major part in defeating the German U-boats, intercepting enemy bombers, and in directing Allied bombers. In 1940, the Fall of France, and the possibility that Britain might be invaded, prompted Oliphant to send his wife and children to Australia. The Fall of Singapore in February 1942 led him to offer his services to John Madsen, the Professor of Electrical Engineering at the University of Sydney, and the head of the Radiophysics Laboratory at the Council for Scientific and Industrial Research, which was responsible for developing radar. He embarked from Glasgow for Australia on on 20 March. The voyage, part of a 46-ship convoy, was a slow one, with the convoy frequently zigzagging to avoid U-boats, and the ship did not reach Fremantle until 27 May. The Australians were already preparing to produce radar sets locally. Oliphant persuaded Professor Thomas Laby to release Eric Burhop and Leslie Martin from their work on optical munitions to work on radar, and they succeeded in building a cavity magnetron in their laboratory at the University of Melbourne in May 1942. Oliphant worked with Martin on the process of moving the magnetrons for the laboratory to the production line. Over 2,000 radar sets were produced in Australia during the war. Manhattan Project At the University of Birmingham in March 1940, Otto Frisch and Rudolf Peierls examined the theoretical issues involved in developing, producing and using atomic bombs in a paper that became known as the Frisch–Peierls memorandum. They considered what would happen to a sphere of pure uranium-235, and found that not only could a chain reaction occur, but it might require as little as of uranium-235 to unleash the energy of hundreds of tons of TNT. The first person they showed their paper to was Oliphant, and he immediately took it to Sir Henry Tizard, the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW). As a result, a special subcommittee of the CSSAW known as the MAUD Committee was created to investigate the matter further. It was chaired by Sir George Thomson, and its original membership included Oliphant, Chadwick, Cockcroft and Moon. In its final report in July 1941, the MAUD Committee concluded that an atomic bomb was not only feasible, but might be produced as early as 1943. Great Britain was at war and authorities there thought that the development of an atomic bomb was urgent, but there was