Dr Ron Butler was a mathematician who worked with Professor Hartree on the development of Hartree's Differential Analyser between 1944 and 1948. Dr Butler worked on problems associated with flying bombs during the Second World War. After the war, Dr Butler moved to the National Physical Laboratory to continue working with Professor Hartree on the Differential Analyser.

Douglas Hartree had already begun his university education but, as a result of the First World War, he opted to work with a team under the Supervision of A. V. Hill on anti-aircraft gunnery. After the war he returned to Cambridge to complete his studies and was awarded a PhD in 1926. His early work on the trajectories of anti-aircraft shells and his interest in mathematics contributed to his later work on the development of calculating machines. he spent some time in the United States of America and whilst there visited Vannevar Bush inventor of the differential analyser. He returned to Britain and constructed his own model of the analyser. Eventually a full-scale machine was built by Metropolitan-Vickers Electrical Co Ltd. Hartree was also involved in the development of digital computer however, by the time the first machine had been built at the University of Manchester he had already left for Cambridge where he became Plummer professor of mathematical physics, which he held until his death in 1958.