NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2019 Apr 7, 02:01 -0700
I wrote: Understanding the table in photo 4 is beyond my pay grade, except to say n=6 corresponds to pivot in the middle.
This is just a thought. A hexagon has the same side length as its circumscribing circle. Maybe the table in photo 4 is a polygraphic scale to draw a regular polygon inside its circumscribing circle.
Test
Sided Polygon Setting from linear scale Photo 2 Setting from Photo 4
6 1:1 130 130
12 1:2 86.7 88.7
18 1:3 65.0 67.0
24 1:4 52 53.8
The side length of a 12 sided polygon is slightly longer than half the side length of a hexagon, because the new side length is a hypotenuse of the two tiny right triangles built on the side of the hexagon. It's the same for the 18 sided and 24 sided figure. I'm relieved all those dreary afternoons spent doing geometric drawing and getting smudgy pencil lead fingerprints all over my work at my secondary technical school 60 years ago weren't wasted. DaveP
