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Peter,

The side by side Bris might be easier to make. A circular side by side or double/triple row may improve handiness.  Glass scratches less than acrylic and easier to clean also. Sven did mention on his web sight that the variable survival sextant wasn't as accurate as the original Bris but did not say by how much. I agree that a peep cursor would be a good add. 

Greg Rudzinski

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