 On 26 October 1942 , Oliphant embarked from Melbourne , taking Rosa and the children back with him . The wartime sea voyage on the French Desirade was again a slow one , and they did not reach Glasgow until 29 February 1943 . But he had to leave them behind once more in November 1943 after he joined the Manhattan Project in the United States as part of the British Mission . Oliphant was one of the scientists whose services the Americans were most eager to secure , and Robert Oppenheimer , the head of the Los Alamos Laboratory attempted to persuade Oliphant to join . The work on the bomb itself made him uneasy , and he preferred to head the team assisting his friend Lawrence at the Radiation Laboratory in Berkeley to develop the electromagnetic uranium enrichment – a vital but less overtly military part of the project . 
