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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Getting ready for a spring demo...
From: Greg B
Date: 2013 Dec 28, 18:13 -0500
From: Greg B
Date: 2013 Dec 28, 18:13 -0500
Hi All,
I'm starting to get ready for a spring talk / demo at a re-enacting event (for re-enactors only.
also known as a "pre-1840 event") I'm starting to build reproductions of Lewis & Clark's
artificial horizons so far I have built a wind screen to "cover a bowl of water" and am working
on a "3 legged wooden 'table' (3" X 4") to hold a spirit level and a 'mirror from a sextant' "
I will pass on the 3ed one - a mercury bath. any suggestions? I disguised a modern 99 cent store
level to look like a period level and I removed the old level lines and redid them to be sensitive
to 1' of arc.my test procedure was to level the level with a high quality machinest level & table.
then I placed the level at one end of a 6ft. 2X4, I then raised the far end 1.2 inches according
to my calculations: (6ft X 12in) = 72in X Tan 0.01666666 deg = 1.2in and the bubble moved
almost entirely out of the marks. Am I correct in assuming I can now resolve 1' of arc?
Will this now be the resolution of my sights? suggestions & critiques gratefully accepted.
~Greg
P.S. I love to do this type of stuff because this is how I learn it's
also been called "experimental archeology".
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