1946. R. Robert Rapp served as a Naval Aerologist from 1942 to He subsequently attended UCLA and worked in the Short Range Forecast Development Section of the USWB. From 1949 to 1952 he attended NYU where he received his Ph.D. From 1952 to the present he has been with the Rand Corporation where he has worked on problems of radioactive fallout, weather and climate modification, the uses and benefits of weather information and other projects involving environmental effects on military operations. Lewis V. Spencer received his Ph.D. in physics from Northwestern University in 1948. He has been engaged in studies of the transport of gamma rays, electrons, and neutrons, and in shielding and dosimetry applications of these transport studies with the National Bureau of Standards (NBS) since that time. Dr. Spencer was one of the primary developers of the fallout shielding technology currently used in national shelter inventory studies. He has been a member of the Advisory Committee on Civil Defense (ACCD) of the National Academy of Sciences since 1958, and has been chairman of the ACCD since 1966, Robert C. Tompkins received his B.S. in chemistry from the Ohio State University in 1944 and took some graduate courses at the University of Chicago in 1946-48. Now with the U.S. Army Ballistic Research Laboratories (BRL), he was employed by the U.S, Army Nuclear Defense Laboratory and its predecessors from 1949 until that organization's absorption into BRL in 1970. During most of that period he was engaged in research in fallout prediction and characterization of fallout particles. Mr. Tompkins participated in fallout-related projects at six U.S. atmospheric nuclear test operations in Nevada and the Pacific between 1951 and 1962. Gilbert J. Ferber received his M.S, in meteorology at New York University in 1958. He has been engaged in research concerning atmospheric dispersion and deposition of radioactivity and other pollutants with the Air Resources Laboratories, National Oceanic and Atmospheric Administration (NOAA) and its predecessor organizations since 1955, Mr. Ferber was also a participant, with fallout prediction responsibilities, in all U.S, atmospheric nuclear test operations in Nevada and the Pacific from 1957 through 1962. Jack C. Greene received his B.S, in electrical engineering from MIT in 1947 and his Masters in engineering administration from the George Washington University in 1970. He served with the Manhattan District at Oak Ridge during WWII after which Ir-3