This volume contains the notes of lectures given at the school on "Nonlinear Dy- namics in Solids" held at the Physikzentrum Bad Honnef, 2-6 October 1989 under the patronage of the Deutsche Physikalische Gesellschaft. Nonlinear dynamics has become a highly active research area, owing to many interesting developments during the last three decades in the theoretical analysis of dynamical processes in both Hamiltonian and dissipative systems. Research...