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    Re: Heath vernier sextant
    From: Stan K
    Date: 2012 Jul 23, 10:06 -0400
    Brad,

    I've tried red and white LEDs behind and in front of the diffuser.  Any of them is better than nothing, and, of course, red would be better for preserving night vision, but none of them are really satisfactory.  Maybe it is just a personal problem :-).

    Stan


    -----Original Message-----
    From: Brad Morris <bradley.r.morris@gmail.com>
    To: NavList <NavList@fer3.com>
    Sent: Sun, Jul 22, 2012 9:00 pm
    Subject: [NavList] Re: Heath vernier sextant

    I use a red LED behind my diffuser.
    On Jul 22, 2012 8:23 PM, <slk1000@aol.com> wrote:
    I was just given a 1940 Heath and Company vernier sextant, as a gift from a 96-year-old friend (yes, 96!) who stopped using it when he got an Astra IIIB.  He bought it used right after World War II.  It appears to be complete and in excellent condition, including three telescopes, a sight tube, two eyepiece filters, a "pick" tool, and the original box and key.  Even the mirrors are in great shape.

    I have a couple of question about it, though:
    1) What are the eyepiece filters for?  From my amateur astronomy days, I would have to call them a sun filter (very dark) and a moon filter (green).  My best guess is that they allow you to view the sun and moon using the telescopes alone, without the sextant.
    2) I'm having a heck of a time trying to read the vernier scale.  The magnifier works (not as well as the trunnion-mounted one on "Heath and Company's best vernier sextant" (on Bill Morris' site), I'm sure) , but it seems that when I have it in a position to read the scale it blocks the light, making it difficult to read the scale.  There is a diffuser screen that I imagine is supposed to help, but how?  With an external light source?  (I'm pretty sure Bill will be able to answer this.)  Even if I could read it, figuring out which of 50 vernier lines aligns with one on the arc seems daunting
    :-).
    3) The sextant does not seem to have any adjustments with holes where the "pick" tool would be used.  It seems a slotted screwdriver would be more appropriate.  The serial number on the certificate matches the sextant.  What else could that tool be for?  Is it possible that this is not the original box, and the certificate was moved from the original box?

    Stan






       
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