changing the structure to move the center of gravity towards the rear, decreasing the camber of the wings, changing the shape of the vertical rudder and using new and larger propellers.

Due to the difficulty of taking off in the low winds in Dayton, they started using a derrick with weights that could be dropped to catapult the machine.

The performance of the machine was an improvement over the 1903 Flyer, but it was still not the performance the Wrights were seeking. It had a tendency to stall in tight turns. This problem was not solved until 1905.

1905 Machine, Wright Flyer III

Changes made to the 1905 machine included enlarging the rudder surfaces, moving the vertical tail further to the rear, using newly designed propellers (bent end), decreasing the camber back to the camber used on the 1903 Flyer and eliminating the wing droop. They also took the important step of unlinking the warp and rudder controls and providing for the separate, or combined, operation in any desired degree.

On October 5th Wilbur took-off from Huffman Prairie and flew for more than 24 miles in just over 39 minutes while completing more than 29 circles of the field at an average speed of 38-mph.

The Wrights were satisfied that they had produced a practical airplane. Others, including the U.S. War Department and foreign governments, were not convinced. Fearing loss of their secrets, they decided not to fly again until they had buyer. The result was that they did not fly in 1906 or 1907.

It was not until February 8, 1908, that the Signal Corps of the U.S. War Department concluded a contract with the Wrights for an airplane. Almost simultaneously, they signed a contract with a Frenchman to form a syndicate for the rights to manufacture, sell or license the use of the Wright airplane in France.

1907 Type Machines

Wilbur and Orville revamped their 1905 machine, to permit the pilot to sit upright instead of lying prone, and to carry at least one passenger. The control system was redesigned to accommodate the new seating position.

The 1907 type machines were built and flown between 1907 and 1909. They were sometimes referred to as Wright Model A although the Wrights never used that designation. The various types were of similar configuration but varied in dimension.

In May 1908 the Wrights took a machine to Kitty Hawk to prepare for the demonstrations they would make in France and at Ft. Myer.

Wright airplanes of the 1907 type include: the machine shipped to Europe in 1907 and flown by Wilbur in France from 1908 to March 1909; the airplane that Orville flew in the first Army tests at Fort Myer and wrecked on September 17, 1908; the airplane assembled at Pau and shipped to Rome for flights by Wilbur in April 1909; one of two machines assembled in Berlin in 1909 and flown by Orville in March and April; the machine used by Wilbur in his flights of September-October 1909 during the Hudson-Fulton Celebration in New York City and the machine flown by Orville at Montgomery Alabama in 1910.

1909, Signal Corps Machine

This airplane was Signal Corps No. 1 and sometimes referred to as the Military Flyer. Some of the differences between this modified machine and the standard 1907-type machine used the previous year were that the wing area was reduced and the propellers were closer together. The reduction in the area of the wing resulted in the need for a higher take-off speed and longer start, necessitating adding 30 feet to the starting rail.

This machine gained fame as the world’s oldest military airplane.

In August 1909, Orville made many demonstration flights during the next two months at Templehof and Potsdam with a standard Model A.

Model B, 1910-1911

The Model B was produced in 1910 and 1911. The first machine was completed on June 29, 1910. It is their first production machine and was flown by Orville for the first time over Huffman Prairie in July of 1909. Some 80-100 were believed to have been built.

The most fundamental change from the Model A was the transfer of the elevator from the front to the rear structure that held the rudder. Two fixed flaps of cloth were added to what remained of the forward structure to provide stability in turns. For the first time also, wheels were added to the undercarriage. It is the Wrights first machine to use a rear stabilizer that is now considered a traditional tail.

Signal Corps Airplanes No. 3 and No. 4, built in 1911, were Wright B Flyers and they were used for training pilots and in aerial experiments.

In 1912 the Navy fit a Model B Flyer, referred to as the B1 Flyer, with pontoons for testing as a seaplane in San Diego Bay, California.

Model R, 1910

The Model R was designed as a high-speed racer for setting speed and altitude records and was equipped with a wheeled undercarriage. It was called the “Roadster” and more popularly, the “Baby Wright.” A smaller version, the “Baby Grand, ” powered by an 8-cylinder, 60-hp engine was flown by Orville at the Belmont Park Meet in 1910. It could reach speeds up to 80-mph.

Model, EX 1911

The EX was a smaller version of the Model B. It was built mainly for flying at exhibitions. It could climb fast and reach nearly 60-mph.

A modified EX, the Vin Fiz flown by Galbraith Perry Rodgers, made the first transcontinental flight in 1911.

On May 13, 1918 Orville made his last flight as a pilot, flying a 1911 Wright airplane

Model C, 1912

The Model C was the successor to the Model B. It became the new standard production airplane for the Wright Company. The model B and the Model C airplanes were the only airplanes built by the Wright Company in quantity. The first Model C airplanes were delivered to the Army in 1912.

It employed a more powerful engine to meet Army specifications and a new control system. The specifications required the machine to climb at a rate of 200-feet per second, have a fuel supply sufficient for a four hour flight and carry a weight of 450 pounds including the pilot and passenger.

The Army originally purchased six Wright Model Cs and five of these airplanes crashed killing six men. The machine was unstable and used a twin-lever control system that was confusing to operate for inexperienced pilots.

The Model C replaced the prominent triangular blinkers of the Model B with vertical vanes attached to the forward end of the skids.

Models K and L subsequently replaced the Model C.

Unfortunately, by 1910 the Wright airplanes were beginning to fall behind the competition. The Model C was such a machine.

Between 1910 and 1915 the Wrights produced 10 different distinct aircraft designs.

What follows is a short description of some more of these designs.

Model CH, 1913

This was the first Wright seaplane. It was essentially a Model C with pontoons added. Experiments were conducted on the Miami River near Dayton, Ohio in the spring and early summer of 1913.

Model D, 1912

The Model D was designed as a light fast scout biplane for the Army. It was similar to the Model R. Its speed was about 70-mph. It had a problem in landing on rough ground, which was an Army requirement. A high landing speed caused Model D to nose over in a ploughed field.

Model E, 1913

This model used a single 7-foot pusher propeller and was designed for exhibition use. It could be dismantled and reassembled quickly. It also had two wheels instead of the usual four that had been used on all Wright airplanes built during the period of 1910-1913.

Model F, 1913

The Model F was built for the U.S. Army. It was the first Wright machine built with a fuselage. It was also the first to use the tractor propellers instead of the pusher type.

Model G, 1913-1914

This was the first deep-water flying boat. Grover Loening under supervision of Orville designed it. It was given the name, “Aeroboat.”

The hull was made of ash and spruce, covered with a special alloy treated to prevent salt-water corrosion.

Model H, 1914

The Model H looked in appearance like the Model F except that the fuselage was continuous. The fuselage was made of wood, veneered with canvas inside and out.

Model HS, 1915

This was a smaller version of Model H. It was the last Wright machine to have an double vertical rudder and the last to user pusher-type propellers.

Models I and J

These were not Wright machines. The Burgess-Wright Company built them. Glen Curtiss was involved with this company.

Orville Wright considered these machines to be infringements of the Wright patents.

Model K, 1915

The Model K was a seaplane built for the U.S. Navy. It was the first tractor plane produced by the Wright Company and the last to use the Wright “bent end” propellers that were first used in 1905.

It was also the first Wright machine to utilize modern-type ailerons on both the upper and lower wings instead of using wingwarping. Wingwarping had been used on all Wright machine and gliders since 1899.

Model L, 1916

This airplane was offered for sale after Orville had sold the Wright Company.

It was a single-place light-scout biplane designed for high-speed reconnaissance. It bore no resemblance to the early Wright biplanes.

Reference: “The Papers of Wilbur and Orville Wright,” by Marvin W. McFarland, Editor.

While engaged in the bicycle manufacturing and repair business in 1897 and 1898 in their shop at 22 South Williams St., the Wrights focused their attention on the problems of mechanical and human flight.

Otto Lilienthal, German engineer and aeronautical pioneer, died in Germany on August 10, 1896 following injuries suffered in a crash the previous day of his latest single-surface glider with an adjustable horizontal tail. This event triggered the Wrights interest in solving the problem of flight and the question of whether they could go on from where he had left off. They decided to begin by conducting “a systemic study of the subject in preparation for practical work.”

Wilbur was familiar with the flying activities of Lilienthal from reading an article on Lilienthal entitled “The Flying Man” in McClure’s Magazine that they had access to in their father’s library. He also had access to books on the work of Cayley, Penaud and Marey.

Wilbur visited the Dayton Public Library to obtain more information but they had nothing on the subject of human flight. He decided to write to the Smithsonian Institution on May 30, 1899.

Here is a copy of that letter including some of my comments:

Dear Sirs;

I have been interested in the problem of mechanical and human flight ever since as a boy I constructed a number of bats of various sizes after the style of Cayley’s and Penaud’s machines. My observations since have only convinced me more firmly that human flight is possible and practicable.

Comment: Bishop Milton Wright, on return from a short trip on church business, brought home a toy Penaud-type helicopter using twisted rubber bands for motive power, arousing the boy’s first interest in flight. They discovered their first mystery about flight when they tried to build larger versions of the toy and found they wouldn’t fly. They didn’t know then that as the linear measurement of a model is doubled it needs about eight times the power to fly.

Sir George Cayley engraved an image of a flying machine on a silver disk in 1799. That imprint was the first to resemble the configuration of a modern airplane. Through the next decade he built both model and full-size gliders.

It is only a question of knowledge and skill just as in all acrobatic feats. Birds are the most perfectly trained gymnasts in the world and are specially well fitted for their work, and it may be that man will never equal them, but no one who has watched a bird chasing an insect or another bird can doubt that feats are performed which require three or four times the effort required in ordinary flight. I believe that simple flight at least is possible to man and that the experiments and investigations of a large number of independent workers will result in the accumulation of information and knowledge and skill which will finally lead to accomplished flight.

The works on the subject to which I have had access are Marey’s and Jamieson’s books published by Appleton’s and various magazine and cyclopaedic articles.

Comment: The Jamieson’s books published by Appleton are somewhat of a mystery because they have never been found. It is known that an Andrew Jamieson was an author of a textbook on Applied Mechanics.

I am about to begin a systematic study of the subject in preparation for practical work which I expect to devote what time I can spare from regular business. I wish to obtain such papers as Smithsonian Institution has published on this subject, and if possible a list of other works in print in the English language. I am an enthusiast, but not a crank in the sense that I have some pet theories as to the proper construction of a flying machine.

Comment: There had been so many failed attempts to fly that many believed that flying was impossible. Wilbur apparently wanted to make it clear he was not some crackpot.

I wish to avail myself of all that is already known and then if possible add my mite to help on the future worker who will attain success. I don not know the terms on which you send out your publications but if you will inform me of the cost I will remit the price.

Yours truly,

Wilbur Wright

On June 2nd, only three days later, Richard Rathbun, assistant secretary of the Smithsonian sent the Wrights a list of works and four Smithsonian pamphlets on the subject of aerial navigation, which further stimulates the Wrights’ interest in gliding as a sport.

On June 14, Wilbur acknowledges Rathbun’s letter and orders a copy of Samuel P. Langley’s “Experiments in Aerodynamics.”

The Wrights decide that control is the primary problem to solve. During July and August they construct and Wilbur tests and flies a biplane kite with a five-foot wingspan that incorporates their idea of wing warping to effect control in the roll dimension. The successful kite experiment encourages them to proceed with the building of a man-carrying machine embodying this principle.

The kite hung on a wall of a room over their bike shop until destroyed about 1905 to make room for an upstairs office.

On November 27 Wilbur wrote to the U.S. Weather Bureau for information on a suitable place to conduct their flying experiments.