![]() |
|
|||||
|
||||||
From: Piccer (no email)
Date: Sun Oct 02 2005 - 06:36:22 EDT
Just as an input for this discussion: I took my boxsextant to the beach to
see if it was of any use and within no time I knew
it is useless
Willem Piccer
----- Original Message -----
From: "george huxtable" <>
To: <>
Sent: Wednesday, September 28, 2005 1:37 AM
Subject: Re: beginner
> 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 ,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.
>
|