NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: magnetic variation calculator
From: Bill Murdoch
Date: 2005 Feb 25, 10:15 EST
From: Bill Murdoch
Date: 2005 Feb 25, 10:15 EST
In a message dated 2/25/05 8:24:29 A.M. Eastern Standard Time,
mdorl@WISC.EDU writes:
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.
I'm in East Tennessee.
One of my "favorite" nautical chart notes is in the area near the entrance
to the Chesapeake Bay. It says "LOCAL MAGNETIC
DISTURBANCE Differences of as much as 6 degrees from the normal variation
have been observed 3 to 17 nautical miles offshore from Cape Henry to Currituck
Beach Light." Normal is 10 degrees 45 minutes west. It puts a little
doubt in the TVMDC. If you were also figuring your longitude by local
variation, you might miss the entrance to the bay.
Bill Murdoch
