text: Prior to World War II, he worked as a physicist in Berlin and as a colloid chemist in Cambridge. During World War II he joined the Chemical Defence Experimental Station at Porton Down, Wiltshire, but in 1940 was transferred to the Air Ministry's Assistant Directorate of Intelligence (Science) and spent the rest of the war with the Air Ministry. Due to his work he was made Officer of the Most Excellent Order of the British Empire in 1946.
  After the war he moved to the University of Bristol Physics Department to do research in solid state physics, but switched to research on crystal dislocation. His work with William Keith Burton and Nicolás Cabrera was to demonstrate the role dislocations played in the growth of crystals. 
  Apart from crystal defects, his wide-ranging research interests at Bristol included the mechanical properties of polymers, the theory of liquid crystals, the mechanics of the interior of the Earth, and the origin of biological homochirality. 
  He was appointed Reader in 1951, Melville Wills Professor in 1954 and Henry Overton Wills Professor and Director of the H.H. Wills Physics Laboratory in 1969. He retired in 1976 but remained active in attending conferences, writing papers and corresponding with colleagues well into the 1990s. He edited the Farm Hall Transcripts from Operation Epsilon well into his eighties.