A true boxkite wing is formed when a biplane wing has vertical panels fitted along its length to form 'cells' within it. This kind of structure was invented by Lawrence Hargrave, an Australian experimenter, in the 1890s. It's advantage was that it could be both stable and strong yet constructed from lightweight materials. Hargrave's work strongly influenced Santos-Dumont's 14-bis and the Voisin brothers' early designs. Henry Farman's 1909 machine, based on the Voisin concept, only had a boxkite tail, but was nevertheless widely refered to as the 'Farman Boxkite'. The name subsequently came to describe any Farman-influenced aeroplane, with biplane lifting surfaces, a pusher propeller and a front elevator.