In Yorkshire in the northeast of England, a human being first imagined the airplane. This scientifically accurate emergence happened a hundred years before the Wright brothers invented the real thing.
At first glance, Yorkshire seems an odd place for the science of aviation to begin. However, history shows that creativity flourishes where cultures mix, and Englandâs largest traditional county certainly boasted plenty of that. Celtic tribes lost to the mists of time, marching Roman legions, Angle farmers settling from Germany, and marauding Vikings invading from Denmark all called it home at one time or another.
The airplaneâs conceptual inventor was Yorkshire baronet Sir George Cayley. Born in December 1773 at Scarborough on the North Sea, Cayley inherited his title, wealth, and large landholdings upon the death of his father. But a greater inheritance had already come his way at birth, for he possessed a brilliant mind.
Few people today know Cayleyâs name even though he single-handedly established the science of aviation and laid a foundation for others to build on. The Wright brothers never would have left the ground without his powerful ideas, for example, but they were far from the first to try.
Sir George Cayley.
National Portrait Gallery, London
That honor belongs to another Englishman, Cayleyâs self-appointed disciple William S. Henson. Thrilled by Cayleyâs visionary writings, Henson galloped off to design a real airplane before the middle of the nineteenth century. Although his premature attempt failed, Henson at least showed the world what the airplane would be.
If Cayley was the thinker, Hensonâfour decades his juniorâwas the dreamer. The two men hardly could have been more different, yet their overlapping efforts synergistically planted the seeds of flight.
The people of Yorkshire are known for a calm and deliberate nature.
George Cayley from an early age broke the mold. Around his tenth birthday, this enthusiastic young aristocrat was excited in particular by news sweeping England: human beings had flown in Europe.
On November 21, 1783, Jean-François Pilâtre de Rozier and the marquis dâArlandes ascended into the heavens in a new invention called the balloon. According to the reports, these Frenchmen drifted over the city of Paris for twenty-five minutes, covering 51/2 miles (9 kilometers) before setting down safely.
At that time, the event was hailed as the first time human beings had ever flown. Today we know this was probably not the case. While history does not provide definitive proof of earlier manned ascents, it is quite likely that large kites (a dangerous way to fly, given their propensity for headlong plunges) carried people aloft more than a millennium before the invention of the balloon. The Venetian Marco Polo lends credence to accounts of earlier aerial forays. Writing in the late thirteenth century, he described personally witnessing people flying aboard large kites in China.
Pilâtre de Rozier and Arlandesâ vehicle of 1783 was the brainchild of Joseph and Ătienne Montgolfier, two brothers in Franceâs papermaking trade. A majestic blue orb of varnished taffeta decorated ornately in gold, this hot-air balloon was open at the bottom and was launched after being filled with smoke from a large outdoor blaze before its restraints were released.
Surprisingly, the Montgolfiers did not know why their balloon sailed into the sky. They did not understand that hot air has a lower density than cold air and is thus lighter, so they instead endorsed the classical notion that it was smokeâs natural tendency to rise that made their invention buoyant. Lending pseudoscientific credence to this flawed theory, they further asserted that smoke contained a previously unidentified substanceâcalled Montgolfier gas, naturallyâthat imparts a gravity-defying upward force called levity.
Their successâand that of their archrival, French physicist Jacques Alexandre Charles with his more advanced hydrogen balloonsâlaunched a rapturous, all-out French obsession with lighter-than-air flight. Part of this euphoria was the uplifting grace of balloons themselves, which lyrically fulfilled humankindâs age-old dream of flight.
But there was more to this rampant âballoonacyâ than poetic sensibilities. With the industrial revolution then under way in England and spreading to Europe, balloons also symbolized manâs growing technological prowess and the heady excitement of new frontiers. Balloons even became a favorite decorative motif in French furniture, plates, paintings, mantel clocks, and chandeliers.
Back in Yorkshire, the success of the Montgolfiers kindled in young George Cayley a lifelong fascination with flight. But the balloon itself didnât hold the Yorkshire boyâs interest for very long. He quickly decided that heavier-than-air vehicles were flyingâs future.
Two factors shaped this conviction. The first was Cayleyâs belief that a flying machine, to be practical, must be dirigible (steerable) so people could fly it where they liked instead of drifting at the whim of the wind. The second was his delight in a flying toy perfected a year after that first balloon flight by two other Frenchmen, the naturalist Launoy and a mechanic named Bienvenu.
Launoy and Bienvenuâs toy was a rudimentary helicopter with a central shaft, corks at both ends with feathers angled to provide lift as they spun, and a bow (as in bow and arrow) drawn taut by winding its string around the shaft. Letting go the wound-up helicopter released the bowâs tension, rotating the feathered shaft to carry it high into the sky.
In his early twenties, Cayley built and tested a copy of this ingenious device, which for him was more than a mere amusement. In size and performance, it greatly improved on the Chinese top, that ancient and ubiquitous toy consisting of a carved propeller mounted atop a stick. Spinning this stick rapidly between oneâs hands would send the Chinese top aloft.
Unlike balloons, man-made amusements such as these were not buoyant. Neither were birds, yet they too could fly. Such being the case, Cayley wondered, why couldnât a man-carrying machine be built that likewise was heavier than the air around it?
To investigate this intriguing idea, Cayley created a laboratory-cum-workshop at Brompton Hall, his ancestral estate at Brompton-by-Sawdon, near Scarborough. There he built models that he dropped down the manor houseâs stairwell in order to study their fall. His wifeâs tolerance of these highly disruptive experiments unfortunately proved low, so he conducted them only when she was away.
By 1799, George Cayleyâs pioneering efforts led him in his mid-twenties to an astonishing conceptual leap: the first scientifically grounded imagining of an airplane. That same year, the French Revolution drew to a close and Napoleon Bonaparte, the general who would be emperor, marched off to begin changing the face of Europe. George Washington died at his Virginia farm at age sixty-seven, the Rosetta Stone was discovered in Egypt, and Ludwig van Beethovenânot yet thirty and already going deafâwas at work on his first symphony.
On a silver disc dated 1799, Cayley inscribed a flying vehicle with an arched main wing, a single-seat gondola, and a tail resembling an arrowâs stabilizing feathers. Attached by a universal joint, this cruciform tail could tilt up, down, or side to side to alter the craftâs direction of flight.
The wing of this proto-airplane was a billowing fabric sail that Cayley apparently proposed with ease of construction in mind. Later in life in a second round of aeronautical experimentation, he would construct manned gliders with fabric wings.
The final feature of this crude etching reveals Cayleyâs greatest realization. Aft of the wing are propulsive paddles worked like oars by the pilot in the cockpit. Cayley called these paddles propellers even though they moved fore and aft rather than rotating.
Cayley understood full well that this fanciful propulsion system would not work and that human muscle power alone would be inadequate to sustain flight. He included this representation of a rowing impetus only as a placeholder for some future propulsion system that would include a first mover, as he called the concept of a mechanical engine.
Steam was then beginning to power Englandâs industrial revolution, but steam engines were too heavy to fly. Consequently, Cayley contended his entire life with the frustrating lack of a suitable power plant. This was the single disappointment in an otherwise astonishingly successful career in the branch of science that he founded.
A century before the Wright brothers, George Cayley etched onto this silver disc historyâs first-ever imagining of the airplane.
National Air and Space Museum, Smithsonian Institution
For humans to fly, Cayley correctly observed, âit is only necessary to have a first mover that will generate more power in a given time, in proportion to its weight, than the animal system of muscles.â2 The development and successive refinement of internal-combustion gasoline engines during the nineteenth century would provide the Wright brothers and other pioneers with this last missing bit of technology by the start of the twentieth century.
Why is it so significant that Cayley called for a separate propulsion system? Because before he came along, people drew the wrong lesson from nature. They assumed that airplanes, if and when such things were invented, must achieve flight by flapping their wings like birds. We call this flapping-wing aircraft an ornithopter.
The trouble with ornithopters is that they are mechanical nightmares. Models can fly this way, but not full-size aircraft because of the enormous complexity and high stresses of ornithopter flight. To get a sense of just how unwieldy a concept this is, try to imagine a flapping-wing jetliner.
We have the advantage of hindsight, but at the time ornithopters looked like not just the logical way to fly but the only way. Leonardo da Vinci thought so, and he arguably possessed the greatest mind of the Renaissance. When his notebooks were rediscovered and published decades after Cayleyâs death, they mesmerized the world.
Sprinkled among Leonardoâs thirteen hundred pages of handwritten notes are more than a hundred drawings that show his fascination with birds and remarkable concepts for human flight. Among these are beautiful illustrations of flapping-wing machines (ornithoptering hang gliders) suggestive of the anatomy of bats and birds. Da Vinci also sketched an unworkable vertical-flight machine that drew inspiration from Archimedesâ screw and anticipated the helicopter.
Like da Vinci three centuries earlier, George Cayley took his inspiration from nature. Studying birds closely, he gleaned insights from their shapes, their flight, and how their wings were articulated and moved. In particular, he was fascinated to note that seagulls, when riding the winds of Englandâs rugged north coast, soared for extended periods without flapping.
Mulling this over gave Cayley an âahaâ moment that was fledgling aviationâs single most crucial epiphany: flight is possible with wings that are held entirely rigid.
This was excellent news indeed. It meant that heavier-than-air flying machines could be designed that would be vastly simpler to construct, operate, and maintain than ornithopters. Yes, rigid wings would do the trickâso long as air flowed over them.
During a descent with gravity tugging, air would of course flow over a flying machineâs wings. But how do you climb or sustain level flight when gravity must be defied? In these challenging flight phases, an impetus would be required to thrust the machine through the air.
This forward thrust had to come from somewhere, Cayley reasoned, and if the wings arenât flapping, then something else aboard the airplane must provide the push. That in turn dictated a separate propulsion system.
In one fell swoop, young Cayley sidestepped the ornithopter trap that even da Vinci had fallen into. Cayleyâs greatest legacy would be the layout for a powered, heavier-than-air flying machine whose wings do not flap because they are called on to provide only lift, not lift and thrust combined. Conceptually, the airplane now existed.
Prescient as he was, Cayley missed the bullâs-eye in two regards with his 1799 design. One was his avoidance of rotating propellers even though the concept of the airscrew, or propeller, had been known to him since 1796. Another was his provision for control around two axes but not the third (the Wright brothers would address both these forgivable failures). In at least one key regard, however, Cayleyâs thinking outstripped that of the Wrights a century later: Cayley placed the airplaneâs elevator, the movable surface that tilts an airplane up or down, at the rear, not the front.
On the other side of his silver medallion, the twenty-six-year-old inventor identified gravity, lift, drag, and thrust as the forces involved in flight. In so doing, he showed himself to be the first person ever to properly understand flightâs underlying scientific principles. âThe whole problem,â he later wrote, âis confined within these limits, viz. to make a surface support a given weight by the application of power to the resistance of air.â3
For Cayley, this 1799 breakthrough was just the beginning. Where other early dreamers envisioned flat panels as wings, Cayley realized that curved or cambered surfaces lift better than do flat ones. He thus invented the concept of the airfoil, as the wingâs aerodynamic profile is called (an airfoil is the shape you would see if you sliced vertically through the wing parallel to the fuselage). Cayley was also the first to realize that dihedral, an upward angle to the wings as they extend outward from the fuselage, increases lateral (side-to-side) stability by making the airplaneâs wings self-righting.
On the other side, Cayley properly identified the physical forces governing flight.
National Air and Space Museum, Smithsonian Institution
In 1804, Cayl...
