A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2015 Oct 19, 13:06 -0700
Steve, you wrote:
"What are some example of a Vernier sextant, please?"
Now, Steve, you know what a vernier sextant is (at least, I sure hope you do!). Basically, any sextant you have ever seen without a micrometer drum (the knob with the minutes of arc on it!) is a vernier sextant. There are some exceptions to this rule but nothing to worry about. Below are images of a sextant from the 1890s and a modern Davis Mk. 3 sextant. Both are vernier sextants --no micrometer. As Geoffrey says, all other things being equal, a vernier is intrinsically more accurate than a micrometer, but micrometers are much easier to read.