This symposium was dedicated to science opportunities with the VLT. All major areas of astronomical research were discussed in the plenary sessions, ranging from where we stand in cosmology to the new frontiers in the solar system. The workshops published in this volume focussed on different ways of finding clusters of galaxies at high redshift, on gravitational lensing by distant compact clusters, on the use of stellar populations as distance, age or abundance indicators, and on the extraordinary progress made in the discovery of extrasolar planets. This book affords a glimpse of what will be at the center of astrophysical research in the forthcoming decade. It is addressed to researchers and graduate students.

This is the second ESO workshop in aseries dedicated to science oppor tunities with the VLT. At the first workshop all areas of astronomical research were discussed. This second workshop is dedicated to research projects on the early Universe and has provided a forum for discussing strategies for studying faint distant objects in the optical and infrared spectral regions. This field is evolving very rapidly. There are several new surveys of galax ies and clusters of galaxies at intermediate redshift and quasars at very high redshift. Major advances in the morphological studies of distant galaxies, surveys of galaxies at high redshift and searches for primeval galaxies have been rendered possible by the new facilities provided by the Rubble Space Telescope and the Keck Telescope. Observational constraints on the evolution and formation of galaxies and large-scale structures as well as the cosmic chemical evolution were criti cally discussed with regard to theory and numerical simulations. In this context, the VLT first generation instrument capabilities were presented comprehensively and their use as cosmological tools discussed . The concluding remarks of the workshop focussed on the analysis of var ious possibilities for the VLT second generation instrumentation. Many of these topics were covered by invited reviews and talks, as well as some contributed talks. They are included in this volume together with the poster papers.

IAU Transactions are published as a volume corresponding to each General Assembly. Volume A is produced prior to the Assembly and contains Reports on Astronomy, prepared by each Commission President. The intention is to summarize the astronomical results that have affected the work of the Commission since the production of the previous Reports up to a time which is about one year prior to the General Assembly. Volume B is produced after the Assembly and contains accounts of Commission Meetings which were held, together with other material. The reports included in the present volume range from outline summaries to lengthy compilations and references. Most reports are in English.

Since 1967. the most prominent events of a General Assembly of the International Astronomical Union are published in a separate volume. The Highlights of Astronomy (volume 9) report on the major scientific presentations made at the XXIst General Assembly July 23-August 1. 1991. Buenos Aires. Argentina. The present volume contains the texts of the three invited Di scourses and of the papers presented duri ng seven Joi nt Discussion Meetings and eight Joint Commission Meetings. The invited Discourses were arranged by the IAU Executive Committee and the Joint Discourses and Commission Meetings by the respective chairpersons. The overall responsability of the General Assembly was carried out by the IAU General Secretary (19B8-1991). Dr. D. McNally. I am indebted to the authors of the invited Di scourses. to the organi zers and editors of the scientific sessions for having provided me with all the material for publication in due time. I want to particularly acknowledge the case with which Dr. J.H. Hughes. who unfortunately died a few days ago from cancer. prepared and checked unti 1 the 1 ast few weeks the report on the new IAU Reference System. This report itself concludes long and difficult discussions among IAU members that he led in a wise and clear sighted manner."