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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Survival Sextant
From: Peter Monta
Date: 2018 May 23, 20:28 -0700
From: Peter Monta
Date: 2018 May 23, 20:28 -0700
It looks like Sven Yrvind has a new type of Bris sextant in the pipeline under testing. He has proven concept. He calls it a survival sextant.
Clever. I guess it's the relative twist that matters---a global twist of the entire instrument would do no harm because of the double reflection. Still, it might be less mechanically stable than a Bris. If one moving part is acceptable, how about a sliding cursor with a sight hole?
He mentions multiple Bris sextants stacked horizontally. That sounds pretty good too, and you get inherent high stability. Each sub-Bris could be spaced from its neighbors by only a few millimeters, so a fair number of angles (a dozen or so?) would still be quite compact. Grinding multiple glass shims would not be all that burdensome---they're very small.
Cheers,
Peter
