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    Re: Swinging the arc: two methods, one preferred
    From: Frank Reed
    Date: 2011 Jan 6, 20:34 -0800

    Hewitt, you wrote:
    "In thinking about this technique further this afternoon, I now visualize it as analogous to inverting the sextant to bring the horizon up to a star. But then, instead of flipping the sextant back to "normal" you hold the scope on the star and rotate the sextant around the axis of the scope. Thus instead of swinging the star (sun, moon, planet) across the horizon, you swing the horizon around the body."

    Yes, that's just right. Now, turn the sextant back right side up and do whatever motion is required to get the same visual effect. You'll find that you're turning from side to side while you're rotating the instrument. As Paul has said, it's hard to describe but easy to do if you follow the simple rule that the Sun or star should remain centered in the field of view. It's not hard to learn at all, and it's not hard to teach if you have the students right there with you. It is, however, hard to explain in words. This whole business would benefit from an animation or a simple video. When you've seen it done, there's nothing to it.

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