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    Arificial horizons
    From: Bruce Stark
    Date: 2003 Jan 3, 19:16 EST

    I haven't had much experience with artificial horizons, but have picked up
    some ideas. Major Ellicot, who DID have a lot of experience, and provided the
    artificial horizons for the Lewis and Clark expedition, said the roof
    sheltering the water should not touch the pan. Just common sense actually.
    Doesn't take much of a puff of air to shake the roof and ruffle the water.
    And I expect that, no matter what kind of liquid you're using you need a roof
    if there's any breeze to speak of. The old mercury horizons had roofs.
    Last spring I built a roof that was quick to set up and take down. It was big
    enough to enclose a nine-inch pie pan, and held in shape by three slip-fit
    dowels. Had a cloth skirt around the bottom to fit it to uneven ground. Thin
    pieces of wood shimmed the water pan more or less level. I got excellent
    results in what were said to be 40 mile an hour winds. I gave it to an
    engineer who was impressed with it. Hoped he'd draw it up, since I don't know
    how, but haven't heard from him.
    Year before last I did some experimenting with a 7 by 9 inch piece of
    top-quality mirror. Rested it on three screws, quarter-inch national fine,
    coming up through a metal plate. Had to pay about $70 for a Starret
    machinist's level. Worked great, but tended to drift off slightly as things
    warmed up in the sun. Also took too much time to set up to suit my taste.
    Main problem, though, was I was afraid someone would damage his or her
    eyesight by accidentally getting a blast of reflected sun. It was strong!
    Water's not much good when you want the stars, or the moon in daylight, but
    it sure is handy for the sun. Properly sheltered, it's perfectly steady.
    I hope others will continue posting their experiences and ideas. For one
    thing, can any liquid other than mercury make it easy to get the daytime
    moon, or the stars? I have no experience with oil, etc.

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