"Roger Helio" wrote in message
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"Wayne.B" wrote in message
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It might be possible but I doubt it. There used to be a sextant
designed for aircraft navigation in WW II that used an artificial
horizon of sorts but those guys were happy to know where they were
within 20 miles or so.

That was not a sextant. It was called an octant.

Here's one:

http://www.icarusbooks.com/images/1458.jpg
That is not an octant. It looks like a bubble sextant as used on aircraft..
An octant is exactly the same as a sextant except that is is constructed to
read to 45 degrees against a sextant's 60.
A sextant can therefore measure a wider angle than an octant.
.. I have an octant that my grandfather used. It is made of
ebony and has ivory engraved scale read with a vernier, but in all essential
respects is identical to a sextant.