NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2012 May 7, 19:37 -0700
Making a simplified Bris Sextant only requires gluing two microscope slides together with a gap at one end. The larger the gap the greater the angular deflection of the reflected Sun. I used a 0.7 mm pencil lead to set a gap and got 1* 57.8' of deflection. Inspect the linked image and you will see that the reflected image is the sum of four images one on top of the other. This must be from the front and back surface reflections from each slide. The best a navigator can probably hope for is 1' to 2' of precision on a home made version. Still this is pretty good for something that can get lost in a shirt pocket.
Greg Rudzinski
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