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    Re: Children's land-locked "Sextant"
    From: Ken Muldrew
    Date: 2007 Nov 29, 09:42 -0700

    On 29 Nov 2007 at 8:25, Fred Hebard wrote:
    
    > I'm not sure the risk is minimal.  Other solutions work fairly well,  such
    > as using a machinist's level on a flat mirror or cooking oil  over Karo
    > corn syrup.
    
    An alloy of 76% gallium and 24% indium will provide a useable metal liquid 
    that isn't mercury (the melting point is 16�C but it can easily supercool 
    to about -20�C). 
    
    Maybe there is a combination of high density liquid and low density glass 
    that could produce a floating mirror?
    
    I remember someone on the list once describing a sealed mercury artificial 
    horizon made from glass stuck together with silicone. I think the mercury 
    still became tarnished after a time, but I can't recall the details. 
    Anyone?
    
    Ken Muldrew.
    
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