A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robert Swartz
Date: 2016 Nov 28, 23:05 -0800
After spending an evening reconditioning a Merganthaler Navy Ball Recording Sextant for a customer, I was able to occasionally get faint ball marks on the recording targets. I recoated the marking pad with black stamp pad ink mixed with ethylene glycol to thin it out. I'm not sure what was used for ink 72 years ago.
What an abomination of a navigation instrument--no wonder the Navy dropped it.