"As far back as 1884 I put thought and labour on the evolution of the flying machine", noted Lawrence Hargrave in a letter of 9 March 1906 addressed to President and Members of The Aeronautical Society of Great Britain.
From 1884 onwards Hargrave read a series of papers on his aeronautical research before the Royal Society of New South Wales and built over the years a series of model flying machines, powered by clockwork, rubber bands and compressed air engines.
Hargrave's invention of the box-kite structure in 1893 (later reflected in the early Voisin aircraft designs) was a highlight of his aeronautical experiments over a number of years with various kite shapes.
As part of his research Hargrave kept a detailed photographic record of his experiments, the originals of many of his key photographs (74 in number) being included in two oversize photograph albums which he titled 'Evolution of the Flying Machine'.
The Hargrave albums were originally presented to the Royal Aeronautical Society in 1920 by Hargrave's widow as part of a major bequest of Hargrave's papers and photographs and further donations were subsequently presented to the Society by Hargrave's daughter Helen Gray and by members he corresponded with.