This publication is a pocket-sized extract of information contained in 'The Reaction Rate Handbook' (DNA 1948H), Revised Edition, and other sources, and is a compendium of useful data for the convenience of atmospheric chemists, physicists, etc. The manual is broken down into five major categories; vis, Atmospheric Characteristics, Chemical Reactivity Data, Radiation Data, Electromagnetic Propagation Data, and Constants and Conversion Factors.