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I sent this email today to the government office that computed these
tables:

Dear Mr. Doherty,

Last year I called your attention to some errors I had found in the on-
line version of  H.O.  249 for Hc's near zero and I checked recently
and these appear now to have been corrected. However, when I was
reviewing the updated version I found some additional errors.
In volume 2 page 158 is completely wrong and appears to be a duplicate
of page 152 and page 133 is also completely wrong and appears to be a
duplicate of page 139! I suspect that there are many other similar
errors hiding in this volume that my cursory review didn't reveal.

Gary LaPook


On Nov 13, 3:34 am, glap...@PACBELL.NET wrote:
> Further comparison shows that page 133 is a duplicate of page 139!
>
> gl
>
> On Nov 13, 1:56 am, glap...@PACBELL.NET wrote:
>
> > Ken,
>
> > My copy, 1970 edition, doesn't have the error you pointed out. I then
> > looked at all pages from 122 through 161 looking at the first entry on
> > each of these pages and found additional differences between my print
> > edition and the online version. Page 155 has a one minute different Hc
> > as  does page 151 for the first entry but I didn't check other values.
> > page 133 is completely different, all tabulations are different ! I
> > computed several of the entries on page 133 and found that the online
> > version has the erroneous values while my 1970 edition has the correct
> > values.
>
> > gl
>
> > On Nov 12, 4:08 pm, Ken Gebhart  wrote:
>
> > > To all List Members,
>
> > > Need help to track down errors!
>
> > > I have been made aware of  many errors on page 158 of Pub 249 Vol 2
> > > Apparently all of the Hc values on the page are wrong!  For example,
> > > for dec 0, LHA 0, Lat 26 (page 158), Hc is shown as 65 deg. When it
> > > should be 64 deg by simple inspection.  All the other numbers are
> > > also off by varying amounts as can be found by computation.  There
> > > are some other errors too, of a different kind on other pages.  For
> > > example, page 160.  Look at the column for dec 15 deg, and go down to
> > > LHA 98.  By simple inspection you can see that there should be a
> > > minus sign before Hc 00-25, but it is not there.  I believe this is
> > > typical of many Hcs  near zero.
>
> > > These errors are present in the US Government Edition, privately
> > > published editions, and the PDF on the NGA website.  I have spoken to
> > > the UK Almanac Office, and they report that the errors do not exist
> > > in their equivalent to 249 V2, or their Rapid Sight Reduction Tables,
> > > and can find no trace or knowledge of them.
>
> > > I am asking anyone who has an older copy of this volume, to check it
> > > for these errors and report the publication date.  Maybe we can track
> > > down when they first appeared.  By the way, a friend did phone the
> > > NGA to report this, and was told that �they would look into it�.
>
> > > Thanks, Ken Gebhart
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