A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Fleming
Date: 2018 Apr 17, 10:46 -0700
You raise an interesting point about the vernier. But I think habit had more to do with its inclusion than sales. When used on a vernier sextant, the vernier was helping decide on a larger range of values, perhaps 30 minutes out of a half degree. In that case it makes the judgement much easier. Whereas 1 in ten maybe not so much.
In any event, It costs almost nothing in the scheme of things and it can help.