It is a great privilege for me to declare open the seventh General Assembly of the International Astronomical Union. We are very grateful to our Swiss colleagues for the invitation to meet in Zürich in these delightful surroundings. We recognize that there are special difficulties at the present time in the organization of arrangements for a congress such as this. It has meant a great deal of hard work for the Local Committee, under Dr Waldmeier, and to them we express our thanks. Almost exactly ten years have passed since the last General Assembly of the International Astronomical Union terminated.