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    Buying a sextant- a cautionary tale.
    From: George Huxtable
    Date: 2006 Apr 27, 22:10 +0100

    On this list, I have frequently expressed my opinion that a cheapo plastic 
    sextant is the appropriate instrument to carry on a small
    boat, in view of the rough-and-ready nature of the observations that result 
    from an unstable platform underfoot, and a viewpoint so
    close to the waves. That remains my view.
    
    However, in recent years I have coveted a "real" sextant, and particularly a 
    Vernier instrument rather than a micrometer. For
    historical reasons, mostly, in that the basic design of a Vernier sextant 
    remains unaltered since its introduction about 250 years
    ago. Although I might keep it on the mantlepiece, rather than install it on my 
    little boat, it would not be just an ornament, but
    would be asked to do a proper job. Such as measuring lunar distances, for 
    example; a precise task which my plastic Ebbco is
    certainly not up to. I am quite aware that the micrometer sextant was a real 
    advance, making it much easier to read an angle,
    without sacrificing precision. But the nice thing about the Vernier is that 
    its precision is so apparent, demonstrated just by a
    close look at the nicety of the scale divisions, though my old eyes are 
    probably not good enought to do it justice. Anyway, A
    Vernier sextant it was to be.
    
    Alex Eremenko has also expressed interest, in a thread "Problem with a sextant", when he wrote-
    
     "And I hope my next sextant will be one of those old ones with Vernier and 
    microscope and no teeth to worry about! If I find a good
    one."
    
    I have been keeping my eye on Ebay, the UK version ebay.co.uk, and decided to 
    bid for a 1920's Heath Hezzanith Vernier sextant that
    appeared.. That model was the "standard" British instrument of its time, 
    widely sold and used. It was being sold by a fellow who had
    used it, as a navigating officer in the 1960's, and had inherited it from his 
    father who had possessed it since the start of his
    merchant-navy career, in the 1920's. So: good provenance, no antique-dealers 
    involved to add their markup and polish the
    scale-divisions off the arc. It was stated that mirrors, shades, and arc were 
    all in perfect condition, though a brass spring-clip
    (that opposed the action of a mirror adjusting screw) was broken and needed 
    replacement. That wouldn't present a problem. What more
    could anyone ask? So I bid, and as there was little contest, got it as ?185 
    (about $300 by my reckoning), which pleased me as quite
    a bargain. I would have paid more. It was interesting to get a message from 
    another mariner, after the bidding had finished, to say
    that he had been unable to bid, and offering to buy from me for more than I had paid.
    
    A point that the seller had emphasised was that although Brasso had been used 
    to polish other parts, only breadcrumbs were ever used
    to clean the silver arc  (a trick I had heard of before). I made a long drive 
    to collect it, and it was a surprise to discover that
    although all the other claims were indeed true, there were serious problems 
    with the arc. Although, over most of the arc, the fine
    divisions were clear and sharp, at angles less than 10 degrees, they had 
    become faint and hard to read. Below 5 degrees, through the
    zero-point, to the end of the off-the arc section, there was no trace of any 
    fine-divisions whatsoever. They had been completely
    polished off. That, of course, made it quite unusable as a measuring 
    instrument, though it would still have some value as an
    ornament.
    
    By this time, money had already changed hands, and the seller didn't quibble 
    at all about making a full refund. That put me back
    where I had started off except for my wasted time, and a wasted long journey 
    through the West-country. Not entirely wasted, I should
    add; glorious Spring weather, lots of blossom out, England at its (rare) best.
    
    My experience shows up the problems that can occur when you buy something as 
    finicky as a sextant, sight unseen, at auction. Will I
    be tempted to try again? Probably, yes. What more can I do to avoid another 
    disappointment? I have no idea. Perhaps others, with
    more experience of these matters, can offer suggestions.
    
    George.
    
    ===============
    
    contact George Huxtable at george---.u-net.com
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    
    
    

       
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