A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Morris
Date: 2016 Mar 29, 16:20 -0700
<<How do they manage that?>>
65 power telescope, precision central bearing, large circle engraved on glass, optical micrometers, simultaneous readings on opposite ends of diameter, repetition, and very great care in making readings.