His first designs for aerial craft appeared in his notebooks around 1872. Many of his early models were ornithopters, which used flapping wings. In 1887, one of his ornithopters flew 82 metres and by the end of 1892 he had constructed 16 different model flying machines.
A meticulous worker, Hargrave understood the importance of recording the diversity of his experiments. Not only did he think that man-made flight was inevitable, but he realised public demand for rapid travel would facilitate the process.
His later designs were based on kites and then a rigid, stable aeroplane. Hargrave's research and experimentation proved basic theories of flight, but he is best known for his development of the cellular kite.
Hargrave began experimenting with kites in 1893. The following year, he demonstrated that four kites attached to one rope could lift 109 kilograms over 5 metres off the ground in a 21 knot wind. He straddled a trapeze below a train of box kites and was lifted into the air at Stanwell Park on 12 November 1894.
In 1889 Charles Bayliss photographed Lawrence Hargrave's collection of model ornithopters, or flying machines. Examples can be viewed below.
Hargrave later presented a selection of Bayliss's photographs to the Engineering Association of New South Wales, in an album entitled 'The evolution of the flying machine'. He enclosed the following letter:
About this item:
This letter was found in a pocket that had been glued to the inside back cover of 'The Evolution of the Flying Machine' (ML F629/H)
Presented to the Engineering Association of New South Wales
The absence of any description of these twenty-five photographs might appear to be an oversight, but it is intentional as after long consideration I am convinced that a careful inspection of the plates can not fail to show the thoughtful mechanic the use of every part of the various machines.
By consigning the pictorial record of a portion of this work to your keeping experimenters will be saved much time and labour; and although some persons may now think it a waste of energy to make such structures, the time must surely soon come when numerous workers will devote their undivided attention to the development of some or all of the various types shown here.
An expressed demand for rapid locomotion is all that is necessary to bring into existance as diverse a variety of flying machines as we see in nature.