Box kite, reproduction, wood / cotton / rope, designed by Lawrence Hargrave 1894, made by Publicity Projects, Revesby, New South Wales, Australia, pre 1971
The Museum of Applied Arts and Sciences holds the largest collection of material internationally of the aviation pioneer, Lawrence Hargrave. While no single individual can be attributed to the invention of the aeroplane, Hargrave belonged to an elite body of scientists and researchers (along with Octave Chanute, Otto Lilienthal and Percy Sinclair Pilcher) whose experiments and inventions paved the way for the first powered, controlled flight achieved by the Wright Brothers on December 17, 1903.
Hargrave's greatest contribution to aeronautics was the invention of the box or cellular kite. This kite evolved in four stages from a simple cylinder kite made of heavy paper to a double-celled one capable of lifting Hargrave sixteen feet off the ground. The fourth kite of the series, produced by the end of 1893, provided a stable supporting and structural surface that satisfied the correct area to weight ratio which became the foundation for early European built aircraft. For example, Hargrave's box kite appears to be the inspiration for Alberto Santos Dumont's aircraft named '14bis', which undertook the first powered, controlled flight in Europe in 1906. Similarly, Gabriel Voisin states in his autobiography that he and his brother Charles, who manufactured the first commercially available aircraft in Europe, owe their inspiration to their construction to a Hargrave box kite, while via correspondence with Octave Chanute, there is also evidence for Hargrave's box kite influencing the aircraft used by the Wright Brothers during their historic flight in 1903.
Hargrave's contribution to aeronautics can also be observed in other ways. For example, he conducted important research into animal movement and produced a number of flapping models which successfully demonstrated a means of propulsion. However, the flapping wing models were unable to ascend or lift from ground level with manpower alone. This prompted Hargrave to design and produce alternative power sources including a variety of engines, the most influential being his three cylinder radial rotary engine. This arguably formed the basis of the idea for the famous French Gnome engine, which became the primary source of aircraft power for the French Allies in World War I.
Beyond aviation, Hargrave is also significant for his exploration work in the Torres Strait and New Guinea. In 1876, for example, he joined Luigi d'Albertis' expedition to the Fly River and on completion, was regarded as an expert cartographer who held an unrivalled knowledge of the region. Hargrave also contributed to the study of astronomy with his development of adding machines to assist Sydney Observatory in their calculations. He similarly researched and wrote on Australian history and was an early proponent for the establishment of a bridge across Sydney Harbour.
Adams, M., "Wind Beneath His Wings - Lawrence Hargrave at Stanwell Park" (September 2004)
ADB Online, "Lawrence Hargrave", http://www.adb.online.anu.edu.au/biogs/A090194b.htm (Downloaded 18/7/2007)
Grainger, E., "Hargrave and Son - A Biography of John Fletcher Hargrave and his son Lawrence Hargrave" (Brisbane, 1978)
Hudson Shaw, W & Ruhen, O., "Lawrence Hargrave - Explorer, Inventor & Aviation Experimenter" (Sydney, 1977)
Roughley, T.C., "The Aeronautical Work of Lawrence Hargrave" (Technological Museum, Sydney Bulletin No.19, 1939)
This replica box kite model is made from wood and paper and was produced by Publicity Projects in Revesby, New South Wales, Australia some time before 1971. It is based on the design of Lawrence Hargrave's October 1894 paper kite which was produced as a duplicate of his September 1894 calico one.
This box kite is a modern reproduction of a duplicate model of Lawrence Hargrave's 90 foot box kite (No 40). The original duplicate is now housed in the collection of the Science Museum in London.
On March 3, 1894, Hargrave produced his first box kite model which consisted of two cells with different surfaces (one was a flat surface made of paper and the other was a curved surface made of red wood). Arguably, this kite was produced as an amalgamation of Hargrave's earlier two-celled flat surface and two-celled curved surface kites. When testing these box kites from a crossbow in calm air in 1893, for example, Hargrave curiously found them to both have the same trajectory. This perplexed Hargrave as he believed there would be a difference in both the lift and thrust of a curved surface as opposed to a flat one. This led him to remark in his 1893 paper to the Royal Society of New South Wales that the laws governing the motion of a body through still air must be distinct from those that determine its action when moving through wind.
It is quite possible that these results are what prompted Hargrave to produce a mixed-cell kite (that is, one with a flat surface and one with a curved surface) to see how the combined surfaces would affect the kite's lift and trajectory any differently (and also how this would affect the kite when placed in different weather conditions). Notably, Hargrave's 3/3/1894 model was tried in a strong wind and although he states that it flew steadily, wet weather caused the paper on the cells to melt. It seems that this failed experiment might have phased Hargrave (or at least caused him to sideline the experiment after he began dabbling with other new ones), since he did not return to the idea of a mixed-celled kite until October of the same year.
The production of this particular kite was meant as a modified smaller-scale version of Hargrave's earlier model dated 24/9/1894 (this model, however, featured only curved surfaces unlike the newly modified one which featured mixed-cells). Although Hargrave does not indicate why he produced this smaller model, it is possible that the problems created by the wind in the original experiment led him to believe that paper, instead of calico, and a greatly reduced weight and surface area of the machine would prove more effective in variable atmospheres. In fact, this particular model which was tested on October 17, 1894, reportedly "slacked the line for 10 or 12 seconds at a time". This meant that the kite was able to generate greater lift than drag and must have been flown in relatively windy conditions.
It would appear that Hargrave's experimentation into curved and flat surfaces took place in a rather erratic fashion and this reflects the very nature of Hargrave's inquisitive mind. He often had many different projects occurring at once, regardless of how they fitted within a 'linear' sequence of development towards achieving man-lifting, artificial flight. Perhaps this was because Hargrave wanted to fully understand the reasons behind the results of all his experiments (even when they failed) and persisted with this until he was satisfied.