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    Re: Children's land-locked "Sextant"
    From: Alexandre Eremenko
    Date: 2007 Nov 28, 23:34 -0500

    
    On Wed, 28 Nov 2007, Robert Eno wrote:
    
    > Consider a black glass artificial horizon. Frieberger
    
    I've seen one of those and tested it in Freiberger's
    office (in Freiberg, Germany).
    The price was something like 900 Euro, but they were very
    nice to me and offered for only 700 (if I pay cash on
    the spot:-)
    To try, we put it on the wood table in their office
    (on the second floor of a brick building in a quiet
    street in a small quiet city) I asked everyone to sit
    down and stop breathing for a while. And aimed my sextant
    at the Sun reflection (SNO-T, 6x scope). It was shaking
    like crazy (5-10 minutes amplitude by eye estimate).
    
    So I decided not to spend 700 Euro for a piece of glass
    in a drame with 3 screws and a pair of levels.
    
    Actually I believe that a handyman with simple tools can
    make such thing himself. Optical quality glass seems to
    be available on the Internet for a reasonable price.
    
    Besides, 30" ADVERTISED accuracy did not seem sufficient
    for the sort of observations I am doing.
    
    Alex.
    
    P.S. I don't know whether Ken is reading this (have seen no
    posting from him for long time)
    but I suggest that Celestaire could make an art horizon of
    heavy iron, perhaps it will shake less
    (the real ones were made of iron for
    another reason: iron does not amalgamate witrh Mercury,
    unlike other metals). Only once I've seen an old iron
    artificial horizon on e-bay, complete, with iron mercury
    bottle). It was sold for $800 about a year ago.
    
    
    
    
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