Very little has appeared in book form about the newest uses of solar energy and its potential for mankind and this surveys the total environment in which thinking about, and experimentation with, this difficult yet super-abundant from of energy is now very active. There are brief but scientifically sound descriptions of every conceivable idea, some still only imaginary or on drawing boards, others that are already proving their practical value in converting the sun's light or heat to power manmade devices. This is keyed to space- age needs; power for the various systems carried by earth satellites where weight and space are important factors. There's a solar engine weighing only 567 pounds, an ""electric"" spaceship powered by sunbeams, or the plan to coat the moon with semi-conductor material, and more. There are also the many practical devices already in use to heat and cool homes, cook, distill water, etc., and the photochemist's search for the secret of photosynthesis is fascinating for what it may mean ultimately to food production for humans. There is some history and a survey of the organizations in the world working in this area. Halacy's robust style uses clean, understandable scientific terminology which makes his book excellent for all general collections.