  The free energy of a lattice model, which is a generalization of the
Heisenberg $XYZ$ model with the higher spin representation of the Sklyanin
algebra, is calculated by the generalized Bethe Ansatz of Takhtajan and
Faddeev. (Talk given at the XXI Differential Geometry Methods in Theoretical
Physics, Tianjin, China 5-9 June 1992)
