The book summarizes the results of solar cosmic-ray (SCR) investigations since 1942. The present monograph, unlike the reviews published earlier, treats the problem in self-contained form, in all its associations - from fundamental astrophysical aspects to geophysical and astronautical applications. It includes a large amount of new data, accumulated during the last two or three decades of space research. As a result of the information burst' in space physics, there are a lot of new interesting theoretical concepts, models, and ideas that deserve attention. The author gives an extensive...