The polhode is the non-plane curve traced on the surface of an ellipsoid with fixed center by its point of contact with a fixed plane on which it rolls, as in the revolution of a top.
-- Oxford English Dictionary
Hence the jabberwockian sounding statement: the polhode rolls without slipping on the herpolhode lying in the invariable planeThe corresponding line on the plane is the herpolhode.
-- Herbert Goldstein, Classical Mechanics
A short poem about polhodes and herpolhodes by David N. Williams.
To home page of Thomas H. Moog - Polhode Inc