No branch of dynamics or physics provides a more profitable or interesting subject of study to the student of physics or engineering than that which deals with the phenomena presented by spinning-tops. Within the last few years the most interesting form of top, namely the gyrostat, has advanced from being a piece of lecture-room apparatus, or a toy, to a position of great practical importance. In the dirigible torpedo, Brennan's monorail car, the Schlick device for rendering a ship steady at sea, and in the gyrostatic compass, the results are obtained by utilising the properties of the gyrostat. Undoubtedly, too, the gyrostat is destined to play an important part in many inventions still to be brought to light.