Note: Do not rely on this information. It is very old.
Gyroscope
Gyroscope is an instrument intended to illustrate the phenomena of rotating bodies, generally the study of the combinations of different rotations imparted to the same body. It consists essentially of a metal-wheel with heavy rim, provided with a stiff and strong axle pivoted inside a circular frame of metal as light as strength conditions will permit. A strong spin may be given to the wheel without disturbing this outer framework, which may be held by the hand during the operation. The general nature of the phenomena observed in such an instrument is indicated in the article on rotation.