Professor Potts' early work was concerned with the statistical mechanics of Ising lattices, where he has made a variety of important original contributions, including the determination of partition functions and correlations for special models. His name has been given to the Potts model, which is the subject of much interest today. Most of his later work has been concerned with Operations Research, a subject on which he has become a world authority. Professor Potts has been an Australian pioneer in the application of operations research to industry. Over a period of many years he developed special methods in operations research and successfully applied them to problems in Australian industries and Government utilities.