Steam engine for a Hargrave kite, 1892.

AUSTRALIA - MARCH 04: Photograph of a steam engine weighing 5 lbs 11 oz, to power a model flying machine designed by the English-born Australian aeronautical pioneer, Lawrence Hargrave (1850-1915). Hargrave was primarily interested in the possibility of powered flight. After experiments using stretched rubber bands and compressed air, he used lightweight steam engines to power model flying machines, with limited success. Hargrave also developed box kites, which formed the basis of a number of successful power driven aeroplanes developed in the first decade of the 20th century, including the 'No 14 bis' plane flown in France by Alberto Santos-Dumont in September 1906. In honour of his achievements, a portrait of Hargrave appeared on the Australian $20 note. (Photo by SSPL/Getty Images)