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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: magnetic variation calculator
From: Michael Dorl
Date: 2005 Feb 25, 07:22 -0600
From: Michael Dorl
Date: 2005 Feb 25, 07:22 -0600
I wonder if Bill M is from the UP (Michigan Upper peninsula)? It's interesting to look at a map showing the section corners in the UP or the iron range in Minnesota. It looks like the section corners were put in by a drunk. Of course they were put in using a compass. I remember a story an old professor I had told about putting in section corners in Kansas. He said they got a wagon, tied a bandana to a wheel spoke and calibrated the wheel. They then drove the wagon across the prairie steering by compass and counting the wheel turns until it was time for another corner. Mike At 08:02 PM 2/24/05 -0500, you wrote: >In a message dated 2/24/05 7:18:09 P.M. Eastern Standard Time, >george@HUXTABLE.U-NET.COM writes: >I'm puzzled. Bill implies that there was no change in variation with >longitude? (Both locations showing variation of -3.797 deg, though 1 degree >apart in longitude?). Was that what he meant to write? > >You are right George. I got the numbers wrong. For a one degree change >in longitude at my location the declination changes from -3.797 to -3.029 >or about 3/4 of a degree. > >Of course it was tongue in cheek. It is pure happenstance that I have a >significant change of declination with latitude at my location. And, the >measurement of azimuth at sea to the required accuracy would be difficult >at best. And, I wonder about the accuracy of the model (A mountain called >Iron Mountain is just to the east of me.). And, no doubt it has taken a >couple of centuries of data gathering to support the model. > >But, it is fun to play. > >Bill Murdoch