Providing a thorough, yet concise treatment of the phenomenological basis of thermal physics followed by a presentation of the statistical theory, this book presupposes no exposure to statistics or quantum mechanics. It covers several important topics, including a mathematically sound presentation of classical thermodynamics; the kinetic theory of gases including transport processes; and thorough, modern treatment of the thermodynamics of magnetism. It includes up-to-date examples of applications of the statistical theory, such as Bose-Einstein condensation, population inversions, and white dwarf stars. And, it also includes a chapter on the connection between thermodynamics and information theory. Standard International units are used throughout.