Recognising the need for further qualifications, he enrolled for a course of evening classes at Battersea Polytechnic to study for a London University degree in physics. He and his friend, Peter Tothill cycled from Teddington to Battersea and back, sometimes to stand guard on the laboratory overnight with the Home Guard. The Blitz made life more difficult. At its height the nominal three evenings a week was cut to Saturday afternoons only. When it was threatened that the course would have to be extended to six years instead of five, due to insufficient practical work, John and Peter devised their own course of experiments, to be carried out during lunch hours at the NPL. This provided valuable experience and achieved the desired result. It also demonstrated to them that physics can be fun. John graduated in 1945 with first class honours, unprecedented for parttime study. His great regret during the war was that the Official Secrets Act precluded him telling his father, an army veteran of the Boer and First World Wars, what he was doing and his father took a dim view of John not joining the services.