Chapter VIII - EXPERIMENTS OF 1904 – 1905
In all their work on their power plane the Wrights’ main incentive had been to gain the distinction of being the first of mankind to fly. They had not designed the machine for practical use. Now, however, even though they did not yet foresee many of the uses for which the airplane was destined, they began to think it could be developed into a machine useful for scouting in warfare, for carrying mail to isolated places, for exploration; and that it would appeal to those who could afford it for sport.
If their machine was capable, as they had demonstrated, of flying by its own power for 852 feet against a 26-mile wind, there was no reason why it shouldn’t go many times that far. But if the machine was to be practical, many improvements would be necessary, and they would need more experience in flying. Much practice would be required, and that would mean more expense in proportion to income, for they would have less time for building and repairing bicycles. But they decided to devote to aviation whatever amount of time seemed necessary. A number of bicycles at their shop were in various stages of completion. But no new ones were started after the Wrights’ return from Kitty Hawk, though some of those on hand were completed and sold. The brothers now began to turn over to Charlie Taylor, their chief mechanic, most of the routine work of the shop.
In January, 1904, the brothers began building a new plane. It was similar to the one flown at Kitty Hawk, there were a number of changes, including more sturdy construction throughout. The weight exceeded that of the original plane by about eighty pounds (In flight, the weight, including the pilot, and 70 pounds of iron bars carried on the framework under the front elevator, was 900 pounds.) The wing camber was changed from 1-20 to 1-25 – that is, the curvature was decreased; and the ribs were tapered from front to rear spar instead of being of uniform depth, as in the earlier model. An entirely new engine went into the 1904 machine. In fact, the Wrights started to build three new engines. One of these had four cylinders of 4 1/8 -inch bore; another, four cylinders of only 4-inch bore, as the one used at Kitty Hawk; and the third was a V-type, of eight cylinders. The 4 1/8 -inch bore was the one .installed in the 1904 plane and gave a satisfactory amount of power – but not so much as the Wrights later developed in the other four-cylinder motor of only four-inch bore. That motor they kept in their shop and used for a kind of guinea pig, trying various improvements and refinements until it produced as much power as they had expected from the V-type motor of eight cylinders and twice as much as the original motor used at Kitty Hawk. They then gave up the idea of completing the V-type motor.
Another change in the 1904 machine was using white pine instead of spruce for the front and rear spars on the wings. Spruce was not available in Dayton at that time, and tests the Wrights made at their shop, in the manner usually employed for ascertaining the strength of woods, indicated that the two woods were about equally strong. (But in actual use, when stresses came suddenly, as in landing, the white pine spars snapped “like taffy under a hammer blow,” though spruce had always withstood such shocks. The brothers rebuilt the wings, with all spars of spruce.)
To obtain practice, their first need was a suitable field, not too far from home. They found a cow pasture, fairly level, handy to an interurban railway, at Simms Station, eight miles from Dayton, toward Springfield. This field, often called the Huffman prairie, was part of a farm belonging to a Dayton bank president, Torrence Huffman. Compared with a modern flying-field the area of sixty-eight acres they wanted to use was not quite ideal. It contained a number of trees, besides being near power wires and poles. But it was as good as they could find and without delay the Wrights introduced themselves to Mr. Huffman to ask if they might rent his pasture for their experiments. He granted the request and told them they were welcome to use the field free of charge. But he said he hoped they would drive his cows to a safe place and not run over them.
By April 15, 1904, the Wrights had built a rough wooden shed at the Huffman pasture, in preparation for their experiments.
Even if they had tried, the Wrights could hardly have kept secret what they were doing here at the Huffman prairie, with an interurban car line and two highways passing the field they were using. But they took special precautions against being thought secretive, for they knew that the best way to avoid being bothered by newspaper people or others was to make no mystery of what they were doing. Before they had even attempted even one trial flight at the Huffman pasture they wrote letters to each of the Dayton papers, as well as to each of the Cincinnati papers, that on May 23 they would attempt to fly and would be glad to have any newspaper representative who felt interested come and watch them. Their only request was that no pictures be taken, and that the reports should not be sensational. This latter stipulation was to avoid attracting crowds, but as it turned out there was no need to be concerned about curiosity-seekers.
About a dozen newspapermen showed up. Also on hand were a number of friends and neighbors of the Wright family. Altogether perhaps thirty-five persons were present – all by invitation.
The Wrights dragged their machine out of the shed to wait for a suitable wind before launching the machine from the short stretch of wooden track. As it happened, the wind was unusually high that day, about twenty-five miles an hour, and the Wrights said they would wait for it to die down a little. When the high wind did cease, it went suddenly to an almost complete calm, and a wind of at least eleven miles on an hour was needed to take off from so short a track. The Wrights said they would try a flight if the wind picked up. But the wind failed to do so. The crowd waited and two or three of the reporters – too experienced to be easily fooled – began to make comments to one another. They hadn’t wanted to come in the first place. Why had they been asked to waste time on such an assignment? Most of the guests, though, had only sympathy for the brothers. They actually seemed sincere in thinking they could fly.
Though sorry to disappoint the spectators, the Wrights showed no signs of embarrassment. They had learned to take events as they came. Finally, after the day had dragged on with no sign of a more favorable wind, one of the brothers announced:
“We can’t fly today; but since you’ve taken the trouble to come and wait so long, we’ll let the machine skim along the track and you’ll get an idea of what it’s supposed to do. With so short a track, we may not get off the ground, but you’ll see how it operates.”
Then the engine misbehaved. It worked all right in the warming-up period, but began to skip explosions as soon as the machine started down the track. This was caused, the Wrights soon learned, by the flow of air over the mouth of the intake pipe – a trouble never experienced with the engine used at Kitty Hawk.
After running the length of the track, the machine slid off the end without rising into the air at all. That wasn’t much of a story for the reporters. Their assumption that they had been sent on a wild goose chase seemed to be confirmed. Would there be a flight the next day? The Wrights couldn’t be sure. First of all they must find out what ailed that engine. They might be able to do that overnight, or it might take longer. However, all who wished to return the next day would be welcome. Indeed, the Wrights said, any newspaper representative would be welcome at any time.
Two or three of the newspapers did return the next day. The engine still sulked, but the wind was a bit more favorable and the Wrights decided to show the reporters what they could. This time the machine rose five or six feet from the ground and went through the air for nearly sixty feet before it came down. An electric contact point in one of the engine cylinders had worked loose, and only three cylinders were hitting. The few reporters present, though now convinced that the age of flying had not yet come, wrote friendly articles and made the most of what they had seen. The versions differed widely. One report had the machine rising to a height of seventy-five feet. In the Cincinnati Enquirer account was a comment that the machine “is more substantially constructed than other machines of its kind.”
None of those newspapermen ever returned. During all their experiments that year and the next, the Wrights had about all the privacy they needed. They used to smile over a comment by Octave Chanute: “It is a marvel to me that the newspapers haven’t spotted you.”
Having disposed of the reporters, the inventors resumed their work.
Almost as soon as the new trials began, the brothers encountered a new difficulty. A track of 60 feet long had been adequate for launching the machine in the wind at Kitty Hawk; but a track of 160 feet, or even one of 240 feet, was not long enough for use at Huffman field where the winds were usually light.
The Huffman field was covered with hummocks from six inches to a foot high. Only a few spots free from hummocks were suitable for a 240-foot track. And landing wheels, such as were used later, would have been impractical on that uneven ground. Laying 240 feet of track, after finding enough ground space free from hummocks, was a considerable job. But frequently, after the track was laid, the wind would change its direction, and then all the work had to be done over. After a few times, the brothers gave up trying to so long a track and ordinarily used one of only 160 feet.
As steady winds of eleven miles an hour, the least that would do for starting from a 160-foot track, were not frequent, the Wrights had to be in readiness to take advantage of occasional gusts of strong wind. With their machine on the track, they waited until they could “see” a flurry of wind coming – that is, until they would see weeds being agitated by the wind in the distance. Then they would start the motor and run the machine down the track to meet the wind gust when it reached the end of the rail. In that way they sometimes succeeded in making a start on a day generally calm. But one such start ended disastrously, and Orville, who was piloting the machine, had one of his narrowest escapes. When the machine first met the flurry of wind, it rose rapidly, but a second later it was on the ground with the wings pointing vertically into the air. It had dived at a steep angle, throwing Orville to the ground. The upper wing spar came down across the middle of his back. But luckily, a section about two feet wide, just wide enough to miss hitting him, was broken out. No other damage was done to the spar, and the Wrights would never account for the seemingly miraculous breakage that provided a space for safety over the very place where Orville lay on the ground. After that accident, Charlie Taylor, who had seen other narrow escapes, gloomily told the neighbors across the road that every time he saw one of the brothers start on a flight he felt that he was seeing him alive for the last time.
Early in July the Wrights made alterations in the machine which located in the center of gravity farther toward the rear than it had been before. In the first trial after those alterations, the machine, after leaving the track, kept turning up more and more and looked as it were going to loop the loop. The center of gravity was so far back that the front elevator, even when turned to its limit, could not check the upward turn. While pointing vertically upward, the machine came to a stop and began to slide backward. By the time it reached the ground it was once more so nearly level that if the skids had had a slight upward bend at the rear ends, the landing might have been made without damage. As it was, the rear ends of the skids dug into the ground; but the damage was slight.
Before their experiments had progressed far in 1904 the Wrights saw that a better method of launching the machine was needed. They decided that a derrick with a falling weight would be the simplest and cheapest device. A 1,600-pound weight, falling a distance of 16 ½ feet, was so geared with ropes and pulleys that it produced a 350-pound pull on the machine through a distance of 49 ½ feet. By this arrangement the machine could be put into the air after a run of only 50 feet, even in a dead calm. Shifting the track was now seldom necessary.
Up to the time the derrick catapult was ready for its first trial in September 7, less than forty starts had been made and many of them failed for lack of speed. But now the length of the flights increased rapidly. The shorter flights had been in almost a straight line, but as the lengths of the flights increased it was necessary to make turns to stay within the field. Then a new trouble – or rather an old one that supposedly had been overcome at Kitty Hawk – began to bother the Wrights. Often in making a short turn they suddenly found themselves in a tail-spin which ended in a crash requiring days, or even weeks for repairs. They soon learned what it was in making the turn that caused the tail-spin; but they found it difficult to avoid, because they had no way of knowing at what angle the air was striking the machine. This led to the “invention” of the first instrument for guidance of a pilot in flying. They simply attached a short a short piece of string at the crossbar beneath the front elevator. When the machine traveled directly forward the string trailed straight backward; but when the machine slipped to either side the string blew to one side or the other and indicated approximately the amount of the side slip. By close observance of this string it was possible avoid entirely the danger of tail-spins, but the pilot learning to fly had so many things to attend to, so it seemed to him, that he sometimes neglected to watch the string closely enough.
After it was found that the derrick permitted the pilot to be launched at any time the Wrights often let the machine stand on the track during the day with the weights raised, ready to start at a moment’s notice. One day in early November, while idly strolling in front of the track, Orville thought he saw a slight movement of the plane on the track. A more careful look did not confirm his first impression; nevertheless he turned and leisurely walked toward the plane. When within a few steps of it he saw that it actually was in motion. The wire that held it against the pull of the 1,600-pound weight was attached to a stake driven into the soft ground several feet. That stake was slowly coming out of the ground. By leaping upon one of the skids, Orville reached the elevator control lever in time to prevent the machine from rising as it rushed down the track. A strained shoulder was the principal damage, though the machine suffered a few slight breakages.
Not until the 51st flight in 1904, when the machine stayed in the air for one minute and one second, did the Wrights beat their best Kitty Hawk record of 59 seconds. The first complete circle was not made until September 20. But toward the end of the 1904 experiments, there were two five-minute flights. In each of these the machine circled the field four or five times without stopping.
The total flying time during 1904 was only 45 minutes. But the knowledge and experience gained from that three quarters of an hour were of almost inestimable importance.
Toward the end of May 1905, the Wrights began assembling a machine all new with the exception of the motor and the propeller-driving mechanism. Strengthening of its structure at places where the previous machine had been too weak in making landings added about 25 pounds more weight. The principal changes, however, were in wing design, adding of some new features not in the earlier machines, and in making the wing-warping and operation of the tail rudder independent of each other. The camber of the wings was changed from 1-25, used in 1904, back to 1-20 as used in 1903 at Kitty Hawk. This change was to enable the machine to get off at slower speed.
The most radical change was the addition of two semi-circular vanes called “blinkers,” between the two surfaces of the front elevator. This device was later patented by the Wrights. The purpose of the “blinkers” was to assist the rear rudder in overcoming the unequal resistances of the two wings when they were warped while making a turn. Gliding experiments in 1902 had shown that the pressure on a fixed vane in the rear of the wings tended to speed the higher wing when the machine slipped in the direction of the lower wing and caused a tail-spin. The vane had to be made moveable to relieve this pressure. It now occurred to the Wrights that if a fixed vane were placed in front of the wings, instead of behind them, its effect would be the reverse of that when the vane was in the rear, and that there would be less need of operating the rear rudder to overcome the unbalanced resistance of the two wings. Moreover, when the machine slipped inward while “banking” a turn, the speed of the low wing would be increased and a tail-spin avoided. The operation of the rear rudder could now be made independent of the wing-warp without danger.
It was found that the “blinkers” entirely removed the danger of tail spinning but that they added to the difficulty of steering, both when flying straight and when making turns. Consequently they were not used in all the flights. (In modern planes the effect of “blinkers” is gained by extending the fuselage far out in front of the wings.)
Though tail-spins could be avoided without use of “blinkers,” by carefully observing the little piece of string that indicated side slip, yet they sometimes occurred. In one flight, in September, 1905, when the “blinkers” were not on the machine, Orville suddenly discovered he was in a tail-spin and that he was about to come down in the top of a forty-foot thorn tree. The thorns were several inches long, and the idea of falling through them to the ground was not alluring. Orville quickly turned the machine into an almost vertical dive while turning in a circle 50 to 100 feet in diameter. The inner wing of the machine hit a branch of the tree, imbedding a thorn in an upright, and tore off the branch. In the dive, the higher wing, because of much greater speed, soon passed the lower wing in the downward plunge and itself became the low wing. The machine thus was in a steep bank with the high side toward the tree, just opposite from what it had been before. When Orville turned the elevator to avoid striking the ground, the machine turned suddenly and unexpectedly away from the tree, because, in this steeply banked condition, the elevator exerted more pressure laterally than it did vertically. (When an aeroplane is banked to 45 degrees the elevator serves just as much for a rudder as for an elevator, and the rudder just as much for an elevator as for a rudder.) Though the machine lightly touched the ground, Orville flew it on back to the hanger, where the branch of the tree was still clinging to the upright. It had been the practice of the Wrights to dive the machine to recover speed in a stall; but this quick recovery was from an entirely different cause – the great difference in the speeds of the two wings.
An amusing flight by Orville in 1905 was made after some weeks of inactivity in flying and after the machine had undergone a number of changes since his last flight. When the machine left the starting rail it began pitching like a bucking bronco. Orville wanted to stop, but at every plunge the plane came down so steeply he did not dare attempt a landing. As soon as he got control of the machine, after going three or four hundred feet, he did land safely. Wilbur rushed up to inquire why he had stopped just when he had really got going. Orville explained that he would have landed even sooner, but had taken the first opportunity to stop without smashing the machine to pieces.
Though the rudder and wing-warp were entirely independent of each other in all the flights of 1905, the Wrights several years later resumed having the two controls interconnected, to operate together, but with an arrangement needed for modifying their relationship when making turns.
Another change that improved control of the 1905 machine was in giving the wings considerably less angle at the tips than in central parts. By this arrangement, the tips stalled later than other parts of the wings and some lateral control remained even after the central part of the wings were in a stalled condition.
After the Wrights had made the blades of their propellers much wider and thinner than the original ones, they discovered that the performance of the propellers in flight did not agree closely with their calculations, as in the earlier propellers. They could see only one reason for this, and that was that the propeller blades twisted from their normal shape under pressure in flight. To find out quickly if this was the real reason, they fastened to each blade a small surface, like an elevator, out behind the blades, set at an angle to balance the pressures that were distorting the blades. They called the surfaces “little jokers.” When they found that the “little jokers” cured the trouble, they dispensed with them and began to give the blades a backward sweep, which served the same purpose.
In the flying season of 1905, the control of the machine was much improved by increasing the area of the front rudder from 50 to 76 square feet, and by moving it to nearly twice the distance from the wings. This added distance made response to the movement of the rudder slower, and control of the machine much easier.
The later control was also improved by enlarging the rear rudder from 20 to 34 square feet, and by moving it to a position three feet farther back of the wings.
On account of frequent rains, the soggy condition of the field, and other weather conditions, only nine attempts to fly were made in the first two months of experiments in 1905, and only three of these lasted for as much as ten seconds. But after the first of September progress was rapid.
During all this time, the newspapers had continued to let the Wrights alone. Indeed, the failure of the newspapers in Dayton and elsewhere to say much about the history-making experiments at Huffman field was often used as an argument to prove that there couldn’t be any truth in the rumors that men had actually contrived a successful flying-machine. “You couldn’t have kept a thing like that secret. Some reporter surely would have heard about it.!”
Dan Kumler, who was city editor of James M. Cox’s Daily News, in Dayton, during those early years of flying, recalled in 1940, not long before his death, that many people who had been on interurban cars passing the Huffman field had seen the Wrights in the air used to come to the Daily News office to inquire why there was nothing in the paper about the flights.
“Such callers,” said Kumler, “got to be a nuisance.”
“And why wasn’t there anything in the paper?” Kumler was asked.
“We just didn’t believe it,” he said. “Of course you remember that the Wrights at that time were terribly secretive.”
“You mean they were secretive about the fact that they were flying over an open field?”
“I guess,” said Kumler, grinning, after a moment’s reflection, “the truth is that we were just plain dumb.”
James M. Cox, owner of the Daily News, has likewise confessed that “none of us believed the reports” of flights.
One fact that kept the earlier flights relatively inconspicuous was that much of the time the plane was within 10 or 15 feet of the ground. Only occasionally was it up as high as 50 feet. There were no flights beyond the field itself, because if necessary to make a forced landing elsewhere, dragging the machine back to its shed might not have been easy.
The Wrights had aimed at first to avoid being in the air when an interurban car was passing. But that precaution soon proved to be unnecessary. Few people ever paid any attention to the flights. One day, though, the general manager of the interurban line was on a passing car when the plane was in the air and he ordered the car stopped. He and the chief engineer of the line, who was with him, got off and stayed a while to look at the incredible sight.
Across from the Springfield pike from the field lived the Beard family, tenants on the Torrence Huffman farm. Whenever the plane landed abruptly Mrs. Beard was likely to dash across the road with a bottle of arnica, feeling sure it would be needed, as sometimes it was. But there few other visitors.
Two somewhat mysterious visitors did come, however. The Wrights saw two men wandering about nearly fields during most of one day and thought they must be hunters, though there was not much game thereabouts. Again the next day the two strangers were seen, and finally they came across the field where the Wrights were adjusting their machine. One of them carried a camera. They asked if visitors were permitted.
“Yes, only we’d rather you didn’t take any pictures,” one of the brothers courteously replied.
The man with the camera set it down off to one side, twenty feet away, as if to make it plain that he was no trying to sneak any shots. Then he inquired if it was all right to look into the shed. The brothers told him to make himself right at home. Was he a newspaperman? No, he said, he was not a newspaperman, though he sometimes did writing for publication. That was a near he came to introducing himself. After the callers had gone, Charlie Taylor, the Wrights mechanic, said: “That fellow’s no writer. At least he’s no ordinary writer. When he looked at the different parts of the machine he called them all by their right names.”
Later the Wrights learned the identity of the visitor. Orville chanced to see a picture in a New York newspaper. His identity was confirmed some time afterward when he and Orville were formally introduced to each other – though neither referred to their previous meeting. The man had been chief engineer for Professor Langley of the Smithsonian Institution.
Toward the end of September, the Wrights were able greatly to increase their distances. On September 26, there was an uninterrupted flight of 11 1/8 miles in 18 minutes and 9 seconds; and on September 29, one of 12 miles in 19 minutes 55 seconds. Then, on October 3, there was a new record of 15 ¼ miles in 25 minutes 5 seconds; another October 4, of 20 ¾ miles in 33 minutes 17 seconds; another, on October 5, 24 1/5 miles in 38 minutes 3 seconds.
The flights of October 3 and 4 would have been longer except that certain bearings had become overheated. By October 5 the inventors had added more grease cups where needed and also installed a larger gas tank. But the tank was not full when that final test began and the flight ended because the fuel was exhausted. It was the intention of the Wrights to make one more test and put the record at more than an hour; but now for the first time the miracle of flight actually began to attract more spectators and the brothers decided it might be prudent to quit for the season before details of the machine’s construction became public knowledge. However, there was one more short flight – just one circle of the field – on October 16.
After the close of the 1905 experiments, a test of the engine showed that it produced more power than when first put into use. This gain was attributed to the increased smoothness of the cylinders and pistons produced by wear.
Looking back over their experiments, the Wrights noted that “in 1903, 62 pounds per horsepower were carried at a speed of 30 miles an hour; in 1904, 53 pounds at 34 miles an hour; and in 1905, 46 pounds at 38 miles an hour.” Thus the weight carried per horsepower was in inverse ratio to the speed – the smaller the weight carried per horsepower, the higher the speed. That seems obvious enough now, but at the time the Wrights were making these experiments many scientists still accepted the “Langley Law,” that the greater the speed, the less horsepower necessary.
The Wrights now knew that the airplane would have practical use – though they did not foresee how safely trans-Atlantic flights would be made – and not even in their wildest dreams did they thing of anyone ever flying at night.
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