On March 28 and 29, 1969, at the occasion of the dedication of the European Southern Observatory, some 90 astronomers from all over the world gathered at the ESO headquarters at Santiago de Chile for discussing problems of the Magellanic Clouds. They came from Argentina, Australia, Chile, Mexico, South Mrica and the United States as well as from Europe; these latter, naturally, mostly from the member states ofESO. The choice of the subject was an obvious one. When erecting the European Southern Observatory as a joint effort in European astronomy, it was agreed from the beginning that the field of research should be the southern sky, so far hardly explored with large telescopes. Among the objects to be investigated, the Magellanic Clouds rank highest, together with the galactic centre region and the southern spiral structure. Being located ten times closer than the nearest large stellar systems accessible to northern observers, and containing a stellar population ranging in age from the oldest down of star formation, the Clouds provide an ideal laboratory for research on to the stage current problems in astrophysics. Yet, most of the northern observational astronomers were hardly acquainted with the Magellanic Clouds; naturally, they are used to think in terms of research projects that can be conducted at their observatories. A survey of the status of knowledge and research on the Clouds therefore appeared in order now that the first- medium size- telescopes of ESO came into operation.

Inhalt
I Principal Properties of the Magellanic Clouds.- Survey of Principal Characteristics of the Magellanic Clouds.- Colour-Magnitude Arrays of the Brightest Stars.- Colour-Magnitude Diagrams of Faint Stars in the Associations and in the Field of the Magellanic Clouds.- Clusters in the Magellanic Clouds.- Supernova Remnants, Planetary Nebulae and Red Stars in the Magellanic Clouds.- Comparison of the Cepheid Variables in the Magellanic Clouds and the Galaxy.- The Short-Period Variable Stars in the Magellanic Clouds.- Properties of the Neutral Hydrogen in the Magellanic Clouds.- II Current Observational Approaches.- Intermediate Band Photometry of the Brightest Tars in the Magellanic Clouds.- A Search for Red Variable Stars in the Magellanic Clouds.- Preliminary Results of a Photometric Study of the NGC 371 Region in the Small Magellanic Cloud.- A Spectroscopic Study of Magellanic Cloud Globular-Type Clusters.- L'Émission H? dans le Grand Nuage de Magellan. Progeammes en Dêveloppement à Córdoba.- Optical Aspects of X-Ray Sources in the Large Magellanic Cloud.- Radio Continuum Observations of the Magellanic Clouds.- Satellites of Stellar Systems in General.- III Current Theoretical Approaches.- Physical Parameters of Supergiants in the Magellanic Clouds.- Cepheid Variables and the Magellanic Clouds.- Evolution of Massive Stars.- Nucleosynthesis in the Magellanic Clouds and the Galaxy.- Importance of Magellanic Clouds Studies for Extra-Galactic Work.- IV Prospects for Future Research.- Possibilities of Narrow-Band Photometry, Especially for Main-Sequence Problems.- Image Tube Work on the Magellanic Clouds.- Application of Objective Prism Techniques in the Magellanic Clouds.- Summary and Desiderata.