PREFACE

The Handbook for 1946 is the 38th issue. The chief improvement in this edition is in the tables of stars. Their positions have been brought up to the 1950 equinox.

Four circular star maps, 9 inches in diameter at a price of one cent each, and a set of four maps, plotted on equatorial coordinates, bound in a cover at a price of ten cents, are obtainable from the Director of University Extension, Univer­ sity of Toronto. For fuller information reference may be made to Norton’s Star Atlas and Reference Handbook (Gall and Inglis, ninth edition (1943), price 12s 6d).

Throughout this Handbook distances are based on the standard value 8".80 for the sun’s parallax, rather than the new value 8".790 as determined by Sir Harold Jones, the Astronomer Royal. The predictions of the minima of Algol are based on a period of 2.867318 days by W. M. Smart, and from a minimum at J.D. 2,429,234.6859 observed by J. S. Hall. Careful observations of three minima by D. W. Rosebrugh, in November 1945 confirmed the Hand­book predictions within about three minutes.

To the Assistant Editor, Dr. F. S. Hogg, the credit for preparing this volume is chiefly due; but sincere thanks are tendered to all those whose names are mentioned in the book and especially to Miss Ruth J. Northcott of the staff of the David Dunlap Observatory.

David Dunlap Observatory,           C. A. Chant
Richmond Hill, Ont., December 1945.