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Amen! + I ave always fitted my sextants with a supplementary handle and
universal joint at right angles to that provided by the manufacurer. This
has proven most useful in taking horizontal angles and in lunar distances
- probably, the new fangled instruments with an electric powerhouse in
the handle would present a small problem, but it can be done - in the
older sextants having only a wood handle, the installation was quite
easy.

On Wed, 17 Nov 2004 20:32:50 -0800 "Gary J. LaPook" 
writes:
> Of course you can use the sextant right side up and accomplish the
> same
> thing. Just set the index on zero and look through the telescope at
> the
> star. Then slowly move the index arm at the same rate that you move
> the
> sextant to the horizontal position while keeping the star in sight
> in
> the mirror through the telescope  until the horizon comes into view.
> Then perfect the setting and take the reading.
>
> gl
>
> George Huxtable wrote:
>
> >This may be a silly question, in which case some pundit will
> explain why.
> >
> >Every sextant I have seen, or seen described or pictured, has a
> similar
> >form. The observer looks horizontally through the telescope, at the
> >horizon, through the part-silvered horizon mirror. The celestial
> body is
> >viewed, by reflection in two mirrors, brought down to the horizon
> by moving
> >the index arm.
> >
> >And yet, for some applications, it's useful to use the sextant
> upside-down,
> >pointing the telescope at a star, and working the index arm to
> bring the
> >view of the horizon (as seen in the "index mirror") up to it. That
> makes it
> >easier to identify the right star of a constellation, because the
> observer,
> >and his telescope, and his left eye also, are looking up directly
> at it. In
> >that case, a pair of open sights could be attached to the
> telescope, for
> >easy preliminary sighting without magnification. Then, after
> identifying
> >the star in the telescope, it could be kept in view while the
> horizon (and
> >there's only one horizon, so never any difficulty in identifying
> THAT) is
> >brought up to meet it.
> >
> >The trouble is that no sextant that I know of has been designed to
> be used
> >that way, so the handles and knobs are all in completely the wrong
> place.
> >That in itself is enough to discourage the use of a sextant
> "upside-down".
> >
> >I can see one advantage to the "normal" use of a sextant, in that
> the
> >observer always looks in a horizontal direction, which is
> comfortable for
> >him. Use in "upside-down" mode requires him to look up into the
> sky, which
> >might be an uncomfortable posture, especially if the altitude was
> great. Is
> >that the only reason (or the dominant reason) why EVERY sextant is
> made the
> >way it is?
> >
> >Has any maker ever experimented with a design which would make it
> easier to
> >use a sextant "upside-down", or better still, either way, perhaps
> by
> >providing an additional handle and an extended adjustment knob?
> That, by
> >the way, would also ease the measurement of lunars.
> >
> >I only ask...
> >
> >George.
> >
> >================================================================
> >contact George Huxtable by email at george@huxtable.u-net.com, by
> phone at
> >01865 820222 (from outside UK, +44 1865 820222), or by mail at 1
> Sandy
> >Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
> >================================================================
> >
> >
> >
>

   

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