This volume contains papers contributed to the NATO Advanced Study Institute ‘Theory of Solar and Planetary Dynamos’ held at the Isaac Newton Institute for Mathematical Sciences in Cambridge from September 20 to October 2 1992. Its companion volume ‘Lectures on Solar and Planetary Dynamos’, containing the texts of the invited lectures presented at the meeting, will appear almost contemporaneously. It is a measure of the recent growth of the subject that one volume has proved insufficient to contain all the material presented at the meeting: indeed, dynamo theory now acts as an interface between such diverse areas of mathematical interest as bifurcation theory, Hamiltonian mechanics, turbulence theory, large-scale computational fluid dynamics and asymptotic methods, as well as providing a forum for the interchange of ideas between astrophysicists, geophysicists and those concerned with the industrial applications of magnetohydrodynamics.

The papers included have all been refereed as though for publication in a scientific journal, and the Editors are most grateful to the referees for helping to get all the papers ready in such a short time. They also wish on behalf of the Scientific Organising Committee to record their appreciation of the dedication of the staff of the Isaac Newton Institute, who coped cheerfully with many bureaucratic complexities, and to give special thanks to the Deputy Director, Peter Goddard, for making the whole meeting possible.