A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Charles McElhill
Date: 2018 May 16, 17:40 -0700
Thanks for the quick response to my question. I think I do remember the addition and subtraction aspect, but it never hurts to ask just in case there was an additional as an advantage. Thoroughly enjoy seeing these old navigation problem of Frank's. Thanks again!