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At 15:06 16/09/2005, Fred Hebard replied to a question from Willem Piccer
about box sextants:
>Willem,
>
>My understanding is that the replicas are not accurate and are not
>suitable for any sort of measurement whatsoever.
>
>The box sextant was an angle-measuring device used by explorers on
>land.  It was used as one might use a transit or theodolite, where it
>was impractical to cart those heavier instruments --the box sextant
>could be carried in a pocket.  I don't believe the accuracy was high
>enough for use at sea, except perhaps in emergency situations, more on
>the order of degrees than arcminutes.
>
>Fred
>
>On Sep 16, 2005, at 9:59 AM, Piccer wrote:
>
>>I followed the dicussion on the plastic sextant with a lot of interest.
>>
>>At home I have a replica of what is called a " box" sextant.
>>I never tried to use it, but can somebody tell me if this is a serious
>>instrument?
>>
>>The only reference I have found is on the website of Stanley, London :
>>they sell  the replica's
>>
>>Many thanks
>>
>>Willem Piccer

============================

In listmember Peter Ifland's lovely book, "Taking the Stars", a couple of
pages are devoted to box sextants, with several photos of
these  instruments. Here's some of what he says-

"The so-called box sextant brought an entirely different approach to a
small, lightweight, easily portable angle-measuring instrument. The box
sextant was designed specifically for explorers and surveyors and enjoyed
popularity through most of the nineteenth century. All the essential
elements of a complete Hadley sextant- an index mirror, a horizon mirror,
colored-glass filters- were contained within two circular brass plates only
3 1/2 inches in diameter ... It is unlikely that the box sextant was much
used at sea except perhaps for small boats and yachts..."

I recall a warning, some years ago on the "sextants" mailing list, to the
effect that "Stanley, London" was a label frequently attached to modern
instruments intended as replicas, which give the appearance of earlier
instruments, but are quite unsuitable for measurement, being made without
attempting to achieve any sort of accuracy. Willem's box sextant may or may
not come into that category; he should regard it with some suspicion.

George.
===============================================================
Contact George at george@huxtable.u-net.com ,or by phone +44 1865 820222,
or from within UK 01865 820222.
Or by post- George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13
5HX, UK.

   

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