Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Name or NavList Code:
    Re: Beating a Dead Horse (aka Worley's Sextant)
    From: Brad Morris
    Date: 2014 Jan 21, 17:10 -0500

    Hah! The word should be 'precedes' not "proceeds".  I thought that sounded funny!

    On Jan 21, 2014 5:07 PM, "Brad Morris" <bradley.r.morris@gmail.com> wrote:


    Thanks for that.  The illustration shows the clamp stamped with "patent greatest angle clamp".  That implies that (1) there *is* an earlier patent than 1921 and (2) the sought after patent proceeds 1900.

    BTW, does anyone have or have seen that artificial horizon telescope? That's sweet!


    Brad….thought you might appreciate knowing that the clamp has been around since at least 1900. (see attached).




    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Brad Morris
    Sent: 20 January 2014 18:43
    To: BrenKinch---.com
    Subject: [NavList] Re: Beating a Dead Horse (aka Worley's Sextant)



    Of course, since my device does say 'patent' it implies that there is an earlier version by the same patentees, on the same topic.  You've got the later one, but its the earlier one we seek!


    On Jan 20, 2014 11:52 AM, "Brad Morris" <bradley.r.morris---.com> wrote:

    Thanks Don, for explaining away those conundrums!

    On Jan 20, 2014 10:47 AM, "Don Seltzer" <timoneer---.com> wrote:


    I think I can explain away your date conundrum. The 1921 patent application states that it is an improvement over the previously used 'greatest angle clamps'. Figures 1 and 2 show the previous design, and Figures 3 and 4 show the improved clamp being claimed. All of your attached photos clearly show the previous model, not the 1921 improvement.

    Don Seltzer


    Hi Don

    Yes! That's it. No doubt about it.

    Unfortunately, it brings up a few issues, one major.

    1). My inspection certificate is dated January 1921. The patent date is November 1921. This little conundrum is not nearly as significant as the next.

    2) Shackleton's Trans Antarctic Expedition began in earnest (pun fully intended) in 1914. How could "the" sextant used by Worsley have this feature? And yet there it is!

    In the attached photos (for the benefit of Frank, I've stopped now to include them) you can see it the patent greatest angle clamp hanging in the box, mounted on the arc, and by itself on the lid of the box.

    Compare to the image from the James Caird Society, showing at a patent greatest angle clamp, pre patent date. http://fer3.com/arc/m2.aspx/Fw-Image-Sextant-Used-Worsley-Huxtable-mar-2009-g7574. Its there, unfortunately without enough resolution to see just how much of a match it is. There's just enough detail in the tourist photo I found in 2009 to show that the general construction is the same.


    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    Attached File:

    (f1-GB184728A.pdf: Open and save or View online)

    : http://fer3.com/arc/m2.aspx?i=126571

    : http://fer3.com/arc/m2.aspx?i=126572

    : http://fer3.com/arc/m2.aspx?i=126574

    Attached File:

    (img/126607.greatest angle clamp.pdf: Open and save or View online)

    : http://fer3.com/arc/m2.aspx?i=126607

    : http://fer3.com/arc/m2.aspx?i=126609

    Browse Files

    Drop Files


    What is NavList?

    Get a NavList ID Code

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

    Enter the email address associated with your NavList messages. Your NavList code will be emailed to you immediately.

    Email Settings

    NavList ID Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site