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George Huxtable wrote:
>
> Those pages and tables need to be taken with a pinch of salt, however.

Most of my reference book are in storage, but as I recall Bauer also had
star-to-star parings in his sextant book, again to be taken with a (large)
grain of salt.

George does well in pointing out some of the problems inherent with look-up
tables.  If you are truly serious about calibrating your sextant within 0!1
to 0!2 your results can be no better than your target accuracy.

Now if for some reason all the pairings from 120d to 10d agreed with your
calculations, with the exception all of being 0!5 off in one direction, you
might have case for index or system/personal error. That would assume the
scale was perfect, a rather large leap of faith.

A sanity check helps.  One evening Alex and I were doing star-to-star, one
pairing in the 90d range.  He was on, I kept coming up 1' off, despite other
pairings being on. We swapped sextants, I hit the mark with his and he was
1' off with mine.  That pretty much tells the tale.  Not an IC problem, not
personal error, so definitely a scale error.  (Unless of course the optics
of my scope were shifting because of the star's  light wavelength and his
was not ;-)

Bill B.


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