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

itself. This quantity indicates the rate of revolution of the axle of the top about its mean position, and is very easily observed.

[*] The instantaneous axis is not so easily observed. It revolves round the invariable axis in the same time with the axis of

, at a distance which is very small in the case when

,

,