NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Paul Dolkas
Date: 2015 Apr 20, 08:56 -0700
The main problem with all these floating mirror schemes is that there’s no guarantee that the reflecting surface is going to be parallel to the surface of the water. In theory it is, if the mirror is perfectly made, which means it almost assuredly is not. Any variation in thickness, density, etc. will produce a slight list to one side, and unless you have a CG adjustment gizmo attached - or are very lucky - I’d be surprised if it works.* Remember – it needs to be level within a hundredth of a degree or so.
That’s the beauty of liquid mirrors – they are always perfectly level.
Paul Dolkas
*That being said, at $3 per mirror, I’d be very happy to be surprised.
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Dave Walden
Sent: Monday, April 20, 2015 6:12 AM
To: paul@dolkas.net
Subject: [NavList] Floating mirror
A $3 plastic camping mirror from REI. Floats in a bucket of water. (backing may have issues after a while)
Not suprisingly, clouds all day, so no testing.
Attached File:
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