History credits Orville and Wilbur Wright for flying the world’s first aircraft, but it was Yorkshire Baronet Sir George Cayley who first proposed, propounded and published the principles of modern aerodynamics. It was George Cayley, who, more than a century before the Wright Brothers took flight, set forth the concept of the modern airplane as a fixed-wing flying machine as opposed to the comical flapping winged machines that many of his predecessors had imagined. It was George Cayley who proposed separate systems for lift, propulsion, and control, and it was he who first identified the four-vector forces that influence an aircraft: thrust, lift, drag, and weight. He also discovered the importance of cambered wings, the characteristic curved shape that is fundamental to flight. George Cayley was the first true scientific aerial investigator and the ‘father of aviation’, yet many of us have never heard of him.
A replica of George Cayley’s flying machine which he flew in 1853. This working model was built in 1973 and flown at the original site in Brompton Dale a for TV show. The glider is currently on display at the Yorkshire Air Museum. Photo: Yorkshire Air Museum
Sir George Cayley’s fascination with flight started from early childhood. The balloon flights of the Montgolfier brothers in the 1780s captivated his fecund mind. But Cayley wasn’t interested in passive ascent. He wanted to build a real flying machine.
His first device was a replica of a toy helicopter designed by Frenchmen Launoy and Bienvenu in 1784. The helicopter had two contra-rotating rotors operated by bow strings. Cayley never saw the original toy, but he did read a description of the device from which he carefully rebuilt it replacing the Frenchmen’s silk-covered frames with feathers stuck in a cork. He continued to build airplane models at his estate in Scarborough, North Yorkshire, believing that one day it would be possible to soar into the skies purely by mechanical means.
George Cayley’s helicopter toy.
The crucial breakthrough came in 1799, when Cayley identified that the first and the most vital step towards mechanical flight was the separation of the system of thrust from the system of lift. Previous designers tried to imitate birds and built machines with huge flapping wings. Few, if any, were successful at all. But Cayley thought differently. He imagined a fixed-wing machine propelled by an auxiliary mechanism. Cayley etched a design on a silver disc, now at the Science Museum in London, that clearly resembles the modern configuration of an airplane, with fixed wings, an underslung carriage like a boat, and a cross-shaped tail for rudder. To generate forward thrust, Cayley’s design shows flapping blades that were to be operated by the pilot in rowing fashion. On the other side of the coin, he recorded a diagram of the four forces acting on the aircraft while flying in a direct line.
George Cayley’s silver disc containing the first ever engraving of a fixed-wing flying machine, and the four forces acting on an airplane.
In 1804 Cayley designed a mechanism which is often seen in science museums today—a whirling arm with an aerofoil at one end and a weight attached to the other to balance the lift produced by the aerofoil when it cuts through the air. Cayley used it test aerofoil designs at various angle of incidence. Shortly after, he built the first model monoplane glider of strikingly modern appearance. The model featured an adjustable cruciform tail, a kite-shaped wing mounted at a high angle of incidence and a moveable weight to alter the center of gravity. Small enough to be thrown with an arm, it was probably the first gliding device to make significant flights.
It was very pretty to see it sail down a steep hill, and it gave the idea that a larger instrument would be a better and a safer conveyance down the Alps than even the surefooted mule, let him mediate his track ever so intently. The least inclination of the tail towards the right or left made it shape its course like a ship by the rudder.
— Sir George Cayley
George Cayley’s first working glider.
By mid-1809 Cayley had worked out the lifting capacities of cambered wings, investigated the movement of the center of pressure, and the problem of streamlining. He had identified correctly that an area of low pressure is formed above the wing which gives the machine a lift. Cayley also discovered that dihedral (wings set lower at their center and higher at their outer ends) improved lateral stability. He continued his research using models and by 1810, Cayley had published his now-classic three-part treatise "On Aerial Navigation" where he laid the foundation of the science of aerodynamics.
Cayley's biggest hurdle was finding an appropriate power source to propel his aircraft. Cayley knew that power produced by human muscle alone would be insufficient to sustain flight. But mechanical power sources of the time were unsuitable for a nimble machine like an airplane. Steam engines were too heavy for flight, so he invented an internal combustion engine using gunpowder as fuel, but it did not work very well. The problem of power was the source of much disappointment and frustration for Cayley, but he did not lose hope.
I feel perfectly confident, however, that this noble art will soon be brought home to man's general convenience, and that we shall be able to transport ourselves and families, and their goods and chattels, more securely by air than by water, and with a velocity of from 20 to 100 miles per hour. To produce this effect it is only necessary to have a first mover, which will generate more power in a given time, in proportion to its weight, than the animal system of muscles.
— Sir George Cayley
For the next three decades, George Cayley put his dreams on hold and pursued other occupations. He became involved in public affairs, published a pamphlet on parliamentary reform and was elected a Member of Parliament for Scarborough. He helped found the Yorkshire Philosophical Society in 1821, cofounded the British Association for the Advancement of Science in 1831 and of the Regent Street Polytechnic Institution in 1838. He invented self-righting lifeboats, tension-spoke wheels, caterpillar tractors which he called “Universal Railway”, and automatic signals for railway crossings. He also contributed in the fields of prosthetics, air engines, electricity, theatre architecture, ballistics, optics and land reclamation, and held the belief that these advancements should be freely available.
During this period of more than 30 years, nothing exciting happened in the field of aeronautics, until William Henson patented a flying machine called the “Aerial Steam Carriage”. Although Cayley reacted unfavorably to Henson’s concept, it did inspire him to turn his attention back to his favorite subject. In 1849, Cayley built his first full-sized glider based on the same designs he created back in 1799, and successfully flew a 10 year old boy on one short flight. In 1853, he built a larger glider and sent his coachman flying 900 feet across a Brompton dale. Some say it was his grandson and not the coachman who took flight. Still others insist it was neither, but the butler instead.
The “Boy Carrier” flown in 1849.
The “Governable Parachute” first flown in 1853.
Cayley died in 1857, shortly before his 84th birthday. He not only laid the foundations of the science of aerodynamics, and invented the modern aeroplane concept, he also built and flew models and full sized machines to demonstrate the principles he formulated. Cayley was the source of inspiration for many 18th and 19th century aviators such as William Henson and John Stringfellow. His contribution to aviation is widely recognized among those who knew him, such as Francis Wenham, Octave Chanute and the Wright Brothers, but to the general public, George Cayley is virtually unknown.
About 100 years ago, an Englishman, Sir George Cayley, carried the science of flight to a point which it had never reached before and which it scarcely reached again during the last century.
— Wilbur Wright, 1909.
References:
# Charles H. Gibbs-Smith, Sir George Cayley: 'Father of Aerial Navigation' (1773-1857), Notes and Records of the Royal Society of London
# Stephanie Watson, Sir George Cayley, Encyclopedia.com
# Miriam Bibby, Sir George Cayley, The Father of Aeronatics, Historic UK
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