A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John Brown
Date: 2016 Jan 7, 03:42 -0800
Attached is a pic of my Blundell Harling Super Duplex Academy 504 - sea navigation model, as endorsed by Podmore. Unusually for a UK made slide rule the trig functions are on the slide. They are divided sexagesimally, which I find slightly inconvenient with my no longer perfect eyesight.