<Ul> <Li> 1944--46--Teacher of mathematics and chemistry, Geelong Grammar School, Victoria . </Li> <Li> 1947--48--Lecturer in chemistry, University of Sydney . </Li> <Li> 1948--51--Scientific Officer, Woomera Rocket Range and Imperial College, London . </Li> <Li> 1952--83--Principal Research Scientist, Aeronautical Research Laboratories, Melbourne, (now part of the Defence Science and Technology Organisation). </Li> <Li> 1981--82--Scientific Adviser (Energy) to the Victorian State Parliament . </Li> </Ul> <Li> 1944--46--Teacher of mathematics and chemistry, Geelong Grammar School, Victoria . </Li> <Li> 1947--48--Lecturer in chemistry, University of Sydney . </Li> <Li> 1948--51--Scientific Officer, Woomera Rocket Range and Imperial College, London . </Li>

When was the first black box flight recorder invented