  We study pion--nucleon scattering with a chiral lagrangian of pions,
nucleons, and $\Delta$-isobars. The scattering amplitude is evaluated to
one-loop $Q^3$ order, where $Q$ is a generic small momentum, using a new
approach which is equivalent to heavy baryon chiral perturbation theory. We
obtain a good fit to the experimental phase shifts for pion center-of-mass
kinetic energies up to 100 MeV. A sigma term greater than 45 MeV is favored,
but the value is not well determined.
