Abstract
The (1+1)-dimensional Hamiltonian Potts model is studied for q>or=4 using finite lattice extrapolation techniques. The ground-state energy and its first derivative give information about the free energy and the latent heat of the classical two-dimensional Potts model, while the gap in the excitation energy corresponds to the inverse of the correlation length. It is shown that the finite latent heat for q>4, when the transition is of first order, comes from the crossing of levels; nevertheless there are no excitations for which the gap would vanish in the thermodynamic limit i.e. the correlation length is also finite.