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    Bowditch Long Term Almanac Tables
    From: Dan Allen
    Date: 2002 Oct 23, 09:39 -0700

    One of the nice features of the Bowditch volumes from 1958 until 1984
    is Appendix H:
    
         Long Term Almanac
    
    It made carrying along a Bowditch (or two from 1975 until 1984)
    self-contained: it
    had the theory and the tables needed to do "lifeboat" navigation.  Now
    of course
    this useful table has been removed with no replacement in later
    editions.  How sad.
    (These editions also had H.O. 211 as Table 35, "The Ageton Method",
    also now deleted.)
    
    The Appendix had two pages for the Sun's GHA and Dec for 10 different
    dates per month,
    for each month of the year.  There are corrections based upon year so
    that the maximum
    error for altitude would not exceed 2.0' of arc.  It also has
    information for 38
    navigational stars in a compact little table with promised errors of
    less than 1.3'
    of arc, as well as a table of the GHA of Aries, along with 2 auxiliary
    tables.  The
    whole thing with explanation takes up about 5 pages.  Very neat.
    
    Question: does anyone know the source of this table?  Is it just
    Newcomb's formulas
    put into a table?  (Newcomb's formulas were the basis of the Nautical
    Almanac before
    computers and DE405.)
    
    Question #2: could we come up with a newer, better, more compact long
    term almanac
    ourselves?  Just a thought.
    
    Dan
    
    
    

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