the observer’s handbook for 1976 is the sixty-eighth edition. I wish to thank all those who assisted in its preparation: those whose names appear in the various sections, those mentioned below, and especially my editorial assistant, John F. A. Perkins.

There are several major changes in this year’s handbook. You will notice that the handbook no longer carries advertisements. The decision to discontinue advertise­ments was made by the Council of the Society, in order for the handbook to qualify (under federal law) as a non-commercial publication. We thank our advertisers for their support over the years.

The pages which were previously occupied by advertisements have been used to ease the crowding of material in the various sections, and to accommodate new material. There is now a set of six new star maps, drawn by John Perkins, and two extra pages of material on variable stars, provided by Janet Mattei of the A.A.V.S.O. Dr. John F. Heard has expanded his descriptions of “The Sky Month By Month”, and Dr. Helen S. Hogg has provided a capsule history of the Society, on the inside front cover.

My thanks go to Dr. Ian Halliday for revising the page of “Miscellaneous Astro­ nomical Data”, to Dr. Cecil Costain for providing information on standard time zones, to Drs. Donald MacRae, C. T. Bolton and R. F. Garrison for revising the section on “The Brightest Stars”, and to many readers of the handbook for spotting errors and inaccuracies and for making helpful suggestions. Special thanks also go to Maude Towne and Isabel Williamson, who have calculated the tables of moonrise and moonset for many years and who are now retiring from this onerous but import­ ant task. The David Dunlap Observatory and Erindale College, University of Toronto, have once again provided financial, technical and moral support for the handbook.

Finally, my deep indebtedness to H.M. Nautical Almanac Office (particularly Leslie V. Morrison, Gordon E. Taylor and Superintendent Dr. G. A Wilkins) and to the American Ephemeris is gratefully acknowledged.

John R. Percy