NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Old Sextant on German money
From: Bill Noyce
Date: 2007 Mar 11, 14:30 -0400
From: Bill Noyce
Date: 2007 Mar 11, 14:30 -0400
> Every French yacht is
> required to carry a signalling mirror. It is just a plain round mirror about
> 12 - 15 cm in diameter with a hole in the middle. You turn in the direction
> of the sun and look through the hole. You then see a red point which marks
> the spot where you are just reflecting the sun rays.
The sun shines through the hole and makes a small spot somewhere on
your face, usually, and the back of the mirror is also silvered. If
you move the mirror so the spot on your face is imaged at the hole,
then the front of the mirror is shining at whatever you see through
the hole. I assume that's the mechanism behind the "red point"
Wolfgang mentions. You need to be able to tell where your target is,
but you don't have to see the light shining on it.
-- Bill
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