NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Ritchie
Date: 2023 Jul 13, 14:23 -0700
Whilst there is much past documentation on NavList and elsewhere on Bygrave Slide Rule history, methods, scales, users, etc., I am unaware of any reference to the manual dexterity aspects of using the instrument. Accordingly, I attach a record of my conclusions on the best ways I have found to handle the specific Bygrave Mark IIA that I purchased in Autumn 2022 from long-standing NavList contributor Francis Upchurch.
I have had much pleasure from using this 100 year old treasure, albeit in quasi laboratory conditions, with white cotton gloves and far from my coffee. Having written a Traditional Bygrave emulator in May 2021, I was familiar with the methods and scales and it was just the manual handling that was new to me. Surprisingly, having now had the opportunity to study a 'real' Bygrave, I have found no need to make any changes to the emulator, though I have made a few small changes to the user notes.
Bill Ritchie
