The Observer’s Handbook for 1957 is the 49th and largest yet published. Interest in astronomy has increased steadily in the last ten years: the current impetus of the International Geophysical Year is coupled with that of rapid and incredible developments in many fields related to astronomy. The advances being made daily in radio astronomy, missiles research and the proposed launching of man-made satellites have led the intelligent layman to feel the need for a greater knowledge of the fundamentals of astronomy. To meet this need, the Royal Astronomical Society of Canada, despite limited funds and staff, is expanding its programme of activities, increasing the size of its library, and broadening the scope of its publications to include articles and data applicable to these new fields.

Those now using the Observer’s Handbook for the first time will find here the most basic astronomical data in a highly usable form. Those readers already experienced in the use of the Observer’s Handbook can accommodate readily to certain new arrangement of the material. Lunar observers will welcome the addition of the ephemeris for the physical observation of the moon.

Cordial thanks are tendered to all those who assisted in preparing this volume, especially to the following: Gustav Bakos, Barbara Gaizauskas, Charles M. Good, James Hogg, Ross Lemire, Isabel K. Williamson and Dorothy Yane. Special thanks are due Margaret W. Mayall, A.A.V.S.O. Recorder, for the predictions of times of maxima of the long-period variables.

Our deep indebtedness to the British Nautical Almanac and the American Ephemeris is thankfully acknowledged.

Ruth J. Northcott
David Dunlap Observatory,
Richmond Hill, Ont., Sept. 1956.

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