The monograph of the famous German specialist in the field of mechanics and theory of gyroscopic instruments K. Magnus highlights the main aspects and applications of the theory of gyroscopic systems. The most typical devices are considered - gyrohorizont, gyrocompass, gyrostabilizer, etc. A significant place is given to the current problems of space flights - the movement of an artificial satellite, a gyroscope with a cavity filled with liquid, etc. Of great interest is the classification of gyroscopic instruments proposed by the author.