Carol L. Cook
In 1256, Roger Bacon published his
Mirror of Alchemy
. His scientific insights and predictions, like scattered seeds, grew and multiplied. Bacon suggested that the surface of the atmosphere must be a kind of “liquid fire” or “Ethereal air.” If “ethereal air” were obtainable, it could be enclosed in these copper spheres, making it possible to carry a man aloft as a cork rises in water. Or else, it might be worthwhile for man to invent a flying instrument that could be made to flap wings, to reach in this way, the treasure of “liquid fire.”
The first important work on the problems of flight came some four or five hundred years ago, when science first began to make significant progress. One of the first serious thinkers about flight was Leonardo da Vinci, who lived from 1452 to 1519. Most famous as an artist, daVinci was also a musician, architect, mathematician—and perhaps, the first aeronautical engineer. He designed a parachute and a model helicopter, which may have actually flown. In his thinking about manner flight, da Vinci was influenced by his interest in birds and spent a great deal of time working on flapping-wing machines. Leonardo did not realize that the motions of a bird’s wing are much more complicated than he could reproduce with his mechanism. Neither did he realize that the power which a man can produce is very small compared to his weight. It was not until a hundred and fifty years after da Vinci’s time that a biologist named G.A. Borelli came to the conclusion that man’s great weight and small power output would make it possible for him to fly by using his own muscles. If Leonardo da Vinci had worked on the design of fixed-wing gliders instead of bird-like machines, he might have moved aviation—at least the science of gliding—ahead by hundreds of years.
But, it was not a flapping machine or an airplane of any kind that first lifted man into air. It was a balloon.
In 1782, Joseph Montgolfier in France wondered what it was that made smoke and sparks rise above a fire. If he could capture the “gas,” or whatever it was in a bag, would it have lifting power? He tried it with a small bag made of silk. Much to his surprise, the bag filled with smoke from the fire soared to the ceiling of the room. Joseph and his brother, Etienne built several larger bags, which they called “aerostatic machines,” and filled them with mysterious “gas.” In 1783, one of the larger balloons built by the Montgolfier brothers soared more than a mile in the air.
Balloonists soon found that they couldn’t fly where they wanted to—they could only go where the wind happened to take them.
While the balloonists and dirigible drivers were trying to make practical use of their clumsy craft, other men believed that man would some day fly in heavier-than-air gliders, and model airplanes. Later, they began to build gliders large enough to carry a man.
During the first half of the nineteenth century, a man named George Cayley, an Englishman, built a whirling-arm device with which he could measure the force on a lifting surface that was moving through the air at various angles. He built and flew model gliders and developed many new ideas about heaver-than-air flights. Cayley, who was called “the father of aerial aviation,” fixed a car to the wings with straights and diagonal bracing. It was the first time diagonal bracing was used to insure the sturdiness of the wings so that they could carry a heavier load. The verdict of history is that aviation would have advanced fifty years if Cayley’s writings had reached a wide enough audience. But, they did not.
Then, Professor Samuel P. Langley, who taught physics at the University of Pittsburgh, began to re-examine the heavier-than-air machine from a new angle. He wondered about the physical forces that allowed Penaud’s flying toy to maintain its equilibrium during a flight of 200 feet. On May 6, 1896, in the presence of Alexander Graham Bell and several other friends, Langley catapulted this flying machine model into the air and it flew 30 miles per hour. Although the propeller stopped, the flying machine came down slowly and settled on the Potomac. It seemed that man was on the verge of successful mechanical flight.
Of the many other experimenters who worked on the problems of flight in the last half of the nineteenth century, only a few can be mentioned here. One was Sir Hiram Maxim, an American inventor who moved to England.
He built a huge machine, weighing several tons and powered by a 360-horsepower steam engine. Its wing area totaled more than 4,000 square feet—more than the wing area of a small transport airplane. On the trial run, the machine lifted off the track. The guard rail failed to hold it and Maxim had to shut off the steam in order to keep from losing control of his machine. It was damaged when it settled back on earth.
A German inventor and engineer named Otto Lilienthal had large bird-like wings and a fixed rear stabilizer or tail. He made more than two thousand flights, experimenting with the method of control, which was accomplished by shifting the weight of the pilot. Lilienthal was the first to demonstrate clearly that controlled heavier-than-air flight was possible for man. In a flight on a gusty day in 1896, Lilienthal crashed and was fatally injured.
Some say that a helicopter powered by a rubber band inspired the invention of the airplane. Wilbur and Orville Wright were indeed fascinated by this toy which their father had given them. In truth, their development of the first airplane was probably the product of their inquisitive, pioneering spirit and their deep interest in all kinds of mechanical things. In 1892, they established the Wright Cycle Company. Building, repairing and selling bicycles became their daily work. They thought of flying when they read about the gliding experiments of Otto Lilienthal in Germany.
In 1899, when Orville and Wilbur were thirty-three and thirty-seven years old, respectively, they began serious work on problems of flight. The Wrights found that Lilienthal and other glider pilots had met disaster because they could not control their machines in the air. Thus, the Wright Brothers singled out the most important problem, which had not yet been solved: how to balance and control the flying machine in the air.
The Wright Brothers searched for some method of making one wing lift more than the other. They hit upon the idea of building two wings held apart by struts so that the whole structure could be twisted like a box with top, bottom, and ends, but no front or back. By thus twisting or warping the wings, the pilot could increase the lift on one wing and decrease it on the other in order to hold the wing level or to bank the airplane for a turn.
The models and gliders built by the Wrights illustrated another ability that helped carry them to success—their mechanical skill.
The Wrights had to build several gliders before they proved very efficient. This achieved, Wilbur and Orville began to think of building a new machine with an engine. The gasoline engine had already been invented.