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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@huxtable.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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