NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tom Sult
Date: 2012 Aug 13, 20:50 -0500
Thomas A. Sult, MD
"But my main objection is that its micrometer drum is too small and lacks a vernier scale. Even worse, its shinny surface reflects light, making it very difficult to read in many circumstances."
For those who _must_ have a vernier, it is a simple matter to make one on paper using a computer drafting program, and then to glue it on to the index, followed by a coat of varnish. I attach some examples that can be printed out. Those with unsteady hands get three goes.
Shine can be removed by rubbing with a piece of emery paper, say 400 grit. Some Freibergers have very respectable arc errors, but I have seen examples having errors of more than 90 seconds, two of them on the bridge of a modern container ship.
The SNO-T, by the way, is supplied with two 'scopes,a 4 x 40 Galilean and a 6 x 32 Keplerian.
Bill Morris
Pukenui
New Zealand
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<Vernier-SNO-T.pdf>
