NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Constructing the next square up on a Mercator chart.
From: David Pike
Date: 2016 Dec 23, 06:36 -0800
From: David Pike
Date: 2016 Dec 23, 06:36 -0800
By way of a festive activity, I seem to remember that in the 1960s to progress from basic to advanced training a student RAF Navigator had to be able to cope with being diverted off the edge of his Mercator plotting chart by constructing the next squares up or down using only his pencil, dividers, and Douglas protractor. It involved drawing a line at an angle equal to the latitude and scribing an arc to somewhere, but I can’t remember how to do it any more, and the www isn’t much help. Can anyone remind me of the construction? DaveP
