---
title: "George Cayley"
chunk: 1/2
source: "https://en.wikipedia.org/wiki/George_Cayley"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:06:03.078841+00:00"
instance: "kb-cron"
---

Sir George Cayley, 6th Baronet (27 December 1773 – 15 December 1857) was an English engineer, inventor, and aviator. He was a pioneer of aeronautical engineering and is sometimes referred to as "the father of aviation", designing the first glider reliably reported to carry a human aloft. He is commonly credited as the first person to understand the underlying principles and forces of heavier-than-air flight: weight, lift, drag and thrust. He was also the inventor of the wire wheel.
In 1799, he set forth the concept of the modern aeroplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control. Modern aeroplane design is based on those discoveries and on the cambered wings he proposed. He constructed the first flying model aeroplane and also diagrammed the elements of vertical flight. He correctly predicted that sustained flight would not occur until a lightweight engine was developed to provide adequate thrust and lift. The Wright brothers acknowledged his importance to the development of aviation.
Cayley represented the Whig party as Member of Parliament for Scarborough from 1832 to 1835, and in 1838, helped found the UK's first Polytechnic Institute, the Royal Polytechnic Institution (now University of Westminster) and served as its chairman for many years. He was elected as a Vice-President of the Yorkshire Philosophical Society in 1824. He was a founding member of the British Association for the Advancement of Science and was a distant cousin of the mathematician Arthur Cayley.

== General engineering projects ==
Cayley, from Brompton-by-Sawdon, near Scarborough in Yorkshire, inherited Brompton Hall and Wydale Hall and other estates on the death of his father, the 5th baronet.  Captured by the optimism of the times, he engaged in a wide variety of engineering projects.  Among the many things that he developed are self-righting lifeboats, tension-spoke wheels, the "Universal Railway" (his term for caterpillar tractors), automatic signals for railway crossings, seat belts, small scale helicopters, and a kind of prototypical internal combustion engine fuelled by gunpowder (Gunpowder engine).  He suggested that a more practical engine might be made using gaseous vapours rather than gunpowder, thus foreseeing the modern internal combustion engine. 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.
According to the Institution of Mechanical Engineers, George Cayley was the inventor of the hot air engine in 1807: "The first successfully working hot air engine was Cayley's, in which much ingenuity was displayed in overcoming practical difficulties arising from the high working temperature." His second hot air engine of 1837 was a forerunner of the internal combustion engine: "In 1837, Sir George Cayley, Bart., Assoc. Inst. C.E., applied the products of combustion from closed furnaces, so that they should act directly upon a piston in a cylinder. Plate No. 9 represents a pair of engines upon this principle, together equal to 8 HP, when the piston travels at the rate of 220 feet per minute."

== Flying machines ==

Cayley is mainly remembered for his pioneering studies and experiments with flying machines, including the working, piloted glider that he designed and built. He wrote a landmark three-part treatise titled "On Aerial Navigation" (1809–1810), which was published in Nicholson's Journal of Natural Philosophy, Chemistry and the Arts. The 2007 discovery of sketches in Cayley's school notebooks (held in the archive of the Royal Aeronautical Society Library) revealed that even at school Cayley was developing his ideas on the theories of flight. It has been claimed that these images indicate that Cayley identified the principle of a lift-generating inclined plane as early as 1792. To measure the drag on objects at different speeds and angles of attack, he later built a "whirling-arm apparatus", a development of earlier work in ballistics and air resistance. He also experimented with rotating wing sections of various forms in the stairwells at Brompton Hall.

These scientific experiments led him to develop an efficient cambered airfoil and to identify the four vector forces that influence an aircraft: thrust, lift, drag, and weight. He discovered the importance of the dihedral angle for lateral stability in flight, and deliberately set the centre of gravity of many of his models well below the wings for this reason; these principles influenced the development of hang gliders. As a result of his investigations into many other theoretical aspects of flight, many now acknowledge him as the first aeronautical engineer.  His emphasis on lightness led him to invent a new method of constructing lightweight wheels which is in common use today.  For his landing wheels, he shifted the spoke's forces from compression to tension by making them from tightly-stretched string, in effect "reinventing the wheel". Wire soon replaced the string in practical applications and over time the wire wheel came into common use on bicycles, cars, aeroplanes and many other vehicles.