Dayton Aviation What Dreams We Have The Wright Brothers and Their Hometown of Dayton, Ohio

While the printing and bicycle businesses took up much of Wilbur and Orville's time, they were constantly searching for new projects to undertake. A new interest began to materialize when Otto Lilienthal's death in a glider accident captured the brothers' attention in August 1896, and they began to consider pursuing aeronautics. The events leading up to this began when Wilbur wrote his father that "Orville is complaining some for a day or two, but is taking quinine and I think will be all right in a few days." [1] Wilbur's prediction proved false, and a few days later Orville developed typhoid fever. Hearing of Orville's sickness, the Bishop responded to Katharine:

I am sorry that Orville is sick, and sorry that I am away when he is sick. While I hope it may prove but a mild attack, I have grave apprehensions that it may prove a severe seigt [sic]. Inform me by mail, and by telegraph, if the latter is necessary. Put him in the best room for air and comfort, sponge him off gently & quickly with the least exposure and follow with mild frictions.

Believing that Orville contracted typhoid from the well water at the bicycle shop at 22 South Williams Street, Milton further advised Katharine to let no one else use the water from that well and to boil and then cool in ice all of the water that they drank. In addition, he counseled them to be "temperate in articles eaten," as well as being regular. [2]

The family consulted Dr. Spitler who had treated both Wilbur and Susan earlier. He had little to recommend; the fever would have to run its course. Katharine delayed her return to Oberlin College to stay in Dayton to assist Wilbur in caring for Orville. Milton also cared for his son after he returned to Dayton on September 4. Orville spent much of the month of September in delirium, and a trained nurse was hired to alleviate the burden on the rest of the family. It was not until six weeks later that Orville was able to sit up in bed and eat some tapioca, his first solid food. [3]

During Orville's illness, Katharine and Wilbur often read the newspaper to him. Since Orville was unconscious, this was more often than not, a way to pass the time while nursing Orville. It was in one of these times that Wilbur read about Lilienthal's death in a gliding accident. Lilienthal's experiments had come to the attention of Wilbur and Orville in July 1890 when the news service they subscribed to for their paper, The Evening Item, included an article on him. Finding the information of interest, the Wrights included a short piece on Lilienthal in their July 26 issue. Then in 1895, a brief newspaper article on Lilienthal attracted the Wrights' attention, and they attempted to learn more about his aeronautical experiments. With this in mind, after Orville's recovery, Wilbur mentioned Lilienthal's death to him. Always interested in scientific subjects, the Wrights began to ponder the question of human flight and a possible solution. [4]

To expand their knowledge, the brothers went to the Dayton Public Library to review books on aviation, and over the next few years Wilbur and Orville read everything they could find on the subject. It was not until 1899 that the Wright brothers began actively researching aeronautics during the off season of the bicycle business. According to Orville, the brothers' fascination with flight was renewed when they read a book on ornithology. The book made them wonder why birds could fly and why man could not fly with something built on a larger scale which emulated a bird's features. [5]

The first active step Wilbur and Orville took in pursuing the question of human flight was a letter to the Smithsonian Institution requesting available information on aeronautical studies. On May 30, 1899, Wilbur wrote requesting papers published by the Smithsonian Institution or others available in English, for he was, "about to begin a systematic study of the subject in preparation for practical work to which I expect to devote what time I can spare from my regular business." Wilbur further illuminated, "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." [6]

Richard Rathbun, Assistant Secretary of the Smithsonian Institution, sent a response to Wilbur on June 2. In his letter, Rathbun included a list of three works related to "aerial navigation" available from the Smithsonian Institution and enclosed four Smithsonian Institution reports. The three works available from the Smithsonian Institution were Progress in Flying Machines by Octave Chanute, Experiments in Aerodynamics by Samuel P. Langley, and The Aeronautical Annual for 1895, 1896, and 1897 edited by James Means. The pamphlets enclosed in Rathbun's response were reprinted from articles originally published in the Smithsonian Annual Report and included: "Empire of the Air," by Louis-Pierre Mouillard; "The Problem of Flying and Practical Experiments in Soaring," by Lilienthal; "The Story of Experiments in Mechanical Flight," by Langley; and "On Soaring Flight," by E.C. Huffaker. Thanking Rathbun for the pamphlets, Wilbur also ordered a copy of Langley's work which cost one dollar and discussed the laws governing the resistance of plane surfaces. [7]

LILIENTHAL GLIDING IN ONE OF HIS GLIDERS, USING HIS WEIGHT TO SHIFT THE BALANCE OF THE GLIDER. (Courtesy of National Air and Space Museum)

It is noteworthy that in Wilbur's correspondence with the Smithsonian Institution he referred only to his own personal interest in aviation. Nowhere did he refer to his brother Orville, but solely discussed his own belief that flight was possible. While in later years, the brothers stated that the initial interest in aviation was a mutual and joint effort, the idea appears to have been Wilbur's. While Wilbur initially pursued this new project, Orville soon became an active participant. The brothers' synergistic partnership over the next few years was one of the factors that enabled the Wright brothers to successfully complete the first free, controlled, and sustained flight in a power-driven, heavier-than-air machine. Two schools of aviation research became apparent to Wilbur as he reviewed the available material on aeronautical history and theory. The first was represented by Otto Lilienthal and Octave Chanute who studied soaring flight. Born in the Pomeranian village of Anklam on May 24, 1848, Otto Lilienthal and his younger brother Gustav were fascinated at an early age with the storks native to the region. By the ages of fourteen and thirteen, respectively, the brothers constructed an unsuccessful fixed wing glider. The failure did not deter the brothers, and through the years, they constructed and experimented with other gliders. [8]

By 1880, Otto was an established engineer who owned a business that produced engines, boilers, marine signals, and mining equipment. In addition, he continued his childhood fascination with flight, although he now attacked the problem with scientific methodology. In 1878, Lilienthal established a workshop in his home from which he conducted research on air pressure and lift. Believing serious research was needed on the principles of flight instead of guesswork guiding the construction of flying machines, Lilienthal focused his attention on preliminary research. The result of his research identified the superiority of a cambered, or curved, wing. In addition, he developed an air pressure table to assist experimenters in determining the wing area needed to support a given weight at a particular speed. [9]

With the results of this research, Lilienthal began experimenting with gliders in 1891. These experiments attracted the attention of American journalists and led to the widespread publicity that Lilienthal received in the United States. It was one of the resulting newspaper articles that attracted the Wright brothers' attention. Lilienthal's flights ranged in length from 300 to over 750 feet using sixteen different gliders. In all of these gliders, the pilot was supported vertically in the center section between the wings. He controlled and stabilized the glider by swinging his body in different directions to shift the center of gravity. Lilienthal suffered a fatal accident in 1896 when his glider stalled in mid-air, and he plunged fifty feet to the ground. He survived until the next day when he died in a German hospital. [10]

Like Lilienthal, Octave Chanute focused on studying soaring flight. Chanute was born in France in 1832, and immigrated to the United States with his parents in 1838. A successful and highly respected civil engineer, Chanute worked for various railroad companies. He began his career in Albany, New York, and subsequently moved westward, eventually settling in Kansas City and then Chicago. During an 1875 trip to Europe, Chanute discovered that many of his European counterparts considered the airplane a possibility. The idea captured Chanute's imagination, and he began taking an interest in aeronautical research. In 1885, Chanute began conducting a survey of all aviation research and literature. He compiled his research, in 1891, into a series of articles reporting the results of aeronautical research and directing a path for future study. These articles were published in 1894 in a book titled Progress in Flying Machines. Along with Lilienthal's work, Progress in Flying Machines became a mandatory source for aviation experimenters. [11]

OCTAVE CHANUTE (Courtesy of National Air and Space Museum)

As a result of his survey, Chanute recommended that engineers should become involved in aeronautical research. He determined that experiments would greatly benefit from engineering knowledge. In addition, because he felt that experimentation with gliders was necessary, Chanute designed and built a number of gliders for testing. Since he was sixty-four years old when he began experimenting in 1896, Chanute hired Augustus M. Herring and William Avery to pilot the gliders during the experiments conducted on the south shore of Lake Michigan, near Chicago. These two also assisted with glider design. [12]

One of the gliders was a biplane glider that he designed and built with the assistance of Augustus Herring. The biplane glider's wings were based on the Pratt-truss system and the pilot was situated by supporting himself by his arms and hanging below the wing, similar to the Lilienthal glider. This glider became the most influential aircraft of the era prior to the Wrights' entry into aeronautics. To date, the Chanute-Herring biplane glider was the most stable and successful flying machine built, gliding up to several hundred feet, but they lacked the essential element of control. This biplane glider design influenced the form of the Wright brothers' future gliders and airplanes. [13]

The second school of research, represented by Samuel P. Langley, focused on powered flight. Langley was born in Roxbury, Massachusetts, in 1834. He first trained as a civil engineer and architectural draftsman. Eventually he turned his attention to astronomy, and in 1887, when he was asked to serve as the assistant secretary of the Smithsonian Institution, Langley was one of the most well-regarded astronomers in the United States. He became interested in powered flight in 1886 at an aeronautical lecture in Buffalo. The meeting was held under the auspices of the American Association for the Advancement of Sciences and had been arranged by Chanute. By 1896 Langley produced his first successful model, the steam driven Aerodrome No. 5. Langley named his models Aerodromes after the Greek term aerodromoi meaning air runners. On May 6, Aerodrome No. 5 flew two flights which unquestionably proved that a large power-driven model could fly. [14]

After his successful tests with Aerodrome No. 5, Langley intended to stop his public experiments and let other enthusiasts continue the quest to achieve flight. But, in 1899, after lobbying efforts by Langley and his friends, the United States granted Langley $25,000, with the potential of another $25,000, to build an aerodrome for military purposes. All of the Langley aerodromes built to fulfill the contract were based on the concepts used in the successful 1896 machine, for Langley believed that he only needed to enlarge the earlier model to successfully carry a man. [15]

Wilbur gave his attention to the former school of research, "partly from impatience at the wasteful extravagance of mounting delicate and costly machinery on wings which no one knew how to manage, and partly, no doubt, from the extraordinary charm and enthusiasm with which the apostles of soaring flight set forth the beauties of sailing through the air on fixed wings, deriving the motive power from the wind itself." Having chosen a research methodology, Wilbur still needed to further define his experiments and research. [16]

The three general aeronautical research issues were wings to lift the machine into the air, a power source to propel the machine, and a means of controlling the machine. The groundwork in the first two areas was already addressed by Lilienthal, Chanute, and Langley. Wilbur felt the available equations and data would provide enough information for him to design his own wings. While he would inevitably encounter further aerodynamic problems, Wilbur believed the groundwork conducted by other aeronautical research was a sufficient base from which to start. As for a power source, Langley's steam engines used to power his Aerodromes could not run a full-scale model, but they did prove that it was possible to build an engine that would propel a flying machine into the air. Wilbur was convinced technology needed to power a full-scale aircraft would be available when it was needed. This assumption was based on the amount of research the automobile industry was directing toward producing a lighter and more powerful internal combustion engine. [17]

That left the question of controlling an airplane. This was a complex issue, for an airplane was the first vehicle that required control of three axes of motion: pitch, roll, and yaw. Pitch, revolving around a horizontal line running from wing tip to wing tip, moves an airplane's nose up or down to initiate a climb. Roll, which determines the lateral altitude of an airplane, revolves around a longitudinal horizontal line running through the center of an airplane from nose to tail, and is used when one wing tip is raised and the other lowered. Yaw, revolving around a vertical line running from top to bottom through the center of the machine, moves the nose to the right or left in a flat turn and determines the direction of the flight path. These components are easily described as the vertical for changing altitude, the lateral for banking or rolling back to level, and the level or horizontal for turning. In attempt to control yaw and pitch, basic devices were established by aeronautical researchers before 1860. Techniques for turning on a level plane (yaw) by using a form of a ship's rudder were proposed by balloonists in the eighteenth century, and ideas to alter the rudder to a horizontal device, called an elevator, were later incorporated to control the pitch, or rise and descent, of airships. [18]

CAYLEY'S SILVER DISK SHOWING HIS CONCEPTION OF THE ELEMENTS OF AN AIRPLANE. (Courtesy of National Air and Space Museum)

In regards to human flight, Sir George Cayley, born in Scarborough, England, in 1773, reached a critical turning point in the field in terms of control. In 1799 Cayley proposed an airplane configuration, based on his research, which was vastly similar to today's airplanes and one of the most important of his original designs. Inherent in Cayley's design was the observation that the system of thrust and the system of lift needed to be separate, meaning that a flying machine needed both fixed wings and a form of propulsion. Cayley's concept was a break from the traditional idea that moving wings would propel a man through the air. This design and the idea of providing separate systems for thrust and lift was a major step forward in aeronautical research, and many individuals in following years based their experiments and research on this concept. This includes Cayley who based the design of his basic glider model of 1804 on these ideas. The glider, the first modern configuration airplane, incorporated a fixed plane with an adjustable rudder and elevator to control both the yaw and pitch. [19]

Alphonse Pénaud also envisioned, independently of Cayley, the use of a horizontal tail as a means to control longitudinal stability. He was a French naval engineer who, because of a debilitating hip disease, had been confined to a wheelchair as a child. In 1871 he built and flew a small, rubberband-powered, monoplane glider. Pénaud designed the glider with a dihedral angle in the wings which led to inherent stability by increasing lift on a wing tipping downward causing the plane to level again. This work with inherent stability was Pénaud's most important contribution to aeronautics. As Peter Jakab described, "Pénaud correctly theorized and demonstrated the fundamentally important concept of aircraft stability that Cayley exhibited, but did not fully understand, in his original 1799 conception of the airplane and later gliders." [20]

Roll was another matter. Few experimenters had dealt with this aspect of control and prior to the Wright brothers there was no concept of lateral control. Researchers needed to break away from the notion that machines operated on one plane, or surface, and the need to achieve inherent stability. If a machine maintained inherent stability, it would only operate on one plane, moving along a straight and level course without any involvement from the pilot. There were various explanations and theories that supported the researchers' quest to achieve inherent lateral stability. Many were convinced that atmospheric gusts and currents shifted rapidly thus defeating the ability of human reflexes to respond, and that what was needed was a stabilizer that could sense these changes and respond accordingly. In addition, few experiments focused on a finished airplane with complete control. Most felt that the first step in human flight was the need to demonstrate a straight flight with a pilot. [21]

Once he determined that he would focus on soaring flight and a means of control, Wilbur needed to define how he would conduct experiments. At the end of the nineteenth century, based on the results of earlier research, there were three approaches as to the best way to conduct aeronautical experiments. The first was to start with the construction of experimental models. The second was the experimentation of full-size gliders before moving to powered aircraft. The third theory, based on the advancements of research, argued that there was sufficient existing research for a full-scale, piloted airplane to be built with little preceding work. The researchers who contributed to the growing understanding of aeronautics in this time each adhered to one of these theories for experimentation. [22]

PENAUD'S 1871 RUBBER-BAND-POWERED MODEL GLIDER. (Courtesy of National Air and Space Museum)

Cayley first demonstrated the value of using models for experiments with his 1804 glider, and this form of experimentation was further pursued by Pénaud. Cayley also played an important role in defining the necessity of the use of gliders, the second of the three theories of aeronautic experimentation. He conducted trials with his first full-size glider in 1849 and again in 1853 with a different glider. The most famous experimenter who made flights with unpowered aircraft in the later half of the nineteenth century was Otto Lilienthal.

Sir Hiram Maxim, an American expatriate living in England who had achieved fame as the inventor of the machine gun, was one of the most prominent proponents of the third theory. His research focused on lift and thrust, not control, and he believed the only significant remainder in tackling human flight was the invention of the lightweight engine to power an aircraft. In an effort to prove this, Maxim constructed a large, four-ton biplane that he equipped with two 180 horsepower steam engines to each power an eighteen foot propeller. The airplane traveled along rails, and during a test on July 31, 1894, it lifted several inches from the rail, broke from the guard rails, and crashed. With this trial, Maxim showed that with enough power a plane could be lifted into the air for a brief time, but he proved nothing new. Lacking all essential elements, except power, needed for a practical flight, his biplane experiment contributed little to the aeronautical field. [23]

Another experimenter who, like Maxim, constructed full-sized, powered aircraft with little previous work with models or gliders was Clément Ader. Ader was a French electrical engineer who was a leader in the development of the telephone. Interested in aeronautics, Ader built and attempted to fly a full-size, steam-powered machine he named the Éole. Like Maxim, Ader gave little thought to controlling his aircraft once it was airborne. In October, 1890, the Éole made a short hop of 185 feet at an altitude of eight inches with no stability. While Ader was technically the first man to leave the ground in a powered flying machine, he did not achieve free, controlled, and sustained flight. For this reason, his experiments, while noteworthy, did not influence the course of aviation. Both Ader and Maxim's aircraft were lifted through the use of a strong power source, but their experiments demonstrated that much remained to be done in researching human flight. Their uncontrollable machines even further proved that there was still much to be understood regarding aerodynamic problems. [24]

In order to research aerodynamics and control, Wilbur chose to follow Lilienthal's example and experiment with gliders. The problem with this form of research was that there was little or no margin for error while operating a glider. Prior to actual glider experiments, an understanding of the problem and a potential solution were needed. Following this method, Wilbur observed birds in order to better understand control. This was not the first time in his life that Wilbur had observed birds for answers to the question of flight. Between 1897 and 1899, Wilbur and Orville often visited The Pinnacles, south of Dayton, to observe the flight of birds. In 1899, while observing buzzards in flight, Wilbur noticed that the birds twisted the tips of their wings as they flew through the air as a means of balancing themselves in roll. [25]

At this time Orville was not an equal partner with Wilbur in his pursuit of human flight, but he was involved in the project. Often the brothers would examine the literature detailing the results and theories discovered by previous experimenters. While Wilbur was the driving force in the project, Orville often participated in discussions and shared ideas on aeronautics with his brother. One example of Orville's level of participation was his suggestion to achieve lateral control. He made a rough sketch of a wing with a stationary section at the center and two adjustable sections on either end. By moving a lever attached to the adjustable sections, one wing section would rotate in one direction while the other wing would turn in the opposite direction. Inherent in this design was the problem that the system needed to be strong, but also light enough for use. [26]

Several weeks later, in July 1899, Wilbur happened upon a workable solution. Previous aeronautical researchers used dihedral angles on the wings to maintain a longitudinal axis on a straight flight, for they erroneously believed that flying an aircraft would be an easy matter of maneuvering the machine on a level plane of air. Understanding that a flying machine needed balancing in three-dimensional space, Wilbur noticed, when observing birds in flight, that soaring birds made subtle changes in their wings to maintain their lateral equilibrium, and he became convinced this was the key to solving lateral control. One evening, while working in the bicycle shop alone, Wilbur sold an inner-tube to a customer. While speaking with the customer, Wilbur picked up the inner-tube box and began idly twisting it. He noticed that as he twisted each end of the box, the top and bottom surfaces remained parallel but the surfaces at each end were at a different angle. That was the answer; instead of treating each wing as a separate unit, he could twist the entire wing structure in either direction to emulate a bird's wings. [27]

This idea of Wilbur's was the first that increased the lift on one wing while simultaneously decreasing lift on the other wing as a way to achieve lateral control. This was to be achieved by incorporating a complete helical twist along the entire wing structure in either direction. Based on how the wings twisted to bring one wing to a greater angle than the other, the Wright brothers named the process wing warping. A major component of the Wrights' contribution to aviation, this function is fulfilled by ailerons in modern day airplanes. [28]

When he conceived of wing warping, Wilbur was operating the bicycle shop while Orville spent the day taking his sister and her friend from Oberlin College, Harriet Silliman, on a tour of Dayton. Harriet was visiting Katharine and staying at the Wright home on Hawthorne Street, and when the three returned home, Wilbur demonstrated his discovery to Orville. Within days the brothers began constructing a model to test the wing warping theory. [29]

The Wright brothers decided upon a biplane configuration for the model based on several facts. First Wilbur's wing warping theory, based upon the twisting inner-tube box, logically suggested biplane wings. Also, their review of aeronautical literature revealed the successful multi-wing designs of various experimenters, the most significant being the Chanute-Herring biplane glider of 1896. The Pratt-truss system used on the glider was, as Peter Jakab suggested in his history of the Wright brothers:

a perfect solution to the dilemma presented by their wing warping concept of maintaining the structural rigidity of a wing that could at the same time be easily flexed for lateral control. By removing the fore-and-aft diagonal wire-bracing of a Chanute-type biplane, but retaining the span-wise trussing, the airframe would take on precisely the same characteristics as the cardboard box with its ends removed.

The wing warping could then be accomplished by pulling on wires attached to the outer edges of the wings, instead of designing a mechanism to maneuver the system. [30]

The biplane model convinced Wilbur that his theory of twisting the wings was possible, and he began to construct a biplane kite with a wing span of five feet and a chord of thirteen inches. The pine framework of the kite was covered with fabric sealed with shellac to make it airtight. The two wings were trussed together with six struts and wires crisscrossed between the wings from side to side, but not from front to rear. The kite included a rear elevator that was attached to the middle of the rear center strut. Wilbur controlled the kite with two sticks, one held upright in each hand. Four lengths of line attached to the top and bottom of each leading edge wing tip strut crossed each other as they ran from the top and bottom of the sticks. By maneuvering the sticks, the kite could either rise upwards or roll off to one side. The kite piqued the curiosity of Wilbur's nephew Milton, and on July 7, Milton stopped by to see the "flying machine" under construction. [31]

On July 24, Orville, Katharine, Harriet, and a few of their friends, including Katharine's good friend, Agnes Osborn, departed on a chaperoned camping trip. Wilbur did not join the camping trip, choosing instead to stay home to operate the bicycle store and test the kite. Sometime after everyone departed for the camping trip, Wilbur flew the kite at Chadwick's hill, a field near Summit and West First Streets. This was a popular kite flying field for school boys and one of them, Frederick W. Fansher, remembered in later years one of the Wright brothers appearing with a peculiar looking box kite. Finding the kite unique, the boys quit flying their own kites to watch Wilbur's experiment which was successful. On Sunday, August 6, Wilbur visited the camp and reported the results of the kite to Orville. [32]

As Orville remembered, Wilbur found, "It responded promptly to the warping of the surfaces, always lifting the wing that had the larger angle.... We felt that the model had demonstrated the efficiency of our system of control." The performance of the kite demonstrated that the wing warping system was more successful than any of the other control methods employed by other aviation researchers. The only question remaining was whether it would work in a full-sized model. Based on the success of the kite, the brothers decided to take the next step in their research and construct a full-scale glider. [33]

While committed to continuing their experiments, the Wright brothers were forced to delay any actions for several months. Through the fall of 1899 and winter of 1900, the brothers were busy assembling their next year's stock of Wright bicycles. During this period, Wilbur made the time to search for a location for the planned glider experiments. On November 27, 1899, he wrote to the Instrument Division of the U.S. Weather Bureau requesting "if possible a report of the wind velocities of Chicago or vicinity for the months of August, Sept., Oct., and November." One of his main criteria for a testing ground was a minimum wind speed of fifteen to twenty miles per hour. The response from the U.S. Weather Bureau included a report for August and September that included average hourly wind velocities at all weather stations in the United States. [34]

While the records from the U.S. Weather Bureau showed that Chicago was the windiest city, Wilbur had already rejected that location. The vast publicity paid to Chanute's experiments in 1896 confirmed to Wilbur that he needed a remote site. Reviewing the report, Wilbur discovered that the sixth highest average wind in the United States was recorded at Kitty Hawk, North Carolina. While he had never heard of the town, Wilbur decided that its merits as a testing ground warranted further investigation. [35]

With his busy schedule readying the bicycle shop for the spring, Wilbur did not immediately respond to the data he received from the U.S. Weather Bureau. It was not until May 1900, that Wilbur began to make preparations for his planned experiments. His first act was to write Octave Chanute. In his letter, Wilbur wrote, "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." He went on to explain his beliefs as to why flight was possible and his ideas for glider experiments. Wilbur planned to erect a tower from which to test a man carrying kite, and he welcomed Chanute's thoughts on the system. Wilbur concluded by asking if Chanute could recommend a location for experiments between September and January, for those were the months that Wilbur would be able to leave the bicycle business. [36]

Chanute's response on May 17 set in motion a correspondence between the two that would last until Chanute's death in 1910. Chanute became both a mentor and a friend to the Wright brothers, and he offered guidance to the Wright brothers throughout their experiments. In his response, Chanute relayed to Wilbur that he believed his idea for a tower would be hindered by the necessary restraining ropes which often created hazards. Chanute himself preferred "preliminary learning on a sand hill and trying ambitious feats over water." As for suitable locations to conduct his experiments, Chanute recommended San Diego, California, and St. James City, Florida. While these two sites had sufficient steady winds, they lacked "sand hills." Maybe, Chanute felt, better locations could be found along the coasts of South Carolina or Georgia. [37]

After receiving Chanute's advice about potential testing grounds, Wilbur wrote to the U.S. Weather Bureau office at Kitty Hawk, which the report from the U.S. Weather Bureau showed had sufficient wind. Joseph J. Dosher, the only bureau employee there, sent a short response describing the beach near his station as a mile wide and clear of any obstructions. The winds in September and October blew from the north and northeast. While Wilbur could board in the village, housing would be a problem. Dosher suggested that Wilbur would need to bring a tent and camp. [38]

In addition, Dosher passed Wilbur's letter onto William J. Tate. Tate responded further to Wilbur's inquiry and highlighted the virtues of Kitty Hawk for aeronautical experimenters. Tate closed his letter with the assurance that he would do anything needed by Wilbur to facilitate his experiments. With Tate's generosity and friendliness along with the prerequisite constant winds, Wilbur chose Kitty Hawk as the site for his experiments. [39]

THE WRIGHT CYCLE COMPANY, 1127 WEST THIRD STREET. (Courtesy of Dayton and Montgomery County Public Library)

With the location selected, Wilbur began to construct a glider. This work, as with the earlier kite, took place in the upstairs of the bicycle shop at 1127 West Third Street. On August 10, Wilbur informed Chanute that it was his intention "to begin shortly the construction of a fullsize glider. Hitherto I have used pine in the frames, but for the large machine I wish to use spruce, a wood not obtainable in Dayton yards." In response, Chanute informed Wilbur of the Keith Lumber Company in Chicago, but he believed that Wilbur could also purchase spruce in Cincinnati. Instead of continuing to search for spruce, Wilbur decided to take a chance that he would be able to purchase spruce for the spars in Norfolk, Virginia. At home in Dayton, he cut, steamed, and shaped ash ribs for the wings along with approximately fifty additional pieces for the glider. He also obtained parts not available in Kitty Hawk such as metal fasteners and steel wire for trussing the wings. Wilbur also cut and sewed yards of sateen fabric to cover the finished wings. The remainder of the construction and assembly occurred in Kitty Hawk. [40]

With the preparations complete, Wilbur could no longer delay informing his father, who was away from Dayton on church business, of his plans. On September 3, a day before he planned to leave for Kitty Hawk, Wilbur sent Milton a letter explaining his intent to experiment with the glider:

It is my belief that flight is possible and while I am taking up the investigation for pleasure rather than profit, I think there is a slight possibility of achieving fame and fortune from it. It is almost the only great problem which has not been pursued by a multitude of investigators, and therefore carried to a point where further progress is very difficult. I am certain I can reach a point much in advance of any previous workers in this field even if complete success is not attained just at the present. At any rate I shall have an outing of several weeks and see a part of the world I have not before visited. [41]

Two days later Katharine informed Milton that she, Orville, and Wilbur were in "an uproar getting Will off." [42]

If the bishop had any fears as to Wilbur's experiments, Katharine attempted to alleviate them by mentioning that she did not "think he will be reckless." In her opinion, the trip would be good for him. She also shared the information that, if it could be arranged, Orville planned to join Wilbur in Kitty Hawk after the glider was assembled. Katharine remembered, in later years, that after hearing the initial news of his son's pursuit, Milton was always supportive of Wilbur and Orville's experiments. [43]

As tentatively planned, Orville left on September 24 to join Wilbur in Kitty Hawk. At this point, Orville became an equal partner in the aeronautical experiments. No longer did Wilbur dominate the project. Orville hired Harry Dillon for $4.50 per week to mind the bicycle shop while the brothers were in Kitty Hawk. Their other employee, Cord Ruse, continued to come in as needed for bicycle repair work, while Lorin and Katharine managed the shop and balanced the accounts. This arrangement did not work long, for on October 13 Orville received a telegram from Katharine announcing the dismissal of Dillon. Orville was not surprised, mentioning that he did not expect Dillon would do and that the shop would have to make due with only Ruse. While they were gone, if Katharine needed sundries for the bicycle shop, Orville informed her that a catalog from E.H. Hall Company in Rochester, New York, was in the store. If anything was needed immediately, Forrer & Scherffer, 22 East Second Street, offered reasonable prices to the Wright brothers. [44]

Wilbur and Orville remained in Kitty Hawk less than one month. The newly assembled biplane glider had a wing span of seventeen feet, five inches, with a five-foot chord and a wing camber of 1 in 23. The total surface measured roughly 177 feet, including twelve square feet for the forward rudder, or elevator. The forward rudder was a horizontal surface mounted in front of the wings, and it was designed to keep the wing's center of lifting pressure and the glider's center of gravity balanced. The Wrights' solution, based on the work of Alphonse Pénaud, was the use of a rudder placed ahead of the wing, known as a canard configuration. The pilot would lie prone on the bottom wing in order to decrease drag. The Wright brothers' first glider was the most advanced heavier-than-air flying machine created to that time, and it was based on their knowledge of previous experimenters' work and their understanding of aerodynamics and control. [45]

During their experiments at Kitty Hawk, the brothers flew the glider both as a kite and as a man-carrying glider with Wilbur as the sole pilot during the manned experiments. Testing the glider was often frustrating. During the trials, the brothers discovered that stronger winds than they had calculated were needed to lift the glider, and even stronger winds were needed to lift the glider and a pilot. Since winds of this strength were not plentiful, the Wrights were forced to operate the glider as a kite for most of their experiments. On the few occasions when the brothers conducted experiments with a man aboard the glider, they were content with their system of control. To their delight, they discovered that the elevator maintained balance while the wing warping system made five to ten-second glides possible. While in Kitty Hawk, the brothers only flew the machine with a man aboard for barely ten minutes and had less than two minutes of actual gliding time. [46]

When they flew the glider as a kite, Wilbur and Orville carefully measured the lift and drag generated by the glider, the velocity of the wind, and the angles of the ropes that held the machine. The measurements indicated that the drag was much less than they anticipated and the same with the lift. In constructing the 1900 glider, the Wright brothers used the data recorded by Lilienthal and the standard lift equations. But the actual results were disappointingly far from the calculations. The glider should have been able to lift its own weight and a pilot in winds of about twentyone miles per hour with an angle of attack of three degrees. The actual performance needed winds of over twenty-five miles per hour and an angle of attack of almost twenty degrees. These results caused Wilbur and Orville to begin questioning the data they relied upon to design their glider. [47]

In addition to raising some disturbing problems, the 1900 experiments yielded some positive information for the Wright brothers' further research on human flight. First and foremost, they discovered that their system of longitudinal and lateral control was a success. The full-size glider confirmed the success of the wing warping system demonstrated on the 1899 kite. In addition, the moveable forward rudder performed as he brothers hoped by limiting the travel of the center of pressure and allowing the pilot to control the aircraft in pitch. While the short glides produced sufficient information for Wilbur and Orville to analyze their control system, they also reinforced the brothers' belief that they had to practice flying to better understand aeronautics. [48]

While Wilbur and Orville were in Kitty Hawk, Katharine remained in Dayton. The brothers' trip coincided with the beginning of the school year, and Katharine was a teacher at Steele High School. Katharine began teaching at the school in 1899, and in 1900 she taught all of the Latin classes. These included two beginning, one second year, and two classes from the previous year. A former student of Katharine's, Samuel Finn, remembered that, when he or another student did not have his lessons prepared, one of them would "raise his hand and ask her whether she thought that powered flight was practical. And she became so enthused that she would talk the rest of the period and consequently we did not have to recite." [49]

In the beginning of 1900, fourteen year old Carrie Kayler was hired to assist with the household work since teaching took up most of Katharine's time. Carrie had previously worked for Lorin's family after their daughter Leontine was born in 1898. Feeling that Carrie still needed training and guidance, Katharine still focused much of her attention on household matters. By October 1901, Katharine reported to her father that, "Carrie has improved a good bit under my constant superintendence." When her two brothers and father were out of town in the fall of 1900, Katharine opted to stay with her friend, Agnes Osborn. Since no one was living in the house at 7 Hawthorne Street, Carrie assisted Netta, Lorin's wife. As soon as Milton returned to Dayton, both Katharine and Carrie returned to 7 Hawthorne Street. [50]

The brothers departed Kitty Hawk on October 23, and immediately upon their return to Dayton, Wilbur wrote Chanute to inform him of the experiments. In his response, Chanute asked for Wilbur's permission to include information on their experiments in an article he was preparing for Cassier's Magazine. Wilbur responded, "It is not our intent to make a close secret of our machine, but at the same time, inasmuch as we have not yet had opportunity to test the full possibilities of our methods, we wish to be the first to give them such test," but he did provide Chanute with several paragraphs of information that he could include in the article. Wilbur also spent some time in the winter of 1900-1901 drafting articles for publication. The two articles he prepared were published in July 1901. "The Angle of Incidence" appeared in the Aeronautical Journal and "The Horizontal Position During Guiding Flight" was published by Illustrierte Aeronautische Mitteilungen, the aeronautical journal in Germany. [51]

Based upon the success of the 1900 glider, the brothers began constructing a larger glider for a 1901 trip to Kitty Hawk to conduct further experiments. With the results of their 1900 glider tests, the Wright brothers reached the point where their work was no longer based on the results of others' research, and any progress would be the result of their own work and experiments. In preparing for their 1901 trials, foremost in their minds was how to accurately determine wind velocity needed to analyze the gliders' performance. Wilbur asked Chanute for advice on an anemometer, an instrument used for measuring wind force and speed, for field use. Chanute responded that he owned two, and the brothers could borrow one. Since the brothers had already expended the amount they budgeted for the 1901 experiments, Wilbur informed Chanute that he and Orville would most likely take Chanute up on his offer. He also extended an invitation for Chanute to visit their camp at Kitty Hawk. While Chanute did not mention a visit to Kitty Hawk in his following letter, he did notify Wilbur that he might be able to stop in Dayton to visit during one of his trips east. What day would be the best to meet with the brothers? [52]

Wilbur's response to Chanute's inquiry illustrated much about the Wright brothers' schedule:

During the months of March, April, May, and June our time is very closely occupied, as our business requires our attention from twelve to fourteen hours daily. After July 4th the tension is considerably relaxed and after September 1st we are almost free for four months. If your trip falls within the months of May or June, we could make your visit much more pleasant and satisfactory if you could arrange to stop off and spend Sunday with us at our home. We are entirely free all day Sunday. We would make most of a visit at any time but during the busy season would be more or less liable to interruptions on business days. [53]

Chanute arrived in Dayton on Wednesday, June 26. The only record of this meeting was relayed by Carrie Kayler Grumbach in later years. Katharine left instructions with Carrie to serve melon for dessert. While preparing the melon, if Carrie found one melon to be better than the others, she was to serve Chanute a piece from that one. As she cut the melons, Carrie discovered one was barely ripe and not fit for consumption. She decided to serve smaller pieces of the preferable melon to all the guests. Katharine disagreed with Carrie's decision and for a while Carrie wondered if she would ever be forgiven. [54]

Despite Wilbur's warning that a weekday meeting would most likely be interrupted by the bicycle business, the meeting with Chanute went smoothly and without interruptions. This was due to the fact that the Wright brothers had hired Charles E. Taylor on June 15, 1901, to assist at the shop, and they were now able to get away from the store for short periods of time, leaving the store under Charlie's supervision. Charlie Taylor was a thirty-three year old machinist, and his wife, Henrietta Webbert, was the sister of Charles Webbert, the Wright's landlord. The Taylor family moved from Kearney, Nebraska, to Dayton in 1894, and Charlie worked at Stoddard Manufacturing for a short time before opening a machine shop that was located five blocks from the Wright brothers' bicycle shop. [55]

Charles Webbert introduced the Wrights to Taylor when he owned the machine shop, and they hired him for work they could not complete themselves. Two of the projects that Taylor assisted the Wright brothers with were the development of the oil retaining wheel hub they designed for the Wright bicycles as well as the original coaster brakes for the Van Cleve bicycles. Charlie later sold the shop and began working for the Dayton Electric Company as a supervisor, but he found that he missed working with tools. Wilbur and Orville offered him a job at the bicycle shop for thirty cents an hour or eighteen dollars a week. This was five cents more per hour than he earned at the electric company, and he gladly accepted their offer. [56]

The bicycle shop was open from Monday through Saturday and closed on Sundays. It stayed open late on Saturday nights, so the Wrights could take care of their customers who worked all week and were unable to get to the shop until the end of their work week. When Charlie began working for the Wrights, he would open the shop each day at seven in the morning. The brothers would arrive sometime between eight and nine o'clock. All three of them would go home for lunch, but at different times so the store was never closed. The workday ended at six o'clock when the shop closed. [57]

The Wrights were often busy pursuing their aeronautical research, and Charlie saw to the customers and bicycle repairs. The brothers spent much of their time working upstairs in the bicycle shop where there was a small office and a workroom. Charlie worked in the workroom located in the back room on the first floor. [58]

As with their 1900 glider, the Wrights designed and constructed the parts for their 1901 glider prior to departing for Kitty Hawk. In a letter to Chanute in May 1901, the brothers stated the glider would "be built on exactly the same general plan as our last year's machine but will be larger and of improved construction in its details." This statement illustrates an important component of the Wrights' aeronautical research. Unlike earlier experimenters, the Wright brothers used each glider as a starting point for their next. Previous aeronautical researchers switched between various designs, never being consistent and building upon their previous work. Wilbur and Orville started with the design of the 1899 kite and built upon that for the 1900 glider, and then used the information to design the 1901 glider. [59]

The 1901 glider had twice the lifting surface of their previous glider, and was the largest glider anyone ever attempted to fly. The increased size was intended to improve the lift capability, a problem that they faced during their first year of experiments. A biplane design, the glider had a span of twenty-two feet and a seven-foot chord with a total wind area of 290 square feet, an increase from the 165 square foot glider of the previous year. The wing camber was increased from the 1 in 23 used in the 1900 glider to 1 in 12. The front rudder was eighteen square feet, and the total weight of the glider was ninety-eight pounds. [60]

When Wilbur and Orville left for Kitty Hawk on July 7, they left Charlie in charge of the bicycle shop. With a dependable and trusted employee to oversee their business, the brothers were able to leave during the busy season, several months earlier than they originally planned. This year while the brothers experimented with their glider at Kitty Hawk, they had several visitors at their camp. Chanute visited the camp from August 4 through 11, and he also recommended two others to assist the Wrights. Edward C. Huffacker, who was building a glider for Chanute, arrived in Kitty Hawk on July 18 and stayed until August 18. George A. Spratt arrived on July 25 and stayed until August 16. Chanute recommended Spratt to the Wright brothers because of his interest in aeronautics and his medical training which would be advantageous in the remote area where the Wrights were experimenting. [61]

While in Kitty Hawk, the Wright brothers conducted between fifty and one hundred glides and kite tests with their new glider. The glides ranged in distance from twenty feet to almost 400 feet, many measuring more than 300 feet in length. At first, Wilbur, who completed all the flying, experienced problems with the glider. After several trials where the pilot kept moving to the rear of the wing, Wilbur finally completed an undulating flight of around 300 feet. The cause of the problem was the thin ribs between the spars that were flexible enough to bow at midpoint causing the center of pressure to move and nose the aircraft into the ground. As soon as the brothers reduced the camber and flexibility of the ribs, the glider's performance improved.

With the glider's improved performance, Wilbur attempted to use the wing warping system to make an intentional turn. When he began the turn, the glider operated as he predicted, but halfway into the turn the glider unexpectedly reversed direction. Caught unaware by this occurrence, Wilbur immediately straightened the glider and landed. This experience was Wilbur's first with what is now referred to as adverse yaw, and, as Wilbur discovered, this occurs when the different drag forces on the two wings cause the aircraft to turn in the opposite direction intended. This new problem increased the Wrights' frustration with the glider. After solving the initial problem with pitch, now the lateral control system did not reliably function. [62]

While the witnesses were impressed with the glider, Wilbur and Orville were disappointed. As with the 1900 glider, the 1901 glider did not perform as well as their calculations indicated it should, and the performance of the glider seemed to create more questions than it solved. The poor performance of lift reaffirmed the Wright brothers' suspicions that the lift tables they used to construct the machine were incorrect. While on the way home from Kitty Hawk, Wilbur reflected on all the questions raised during the 1901 trials and the remaining work needed to achieve human flight and predicted that man would never fly in the brothers' lifetimes. [63]

After returning to Dayton, Wilbur received a request from Chanute to present a paper on the brothers' experiments at the Western Society of Engineers meeting in Chicago on September 18. Katharine shared with her father that, "Will was about to refuse but I nagged him into going. He will get acquainted with some scientific men and it may do him a lot of good." Finally accepting Chanute's offer, the family had quite "a picnic getting Will off to Chicago. Orv offered all his clothes so off went 'Ullam' arrayed in Orv's shirt, collars, cuffs, cuff-links, and over-coat. We discovered that to some extent 'clothes do make the man' for you never saw Will look so 'swell'." [64]

While Wilbur and Orville focused most of their attention on aeronautical research and experiments, Milton was once again becoming involved in a church controversy. The problem began in 1893 when Milton resigned as the Old Constitution publishing agent to focus more of his attention on the legal matters in regards to the disposition of the church property between the Radical and Liberal branches of the church. In order to keep the business in the family, Milton nominated Wilbur as his successor. How-ever, in the election Wilbur lost to Millard F. Keiter, a preacher in the Old Constitution.

Keiter served as the publishing agent from 1893 to 1901, and he was confident of being reelected in the April 1901 election. A month prior to that election, George D. Crane, an accountant from Fort Wayne, Indiana, appeared in Dayton to audit the account books of the publishing house. The publishing board, led by Milton, questioned a number of Keiter's business affairs and transactions, and they instigated Crane's audit. Milton's fears were confirmed when the audit disclosed a shortage of almost $6,800 in the accounts. At the General Conference in April, Keiter was removed from office and succeeded by W.H. Clay. Since a consensus could not be reached at the General Conference, a special committee of five was appointed to investigate the matter. [65]

1901 GLIDER BEING LAUNCHED IN KITTY HAWK, NORTH CAROLINA. (Courtesy of Wright State University, Special Collections and Archives)

While the Wright brothers supported their father in "the publishing house controversy," they also focused much of their spare time on the flying machine. Katharine reported to her father, "We don't hear anything but flying machine and engine from morning till night. I'll be glad when school begins so I can escape." The one exception to flying machine research that attracted the brothers' attention was the construction of a one-cylinder illuminating gas engine, mentioned by Katharine, for use in the bicycle shop. Wilbur and Orville planned to power their newly purchased drill press and band saw using an overhead line shaft powered by an engine. Instead of purchasing an engine, the Wright brothers decided to build one. With the assistance of Charlie Taylor, who had a minimal knowledge of engines, the brothers set to work. Katharine reported to her father in October, "Orv's engine is being made and, as usual, he is very enthusiastic over it. I hope he can make it go." Katharine's concern was moot; the engine was successful. [66]

After returning to Dayton, based on the performance of their 1901 glider, Wilbur and Orville began questioning the lift and drag data they drew from Lilienthal's published work. "We had taken up aëronautics merely as a sport," Orville reported. "[We] reluctantly entered upon the scientific side of it. But we soon found the work so fascinating that we were drawn into it deeper and deeper." The first step in proving their theory that the formulas for calculating lift and drag were incorrect was to actually confirm there was an error. [67]

Lilienthal's tables included the lift and drag coefficients for the specific wing shape that he used on his gliders. Inherent in the formula Lilienthal used to determine these coefficients was Smeaton's coefficient. John Smeaton was a mid-eighteenth century British engineer who determined that the general relationship of pressure and velocity to air was a constant 0.005, known as Smeaton's coefficient. This figure became a standard value that was used without question for nearly 150 years. While the brothers considered the possibility of an error in Lilienthal's figures, one explanation, they concluded, was that the widely accepted Smeaton's coefficient was in error. [68]

Wilbur and Orville designed a mechanical analogue for Lilienthal's tables to prove that a problem existed. Peter Jakab, in his study of the brothers' process of invention, described the theory behind the test:

They would first record the actual angle of attack at which the lift of the curved surface balanced the opposing pressure generated by the wind hitting the flat plat. They would then calculate what that angle should be based on the values in Lilienthal's table. From a comparison of the two results the Wrights would be able to evaluate the accuracy of Lilienthal's coefficients. [69]

To do this, the brothers recreated the situation represented in the tables by mounting a bicycle wheel on its side with a cambered Lilienthal airfoil fixed to the front of the rim.

If Lilienthal was correct, the wheel would remain stationery when placed in a strong wind. If he was wrong, the air pressure would cause the wheel to turn. When they could not get enough wind to turn the wheel, the Wrights mounted the apparatus horizontally over the handlebars of a bicycle and rode furiously up and down the street. The wind caused the wheel to turn, proving an error existed in Lilienthal's coefficients. But was this error in Lilienthal's work or Smeaton's coefficient as they predicted? [70]

To verify the results, Wilbur and Orville constructed their first wind tunnel. Invented by Francis Herbert Wenham and John Browning in 1871, the wind tunnel provided an atmosphere to test reactions of objects to an artificially induced flow of air. This invention provided a new means to study aerodynamic wing design, but early wind tunnel experiments produced little useable aerodynamic information. What data they yielded on flat and curved wing surfaces was not used, for there was little knowledge how to apply this information in designing flying machines. The Wright brothers were the first to use a wind tunnel "to systematically collect specific data on a wide range of prospective wing shapes to be used in conjunction with the established lift and drag equations." In fact, they were the first to use a wind tunnel to obtain information in a form that could be assimilated into the design of an airplane. [71]

The Wrights' wind tunnel was of simple construction, consisting of a wooden trough with a small fan at one end driven by the overhead shaft used to power the equipment in the bicycle shop. The wind tunnel measured eighteen inches long and had a glass window on the top to observe the interior during the tests. Wilbur and Orville placed what they called a balancing vane inside the wind tunnel for the test. The balancing vane consisted of a vertical rod with two surfaces, one curved and one flat, mounted on it. Similar in theory to their test using the bicycle, this test was more precise. The results confirmed the results of the first test and the existence of an error in the tables. [72]

After identifying the error, nothing was left for the brothers except to systematically check all of the coefficients in the Lilienthal table. First, they decided to take a closer look at Smeaton's coefficient. By comparing figures for the coefficient published by the U.S. Weather Bureau with their own estimates based on their gliding experiments, the Wrights determined that 0.0033 instead of 0.005 should be used as the coefficient used in the formula to determine lift and drag. [73]

By mid-October 1901, Wilbur and Orville finished their second wind tunnel. Larger than the first, the second wind tunnel was six feet long, sixteen inches square on the inside, and had a glass viewing window on the top. A metal hood at one end shielded a two-blade fan that was driven at a speed of 4,000 rpm. The brothers planned to use the wind tunnel to test models of wings at every angle of attack. As Peter Jakab described, "they were designed to measure values related to the actual aerodynamic forces acting on the model surface in terms that could be substituted directly into the equation [for lift and drag]." For wings, Wilbur and Orville used a variety of shapes and sizes to determine the most efficient lifting surface. The Wrights also constructed three metal balances designed to balance lift against drag during the tests. The wing models and balances were constructed of bicycle spokes and hacksaw blades, and they enabled the brothers to measure what was occurring as the wind flowed around the wing models placed on the balance. In his first involvement in the Wright brothers' aeronautical experiments, Charlie Taylor ground down some old hacksaw blades for the brothers to use to create the wing models. [74]

Wilbur and Orville began testing thirty-eight model surfaces to determine specific information regarding wing design. For instance, how far apart should the wings be on a biplane? Should the upper and lower wings on a biplane have the same camber? Were two or three wings better? These experiments lasted for approximately three weeks during the month of December. Using the results for the wind tunnel tests along with measurements for lift, drag, and velocity that they made with their gliders at Kitty Hawk, Wilbur and Orville ultimately created the correct information needed for the lift and drag of various wing shapes. According to Wright biographer Fred Howard, these tests were the most beneficial aeronautical experiments ever conducted with so few materials and at such a low expense. [75]

While the Wright brothers focused on their aeronautical research, another significant event of the year was the continuation of their father's involvement in the Keiter Affair. The hearing recommended by the General Conference in regards to Milton's claims against Keiter was held in February 1902. At that time, Keiter convinced four of the seven board members that the accountant was in error and that any mistakes were the result of carelessness rather than an attempt to defraud the church. Milton was one of the three board members who did not accept this explanation, and he asked Wilbur to look at the books.

While Wilbur was not an accountant or a bookkeeper, he was meticulous and had experience keeping the books of his and Orville's businesses. In his review, Wilbur compared the books with the annual reports of the printing house, and he discovered there were failures to report receipts and many other errors. Specifically, Wilbur uncovered that Keiter used some of the funds to purchase personal clothing, pay his own insurance premiums, and buy construction materials for his own home.

As in the controversy that resulted in the split of the Church of the United Brethren in Christ, Milton launched a campaign against Keiter by outlining his arguments in pamphlets. Wilbur, as before, assisted his father in compiling three pamphlets, and much of Wilbur's spare time was spent on these projects. One of the reports included a detailed report of Wilbur's findings in the account books. Wilbur's involvement in the controversy dictated that further aeronautics would have to wait until his father no longer needed his support. [76]

The importance of family to the brothers was illustrated by the fact the even though they were too busy with their bicycle business and assisting their father to continue their aeronautical experiments, Wilbur and Orville still had time to visit with Lorin's family and entertain their nieces and nephews. In addition to sharing Sunday dinner at 7 Hawthorne Street, the family members often saw each other during the week. In October, Ivonette and Milton were invited to a birthday party, and Leontine felt left out of the festivities. In order to appease her, Orville shared some candy with her and created a party all her own on his lap. [77]

In adulthood, Ivonette shared fond memories of her two famous uncles from this time period:

Orville never seemed to tire of playing with us. If he ran out of games he would make candy. If he happened to be busy with something else, he would make caramel, which was easier to make and the kind children couldn't eat fast. If he had time, he made fudge with a long thermometer to test how long it should be boiled.

Ivonette remembered that Wilbur also enjoyed playing with the children, although not for as long as Uncle Orv. If Wilbur was tired of visiting with whichever niece or nephew was sitting on his lap, "he would straighten out his long legs and we would slide off. That was a signal for us to find something else to do." Sometimes during evening visits, Wilbur and Orville would entertain Lorin's children with a shadowgraph show. There were always two characters who were portrayed: Sam Bonebrake, who was tall and thin, and Jim Higgenbottom, who was short and fat and had a high squeaky voice. The brothers would spend hours at the bicycle shop constructing the metal figures for the show. [78]

One of the holidays that the Wright brothers' nieces and nephews fondly remembered was Valentine's Day. Lorin's children would make Valentine's Day cards for their relatives who lived at 7 Hawthorne Street. Then they would quietly sneak onto the porch to drop off the cards, and then stomp away loudly. The stomping would attract the attention of those inside, so they would come out onto the porch and find the cards. Leontine recalled:

Uncle Orville couldn't restrain himself from adding to the excitement of this occasion. Maybe he just guessed when we were coming but I think my father was in on the game and somehow let it be known that we were on our way. No matter how well laid our plans Uncle Orville would burst out of the door just as we were making our escape.

While Leontine and Lorin's other children devised many ideas to prevent their Uncle from seeing them, there were only a few times that they were successful. [79]

Visits to 7 Hawthorne Street were not without discipline. When the children needed punishing, their grandfather Milton would lock them in a closet under the stairs until they were ready to behave. This punishment was not as severe as it sounds, for the closet had a window and was stocked with books and magazines. In another method, according to Ivonette, "He would put us on the floor, turn a chair over us, then sit on it so we couldn't get up. When he thought our dignity had a jolt, he would let us out." Good table manners were essential, and if Lorin and Netta were not with them, the children's bad manners were corrected with the statement, "I believe we have a Goop with us today." This comment was based on The Goop Tales, Alphabetically Told, by Gelett Burgess which humorously described the various faults good children should avoid. [80]

While the Wright family continued life as normal, Wilbur and Orville continued to puzzle over their flying machine. Despite the successful data obtained from their wind tunnel experiments and the brothers confidence in the results, Wilbur and Orville chose not to construct a powered machine in 1902 but another glider. One of their reasons for building a glider was the need to solve the lateral control problems, or adverse yaw, Wilbur experienced in the 1901 glider. The completed 1902 glider had a slightly larger surface than the 1901 glider, with a wing area of 305 square feet. Wilbur and Orville started with the design of the 1901 glider and incorporated the results from their wind tunnel tests. The tests indicated that the most efficient wing for adequate lift would be a camber between 1/24 and 1/30, depending upon how the wings were rigged, with a five foot chord. The wings on the 1902 glider had a thirty-two foot wingspan compared to the twenty-two feet of the 1901 glider. In addition, to address the problem of lateral control, a two-surface fixed vertical rudder was added to the rear of the machine. [81]

During July and August 1902, the Wright household at 7 Hawthorne Street was full of frantic activity as Wilbur and Orville prepared once again to travel to Kitty Hawk. On August 20, Katharine relayed to Milton, "The flying machine is in process of making now. Will spins the sewing machine around by the hour while Orv squats around marking the places to sew. There is no place in the house to live but I'll be lonesome enough by this time next week and wish that I could have some of their racket around." Katharine went on further to tell her father, "They really need to get away for a while. Will is thin and nervous and so is Orv." Kitty Hawk would be a good remedy for the brothers, "They think that life at Kitty Hawk cures all ills, you know." [82]

While the brothers prepared to depart for Kitty Hawk, they had some reservations. Wilbur especially felt that he should stay in Dayton to assist his father with the Keiter affair. Wilbur's concern stemmed from the fact that while Milton continued his fight against Keiter, the general opinion of the church's ruling body was against him. Feeling that they did not want to bring the controversy into the public realm, the rulers were content with having dismissed Keiter from his post in the publishing house. Milton desired further action against Keiter; specifically he wanted criminal charges filed against him. Sensing the backlash against Milton, Keiter filed disciplinary charges against him in May 1902. The charges accused Milton of libel, insubordination, and breach of the guidance of the church which urged all members to settle their differences out of court. Believing the charges were without any legal basis, Milton ignored them. [83]

The presiding elders of Milton's circuit, the Fairmont Circuit, appointed a special commission to investigate Keiter's charges and Milton's conduct. In response, the commission scheduled a hearing at the annual conference meeting on August 28. Milton, as bishop, rescheduled the meeting until October claiming the need to complete some other pressing business. The notice was ignored, and the hearing convened. The hearing resulted with a verdict of guilty on all three charges, and Milton was ordered to confess his error and apologize to the members of the conference. If this was not carried out within sixty days, he would face indefinite suspension. Believing in his opinion and actions, Milton ignored the decision and proceeded with business as usual. [84]

Wilbur and Orville were not in Dayton when the hearing results were announced. Although they considered staying in Dayton to support their father, the brothers eventually left for Kitty Hawk. They departed on August 25 and stayed until October 28. As in the previous year, throughout their stay, the brothers had many guests. The first visitor was their brother Lorin; followed by George A. Spratt, who had visited the previous year; and Octave Chanute, who brought his assistant, August M. Herring. [85]

During their stay, the brothers made 700 to 1,000 glides that proved the glider was a success from the beginning. In the first two days of the glider experiments, Wilbur and Orville made over fifty glides with their machine. As they had in previous years, the brothers first flew the glider as a kite. These trials showed the new wing configuration improved the lift to drag ratio, the problems with longitudinal control were reduced, and the new fixed vertical rudder counteracted the adverse yaw. The next step was to fly the kite as a glider. This was the first year that, in addition to Wilbur, Orville also piloted the glider. In order to give themselves an opportunity to become familiar with the controls, they secured either the wing warping or forward elevator controls. As with the earlier flights, the glides showed the improvements over the 1901 glider. [86]

While the 1902 glider solved some of the problems experienced with the earlier gliders, a new problem arose. The glider responded to crosswinds, and in some instances, these winds tipped one wing of the glider towards the ground. In an attempt to solve this problem, the brothers altered the wings so the tips were approximately four inches lower than before, creating a negative dihedral. This solution caused greater problems with lateral control than experienced in the 1901 glider. On September 23, Orville piloted the glider with both controls free. At one point he activated the wing warping by shifting in the hip cradle to raise a dropping wing. Preoccupied with the wings, Orville lost track of the elevator, and the airplane crashed nose first into the sand. Orville survived the accident, but the damage to the machine took several days to repair. [87]

Once the glider was repaired, Wilbur and Orville resumed their experiments. During the last flight of 1901, Wilbur experienced a new problem when he neglected the forward rudder during a turn and the glider dove to the ground. This reoccurred when Orville started flying the repaired glider. The brothers termed this phenomenon "well-digging," and it is now known as a tailspin. Their phrase was based on how the glider slid out of control, falling from the sky, with one wing tip landing in the sand first. The depression made from the wing made the Wrights think of a well. [88]

It was evident to Wilbur and Orville that the new vertical rudder, or tail, played a role in the occurrences of well-digging. Orville shared his remembrance of how he happened upon the solution with Fred Kelly:

But even after it was evident that the tail had something to do with the machine's peculiar behavior, neither brother was prepared to explain why. Then one night Orville drank more than his customary amount of coffee. Instead of going to sleep as usual the moment he got into bed, he lay awake for several hours. Those extra cups of coffee may have been important for the future of practical flight for, as he tossed about, he figured out the explanation of the phenomenon caused by the tail.

During those hours, Orville concluded that making the vertical tail moveable would solve the problem. By moving the tail when a tailspin began, the pressure that caused the glider to pivot about the low wing could be avoided. [89]

Wilbur agreed with Orville's assessment but added a suggestion. Hesitant to add another control to manage, Wilbur suggested controlling the tail and the wing warping with the same system. This would still have the positive effect of a moveable vertical rudder, but avoid further demands on the pilot. Enthusiastic about the idea, the brothers attached the wires controlling the tail to the wing warping system. These alterations to the 1902 glider created a three dimensional system of control. The forward elevator controlled the glider in the pitch axis, the wing warping in the roll axis, and the moveable rudder in yaw. In this final form, the 1902 glider was the first fully controllable aircraft. The 1902 experiments were a success. [90]

While Wilbur and Orville were in Kitty Hawk, they once again left Charlie Taylor in charge of the bicycle shop. Katharine did not get along well with Charlie, and she often informed her brothers of the difficulties she experienced. In a September 4 letter, she stated, "The business is about to go up the spout to hear Charles Taylor talk." Katharine did not believe any of Charlie's complaints were credible, but she did have a problem. The brothers left for Kitty Hawk without leaving any checks. She did not, "enjoy going to the store after money. Mr. Taylor knows too much to suit me. I ought to learn something about the store business. I despise to be at the mercy of the 'hired man'." A month later, when Katharine once again apprised her brothers of the situation, she and Charlie were no longer talking. "I simply can't stand Charles Taylor so I steer clear of the store. I have been in twice to telephone but we never said a word to each other!" [91]

With the success of the 1902 experiments, Wilbur and Orville felt that they were in a position to attempt powered flight. In later years, Orville described the 1902 glider experiments as demonstrating "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." Prior to any other research after the experiments, the ever cautious brothers constructed another wind tunnel to confirm the accuracy of their 1901 wind tunnel test. With the results verified, the brothers began working on propellers and an engine for their flying machine. [92]

Originally, the Wrights thought of using the theory of screw propellers developed by maritime engineers and then applying their formulas to make the propellers suitable for air. After researching ship propellers, they discovered that these propellers were not based upon any theory and provided none of the information the brothers sought. The brothers spent weeks discussing alternative propeller theories and attempting to solve the problem of creating a propeller for their airplane. [93]

Charlie Taylor was a witness to many of these discussions, and he recalled, "Both boys had tempers.... They would shout at one another something terrible. I don't think they really got mad, but they sure got awfully hot." Orville remembered that these arguments often had the effect of each convincing the other of their point. "After long arguments, we often found ourselves in the ludicrous position of each having been converted to the other's side, with no more agreement than when the discussions began." [94]

Instead of being a hindrance, Charlie felt that these arguments were part of the reason the Wright brothers succeeded. Through this process, Wilbur and Orville developed approaches to a problem, and without each other and these discussions, Charlie felt that neither of the Wright brothers would have made strides towards solving the problem of human flight. It was their partnership and how Wilbur and Orville worked together, such as arguing over theories, which contributed towards their success. [95]

One of the Wright brothers' future students, Benjamin Foulois, noticed how well Wilbur and Orville complemented each other. He found that Orville was the more talkative of the two, but that was not saying much. Both brothers were quiet, but Orville was the one who would answer when you spoke to the two of them. Wilbur would either nod in agreement or add an incomplete sentence to Orville's response. They never answered a question without first thinking through their reply, and sometimes they took so long to answer that Foulois thought they were not going to acknowledge his question. [96]

Finally, after many discussions, Wilbur and Orville began to establish a rationale for developing an airplane propeller. The first step in the process was the realization that a propeller functioned as an airplane wing moving in a spiral course. The spin provided thrust to move the plane. By March 1903, after many experiments using the wind tunnel, the theory became clear. The brothers then designed a transmission system for their airplane, and it evolved from their experience in the bicycle business. They linked twin pusher propellers to the engine with a set of bicycle chains. [97]

Immediately after returning to Dayton, Wilbur sent inquiries to gasoline engine manufacturers about prices and delivery times for an engine weighing no more than 180 pounds with an output of eight to nine horsepower. No positive responses were received, and the brothers were forced to confront the construction of an engine themselves. While the brothers worked on the plane's structure, they asked Charlie Taylor if he could make an engine. While he had only worked on a gasoline engine and never built one, Charlie said he would "get busy and make one." Wilbur, Orville, and Charlie had gained experience in 1901 constructing the illuminating gas engine to operate the line shaft in the bicycle shop, and with the limited knowledge the three of them possessed, the Wrights were confident they could build an engine for the airplane. [98]

Wilbur, Orville, and Charlie did not make any drawings for the engine. They would discuss each part and sometimes make a sketch. Charlie would then use the sketch, usually drawn on a piece of scratch paper, to fashion the component. By constructing the engine themselves, Charlie was limited to the machinery for metal working already in the bicycle shop. Therefore, he built the engine using only a lathe and drill press operated by belts propelled by a stationary gas engine. [99]

Besides the two prerequisites Wilbur listed in his inquiries to the engine manufacturers, an airplane engine needed one other requirement. That was to run smoothly so no strain was placed on the transmission chains. In order to decrease the weight of the engine, the Wrights chose to cast the crankcase from aluminum. In the final engine, the motor block was made of cast aluminum and the cylinders of cast iron. The engine was water cooled with a separate radiator and a water jacket cast into the block. The fuel would be gravity fed from a can mounted several feet above the engine on a strut. [100]

Charlie began working on the engine in December 1902 in his spare time from repairing bicycles. First he built a "skeleton model" to observe how each part would function. Charlie found that "Orv and Will were pretty thorough that way,—they wouldn't take anything for granted but worked everything out to a practical solution without too much haste." After working through the design, Charlie started constructing a fourcylinder engine. [101] By February 12, 1903, the engine was ready for the first test. During a test the following day, the motor body and frame broke. Charlie had the rebuilt engine in operation by May. [102]

Since they felt they were nearing success with powered flight, Wilbur and Orville applied for a patent on March 23, 1903. They did not include a power source in their patent application, for they were applying for a patent on their flying machine, not the source of its power. What they sought to patent and protect were the basic principles they incorporated into the 1902 glider such as the wing warping system, complete with rudder. [103]

LANGLEY'S GREAT AERODROME AFTER TAKE-OFF ON DECEMBER 8, 1903. (Courtesy of National Air and Space Museum)

The U.S. Patent Office quickly responded to the Wrights' application indicating that they found that their application included inadequate drawings and a vague description. For many years the patent office had been receiving a steady flow of patent applications for various types of flying machines. It was decided, in order to dismiss many of these claims, that an applicant needed to prove that their machine could fly. While the Wrights knew their machine could fly, they could not convince the officials. Resubmitting the application, Wilbur attempted to clarify the language. He even went so far as to send a cardboard box to describe the wing warping technique. Once again the claim was rejected. In his response, the reviewer suggested to the brothers that they employ a patent attorney to assist with their application. After considering his suggestion, Wilbur and Orville decided to wait until they successfully flew a powered aircraft before further pursuing a patent. [104]

On September 23, 1903, Wilbur and Orville left for Kitty Hawk to test their power-driven machine. The machine was almost complete, but it was never fully assembled in Dayton since there was insufficient space in the bicycle shop. Charlie Taylor remembered that when the center section was assembled it blocked the passage between the shop and the workroom on the first floor. In order to serve customers, they had to walk out the side door of the workroom and around to the main door of the store. While Wilbur and Orville were intent on completing the flyer and leaving for Kitty Hawk, they always made time for the customers. The bicycle shop was their main source of income to fund their experiments, and they could not ignore the bicycle business and focus only on their aeronautical experiments. [105]

Since they could not weigh the assembled flyer, the brothers weighed the individual parts to estimate the overall weight of the machine at 675 pounds. While the machine weighed more than they had estimated, the engine also produced more horsepower than needed, so Wilbur and Orville believed there would be no difficulty. [106]

Vowing to stay at Kitty Hawk until they achieved success, the Wright brothers encountered a few problems. On November 5, when the machine was almost fully assembled, a propeller shaft broke. Wilbur and Orville shipped the parts to Charlie Taylor in Dayton for repair, and the repaired shafts arrived back in Kitty Hawk on November 20. On November 28 the propeller shaft broke once again. Requiring replacements, Orville returned to Dayton on December 3 to assist Charlie with the construction. Orville departed once again for Kitty Hawk on December 9 with an improved propeller shaft. [107]

While the Wrights were preparing for another trial flight in Kitty Hawk, Samuel Langley was also ready to test his man-carrying, powered machine. His pilot, Charles Matthews Manly, assisted in the construction of a very light petrol powered engine to drive the machine. Manly tested the aerodrome twice, once on October 7 and again on December 8. In both instances the Aerodrome was launched from a houseboat moored in the Potomac River, and each time the model plunged into the river immediately after it was launched. As a result of these two tests, the United States government withdrew its financial support of Langley's research, and Langley abandoned the project with the belief that years of research was still needed for success. [108]

ORVILLE WRIGHT TAKES OFF AT 10:35AM IN THE FIRST FREE, CONTROLLED, AND SUSTAINED FLIGHT IN A POWER-DRIVEN, HEAVIER-THAN-AIR MACHINE. (Courtesy of Wright State University, Special Collections and Archives)

Without knowledge of Langley's failed tests, on December 14, Wilbur and Orville made their first and unsuccessful attempt with the powered machine. With Wilbur as the operator, the engine stalled 32 seconds into the flight. Wilbur landed safely 105 feet beyond the starting position. Even if this had been a successful flight, it would not have been the world's first free, controlled, and sustained flight in a power-driven, heavier-thanair machine, for the plane took off pointing down a gentle slope to aid in generating the necessary speed for takeoff.

Tests resumed on December 17. The first trial, with Orville as pilot, was a success. At 10:35 a.m. Orville flew a distance of 120 feet in twelve seconds at a speed between seven and eight miles per hour. The first free, controlled, and sustained flight in a power-driven, heavier-thanair machine was documented with a photograph taken with the Wrights' camera by John T. Daniel of the Kill Devil Life Saving Station. The brothers conducted three more successful flights that day. The longest flight was made by Wilbur who flew a distance of 852 feet in fifty-nine seconds. Following this flight, a sudden gust of wind damaged the machine beyond repair. [109]

Upon their success, Orville sent a telegram to their father. With this telegram, the world was made aware of the Wright brothers' success following four years of dedicated research. The inventive process used by Wilbur and Orville enabled them to achieve human flight, and the entire four years of research cost the brothers less than one thousand dollars. From their initial concept of the need to experiment with gliders to their focus on controlling a flying machine, the Wright brothers brought a unique and new outlook to aeronautical research. Their work with a wind tunnel established errors in the accepted data tables and enabled them to achieve sufficient lift. The wing warping system devised by the brothers along with the use of an elevator and rudder solved the problem of three dimensional control. It was these efforts and the brothers' synergistic working relationship that brought them success. [110]