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    Re: Celestaire vs Freiberger Yacht Sextant
    From: George Huxtable
    Date: 2004 Aug 2, 10:40 +0100

     Joel Jacobs  wrote:
    >From my experience, if your going to do serious navigation relying on
    > twilight sights, the 7/8 scale sextants are very lacking. Their optics are
    > not very good, and there small size mirrors are not anywhere as effective
    > when taking star sights or high altitude sun sights.
    Something about that puzzles me. Why should it be so, I ask?
    First, I should make it clear that I have never even handled such a 7/8
    size sextant; and that observations on my own small boat have never passed
    beyond a plastic job, though I have used many "posh" sextants, belonging to
    others. So I make no claims to being an expert on sextants.
    Yet, it seems to me that if you were to shrink a sextant to 7/8 of its
    original size, and shrink its mirrors correspondingly (in both directions)
    while preserving the same angular field-of-view of its telescope, then
    (because the distance from the eye to those mirrors is also reduced to 7/8)
    the patch of sky that the mirrors subtend would be exactly the same as
    So, in those circumstances, why should the smaller mirrors present any
    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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