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This is a response to  Alex Eremenko-

>On Wed, 29 Sep 2004, George Huxtable wrote:
>
>> Alex Eremenko asked about the precision of
>> sextants and sextant measurements.
>> This is a matter which surfaces from time to time on Nav-L,
>
>I think I read all previous discussions related to sextants,
>all I could find using the search engine.

Try the threads starting about 16 March 03, with headings such as "sextant
accuracies", and "sextant accuracy and anomalous dip", though these veered
off into other territory without changing threadname. You may find other
discussions if you search for threads which include the word "accuracy".

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

I had written-

>> And yet, on this list, the finer points of calibration
>> of these expensive
>> and exotic instruments, ancient and modern,
>> are discussed in detail,
>
>You are not objecting this, do you?

No, not at all, but I suspect that for many, all those instruments will be
used for is for altitudes, in which such exactness is rather wasted (though
it does no harm, of course!).

For anyone intending to measure lunar distances (which includes Alex), he
needs all the precision he can get, and that's why I said that in that case
he is asking the right questions.

What I was trying to do was to take some of the magic and mystery out of
the sextant when used as a tool to measure altitudes from a small vessel,
for which it is vastly over-qualified.

>> There's another list which is devoted to sextants

>Could you please give me the address?

Below is a copy of a message of a few years back from Will O'Neil, who
looks after the "sextants" list. He's an occasional contributor to Nav-L
also.

You will find much less traffic than on Nav-L, and it's less concerned with
technical matters, and more with questions of genuineness or fakery,
purchasing, identification, maker's marks and numbers. So it perhaps
appeals more to the collectors, in my view. It's worth being a member of
both Nav-L and the sextants list, as are many of us.

I'm sure Will will assist any prospective joiner to sign up.

=====================
From: "Will O'Neil" 
Subject:      Hi & "the other list"
To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM

Just joined the list. I did a lot of star sights as USN navigator in 1960s
(and a few more thereafter until sextants pretty much disappeared from USN
bridges). Presently an amateur student of history of navigation and
navigating instruments, and collector of old instruments.

I'm also the moderator of another list (or group) in a subject area closely
related to that of navigation-l. This is the group Sextants hosted on
Yahoo! Groups. (Nothing to do with Yahoo! -- they just provide place for
such things.)

The group isn't restricted to sextants; it also deals other instruments for
measuring visual dihedral angles at sea, aloft, or in the field; the use of
such instruments for navigation, surveying, and like purposes; and other
related matters including marine and air navigation, surveying, and the
industry and technology that produced these instruments. Everyone is
welcome to post information and questions regarding history, specific
instruments, sales, wants, etc.

Naturally, there's a certain overlap in subject matter with navigation-l.
Sextants runs a bit more to history, however.

One reason I set it up as a Yahoo! group in the first place is that it
allows storage of archival material, including documents, images, etc.
Sextants has e-copies of a number of important articles on sextant history,
a bibliography of materials relating to sextants, and pix of some
instruments owned by members.

Membership is open (and it's easy to  if you decide it's not for
you). Most people use the Web interface, at

http://groups.yahoo.com/group/Sextants

You can also treat it like a list. Send message to

Sextants-subscribe@yahoogroups.com

There are about 100 members and the traffic volume isn't going to overwhelm
anyone, I'm pretty sure.

If you are not already registered with Yahoo! Groups for some other
purpose, you will be asked to sign up. They will want some information, of
which only your e-mail address actually has to be correct. There is no
other way to get access to this group except via Yahoo! Groups.

If you have any questions, just send me an e-mail: will.oneil@pobox.com.
I'll do my best to answer. Some people have had difficulties in getting the
Yahoo! Groups software to accept their subscriptions -- let me know if this
happens to you and I'll try to "force" your subscription through.

Will O'Neil

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

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