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    Re: Do We Still Need to Use Sextants?
    From: Brad Morris
    Date: 2013 Apr 9, 18:39 -0400

    Hi Alan

    A contributor before your time, Nicolas de Hilster, wrote extensively about cross and back staffs.  He may still be lurking, I don't know.

    You may see his NavList posts about the Davis Quadrant (cross staff) here
    http://www.google.com/search?hl=en&client=ms-android-verizon&site=webhp&ei=_JVkUfTPOuPO0QGx84HACA&q=site%3Afer3.com+hilster+davis+quadrant&oq=site%3Afer3.com+hilster+davis+quadrant

    He also maintains a website which will more directly answer your questions about the cross and back staff.
    http://www.dehilster.info/index.php?doc=http://www.dehilster.info/instrumenten/crossstaff/index.html

    In so far as the quadrant (pendulous mass and protractor), try to understand that on the deck of a ship, the pendulum will always be rocking, no matter how finely the scale is divided.  You may wish to try your hand at this when on land to see your results.  I'd recommend that you find the largest protractor you can to start, and use a very fine cord for the pendulum.  Sight either the moon or stars, as the sun will be blinding ;-(  That's not a winking eye, that's a blinded eye!

    Brad

    On Apr 8, 2013 11:59 PM, "Alan S" <alan202---.net> wrote:

    Brad Morris:

    I threw that protractor/string/weight in, almost for laughs. Say the protractor was divided into degrees, and half degrees, 30 minutes of arc equaling 30 NM. Could one estimate 1/4 of a degree, which would be worth 15 NM, I believe. I don't know, however any fixes obtained would be pretty loose, I think.

    All this leaves us where. Strikes me that absent electronics, one had best get some practice using the sextant. As for the other devices you mentioned, I have seen/read references to them and their down sides. I have no idea as to the accuracy that might be expected using them.
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