Part 18

The system of operating wireless telegraphy is in some respects similar to that of the ordinary telegraph. The Morse Code is largely used in America, and a modification of it, called the Continental Code, in Europe. When the wireless operator wishes to send a message to another station he “listens in,” as it is called, by connecting his receiving apparatus with the adjacent antenna and the ground. He has the telephone receiver attached to his ears. Next he adjusts his receiving circuits for a number of wave lengths. If he catches no signals in his telephone receiver he understands that no messages are being sent within his area. Then he “throws in” the transmitting apparatus, which automatically disconnects the receiving end. He gives the letters that stand for the station with which he wants to communicate, and adds the letters of his own station. He does this a number of times, to insure the other station picking up the call. Then he “listens in,” and if he receives the clicks that show that the other station has heard him he is ready to establish regular telegraphic communication.

A number of distant stations may be sending messages simultaneously. In that case the operator tunes his instrument, or in other words adjusts his apparatus to suit the wave length of the station with which he wishes to communicate. In this way he “tunes out” the other messages, and receives only the one he wants. If, however, the stations that are sending simultaneously happen to be situated near together, as in the case of several vessels near a shore station, the operator is often unable to do this “tuning out,” and must try to catch the message he wishes by the sound of the “spark” of the transmitting station, if he can in any way distinguish it from the “sparks” of the other messages.

There are several ways of determining when the two circuits are in tune. One is to insert a hot-wire current meter between the antenna and the inductance, which indicates the strength of the oscillatory current that has been established. A maximum reading can then be made by manipulating the flexible connections, and this will show whether the two circuits are in accord. The other method is by using a device that indicates the wave length. This measures the frequency of one circuit, and then the other circuit can be adjusted to give a corresponding wave length. The larger the antenna the longer will be the wave length and the greater the power of the apparatus. It is usual to employ a short wave length for low-power, short-distance equipments, and a long wave length for the high-power, long-distance stations.

Wireless telegraphy has already proved itself of the greatest value on the ocean. It has sent news of storms and wrecks across tossing seas and brought rescue to scores of voyagers. Ships may now keep in constant communication with their offices on shore. The great lines send Marconigrams to each other in mid-ocean, and publish daily papers giving the latest news of the whole world. Greater distances have so far been covered over water than over land, but this branch of the service is being rapidly developed, and it must prove in time of the greatest value across deserts and wild countries, where a regular telegraph service would be impracticable. In such a country as Alaska, where there are constant heavy sleet and snow storms, the wireless should prove invaluable.

The telegraph and cable companies did their best to ignore the claims of the wireless systems, but they have been compelled to acknowledge them at last. Rival companies have sprung up, using slightly different varieties of apparatus. Each of the big companies that were ready to compete with the Marconi Company by 1906, the German Telefunken Company, the American National Electric Signaling Company, the American De Forest Company, and the British Lodge-Muirhead Wireless Syndicate, had certain peculiar advantages over the others. The laws relating to the uses of wireless, and especially the rights of governments to the sole use of the systems in case of war, are in a confused condition, but eventually order must come from this chaos as it did in the history of the telephone and telegraph.

Wireless has brought the possibility of communication between any two individuals, no matter where they may be situated, within the realm of fact. A severing of communication with any part of the world will be impossible. Storms and earthquakes that destroy telegraph systems, enemies that cut submarine cables, cannot prevent the sending of Marconigrams. The African explorer and the Polar adventurer can each talk with his countrymen. The use of this agency is still in its earliest youth, but it has already done so much that it is impossible to say to what a stature it may grow. It should cut down the rates for using wire and cable systems, and ultimately place the means of communicating directly with any one on land or sea within the reach of every man. All the world’s information will be at the instant disposal of whomsoever needs it, and all this is due to those electro-magnetic waves that permeate the ether, waiting to be put into service at the touch of man.

XVI

THE WRIGHTS AND THE AIRSHIP

Wilbur Wright 1867-

Orville Wright 1871-

Men have always wanted to be able to fly. So long as there have been birds to watch, so long have men of speculative minds wondered at the secret of their flight. Early in recorded history men built ships to sail across the seas, but the problem of air navigation has always baffled them. The balloon came into being, but the balloon for years was only a toy, dependent on the wind’s whim, and of the least possible service to men. The problem of aerial navigation was to master the currents of the air as the sailing-vessel and the steamship had overcome the waves and tides at sea.

The history of invention often shows that some great thinker, or school of thinkers, has stated a scientific conclusion that generations of later men have never dared to question. The laws of Aristotle in regard to falling bodies were never doubted until Galileo began to wonder if they could be true. Sir Isaac Newton had stated, and mathematical computations had proved his words, that a mechanical flying-machine was an impossibility. Any such machine must be heavier than the air it flew in. The weight of Newton’s authority and the weight of figures were compelling facts, such as scientists had no mind to doubt. But in spite of these facts men could see that birds flew, although they were often a thousand times heavier than the air they went through. And that sight kept men speculating, in spite of all the figures and scientific dicta of the ages.

It was known for centuries that if a kite was held in position by a string reaching to the ground the wind blowing against it would keep it supported in the air. Now if the kite, instead of being stationary in moving air, were to be moved constantly through quiet air it would also stay up. The motive power might be supplied by a motor and propellers, but in order to do away with the string which holds the kite in position the aeroplane, which is only a big kite in principle, must have some way of balancing itself so that it will stay in the proper position in the air.

A German engineer, Otto Lilienthal, made a study of the mechanics of birds’ flights, and determined to learn their secret by actual trial. He built wings that were similar to those of the hawk and buzzard, the great soaring birds, and in 1891 he began to throw himself from the tops of hills, supported by these wings, and glided through the air into the valleys. In this way he learned new laws of flight, contradicting many theories of the scientists, and opening a new world of speculation. But in August, 1896, his wings broke in a sudden gust of wind, he fell fifty feet, and died of a broken back.

It was this problem of balancing that had cost Lilienthal his life. He had tried to balance himself by throwing his weight quickly from side to side as he held to his “gliding machine.” His pupil, Percy S. Pilcher, an Englishman, continued his experiments, trying the same method of balancing, but in September, 1899, his wings broke, and he met the same fate as his teacher. It seemed that men could not shift their weight quickly enough to meet the gusts of wind.

Meantime new theories of flight were being worked out in the United States. Professor S. P. Langley, of the Smithsonian Institution, had made experiments with plates of metal moved through the air at various rates of speed and at different angles, and had published his new conclusions in regard to the support the air would furnish flying-planes in 1891. In 1896 he built a small steam-aeroplane that flew a distance of three-quarters of a mile down the Potomac River. And in the same year Octave Chanute, of Chicago, with the aid of A. M. Herring, built a multiple-wing machine and tried it successfully on the banks of Lake Michigan. But the problem of balancing was not yet solved, and here Wilbur and Orville Wright entered upon the scene.

The Wrights’ home was in Dayton, Ohio, and there they had spent their boyhood, in no way distinguished from their neighbors. Their father had been a teacher, an editor, and a bishop of the United Brethren Church. He had traveled a great deal, and was an unusually well-educated man. Their mother had been to college. Their two older brothers and their sister were college graduates, and the younger boys would have had the same education had their mother not died and they decided to stay at home and look after affairs for their father, who was often away. In telling the story of their invention in _The Century_ for September, 1908, they said, “Late in the autumn of 1878 our father came into the house one evening with some object concealed in his hands and, before we could see what it was, tossed it into the air. Instead of falling to the floor, as we expected, it flew across the room and struck the ceiling, where it fluttered a while and finally sank to the floor. It was a little toy known to scientists as a helicoptere, but which we, with sublime disregard for science, dubbed a ‘bat.’ ... It lasted only a short time, but its memory was abiding.” At that time Wilbur was eleven and Orville seven years old.

These two brothers, scientifically minded, started a bicycle shop, and bade fair to become ordinarily prosperous citizens of Dayton, much like their neighbors. They were, however, deeply interested in news from the world of science and invention, and when they read in 1896 that Lilienthal had been killed by a fall from his glider they began to wonder what were the real difficulties that must be overcome in flying. Further reading awakened a deep interest in the problem of the airship, and they worked upon it, at first as a scientific pastime, but soon in all seriousness. They built models in their workshop, and experimented with them. Then, in 1900, Wilbur wrote to his father that he was going on a holiday to a place in North Carolina called Kitty Hawk, to try a glider.

The Wrights realized in 1900 that the only problem to be solved was that of equilibrium. Men had made aeroplanes that would support them in motion, and also engines that were light enough to drive the planes and carry their own weight and that of the aviator. But when the wind blew the aeroplane was as likely as not to capsize. Their study was how to keep the machine from turning over.

The air does not blow in regular currents. Instead, near the earth, it is continually tossing up and down, and often whirling about in rotary masses. There is constant atmospheric turmoil, and the question is how to maintain a balance in these currents that bear the machine. Put in technical form it is how to make the centre of gravity coincide with the centre of air-pressure.

The shifting of the air-currents means that the centre of air-pressure moves. The aeroplane is sailed at a slight angle to the direction in which it is heading, and the centre of air-pressure is on the forward surfaces of the machine. The wind strikes the front, but rarely touches the back of the plane, and so gains a great leverage that adds materially to its power to overturn the machine. As the wind veers continually it is easy to see the aviator’s difficulty in keeping track of this centre of pressure.

Both Lilienthal and Chanute had tried to balance by shifting their weight, but this was extremely exhausting, and often could not be done in time to meet the changing currents. The Wrights realized that a more automatic method of meeting these changes must be found, and they worked it out by shifting the rudder and the surfaces of the airship as it met the air-currents.

The earlier aviators had found that two planes, or “double-deckers,” gave the best results. The Wrights adopted this type, believing that it was the strongest form, and could be made more compact and be more easily managed than the single plane, or the many-winged type. They built their gliding-machine of cloth and spruce and steel wire. But instead of the aviator hanging below the wings, as in the other planes, he lay flat across the centre of the lower wing. A horizontal rudder extended in front of the plane instead of behind it. This not only guided the flight of the machine, but counterbalanced the changes of the centre of air-pressure. To steer, the wings were moved by cords controlled by the aviator’s body. They considered that the shiftings of the air were too rapid to be followed by conscious thought, and so their plan was to have a plane that would balance automatically, or by reflex action, as a bicycle is balanced.

Langley had adopted wings that slanted upward from the point at which they joined, copying the wings of a soaring buzzard. The Wrights doubted whether this was the best form for shifting weather, and built theirs more on the pattern of the gull’s wings, curving slightly at the tips. They were made of cloth, arched over ribs to imitate the curved surfaces of bird’s wings, and were fastened to two rectangular wooden frames, fixed one above the other by braces of wood and wire.

Their next step was to try to find some method by which they might keep their gliding-machine continuously in the air, so that they might gain an automatic balance. The old method of launching the plane from a hill gave little chance for a real test. Study taught them that birds are really aeroplanes, and that buzzards and hawks and gulls stay in the air by balancing on or sliding down rising currents of air. They looked for a place where there should be winds of proper strength to balance their machine for a considerable time as it slid downward, and decided to make their experiments at Kitty Hawk, North Carolina, on the stretch of sand-dunes that divided Albemarle Sound from the Atlantic Ocean. They calculated that their gliding-machine, with 165 square feet of surface, should be held up by a wind blowing twenty-one miles an hour. The machine was to be raised like a kite, with men holding ropes fastened to the end of each wing. When the ropes were freed the aviator would glide slowly to the ground, having time to test the principle of equilibrium. This plan would also do away with the former need of carrying the plane up to the top of a hill before each flight.

They found in practice that their plan of raising the plane like a kite was impracticable, and that the wind was not strong enough to support it at a proper angle. They had to glide from hills as others had done, but they discovered that their theory of steering and balancing by automatically shifting surfaces worked very much better than the old method of shifting the aviator’s weight.

In 1901 and 1902 the Wrights continued their gliding experiments at Kitty Hawk. Their new machines were much larger, and they added a vertical tail in order to secure better lateral balance. Sometimes the wind was strong enough to lift the aviator above the point from which he had started and hold him motionless in the air for half a minute. They made new tables of calculation for aerial flight, and found that a wind of eighteen miles an hour would keep their plane and its operator in the air.

Their next step was to place a gas-engine on their aeroplane and attempt actual mechanical flight. After many experiments they succeeded, and on December 17, 1903, the first airship made four flights at Kitty Hawk. In the longest flight it stayed in the air fifty-nine seconds, and flew against a twenty-mile wind. It weighed, with the aviator, about 745 pounds, and was propelled by a gas-engine weighing 240 pounds, and having twelve or thirteen horse-power. That test assured them that mechanical flight was possible.

The Wrights had now solved the real problem of aviation, equilibrium. They were ready to try mechanical flights in places where the wind-conditions were less favorable than at Kitty Hawk. They secured a swampy meadow eight miles east of Dayton, and, using that secrecy which they have always believed was necessary to the protection of their interests, began to fly there. Their airship flew well in a straight course, but there was difficulty in turning corners. Sometimes it could be done, but occasionally the plane would lose its balance as it turned, and have to be brought to the ground. In time they remedied this, and on September 20, 1904, they were able to make a complete circle. Later in that same year they made two flights of three miles each around a circular course.

The Wrights’ system of balance, the great original feature of their invention, is attained by what is called the warping of the wings. When they are flying, and some cause, such as a change in their position, or a sudden gust of wind, makes the airship tip, a lever is moved, and the two planes warp down on the end that is canting toward the earth. Simultaneously the two opposite ends of the planes warp up. The lower ends at once gain greater lifting power, the upper ends less. Therefore the airship stops tilting and comes back to an even flight. The lever is instantly moved to keep the machine from tipping to the other side.

WILBUR WRIGHT ORVILLE WRIGHT

CABLE ADDRESS: WRIGHTS, DAYTON

WRIGHT BROTHERS

1127 W. THIRD STREET DAYTON, OHIO

July 22, 1911.

George W. Jacobs & Co.,

Philadelphia.

Gentlemen:--

Replying to yours of June 26th we are herewith enclosing a photograph of our first flight made at Kitty Hawk, North Carolina, on December 17, 1903.

Yours truly,

[Signature: Wright Brothers.]

When the airship came to turn a corner it was apt to “skid.” It slid from its balance, owing to the change in its course against the currents of air. The Wrights overcame this by having the planes of their machine warp at the same instant that the rudder shifts the course, by this raising one wing and lowering the other, so that the aeroplane cants over and makes the circle leaning against the wind, on the same principle that a bicycler takes a curve on an angle instead of riding upright. The problems of balance and of turning corners were therefore both met and solved by warping the planes to meet the conditions of the airship’s contact with the wind.

One of the chief reasons for the Wrights’ success was that they had studied their subject long and faithfully before they tried to fly. They had worked with their gliders several years, and had made new calculations of the changing angles and currents of air. They had been in no hurry, and when they built their first real airship they made use of all the principles of aerodynamics that they had discovered. They knew that their machine would fly before they tried it, because they knew exactly what its various surfaces would do in the air. The propeller was the only part of their airship they had not studied when they began to build. When they found that they could not use the figures that had governed the construction of marine propellers they set to work to solve this problem in the same thoroughgoing way. They mastered it, and their success with their propeller is the feature of their airship in which they take the greatest pride.

The first official statement of their progress in flying was made in letters of the Wrights in the _Aerophile_ in 1905, and to the Aero Club of America in 1906. These declared that they had begun actual flight with a motor-driven aeroplane on December 17, 1903, had then spent the year 1904 in experimenting with flights in circular courses, and had so learned the proper methods of control of the planes by 1905 that they had at last made continuous flights of eleven, twelve, fifteen, twenty, twenty-one, and twenty-four miles, at a speed of about thirty-eight miles an hour, and had been able to alight safely in each instance, ready to fly again as soon as their fuel was replenished.

Until that date the inventors had been singularly successful in keeping their experiments from public knowledge. They had reached agreements with the farmers who lived near their field outside Dayton, and with the local newspapers, that no notice should be taken of their flights. But finally one of their flights attracted so much attention that a score of men appeared with cameras, and the Wrights decided that it was time to stop their experiments. They dismantled their machines, made public statements of what they had accomplished, and started to negotiate with various governments for the purchase of their aeroplanes for use in war.

In December, 1907, the Signal Corps of the United States army invited proposals for furnishing a “heavier than air flying machine.” The Wrights submitted a bid, proposing to deliver a machine that would meet the specifications for $25,000. Their offer, with those of two others, was accepted. By now their names and something of what they had accomplished were very generally known, and when they began the preliminary tests of their machines at their old grounds at Kitty Hawk, near Kill Devil Hills, a legion of reporters was on hand. The Wrights still tried to preserve as much secrecy as possible, and the newspaper men to furnish as much publicity. The flights could not be concealed and the trials were announced as thoroughly satisfactory. On May 10, 1908, ten ascensions in the government airship were made, the longest being over a mile and a half. On succeeding days longer flights were made, one of two miles at a speed of forty-six miles an hour. Orville Wright made a flight with a passenger on board, and a little later Wilbur flew eight miles, at a rate of forty-five miles an hour. The reporters assured the world that the Wrights had proved the success of the “heavier than air” machine. As one of them wrote, “Then, bedraggled and very sunburned they tramped up to the little weather bureau and informed the world, waiting on the other side of various sounds and continents and oceans, that it was all right, the rumors true, and there was no doubt that a man could fly.”