On a Dynamical Top, for exhibiting the phenomena of the motion of a system of invariable form about a fixed point, with some suggestions as to the Earth's motion

by James Clerk Maxwell

[*] When two of the axes have equal moments of inertia, or

, then the angular velocity

is constant, and the path of the invariable axis is circular, the number of revolutions of the body during one circuit of the invariable axis, being

The motion is in the same direction as that of the rotation, or in the opposite direction, according as the axis of

is that of greatest or of least moment of inertia.

[*] Both in this case, and in that in which the three axes are unequal, the motion of the invariable axis in the body may be rendered very slow by diminishing the difference of the moments of inertia. The angular velocity of the axis of