Two On A Big Ocean The Story of the First Circumnavigation
of the Pacific Basin
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Re: The Perfect Sextant

From: Alexandre E Eremenko (no email)
Date: Fri Jun 02 2006 - 14:45:17 EDT

  • Next message: jean-philippe planas: "Re: The Perfect Sextant"

    On my opinion,
    there are different "perfect sextants" for different
    tasks:-)
    It is possible that "C. Plath--Cassens-Plath chimera"
    described in Robert's message is perfect...
    for taking very precise sights from an aircraft carrier's
    bridge:-)

    It is my impression that the general opinion of
    practitioners in this
    list is that one cannot take the altitudes from a small boat
    with accuracy more than 1' or so. Currently I am experimenting
    with a "boat sextant", (the round one) made in XIX century
    by Troughton and Simms, scale reading to 1' (recently bought on e-bay
    for approx. the price of a good plastic sext).
    It fits to my pocket. If I will be able to measure altitudes
    to 1' or 2' accuracy, I will conclude that this is the
    "best sextant" for a small boat.
    (My limited experience shows that an ideal sextant for a small boat
    should be SMALL and light:-)

    Speaking of the "Best sextant" (say, for land observations
    of maximal precision) I am still in doubt what is better:
    a) C. Plath frame, Cassens-Plath gimmicks etc., as described
    in the original message, or...
    b) a good late XIX- early XX century vernier, silver scale,
    10" reading, 3 telescopes, ivory handle etc. sextant,
    I am shopping for now:-)

    Speaking of combining the best features of all sextants known to me,
    I would include:
    a) Soviet illumination device, SNO (no battery!)
    b) Inverting scope with cross-wires
    c) Eyepiece filter (a very useful thing).

    And NO enclosed "Trommel", of course.

    Alex

    On Fri, 2 Jun 2006, Greg R. wrote:

    > As far as I'm concerned, the "perfect sextant" is the one that gets the job done at the time (i.e. lets me fix my position with reasonable, consistent, and repeatable accuracy).
    >
    > Having said that, I'd just about kill for a chance to take some sights with your dream sextant - I might just have to eat the words I just wrote.... :-)
    >
    > --
    > GregR
    > ----- Original Message -----
    > From: Robert Eno
    > To:
    > Sent: Thursday, June 01, 2006 10:20 AM
    > Subject: The Perfect Sextant
    >
    >
    > C.Plath frame; Cassens and Plath handle (because it can be completely taken apart); Cassens and Plath horizon shades (larger than C.Plath); C.Plath Bubble attachment (earlier version with the adjustable bubble - a superb piece of engineering and craftsmanship); Cassens and Plath or C.Plath 4 x 40 scope and a 6 x 30 for optional use.
    >
    > Ok, that's a start. Anyone else care to wade in?
    >
    > Robert


  • Next message: jean-philippe planas: "Re: The Perfect Sextant"



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