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    Re: Artificial horizons
    From: Geoffrey Kolbe
    Date: 2003 Jul 11, 15:35 +0100

    I tried floating a thin glass mirror on a bowl of Mercury. It had the
    advantage that surface tension effects kept the mirror away from the sides
    of the bowl, so the bowl need only be marginally larger than the mirror.
    Furthermore, the bowl could be covered and sealed with a lid of plain, flat
    glass. The sealed bowl with floating mirror could then be picked up and
    stowed in any orientation, which would make this arrangement portable
    It worked pretty well, but I had to be careful that there was no dirt on
    top of the mercury on or the mirror, or the mirror would not sit level.
    Geoffrey Kolbe.
    Dr Geoffrey Kolbe, author of "Long Term Almanac 2000-2050" for sun and
    selected stars, with concise sight reduction tables.
    Available online from www.pisces-press.com

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