A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2017 Apr 25, 12:36 -0700
A few years back there was posting on a planned trip down the Grand Canyon as Powell did it and some questions on how he used sextant, artificial horizon, and chronometers. I can't find these old posts in the archives but have found the documentary this guy did on YouTube which may be of interest to you (see link).