A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Bob Goethe
Date: 2016 Nov 5, 21:13 -0700
Dear Paul and Gary,
Thank you so much for reading the user manual on the Navigator's Slide Rule carefully enough to note that I had made a serious error with the great circle calculation for Port Hardy to Dutch Harbor...and Paul, for the painstaking effort you made in re-working the problem both by slide rule and calculator. This was hugely helpful in getting me back on track.
What I learned out of this is that, by golly, if you swap out the latitude of your departure point and substitute the latitude of your destination, and vice versa, nothing else in the Bygrave equations works properly. Bone headed error to make.