basic in the making of propellants such as cordite, high explosives, dyes, fertilizers, and other products but availability was limited due to World War I. The NRC, through its committee, recommended importing Chilean saltpeter and the construction of four new ordnance plants. These recommendations were accepted by the War Department in June 1917, although the plants were not completed prior to the end of the war. In 1918, Wilson formalized the NRC's existence under Executive Order 2859. Wilson's order declared the function of the NRC to be in general: "(T)o stimulate research in the mathematical. physical, and biological sciences. and in the application of these sciences to engineering, agriculture. medicine. and other useful arts. with the object of increasing knowledge, of strengthening the national defense, and of contributing in other ways to the public welfare." During World War I, the United States was at war, the NRC operated as the Department of Science and Research of the Council of National Defense as well as the Science and Research Division of the United States Army Signal Corps. When war was first declared, the Council had organized committees on anti-submarine and gas warfare. On June 1, 1917, the council convened a meeting of scientific representatives of the United Kingdom and France with interested parties from the U.S. on the subject of submarine detection. Another meeting with the British and French was held in Paris in October 1918, at which more details of their work was disclosed. As a result of these meetings, the NRC recommended that scientists be brought together to work on the problems associated with submarine detection. Due to the success of council-directed research in producing a sound-based method of detecting submarines, as well as other military innovations, the NRC was retained at the end of the war, though it was gradually decoupled from the military. NRC's Articles of Organization have been changed only three times: in 1956, January 1993, and July 2015. The Academies The National Academy of Sciences, National Academy of Engineering, and National Academy of Medicine are honorary membership organizations, each of which has its own governing Council, and each of which elects its own new members. The membership of the three academies totals more than 6,300 scientists, engineers, and health professionals. New members for each organization are elected annually by current members, based on their distinguished and continuing achievements in original research. By the terms of