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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2017 Jan 29, 02:37 -0800
Randall you wrote: For an artificial horizon I use a first surface mirror on a round metal plate. It is adjusted on 3 screws with 40 TPI. Using 2 spirit levels I routinely get less than a mile accuracy in any wind. Ahmundson used this in his polar explorations. Instructions for making the levels are posted in the archive.
Did Amundsen always use a mirror? I always thought that at the South Pole at least he poured liquid mercury into a tray. Carefully stored it would probably still be liquid. Photo and text here http://www.southpolestation.com/trivia/igy1/polesurvey1.html (photo possibly taken earier in the jourey), but I could be persuaded that you can’t always believe everything you see and read on the www. I've also read that he took a mirror and a spirit level as stanby in case the mercury froze https://www.theguardian.com/notesandqueries/query/0,,-1024,00.html DaveP
