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    Re: Watch into Compass?
    From: Dave Weilacher
    Date: 2004 Feb 11, 16:24 -0500

    I had actually thought the boy scout method was a reasonable way of 
    determining south as opposed to 180 degrees true.  Accuracy to the umpth 
    degree is pretty nearly useless when you hiking about in the woods.
    -----Original Message-----
    From: "Noyce, Bill" 
    Sent: Feb 11, 2004 3:31 PM
    Subject: Re: Watch into Compass?
    > Here's a puzzle: can you modify the Boy Scout watch method so that it
    > does not confuse azimuth with local hour angle and thus becomes a
    > somewhat more accurate compass?
    How about this procedure:  Point the hour hand directly at the Sun
    (in general this requires tilting the watch into the sky).  Rotate
    the watch around its hour hand (which remains pointing at the Sun)
    until 12:00 is also pointing into the sky at the same altitude (but
    generally in quite a different direction).  Now the face of the watch
    points north (in most of the northern hemisphere).
    If the watch reads local apparent time and the sun is over the equator,
    the only errors are caused by imprecision of pointing, though they may
    be greatly magnified by the geometry.  Corrections for daylight savings,
    longitude within zone, and equation of time are obvious, though perhaps
    only the first is worthwhile.  It's not clear what, if anything, needs
    to be done about declination.
    Is this the kind of procedure Frank is envisioning?  Has he tried it?
            -- Bill
    Dave Weilacher
    .US Coast Guard licensed captain
    .    #889968
    .ASA instructor evaluator and celestial
    .    navigation instructor #990800
    .IBM AS400 RPG contract programmer

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