At the XV. General Assembly of the International Astronomical Union in Sydney 1973, Commission 10 for Solar Activity requested the incoming Organising Committee to establish a small group to recommend a standard nomenclature for solar features and to prepare an illustrated text which would clear the jungle of terms for the benefit of solar physicists as well as of theoreticians and research workers in related fields. The challenge was taken up by the president of Commission 10, Prof. K. O. Kiepenheuer, and his persuasive advocacy has led eventually to the present book. In the course of the...