John H. Beynon was born in Ystalyfera, Wales, the older of two sons whose parents ended their education at secondary school. Beynon grew up in a coal mining town and attended a local university, the University of Wales at Swansea (Swansea University), during the early years of the Second World War. Graduating with a degree in physics, Beynon decided that the pursuit of a PhD was a waste of time and money and he committed himself fully to wartime work, including the development of weapons system used to track targets while a weapon was in motion. He spent much of his career in industry, principally working at the Imperial Chemical Industries (ICI), a British chemical company. Upon his arrival at ICI, Beynon's supervisor, A. J. Hailwood, immediately gave Beynon the task of building a mass spectrometer, a device with which he had no conceptual underpinnings. Creating this technology, however, proved to be pivotal in Beynon's career. Even without a PhD Beynon made himself and his work central to the development of mass spectrometry as a field of study and as a tool of chemical analysis and knowledge. Uncertain about remaining in industry his entire life, Beynon spent time at Purdue University, Swansea University, and the University of Essex. Being outside of industry allowed Beynon the opportunity to publish his research for the wider scientific community, ultimately contributing over 350 articles and other publications to the annals of science. He founded the Mass Spectrometry Unit at Swansea University, and was also a founding member of both the British Mass Spectrometry Society and the American Society of Mass Spectrometry. All through his long career Beynon trained a number of students (one of whom is Gareth Brenton; Brenton's reflections on his mentor are recorded in the appendix to this transcript) and did much to advance the field of mass spectroscopy. The interview concludes with Beynon's reflections on the politics surrounding the formation of an international mass spectroscopy committee. Throughout the interview Beynon details many of the scientific discoveries that came of out mass spec research, as well as a number of the refinements and improvements to mass spec technology.