A gyroscope is a solid that spins so quickly around an axis that on the average the gravitational field is small compared to that of centrifugal forces.
The gyroscopic balance, also known as the counterweighted gyroscope, allows observation of the principal gyroscopic phenomena.
The exemplar presented here is composed of a brass disk (diameter 6.4 cm) revolving around its axis inside a ring (diameter 12 cm), it too brass, concentric to the disk and at right angles to it. The disk is in fact suspended at the ends of one diameter of the ring by means of the well-sharpened ends of a steel axial pin to which it is rigidly attached.
Along the extension of the pin a steel rod (length 28 cm) is attached to the ring. It is held, by a cursor and gimbals, by a brass column on a base of brass and polished wood.
A platform with a counterweight represented by some brass disks is suspended from a cursor that slides along the staff; with its sliding it provides balance to the system by bringing the centre of gravity to coincide with the centre of the gimbals and allows it to be moved to one side or the other of the latter. From this comes the name of the instrument.