The Handbook for 1953 is the 45th issue and its circulation is 5000. The Officers of the Society appreciate the increase in advertisements which will help to meet our mounting expense. With regret the price has been raised to 50 cents. In this issue the tables for sunrise, sunset, twilight, moonrise and moonset are given for latitude 54° N. instead of 52° N. The range now covers the latitudes of all the centres. 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 Carol Henderson, Frank E. J. Cariou, Eric Harvest, Malcolm Lennox, Donald Morton and Peter Saxton. Our deep indebtedness to the British Nautical Almanac and the American Ephemeris is thankfully acknowledged.
David Dunlap Observatory,
Richmond Hill, Ont., November 1952.