Poinsot kinematic representation of the motion of a body in the Hess case

On the zero level of the momentum integral, analytic and qualitative properties of the Hess solution of the classical problem on rotation of a heavy rigid body about a fixed point are studied. The explicit time dependence of the phase variables is expressed in terms of Jacobi elliptic functions. The time and the spatial evolution of the angular velocity and angular momentum are investigated. The motion of the body is represented by the rolling motion of the body's ellipsoid of inertia on a fixed plane in space.