Harry Kauper was born on 12 March 1888 at Hawthorn, Melbourne. Like Hawker he became an automotive mechanic, specialising in the electrical systems. He too came to England to study aviation and after working at Sunbeam joined the Sopwith Aviation Company in June 1912. Working at Brooklands he introduced Hawker to Sopwith. Apart from accompanying Harry on the Circuit of Britain Race he also went with him when Hawker demonstrated the Sopwith Tabloid to the Australian public. He developed the Sopwith-Kauper interrupter gear to allow a machine gun to fire through the propellor arc. He returned to Australia in 1919 and had a successful career in radio broadcasting.