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Found the problem:

In Moore's "The New Practical Navigator", it has a table of declinations
for the Sun. One of the pages is "A Table of the Sun's Declination, for
the years 1792, 1796, 1800, 1804. Each being Leap-Year.  The facing page
is "A Table of the Sun's Declination, for the year 1800".

I was looking at the page titled, "A Table of the Sun's Declination, for
the year 1800", which lists March 1, 1800 as 7degs 33mins South. Which is
correct.

The other table, the one titled "A table of the Sun's Declination, for
the years 1792, 1796, 1800, 1804, each being Leap-Year" lists March
1, declination as 7degs 11mins South. Which is ok for 1792, 1796, and
1804, but not for 1800, because 1800 is not a leap year.

This table should has been labeled only for the years 1792, 1796, 1804, each
being a leap year.  The year 1800 has it's own table on a page all by
itself.

The "error" really is not in the calculations, but in labeling. A pencil
line through 1800 on the leap year page would fix the error. ( I think,
it was probably a printing typo ).

-- Gordon







At 11:02 PM 5/7/99 -0700, you wrote:
>In the first part of the 1984 edition of Bowditch where it tells
>about the him and his family, it talks about an error found by
>Bowditch in the 13th edition of "The New Practical Navigator" by
>Moore, dated 1798.  To quote, "The most significant error was listing
>the year 1800 as a leap year in the table of the sun's declination.
>The consequence was that Moore gave the declination for March 1, 1800,
>as 7degs 11mins.  Since the actual value was 7degs 33mins, the calculation
>of a meridian altitude would be in error by 22 mins of latitude."
>
>Interestingly enough, I have a copy of the Moore's book dated Jan. 30, 1798,
>unfortunately the title pages are missing from the book, along with his
>picture, but the preface states that the book has been through 12 previous
>editions.
>
>I checked the "error" and found that 1800 is not listed as a leap year and
>it gives the correct declination for March 1, 1800 as 7degs 33mins South.
>
>-- Gordon
>
>
>                                     ,,,
>                                    (. .)
>         +-----------------------ooO-(_)-Ooo----------------------+
>         |  Gordon Talge WB6YKK            e-mail: gtalge@pe.net  |
>         |  Department of Mathematics      QTH: Loma Linda, CA    |
>         |  Notre Dame High School         Lat.  N  34� 03.1'     |
>         |  Riverside, CA 92506            Long. W 117� 15.2'     |
>         |  http://www.pe.net/ND                                  |
>         +--------------------------------------------------------+
>
>
                                     ,,,
                                    (. .)
         +-----------------------ooO-(_)-Ooo----------------------+
         |  Gordon Talge WB6YKK            e-mail: gtalge@pe.net  |
         |  Department of Mathematics      QTH: Loma Linda, CA    |
         |  Notre Dame High School         Lat.  N  34� 03.1'     |
         |  Riverside, CA 92506            Long. W 117� 15.2'     |
         |  http://www.pe.net/ND                                  |
         +--------------------------------------------------------+

   

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