Blak History Month: David Unaipon. Inventor, writer, orator and campaigner.

David Unaipon, a Ngarrindjeri man born in 1872 at Point McLeay Mission in South Australia, registered patents for 10 inventions between 1909 and 1944 — including an improved handpiece for sheep shearing, a centrifugal motor, a multi-radial wheel and a mechanical propulsion device.

His sheep shearing handpiece — patented in 1909 — transformed circular motion into linear motion and delivered significant economic benefits to Australia's wool industry. Its design is still in use today. He never saw a penny from it. His designs were largely stolen or used without financial credit, and he was never able to afford to take out full patents on many of his ideas.

Then there's the helicopter. In 1914, Unaipon anticipated the principle behind helicopter flight by applying the aerodynamic theory of the boomerang — years before the first helicopter flew in 1930 using almost exactly the same principle he had described. He got there first. He got no credit.

Unaipon was also credited as Australia's first published Aboriginal author — writing newspaper articles through the 1920s, chronicling Aboriginal mythology, and compiling a manuscript of legends that was later stolen by an anthropologist who published it under his own name without any acknowledgement. That manuscript, in Unaipon's own handwriting, survives today in the Mitchell Library in Sydney. Its words are printed in tiny text on the very $50 note that bears his portrait.

He spent much of his life travelling across southeastern Australia — preaching, lecturing on science, advocating for Aboriginal rights, and participating in royal commissions — while often being refused accommodation in the towns he visited because of his race. He did all of this with dignity, patience and relentless intellectual energy until his death in 1967, aged 94. He died just months before the 1967 referendum finally counted Aboriginal people as citizens.