The author of the article below meticulously substantiates what he believes is wrongdoing by the Wrights. His
- backdating experiments,
- concealing data,
- covering up mistakes,
-making false claims, false statements & false promises.
He claims the brothers' goal was to credit themselves for another inventor’s discovery of key elements of
their success. That inventor was an academic, Dr. George Spratt, who assisted the Wrights with their wind tunnel experiments and was present at Kitty Hawk throughout the critical years. Spratt had
been a close friend of the Wrights. Like Octave Chanute, he became estranged when the Wrights started their "Patent Wars".
However, unlike Chanute, Spratt went further alleging plagiarism & dishonesty by the Wrights. Orville Wright authorized his biographer to heap ridicuule on Spratt, equating Dr. Spratt with wing-flapping aeronautical oddities which he described as "incompetent, hilarious and sad" (Kelly, p. 469).
George A. Spratt, Forgotten Friend of the Wright Brothers
by Donald C. Paulson
The Wright brothers said it was the data from their wind tunnel experiments that made their invention of the airplane possible. It was, as Orville stated, "the key to our success". Numerous books have been written describing each step in their march to success, except for one curious omission. Though urged by historians, neither Wilbur before his death in 1912, nor Orville who lived until 1948, would ever reveal the details of their wind tunnel experiments. An analysis of the original data and letters reveals the likely reason.
Wilbur and Orville Wright acknowledged they did not make friends easily, but one whose friendship they treasured was a like-minded aviation enthusiast named Dr. George A. Spratt. Spratt worked with them at Kitty Hawk in 1901, ‘02, and ‘03, not as a doctor, but as a friend and assistant, sometimes contributing his aviation knowledge. Both Orville, and the normally taciturn Wilbur, showed they were genuinely fond of Spratt signing their letters to him as, "ever your friend" and, "truly your friend", the only letters in the entire record of Wright correspondence that ended with such warmth of expression.
their years of friendship, Spratt and the Wrights exchanged almost 80 letters filled with news, ideas and light hearted humor. There is no doubt the Wrights appreciated Spratt. Soon after
home from his 1902 stay at Kitty Hawk, Spratt sent the Wrights ten dollars to reimburse them for his keep at their camp. The Wrights returned the money with a note saying, "We owe you, not you us." 
of the Spratt/Wright relationship began on July 25, 1901 when Dr. Spratt arrived at the Wrights’ camp at Kitty Hawk, North Carolina, from his home in Coatesville, Pennsylvania. He came at the
invitation of Octave Chanute, at that time, the best known aviation authority in the United States and perhaps the world. Before his retirement, the 66 year old Chanute had been a well known bridge
designer and civil engineer. Now, his interest was aviation. Chanute, a French born naturalized American citizen, had traveled extensively in the United States and Europe. During his travels he
collected articles describing early flight experiments. In 1894 he wrote a book entitled Progress in Flying Machines that summarized the developments
up to that time. It was the definitive reference on aviation in its day. Chanute also wrote articles, designed gliders and sponsored flight experiments. His
knowledge and reputation made him a one-man world-wide clearing house for aviation experimenters.
George Spratt first wrote to Chanute in December 1898. The 28 year old medical doctor had recently stopped practicing medicine due to his own poor health, the result of rheumatic fever as a child. Now he earned a meager living by overseeing a small farm owned by his father. In his spare time Spratt pursued his main interest, research to uncover the secrets of flight. In his first letter to Chanute, Spratt described his ideas of how curved wings cause "lift", phenomena known but not understood. Chanute gently told him his ideas were "mere speculation" and he should find answers by experimenting. Spratt took up the call. He had a well equipped wood working shop, bought using an inheritance, but he had very little income so he had to improvise equipment and instruments for his experiments. From time to time Chanute sent him small sums of money to continue his research. Spratt was meticulous in his accounting. In one of his letters he reported the results and cost of an experiment. The results, he said, were not consistent adding, "a fellow can't be scientifically accurate spending only seventy-one cents." To a visitor who asked what he was making in his shop he said, "shavings". To another he said he made "mistakes, and when I’ve made all that are possible, I expect to have a good product".
At a time
when the public and even most scientists thought that manned flight was an unattainable dream, Spratt showed remarkable prescience in predicting the role aviation would eventually play. In 1899 he
wrote to Chanute, "this is a remarkably interesting study. I do not see why people hold it so in ridicule, it will come out on top of all methods of transportation in time." In September, 1900 he
wrote, "air navigation will be of immense value in carrying the goods of the world….success
is not far off." Spratt was right, and he would play a part and then be forgotten.
Spratt’s first attempt at research was ambitious, overly so. He tried to measure the air flow and pressures along the surface of small wing shapes using homemade instruments. That’s what the seventy-one cents went for. Next he tried to measure the forces on the wing caused by air flow. But it required a consistent flow of air. He reported to Chanute that he had built a wind tunnel on a hilltop to direct wind past his wing shapes, but the natural wind was too variable. To generate a wind he tried a bicycle driven fan, an electric fan, even a blacksmiths bellows but nothing gave the velocity or consistency he needed. An internal combustion engine would work but they were expensive, well out of Spratt’s reach. But he did have some success.
Earlier researchers had concluded that the center of pressure on a wing moves forward, towards the front edge of the wing, as the angle of attack decreases until, at a zero angle of attack, it is at the front edge. In early 1900 Spratt told Chanute that when air flows over a cambered wing surface, he found the center of pressure reverses at a low angle of attack. Chanute told him that, as far as he knew, this was an original discovery. Spratt’s findings were not entirely accurate but this conclusion would later prove to be valuable.
Spratt next turned his attention to the problem other researchers had encountered and failed to solve, how to accurately measure a wing’s lift and drag (called "drift" in those days). In 1895 in Otto Lilienthal, the German glider pilot, published lift and drag tables based on his glider experiments. The data was sparse, based on only one wing shape, but it was the best data then available. The Wrights used it to design the wings for their 1900 and 1901 gliders. However, their flights at Kitty Hawk showed the glider’s lift was much less than predicted. They became convinced the Lillienthal’s data was wrong.
The Wrights, as well as other serious experimenters, knew that accurate lift and drag data would be immense value in solving the problems of flight. With accurate data, a builder would be able to determine the most efficient wing shape. He could calculate the wing area needed for the weight of his aircraft. The same data could be used to calculate the propeller thrust needed to overcome drag for manned flight. The other difficulties of stability and control still existed, but by 1901 the Wrights were well on the way to solving those problems. But they had not yet begun to consider how to get accurate lift and drag data.
accurate lift and drag data required two inventions. The first was a powered wind tunnel. The second was accurate measuring instruments. Powered wind tunnels were not new. The first known use
of a wind tunnel for flight research occurred more than forty years earlier when Wenham and Browning built one in England. Later, Hiram Maxim (of machine gun fame), an american living in England, built a wind tunnel for research. In the United States, Professor Marey and Albert Wells both built wind tunnels as did Dr. Albert Zahm at Catholic University in Washington, D.C. These researchers put instruments inside their wind tunnels to measure the forces of lift and drag of small wing shapes. Since lift and drag are separate forces, they tried to measure them separately, but that required identical test conditions for each measurement. In spite of persistent efforts their results were inconsistent and the data was not reliable.
Spratt was aware of this measurement problem. In March 1900 he sent Chanute a letter in which he gave his idea for the solution. He wrote that the measurement of lift and drag could be made accurate if they were measured together, as a ratio, rather than separately. A drag-to-lift ratio could be determined by attaching a small wing shape vertically at the end of an arm. If the arm was free to move, a flow of air would cause it to rotate to the angle at which the forces of lift and drag would exactly balance each other. This angle (called the tangent angle) would be the drag-to-lift ratio for that wing shape at that angle of attack. A person could measure the tangent angles for a whole series of wing shapes at several angles of attack and develop a complete table of ratios for any shape of wing. If the researcher then made a separate measurement of lift, he could use the ratio to calculate the drag. From this data it was a simple matter to produce a set of graphs that would accurately show the flight characteristics of any wing shape at any angle of attack. It was, as engineers like to say, a simple but elegant solution to a difficult problem. In May, 1901 Spratt sent Chanute a drawing showing his design for a tangent angle instrument to measure the drag-to-lift ratio.
By this time Wilbur Wright had been in contact with Chanute for a year. He began his correspondence with Chanute the previous May with a letter introducing himself, expressing his interest in manned flight, and asking for advice. As was his habit, Chanute quickly answered. The exchange began a correspondence that would continue until Chanute’s death 10 years later.
A few months after Wilbur’s letter to Chanute, the Wrights made their first trip to Kitty Hawk, North Carolina to assemble their initial attempt at a manned glider. It was a Pratt-Chanute "two surface" design pioneered by Chanute. Wilbur added his invention, wing-warping, that allowed the pilot to adjust the roll angle in flight (Previous pilots had shifted their weight to adjust roll and pitch angles). To control the pitch angle, the Wrights used an elevator in front of the wings (they called it a horizontal rudder). The wing warping method and the front elevator made it possible for a person to control a glider having a much greater wing area than any experimenter had tried. The control results were encouraging, Wilbur (who did all the flying) could skim the ground under complete control. The problem was lift. The glider had much less lift than the Lilienthal tables predicted. Wilbur estimated his time in the air was only about two minutes that summer. Still, they were encouraged by the control they had achieved.
During the winter and spring of 1901 the Wrights built a new glider. To improve lift they increased the wing area by 70% to 315 square feet including the front "rudder". They invited Chanute to witness their tests. Chanute accepted and then asked if he could invite George Spratt and another aviation enthusiast, Mr. E. C. Huffaker. The Wrights reluctantly agreed.
The Wrights arrived at Kitty Hawk in early July and began building a large shed and assembling their new glider. Huffaker arrived on July 18. He had some aviation experience having previously worked for Professor Samuel P. Langley, secretary of the Smithsonian institution, on the governement’s "aerodrome" manned aircraft project. The Wrights took a dislike to Huffaker, later referring to him as a poor workman, lazy, sloppy and unkempt; traits abhorrent to the Wrights.
arrived on July 25 to an already hostile camp.
The Wrights were pleasantly surprised. In contrast to Huffaker, here was an enthusiastic helper, a careful worker, a naturalist, a knowledgeable person and a likable companion. The Wrights and Spratt became good friends.
27, 1901 the Wrights began their gliding tests. They expected to begin where they had left off the year before, but they were quickly disappointed. In contrast to their 1900 glider, their new glider
was unstable. It pitched up and down nearly out of control. Wilbur said he had to use the full travel of the front elevator just to keep it from either diving into the ground or climbing until it
stopped flying. Twice it had stalled and fallen to the ground. Fortunately, because their design had the elevator control ahead of the wings, the glider was kept from nosing down into a dive.
None-the-less, Wilbur decided it was not safe to fly. So, after only two days, they stopped the tests. This loss of pitch control was an unexpected and baffling problem, it hadn’t happened the
year before. The Wrights studied the problem, but didn’t come up with the cause or solution.
After some time, the Wrights asked Spratt if he had any ideas. Based on his experiments, he thought the center of pressure was reversing as the glider approached level flight. This would account for the erratic behavior. Huffaker agreed with Spratt. The Wrights decided to test the theory. They removed one of the glider’s wings and flew it as a kite. When the angle of attack was reduced, the wing started to pitch and buck. That proved the center of pressure was moving and causing the problem. During the following week, the Wrights and their guests modified and strengthened the glider’s wings.
Footnote - Two months later, at Chanute’s invitation,
Wilbur gave a talk before the Western Society of Engineers in Chicago. At that time Wilbur gave credit to both Spratt and Huffaker for the accurate analysis of the glider’s pitching problem. However, in all later talks and articles, the Wrights would simplify the story by saying they observed the wing was unstable and proved it by flying the wing as a kite. There was never any further mention of Spratt or Huffaker in their talks or writing.
On August 7 the Wrights resumed their gliding and found the pitch control problem was solved, Wilbur could now make long straight glides. But their glider still didn’t have as much lift as they expected. They were now convinced that the lift data they were using was wrong. They would need accurate data if they were to continue. Spratt told them of his ratio method that would eliminate the errors other researchers had encountered in trying to get accurate lift and drag data.[26,27]
When the Wrights returned home in late August 1901 they were discouraged and said they doubted they would ever resume their experiments. Wilbur is quoted as saying the problems of flight were still so difficult that "man would not fly for fifty years." But home, rest and a new approach changed their mind. They would use Spratt’s idea of taking ratio measurements instead of trying to get absolute values of lift and drag as others had tried to do.
They built a wind tunnel and used their (natural) gas engine shop engine to power a fan that would generate a flow of air. Then they designed and built a measuring instrument they called a "lift balance". It had two purposes. It could measure the comparative lift ratios of various wing shapes and it could be reset to measure the drag-to-lift ratios (tangent angles). While this instrument was a ratio measuring instrument, its design was unlike anything Spratt had described.
On November 22, 1901 Wilbur wrote Chanute that that they had perfected their wind tunnel and measuring methods. He added that they would now begin, "making a large number of models of typical (wing) shapes, and will measure them with the greatest of care." The wing shapes were made by bending sheet metal to a variety shapes. They called them "surfaces".
The next three to fours weeks of intense research they later described as one of the most interesting times of their lives. They said they could hardly wait to get up in the morning and start the experiments.
On December 1, 1901, nine days after they began, Wilbur informed Chanute that they had completed the measurement of the lift properties for 25 (wing) "surfaces" (of an eventual 34 surfaces listed in their data tables.) at 14 different angles of attack. Wilbur said that a set of measurements on one surface now took only about an hour to run. By projecting Wilbur’s time estimate, the lift measurements for the final 9 surfaces would have been completed on December 2nd or 3rd.
set of entries in their data tables show they then measured the tangent angles for 28 of the wing shapes (They apparently decided that 6 of the 34 wing shapes were no longer of interest to
Using Wilbur’s estimate of one hour required for each set of measurements, the 28 sets of tangent angle measurements would have been completed about December 6th or 7th. These dates agree with a letter their sister Katharine wrote on December 7 to their father that, "The boys…. had finished their experiments. As soon as the results are put in tables, they will begin work for next seasons bicycles". From this reference to "putting the data in tables" we can assume the Wrights kept a diary showing the results of each test (it has never been found). The compiled data was written as tables in a bound notebook, three pages of lift data followed by three pages of tangent angle data. (The original notebook is now at the Franklin Institute in Philadelphia).
Then something happened that the Wrights never revealed. Probably while graphing the data, they discovered their lift balance instrument was not accurate at low angles of attack when it was used to measure tangent angles. The notebook shows they crossed out all three pages of the tangent angle data, 392 measurements, probably representing about 28 hours of work. Then, using a new instrument that they later called their "special machine for tangentials," they re-ran the tangent angle measurements for all 28 surfaces. This time they got accurate results and wrote this data in tables on the next three pages of their notebook. Both the estimated time that Wilbur said it took to complete the measurements and
Katherine’s letter to their father indicates they must have completed first set of tangent angle measurements by December 7. In letters to both Chanute and Spratt Wilbur said they ended their wind tunnel tests by December 15.[35,36] So the new tangent angle instrument must have been built and the new tangent angle data gathered between December 7 and 15. The measurement problem, the design of the new instrument, and the date it was built would seem unimportant except for the Wrights subsequent actions.
Two months later, In February 1902, Wilbur wrote to Chanute telling him to ignore some earlier tangent angle data they had sent him (Chanute was doing some calculations for them) because the lift balance instrument, when used to measure the tangent angles, "was not well adapted to that purpose". Then Wilbur added, "We accordingly, before (author’s italics) commencing our final tests constructed a ‘special machine’ for tangentials." But an analysis of the crossed-out with other tangent angle data known to have been done using the lift instrument shows the same errors. So, the crossed out tangent angle data must have been measured using their lift balance. But why would Wilbur claim they had built a new tangent angle instrument before commencing their final tests when the new instrument must have been built after they found the measurement problem and certainly after after December 7? Did this claim to earlier construction and use have anything to do with a letter they received from Spratt?
On November 21, 1901, just as the Wrights were beginning their measurements, Spratt had sent both Chanute and the Wrights a description, a drawing, and a photograph of his latest tangent angle measuring instrument. When Wilbur answered Spratt’s letter on December 15, he told Spratt his new tangent angle instrument was "ingeniously designed and should give good results". He didn’t mention the problem they had encountered trying to measure tangent angles. Nor did he tell Spratt that because their lift balance instrument had caused tangent angle errors they had had to build a new tangential angle instrument. Why so secretive? Was he afraid Spratt might think they had used his design as the basis for their new instrument? And is that why he later wrote to Chanute that they had built their final instrument earlier than the evidence shows?
If they used Spratt’s design, a comparison of the two would show the comparison. However, the Wrights did not reveal their design until 45 years later. Spratt’s letter and design was not in the Wright files when they were released after Orville’s death in 1948. However the identical letter Spratt sent to Chanute did survive so the comparison canbe made, but its not conclusive. Spratt’s instrument was for use out-of-doors in natural wind (he still had no way to generate a flow of air flow). His design used a parallelogram made from two discs and a connecting belt. An arm on one of the discs held the wing vertically. A steady wind would rotate the wing to the tangent angle for the wing. As Wilbur observed in his letter, the design was sound, but it required a steady wind (which Spratt never achieved). The Wrights’ instrument was a parallelogram made from hacksaw blades. The wing was attached vertically to one side of the parallelogram. The wind rotated the parallelogram to the tangent angle for the particular wing and angle of attack.
Were the two designs the same? Substituting a parallelogram made from hacksaw blades for Spratt’s disc and belt arrangement doesn’t constitute much of a design change, certainly no change in the operation of the instrument or in its principle of operation. But Wilbur seems to confirm their "borrowing" from Spratt’s design when in 1909, after a complaint from Spratt, Wilbur admitted they had used Spratt’s "idea" in their tangent angle instrument but "in a design different than yours". So it’s clear, they had studied Spratt’s design before they built their own final tangent angle instrument. This admission was not something they ever publicly acknowledged.
When the Wrights built their 1902 glider, they used the results from their wind tunnel experiments. Spratt was not aware of his contribution to their success when they again invited him to Kitty Hawk. But he now witnessed new world’s records both in distance and time-in-the-air. The flights were so successful that the Wrights decided they were ready for powered flight.
Their 1903 aircraft was appropriately called the "flyer" and Spratt was again their guest. Broken propeller shafts caused delays and by early December it was cold and Spratt decided to leave. He missed their historic December 17 flight by two weeks. In early January Wilbur sent him a long letter describing the events.
After 1903 the Wrights did their development at Huffman prairie near their Dayton home. The correspondence with Spratt continued. Spratt was generally critical of the design of the Wright aircraft feeling it was unsafe. He, like most would be aircraft inventors at that time, believed an aircraft should be automatically stable in the air. He was trying to develop such a design. In November 1906 the Wrights asked if they could visit the Spratts (he was now married and had a one year old son) at his home in Coatsville "to spend a day spinning yarns…"  They spent a pleasant Sunday afternoon together.
letters between the Wrights and Spratt continued, but with less frequency. The friendship was now on shaky ground. In the September 1908 issue of Century magazine Orville wrote an article describing
the prelude to their invention of the airplane. He gave he and his brother the credit for analyzing the cause of the instability problem in their 1901 glider without mentioning Spratt. Orville
wrote that it was after their 1901 gliding tests they became convinced of the need for more accurate aeronautical data. He added that it was for this reason they built a wind tunnel and invented two
measuring instruments for gathering data. And by this means, Orville wrote, "we eliminated the measurement errors that other experimenters had encountered." He added that their success in
inventing the airplane was the result of their laboratory experiments, "which alone made an early solution of the flying problem possible." Spratt was astonished to find that his name was never
mentioned in the article or in any interviews the Wrights gave. This was a bitter pill for him. He felt his help had been important, even crucial to their success. If the data they obtained in their
wind tunnel experiments was the key their success, then he was the one who gave them the key. By now he was completely disillusioned with the Wrights. On September 29, 1909, he wrote to them saying
they had taken his ideas and methods and claimed for themselves complete credit, never even mentioning him. Wilbur answered on October 16 saying, "It is quite true that before we had very
seriously taken up the subject of lifts and drifts (drag) of surfaces, you told us your idea of balancing the lift of a surface against its drift… and that later, when we took up that subject, we
utilized the idea in a machine (measuring instrument) of different design than yours.*" Wilbur added that they considered Spratt’s contribution merely an "idea". (They would never call Spratt’s
contribution a design or a method, it was just an idea.) Wilbur added that they considered Spratt’s idea a "loan" that they had repaid with ideas and data that they had give him. Wilbur added, "I
cannot help feeling that in doing so we returned the loan with interest and that the interest many times outweighed the value of the loan
itself." In early 1902 Wilbur did send him a few graphs of data they had generated and there is a later reference to additional unspecified wind tunnel data they gave Spratt. But Spratt felt their wind tunnel data had benefited the Wrights, not him.
*The Wrights opinion that a design change eliminated any debt to the inventor changed, when in later years Glenn Curtis used ailerons instead of wing warping for roll control on his aircraft. The Wrights then claimed that their wing warping method included any designs that accomplished the same purpose. They won the law suit.
By late 1909 Spratt decided the friendship was over; he didn’t answer Wilbur’s letter. A year later Wilbur sent Spratt another letter in which he tried to rekindle the friendship. Spratt ignored that letter too. Spratt had become bitter, even volunteering his services in lawsuits opposing the Wrights.After Wilbur’s death in 1912, Orville was occasional asked about Spratt. He maintained that Spratt had played no role in their success. In 1920 Orville was asked about Spratt in a deposition. Orville testified that Spratt’s only contribution was an "idea" for a test instrument "freely given to them in the summer of 1901
Two years later, in November 1922, Orville wrote to Spratt asking the temporary return the letters he and Wilbur had sent so that he could refresh his memory in order to "begin writing the history of the development of our first aeroplane". Spratt answered, "I do not see how you can give a correct account of this without bringing yourselves to open censure". Spratt refused to part with the letters and told his son that if he sent the letters they would never be returned. Such was his distrust of Orville.
later, when many prominent people including Charles Lindbergh urged Orville to write the details of their wind tunnel experiments, Orville said he would not do so because, "no one today would
understand the tenor of those days". Nor would he agree to cooperate with anyone else to write the story. Neither brother was ever willing to have that part of their history examined.
After the Wrights had achieved world-wide acclaim they appeared obsessed with getting sole recognition for every aspect of their invention. In talking to reporters and in published articles they spoke of their 1901 their wind tunnel experiments only in general terms and omitted any mention of Spratt. Only recent examinations of the Spratt, Chanute and Wright correspondence along with the Wright’s data notebook make clear there was more to the story than the Wright’s were willing to tell.
- Wilbur, in his February 1902 letter to Chanute, must have backdated the date he said they built and used their "special" tangent angle instrument. This
backdating would have the effect of eliminating any suspicion that they had used Spratt’s design as the inspiration for their own instrument if that question should ever arise. However Wilbur, in his
1909 letter to Spratt did admit they had built a new tangent angle instrument (not saying why) of a "different design" than Spratts. It could only have been built after they knew their tangent angle
was wrong and well after they had received Spratt’s letter.
- Throughout their lives neither brother ever mentioned their first set of tangent angle data that they crossed out. Yet it was an important event, they
had to discard 40% of their total data. They would have realized that any discussion of the problem would have invited questions of what had happened and how they solved the problem. As
Spratt wrote to Orville in 1922, "I do not see how you can give a correct account of this without bringing yourselves to open censure".
- The design of their tangent angle instrument was kept totally secret until 1939 and then Orville gave only written description. A complete description was not revealed until 1946.
- The letter Spratt sent to the Wrights on November 21, 1901 in which he showed them his design was not in the Wright files when their papers were released for examination after Orville’s death. It is only because Spratt sent an identical letter, photograph and drawing to Chanute that we know the details of the Spratt design and can compare the two.
- The notes the Wrights must have kept during their wind tunnel experiments have never been found. They would confirm when the final tangent angle
instrument was built and probably show sketches.
These notes must have existed because their sister, Katharine, mentions them in her December 15, 1901 letter to their father.
- The Wrights never revealed the details of their wind tunnel experiments and Orville, after Wilbur’s death, would not cooperate with any author who attempted to examine this aspect of their work.
- Finally, The Wright’s promise in 1909 to give Spratt credit for his contributions was never fulfilled. Quite the opposite, while admitting to him in private they owed him a debt, in public they made every effort to conceal his contributions.
Had the Wrights publicly acknowledged Spratt’s contribution, their claim to the invention of the airplane would not have been affected. Further, they could then have given the world the details of their wind tunnel experiments, the " key", as they called it, to their success.
Spratt continued his aviation research. He spent years trying to develop a stall-proof and spin-proof aircraft. It was not until 1925 that he finally succeeded. By that time aviation development had long surpassed both the Wrights and Spratt. Spratt died in November 1934, bitter at the Wrights and ignored by aviation historians.
Orville died in 1948 insisting to the end that they had invented the airplane without help from anyone.
article could not have been written without the help of the finest gentleman I have ever known, George G. Spratt, Dr. Spratt’s son. His generosity and his considerable intellect made this research
possible. An inventor in his own right, he perfected the "controlwing" aircraft and developed the helicopter mine sweeping system now used by the Navy. In his spare time he designed and built seven
aircraft. The Spratt father and son team encompassed 100 years of aviation history. George G.
died in 1998.
- Wilbur Wright to George A. Spratt, November 12, 1902, Private papers of George G. Spratt. The quote is the final sentence in the letter.
- George A. Spratt to Octave Chanute, December 28, 1898, Manuscript Division, Library of Congress
- Octave Chanute to George A. Spratt, December 24, 1898, Manuscript Division, Library of Congress
- George A. Spratt to Octave Chanute, October 12, 1899, Manuscript Division, Library of Congress
- George A. Spratt to Octave Chanute, August 26, 1899, Manuscript Division, Library of Congress
- George A. Spratt to Octave Chanute, September 1, 1900 Manuscript Division, Library of Congress
- George A. Spratt to Octave Chanute, June 24, 1900, Manuscript Division, Library of Congress
- George A. Spratt to Octave Chanute, March 26, 1900, Manuscript Division, Library of Congress
- Octave Chanute to George A. Spratt, April 2, 1900, Manuscript Division, Library of Congress
- Tom D. Crouch, The Bishops Boys, A Life of Wilbur and Orville Wright, W. W. Norton, New York, 1989 p.149
- Marvin W. McFarland, ed., The Papers of Wilbur and Orville Wright (New York: McGraw-Hill, 1953, cited hereafter as Papers)Vol. 1, p.552
- George A. Spratt to Octave Chanute, March 4, 1900, Manuscript Division, Library of Congress
- George A. Spratt to Octave Chanute May 23, 1901, Manuscript Division, Library of Congress
- Wilbur Wright to Octave Chanute May13, 1900, in Papers, vol. 1, p.15
- Wilbur Wright to Octave Chanute July 1, 1901 in Papers, vol.2, p.64
- Tom D. Crouch, The Bishops Boys, A Life of Wilbur and Orville Wright, W. W Norton, New York, 1989 p.206
- Tom D. Crouch, The Bishops Boys, A Life of Wilbur and Orville Wright, W. W. Norton, New York, 1989 p.208 and Wilbur Wright diary A, in Papers, vol.1, p.71
- Wilbur Wright to George A. Spratt, September 21, 1901, in Papers, Vol. 1, pp.118-119
- Wilbur Wright to George A. Spratt, September 21, 1901, in Papers, vol.1, pp.118-119 and September 16,1902, pp. 253-254, and affidavit of Wilbur and Orville Wright in Wright vs Curtiss 1909 "We found him (Spratt) an excellent companion, the most wonderful raconteur we had ever met, and an earnest student of birds and the principles of flight. We formed a very favorable opinion of his character we still retain it."
- Tom D. Crouch, The Bishops Boys, A Life of Wilbur and Orville Wright, W. W. Norton, New York, 1989 p.209 and Wilbur Wright diary A, July 30, 1901, in Papers, vol.1, pp.76-78
- Wilbur Wright diary A, July 29, 1901, in Papers, vol.1, p.71
- Tom D. Crouch, The Bishops Boys, A Life of Wilbur and Orville Wright, W. W. Norton, New York, 1989 pp.209-213.
- Wilbur Wright, "Some Aeronautical Experiments" paper published in the Western Society of Engineers, Journal, December, 1901, from a lecture given by Wilbur Wright to the Society meeting in Detroit, September 18, 1901, in Papers, Vol.1, pp.99-119
- Chanute-Huffaker diary, August 8, 1901, in Papers, vol. 1, p. 81
- Wilbur Wright to George A. Spratt, October 16, 1909, in Papers, vol.1, pp.967-8
- Montgomery vs United States. Orville Wright deposition January 13, 1920, Manuscript Division, Library of Congress.
- Tom D. Crouch, The Bishops Boys, A Life of Wilbur and Orville Wright, W. W. Norton, New York, 1989 p.213
- Wilbur Wright to Octave Chanute, November 22 and 24,1901, in Papers, vol.1, pp.159-163
- Wilbur Wright to Octave Chanute, December 1, 1901, in Papers, vol.1, pp.168-171.
- Wilbur Wright to George A.Spratt, December 15, 1901 & January 1, 1902, Papers, vol. 1, pp.181-182
- Wright notebook labeled 15:43, Franklin Institute, Philadelphia, Pa.
- Katharine Wright to Rev. Milton Wright December 7, 1901, in Papers, vol.1, p.171
- Wright notebook labeled 15:43, Franklin Institute, Philadelphia, Pa.
- Wilbur Wright to George A. Spratt, December 15, 1901 continued on January 1, 1902, Papers, vol. 1, pp.181-182
- Wilbur Wright to Octave Chanute, December 15, 1901 in Papers, vol.1, pp.173-181
- Wilbur Wright to Octave Chanute, February 7, 1902 in Papers, vol.1, p.211
- George A. Spratt to Octave Chanute, November 21, 1901, Manuscript Division, Library of Congress. Letter indicates identical drawing, photograph and description that were sent to the Wrights. Wright copy is missing from their files at the Library of Congress.
- Wilbur Wright to George A. Spratt, December 15, 1901 continued on January 1, 1902, Papers, vol. 1, pp.181-182, referencing a letter, photograph, description and drawing Spratt sent to the Wrights on November 21 or 22.
- Wilbur Wright to George A. Spratt, October 16, 1909, in Papers, vol.1, pp.967-8
- Wilbur Wright to George A. Spratt, November 10, 1906, private files of George G. Spratt
- Century Magazine. September, 1908, vol. XXVI, no.5, pp.641-650, article by Orville Wright.
- George A. Spratt to Wilbur Wright, September 29, 1909. This letter is referenced in Wilbur Wrights answer October 16, 1909, Papers Vol. 2 p.967, though it was not included in the Wright papers given to the Library of Congress.
- Wilbur Wright to George A. Spratt, October 16, 1909, in Papers, vol.1, pp.967-8.
- Montgomery vs United States. Orville Wright deposition January 13,1920, Manuscript Division, Library of Congress.
- Orville Wright to George A. Spratt, November 17, 1922, the private papers of George G. Spratt.
- George Spratt to Orville Wright, November 27, 1922. Manuscript Division, Library of Congress.
- Recollections of George G. Spratt as told to the author.
- Charles A. Lindbergh, The Wartime Journals of Charles Lindbergh (New York) Harcourt Brace Jovanovich, 1970, p.277