The New Student's Reference Work/Gyroscope

MAXWELL'S DYNAMICAL TOP

Gyroscope (jī′rō-skōp), an instrument used to illustrate many of the phenomena which occur in the dynamics of rotation. It consists of a flywheel with a heavy rim, supported in such a way that it may rotate freely about any one of three axes, each at right angles to the other two. The instrument was designed by Bohnenberger (1817) and perfected largely by Foucault (1852) for the purpose of illustrating the various motions of the earth, especially the stability of the axis of rotation, the rate of rotation and the precession of the equinoxes.

The theory of the gyroscope is too intricate for our limited space. For an attractive elementary presentation of this subject, see Worthington's Dynamics of Rotation or Perry's Spinning Tops.

The accompanying figure shows what is perhaps the simplest and most beautiful of gyroscopes, namely, Maxwell's dynamical top. This instrument is supported at its center of gravity, and the three axes about which it may rotate all intersect at this point of support. An ordinary top is merely a gyroscope which is supported below the center of gravity and on a plane.