NavList:

Mike   There have been 12 editions of Mary Blewitt/Pera http://www.telegraph.co.uk/news/obituaries/1366813/Mary-Pera.html and several reprints.  The relevant pages change occasionally, but fortunately not that often. My most recent reprint is 2012.  I can’t remember where my earlier edition is.  The daily pages for the 12^th edition are 27, 28, 29th July 1997 and 6, 7, 8^th Dec 1997.  You need to state the dates on the pages you’ve got before anyone can set you a question.  Hopefully, a marine navigator will pick this up.  I’m a primarily a bubble sextant/ Air Almanac (AA) person and there are places (e.g. Moon and Polaris corections) where the AA (not used by Blewitt) goes for speed and simplicity over the greater precision of Appendixes C, D, and E of the Nautical Almanac used by Mary Blewitt.  DaveP