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    Re: Sextant Accuracy and anomalous dip
    From: Bruce Stark
    Date: 2003 Mar 22, 15:39 EST

    In response to a posting of mine, Jared wrote:
    >That sounds logical, but it is not at all the process Combe described.
    Remember, he's talking about "marching into town to find a flat spot" or
    finding some local fort and being thrown out of it. He's very definitely NOT
    at any "local station", and it sounds like he is often some miles away from
    one, in any random direction.
     Something is missing from this picture, I think.<
    I wrote an answer yesterday, but apparently it didn't go through. It went
    something like this:
    Maybe the confusion comes from Capt. Combe's interest in explaining what it
    was like to use an artificial horizon, rather than what he got from the
    At a known longitude he could have found the chronometer's error on
    Greenwich. At an UNknown longitude he could only have gotten a "fresh rate."
    For either job he could have chosen between time sights and equal altitudes.
    As to the need for a level spot, perhaps it had to do with convenience in
    setting up the artificial horizon and sextant stand in proper relation to
    each other. Also, they had to have a place for the camp stools, and room to
    crawl around to get in position to take the observation.
    In some places, because of steep ground and trees, the only flat spot with a
    view might have been a street.

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