We Australians excel at remembering and celebrating our sporting heroes, from cricketers to particularly successful race horses, but are not so good at celebrating the great people who helped build our civilization, particularly when those builders are Australian. Today, I want to celebrate the birthday of an Australian aviation pioneer, Lawrence Hargrave.
Aviation Pioneer
Lawrence Hargrave was born in Greenwich, England in 1850. His family immigrated to Australia in 1865 where Lawrence began to study law but took an engineering apprenticeship at the Australasian Steam Navigation Company in Sydney in 1867 after failing his matriculation examination. The apprenticeship taught Lawrence valuable engineering skills that would be extremely valuable to his later experiments.
From 1872 Lawrence served as an engineer on board several expedition ships until he took a position as an assistant astronomical observer at Sydney Observatory in 1878. At the observatory Lawrence designed and built adding machines to aid his calculations, and postulated that the eruption of Krakatoa was the cause of brilliant sunsets seen during 1883. Lawrence only held this position for five years before retiring in 1883 and devoted the rest of his life to pursuing his own research work.
Lawrence studied the movement of waves, fish, snakes, and birds before focusing his research on understanding the flight of birds and developing flying machines. He lived and conducted his experiments in Stanwell Park, an area that is a popular hang gliding spot today.
Hargrave conducted a huge number of experiments, constructed dozens of model aircraft, wings, and engines, and communicated the results of his work in papers presented to the Royal Society of New South Wales. Hargrave’s greatest contributions to the science of aviation are:
- The rotary engine,
- The box kite, and
- The development of curved aerofoils.
Hargrave (like Cayley and the Wright brothers) broke the development of the flying machine down into separate problems, lift, control, and propulsion. He knew that the main obstacles to a flying machine were efficient wings, and a light but powerful engine.
Hargrave’s aeronautical experiments began with models powered by rubber bands. Most of these had wings that flapped but some of his later models had propellers. As he reached the limits of what he could achieve with rubber bands as his power source, he started to think about building engines powered by compressed air.
Hargrave spent three years developing his compressed air engines and in early 1889 created one of his most significant inventions, the radial rotary engine. The engine featured three cylinders arranged in a circle around a central crank. Instead of turning the crank, the crank was fixed to the body of the flying model and the cylinders rotated around the crank. The advantages of this engine were that it had simple but efficient valve timing, and very smooth running with little weight because the cylinders acted as the engine’s flywheel.
These advantages also lent themselves to the radial rotary internal combustions engines that dominated aviation throughout WWI. Although publications detailing Hargrave’s invention were available in Europe, it is not known whether European engine manufacturers were aware of them and it seems that these rotary engines were developed independently of Hargrave’s work. Hargrave also tried to develop internal combustion versions of his engine but his experiments were hindered by the weight of available materials and the quality of the machining he had access to and they never developed sufficient power to propel a practical flying machine.
While trying to develop a suitable engine, Hargrave also put great effort into developing an efficient and stable lifting surface. He started working with kites and it was while performing these experiments that he developed the invention he is most widely recognized for, the box kite.
While today mention of a box kite conjures up an image of child’s toy, when Hargrave developed his box kite they were the most powerful and efficient aerodynamic lifting devices yet developed, and they were also exceptionally stable (and so, safe) in the air. Hargrave built a set of kites, each three and a half metres wide by three metres long, and used four of them to lift himself off the ground in November 1894.
The lifting power and stability of Hargrave’s box kites meant that they were copied by aviators and experimenters around the world. Giant box kites formed the basis of many successful European aeroplanes including Alberto Santos-Dumont’s 14-bis aircraft which made the first successful aeroplane flight in Europe.
Hargrave’s first kites had flat surfaces, but he had learned from his own experiments and reports of other experimenters’ work that curved surfaces produced more lift. Hargrave tested a range of model gliders and kites with curved aerofoils, and added curved surfaces to his successful box kite design. Through these experiments Hargrave developed an improvement over the Lilienthal aerofoil, which at the time was probably the most efficient wing design. Hargrave’s work was continued by A. A. Merril in the U.S. who improved Hargrave’s aerofoil still further. Merril’s improved aerofoil was used by the Wright brothers in their later gliders and, eventually, their Wright Flyer.
Hargrave continued to try to build a flying machine powerful enough to lift a person and designed several aeroplanes that were, in their basic form, powered versions of his box kite, but two factors prevented his success. He was never able to build an engine light and powerful enough to make such a machine fly. Furthermore, despite his diligent experiments, the propellers he designed had maximum efficiencies of less than 20% at a time when other aviation pioneers, like the Wrights, were building propellers capable of achieving efficiencies of around 70%.
In 1906, with failing health, Hargrave was forced to give up full time work on aeronautics, but he continued to experiment and investigate for the rest of his life. His other work includes experiments into hydroplanes, a gyroscopic one-wheeled car, and wave propelled ships.
Hargrave created many original devices and inventions but chose not to patent any of them, despite needing the money. He believed that free and open scientific communication was key to furthering progress. Hargrave wrote:
“Workers must root out the idea [that] by keeping the results of their labours to themselves a fortune will be assured to them. Patent fees are much wasted money. The flying machine of the future will not be born fully fledged and capable of a flight for 1000 miles or so. Like everything else it must be evolved gradually. The first difficulty is to get a thing that will fly at all. When this is made, a full description should be published as an aid to others.”
I have written before about the Wright brothers’ development of the aeroplane and how the machine did not emerge from the workshop fully fledged and evolved gradually, based on the work of other aviation pioneers. The Wrights themselves were keenly aware of this, and generally gave credit where credit was due to other aviation pioneers and experimenters. In 1911 Wilbur Wright wrote:
“Six very remarkable men who in the last decade of the nineteenth century raised studies relating to flying to a point never before attained. Lilienthal, Chanute, Langley, Maxim, Ader and Hargrave formed by far the strongest group of workers in the field that the world has seen.”
Hargrave died in July 1915 as a result of complications following an appendectomy. He was a skillful experimenter who possessed the drive to persevere through failures. Though his dream was to achieve heavier-than-air powered flight, he took solace in the fact that he was contributing to the total of human knowledge. The Wright brothers were aware of Hargrave’s work on curved aerofoils and built on his research to develop the first successful aeroplane. Until 1994 Hargrave and his flying models appeared on the Australian 20 dollar bill. Despite this, Hargrave and his contributions to engineering and aviation are not widely known in Australian society.
Octave Chanute, a respected aviation pioneer who, at the end of the 19th century, compiled a detailed reference of aviation development up to that time, featuring the work of around 170 individuals, wrote:
“If any man deserves to fly, that man is Lawrence Hargrave of Sydney, N.S.W.”
David Gozzard 