Escape and evasion map printed on playing cards distributed to Prisoners of War which could be soaked and pealed apart revealing the escape map. Many of the maps of the Pacific region were printed by the US Army Map Service, while the UK was responsible for many of the European Theatre maps. Many of the US Navy charts were folded in envelopes and distributed to the air crews before a mission, and to be turned in when the mission was successfully completed. They were called "drift charts" by the Navy, "...since their prime purpose was to indicate to aircrews survivors in their life rafts
British contribution to the Manhattan Project the work" on the bomb, it would be "better for us to go along for the present without sharing anything more than we could help". In December 1942, Roosevelt agreed to restricting the flow of information to what Britain could use during the war, even if doing so slowed down the American project. In retaliation, the British stopped sending information and scientists to America, and the Americans then stopped all information sharing. The British considered how they would produce a bomb without American help. A gaseous diffusion plant to produce of weapons-grade uranium per day was estimated to cost up