While the Keiter incident simmered, Wilbur had a business to run and a problem to solve. With typical thoroughness, he went back to the beginning. He assumed nothing and looked at everything with a fresh eye. As he studied the problem, he began to suspect more and more that the fault lay in the data on which he had based his design, specifically Otto Lilienthal’s lift and drag tables.
Lilienthal, Langley, and virtually everyone who had researched aerodynamics had utilized a whirling-arm device. But a whirling arm was an “open” system and inaccuracies were inevitable. Lilienthal had attempted to account for discrepancies by running multiple tests, the theory being that inaccuracy could be factored out by repetition. Still, there was no avoiding that the method was slapdash.
In 1871, a remarkable English marine engineer and Aeronautical Society member named Francis Herbert Wenham built the first wind tunnel, a “closed” system, to test how different airfoil shapes would react to air currents. Wenham had a variety of interests and would make contributions to many fields, but none more than aviation. He was the first to note that the camber of a wing should not necessarily be uniform, an arc of a circle, but should be thicker at the front and trail off at the rear, similar to the birds he watched soar across the skies in locales as far flung as Egypt. He had contributed an article for the first Aeronautical Annual, titled “On Aerial Locomotion and the Laws by which Heavy Bodies Impelled through Air are Sustained,” a reprint of a paper he presented upon founding the Aeronautical Society in 1866. Eventually, Wenham attempted to build a glider of his own and when it failed to fly, resolved to determine the cause by taking more precise measurements of airfoils than any previously achieved. Aware of the deficiencies of a whirling arm, he began to experiment with air rushing through an enclosed box.
Wenham’s design, however, suffered deficiencies of its own and turned out to be of limited utility. Subsequent versions were improved but still unable to guarantee accurate measurements. Few were willing to eschew the whirling arm for an unproven technology. But Wilbur and Orville realized that a wind tunnel was precisely what they needed to move past Lilienthal’s inaccuracies and obtain measurements that would allow them to correct the design flaws of the 1901 glider. They simply needed one that worked. So they set to build an improved model, bringing to the task their combination of incisive reasoning and flawless craftsmanship, spiced as always with a touch of Wilbur’s genius.
Wilbur described the product.
My brother Orville and I built a rectangle-shaped open-ended wind tunnel out of a wooden box. It was 16 inches wide by 16 inches tall by 6 feet long. Inside of it we placed an aerodynamic measuring device made from an old hacksaw blade and bicycle-spoke wire. We directed the air current from an old fan in the back shop room into the opening of the wooden box. In fact, we sometimes referred to one of the two open ends of the wind tunnel as the ‘goesinta’ and the other end as the ‘goesouta.’ An old one-cylinder gasoline engine (that also turned other tools in the shop, such as our lathe) supplied the power to turn the fan. This was because there was no electricity in our shop. In fact, even the lights were gas lights.
It took us about a month of experimenting with the wind tunnel we had built to learn how to use it effectively. Eventually we learned how to operate it so that it gave us results that varied less than one-tenth of a degree. Occasionally I had to yell at my brother to keep him from moving even just a little in the room because it would disturb the air flow and destroy the accuracy of the test.
Their wind tunnel was the most sophisticated ever constructed and the Wrights experimented with their invention for two months, testing two hundred airfoil shapes and configurations. They were obsessively precise and their measurements were more accurate than any previously achieved. When they concluded their testing just before Christmas 1901, they had confirmed that Lilienthal’s tables were “full of errors.” The brothers were exhilarated by the result. “From all the data that Orville and I accumulated into tables, an accurate and reliable wing could finally be built.” And Wilbur understood the import. “As famous as we became for our ‘Flyer’ and its system of control, it all would never have happened if we had not developed our own wind tunnel and derived our own correct aerodynamic data.”4
The return to Kitty Hawk in 1902 resulted in the explosive leap forward the brothers had expected the year before. They arrived in late August with a radically new design for the glider. The wing had an aspect ratio of 1:6, doubled from the previous incarnation, which meant a longer and narrower design. The camber was 1:20, not far from the 1:23 that Lilienthal had employed but, as Wenham had hypothesized, it was not an arc but rather had its peak near the leading edge.
The 1902 glider featured another significant change, the addition of a fixed two-pane rudder at the rear to compensate for the tendency Wilbur had encountered for the wings to dip too severely when the warping mechanism was employed.
Still, with the Keiter business unresolved, Wilbur’s focus continued to be divided. To aid his father’s cause, he studied every detail, participated in setting the finest points of strategy, and on three occasions traveled to Huntington to participate in the defense.
Once at Kitty Hawk, however, the Keiter matter was forced into the background as the new design was tested. There were days when the brothers—Orville was by now going into the air as well—might make as many as seventy-five glides, some as far as three hundred feet. The only remaining issue was that the strange “skidding” that Wilbur had experienced the previous year had not been eliminated by the fixed rudder. Orville hypothesized that perhaps the rigidity of the rudder was contributing to the problem and that a hinge might improve the glider’s response. This was Orville’s first significant theoretical proposal and “he would raise the issue carefully. All too often, he suspected his older brother reacted against his suggestions on principle.”5 But Wilbur reacted well. They also decided that a single pane would work as well as the double and rebuilt their glider with a movable rudder linked to the wing-warping hip cradle.
The rudder was the last piece of the puzzle. The Wrights had created a three-axis system that could turn an aircraft efficiently and maintain a constant position relative to the ground. The new model soared with complete control and the brothers took turns feeling the exhilaration of their invention. By the time they left North Carolina three weeks later, they had completed perhaps one thousand glides, attaining distances of as much as six hundred feet.
On October 5, the day before the new glider was completed, Wilbur and Orville had visitors. Octave Chanute showed up at Kitty Hawk and brought with him Augustus Herring.
Herring had been as unsuccessful out of aviation as in. Once again out of money, he had contacted Chanute, who seemed to have a limitless capacity to give people one more chance, and asked for patronage for another glider. Chanute had agreed and suggested Herring test his design at Kitty Hawk, where great things were afoot.
Herring’s glider failed and, as he could see for himself, the Wrights’ did not. More significant, he saw why the Wrights had been so much more successful than he. Herring slunk away after ten days but he left with at least a cursory notion of what it would take to successfully fly a heavier-than-air craft.
Wilbur and Orville had their biggest successes after Herring and Chanute departed, making more than 250 glides in “any kind of weather,” including a 30-mph wind. The control issues had been solved. They had created a craft that could fly. At that point their research became congruent with Langley’s—all they needed was a means of propulsion.
But while Langley and the Wrights raced to be the first to achieve fixed-wing flight, another sort of aviation was capturing the public’s imagination.
* * *
*1 As was subsequently discovered, this is because the bank angle starts the aircraft turning, which speeds up the wing on the outside of the turn (the high wing). The faster wing produces more lift, which rolls the aircraft into a steeper bank.
*2 The order was reversed in 1905
and Milton Wright was restored to his post. Millard Keiter moved to Kentucky, where he was eventually indicted for land fraud.
Gas Bag
The press, many scientists, and most government officials remained skeptical of the prospects for heavier-than-air flight. There were even periodic calls to investigate the $50,000 given to the incorruptible Langley. Lighter-than-air flight, however, was an exciting new technology that seemed to many the obvious solution to the flying problem. The fascination with balloons was largely the work of one man with the courage of a tightrope walker (which he was) and the audacity of P. T. Barnum (whom he rivaled).
Thomas Scott Baldwin was born either in Missouri in 1854 or in Illinois in 1857, although he later claimed to have begun life in a log cabin in 1861. His parents seemed to have died when he was about twelve, either together or separately. Baldwin later told reporters he had seen them gunned down before his eyes by Confederate renegades during the Civil War, which was mathematically impossible for whatever birth date was correct, although no one ever seemed to notice or care. His schooling ended when he ran away from an orphanage with his older brother Samuel, probably when he was about fourteen.
As an adult, Baldwin favored titles. In the 1880s, despite his limited education, he dubbed himself “professor,” once again with the acquiescence of the press. He changed “professor” to “captain” in the ensuing decade—an appellation he retained until 1917, when he actually acquired military rank, commissioned in the army as a major.
According to Baldwin’s own recollections—apocryphal, certainly, although no one knows to what extent—he began his professional career as a tumbler in the W. W. Cole circus but soon took his skills to the trapeze and the wire. “What I acquired in these days helped me as an aeronaut,” Baldwin said later. “I learned in walking the tightrope that it is not so much a matter of practice or of any peculiar muscular movement or strength as it is in keeping at it until you have the ‘feel’ of confidence, and when once this comes to a man, he is equally at home on wire, rope or ground.”1
Baldwin soon tired of circus life, or perhaps he couldn’t abide being someone else’s employee. He had his own ideas about what people would pay to see and by age twenty had set out on his own. One of the things he was convinced people would pay to see was a man floating off to an uncertain fate, so he began dabbling in ballooning in 1881.
Manned balloons of that time were either “captive,” attached by a long tether to a fixed point on the ground, or “free,” left to the mercy of the prevailing winds. The only means of control for either sort was varying the altitude by manipulating the hydrogen gas in the bag.
Although there was good money in public demonstrations of either of those methods, Baldwin saw the future as being in “airships”—balloons as a conveyance. But if balloons were to take you where you wanted to go, they would need a mechanism to make them “dirigible”—steerable. And of course for round-trips it wouldn’t do for a dirigible balloon to sail at the mercy of air currents, so a means would be required to maintain forward thrust against the wind.
At first Baldwin admitted that he accepted the conventional wisdom that “balloons had little to do with aerial navigation,” but as he studied the subject he concluded “the popular notion of balloon manipulation was entirely incorrect. A balloon does not ‘go up,’ but rather is forced up by the closing of the air below it as it rises, and this pressure forces it higher and higher as a wedge—the content of the balloon is a cork and the air is the water. Hydrogen being thirteen-fourteenths lighter-than-air—by displacing so many feet of air—the air served as a brace to the balloon, as there is normally seven tons of air pressure on a man’s body. It was getting this fact firmly fixed in my mind that I felt I would some day make a dirigible balloon a success.”
In 1885, Baldwin took his talents and his ambitions to the boom-town of San Francisco. He first got the city’s attention by walking a tightrope from the balcony of Cliff House to Seal Rocks and back, a round-trip journey of nine hundred feet over pounding surf one hundred feet below.2 In his quest for both adulation and riches, the first only as a means to the second, he decided to add a wrinkle to the standard balloon demonstration. He would rise up in a captive balloon and then parachute out. Parachutes had also been around for almost a century but they were stiff, rigid, and extremely unreliable; if positioned incorrectly, they would fail to catch the wind and carry their unfortunate passengers straight—and quickly—to their deaths. Baldwin decided to vent the silk canopy and attach flexible ropes, an arrangement that would better allow the contraption to right itself in the air. Like most daredevils, Baldwin rigorously tested his theories before risking his life on them.
“I studied the matter for months. I experimented with sand bags just my own weight and did not venture a jump until I had the ‘feel’ that it could be safely done. I made most of my jumps in water, and if it had not been that every particle of my body was hard as iron from former training as a gymnast and taking of all kinds of jolts, I would not have lasted through these early experiments.”
While Baldwin’s canopy seemed safe enough, remaining attached to it promised to be a challenge. He had built no harness or any other means of tethering himself to the apparatus. As the parachute descended, Baldwin grasped a ring that held the cords, trusting that a gust of wind would not jerk the ring out of his hands.
Finally ready for a public exhibition, Baldwin offered to prove the efficacy of his invention by a public test jump—assuming, of course, someone was willing to pay him to do it. “I went to Mr. Morton of the Market Street Cable Line and told him I thought I had an exhibition that would be a good feature for the Golden Gate Park, and he asked me what it was, and I told him a parachute jump. I said I would jump for a dollar a foot, and he answered: ‘Go ahead and jump a thousand feet!’ ”
In January 1887, Baldwin did precisely that, floating gently to the ground below and his thousand-dollar prize.
Baldwin soon took his parachute show on the road, venturing higher and higher for greater prize money. In May 1888, in Minneapolis, “Professor Baldwin” performed his greatest feat. He allowed the balloon to take him five thousand feet into the air, then parachuted to a predetermined spot on the ground for his usual dollar-a-foot fee.*1 Not content to restrict his fortunes to the domestic market, Baldwin crossed both oceans, performing across Europe and in Asia in venues as exotic as Siam.
But Baldwin had not given up his “visions of an airship.” While in Germany, he met with Count Zeppelin and kept himself abreast of developments in aerodynamic research. As he studied the problem, he correctly surmised that control, both of altitude and direction, were offshoots of propulsion and center of gravity. Ultimately, he turned to the same devices that provided inspiration to fixed-wing inventors. “As the bicycle and automobile developed, they revealed to me a way of overcoming the one vital difficulty, that of providing power for an airship, and now aerial navigation has become merely a mechanical proposition.” Baldwin decided internal combustion engines provided the closest approximation of the power source he sought. To provide the actual thrust, Baldwin “spent many months at the Santa Clara College, studying the law of fluid movement, for air is a fluid, the only difference being in matter of density.” He concluded that a propeller had to be of a particular design. “We found by a series of experiments that the air in striking a blade of a parabolic curve at a certain angle—say forty-five degrees—goes up over the blade instead of down as commonly believed.”
In October 1901, while Baldwin was still attempting to devise the proper configuration of propulsion and directional control for his airship, Alberto Santos-Dumont, a young Brazilian coffee heir living in Paris, stunned the world—and won 100,000 francs for himself—by successfully navigating a motorized balloon around the Eiffel Tower before returning to his starting point.*2 Santos-Dumont was a fixture in Paris haute société. Barely one hundred pounds, he wore only the best clothes, dined nightly at Maxim’s, and counted among his many intim
ates Gustave Eiffel—the tower’s designer—the jeweler Louis Cartier, and members of any number of royal families. On his trip around Eiffel’s tower, he used bicycle pedals to start a small gasoline engine that turned his propeller at 180 revolutions per minute. For his achievement, he received notes of congratulations from Jules Verne and H. G. Wells.
Although Santos-Dumont had developed a dirigible airship, the propulsion was weak and control problematic. There were many who thought the Eiffel Tower circuit was based more on a fluke of wind currents than in efficacy of design. (In one of his many previous attempts, Santos-Dumont had drifted helplessly into the wall of a hotel and was left hanging from the roof after the gas bag exploded.) In order to gain sufficient thrust to give him control in more than a light breeze, Santos-Dumont tried a bigger motor but that added so much weight as to defeat the purpose. Neither he nor anyone else seemed to know quite how to proceed.
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