Because of this experience and the difficulty in producing sufficient penicillin, Florey switch his focus to children, who could be treated with smaller quantities of penicillin. Florey expected that penicillin would be hailed as a breakthrough, but he was disappointed; his results aroused little interest. He would spend the next two years attempting to drum up interest in what he believed to be the most important medical discovery of the century. He was elected a Fellow of the Royal Society in March 1941, but his work with penicillin played little part. North American supply As the war heated up with German air raids on the United Kingdom, Florey and Ethel decided to send their children away to a safer country in July 1940. The United States was not yet at war, and John Fulton, the Sterling Professor of Physiology at Yale University, and his wife Lucia agreed to care for them at their home in New Haven, Connecticut, "for the duration". In April 1941, Warren Weaver met with Florey, and they discussed the difficulty of producing sufficient penicillin to conduct clinical trails. Weaver arranged for the Rockefeller Foundation to fund a three-month visit to the United States for Florey and a colleague to explore the possibility of production of penicillin there. Florey and Heatley left for the United States by air on 27 June 1941. In New Haven Florey met Fulton and was reunited with the children. Fulton introduced him to Ross Harrison, the Chairman of the National Research Council, and Harrison introduced him to Charles Thom, the chief mycologist at the Bureau of Plant Industry of the United States Department of Agriculture (UDSDA), and the man who had identified the mould reported by Fleming. Thom took them to Washington, D.C., to see Percy Wells, the acting head of the USDA's four laboratories, and Wells sent them to Orville May, the director of the UDSA's Northern Regional Research Laboratory (NRRL) in Peoria, Illinois. May arranged for them to meet with Robert D. Coghill, the chief of the NRRL's fermentation division, who raised the possibility that fermentation in large vessels (deep submergence) might be the key to large-scale production. On 17 August, Florey met with Alfred Newton Richards, the chairman of the Medical Research Committee of the Office of Scientific Research and Development, who promised his support. Florey returned to Oxford in September without undertakings to produce the kilogram quantities of