PREFACE

The Handbook for 1955 is the 47th issue and its circulation is 5500. The Officers of the Society appreciate the increase in advertisements which will help to meet our mounting expense.

In this issue the tables of the principal elements of the solar system have been revised. Four circular star maps 9 inches in diameter at a price of two cents each and a set of four maps plotted on equatorial co-ordinates at a price of twenty cents are obtainable from the Director of University Extension, University of Toronto. Toronto 5.

Celestial distances given herein are based on the standard value of 8".80 for the sun’s parallax, not on the more recent value 8".790 determined by Sir Harold Jones; and the calculations for Algol are based on Olin J. Eggen’s epoch 2432520.6303 and period 2.86731525 d., as published in the Astrophysical Journal, 1948.

Cordial thanks are tendered to those who assisted in preparing this volume, especially to the staff of the David Dunlap Observatory, and also Miss Olga Mracek, John Crawford, Basil Kerr, Malcolm Lennox, Donald Morton and Ghislain Roy. Our deep indebtedness to the British Nautical Almanac and the American Ephemeris is thankfully acknowledged.

C.A. Chant
David Dunlap Observatory,
Richmond Hill, Ont., October 1954.