A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2020 Aug 16, 08:55 -0700
Saw this interesting sextant certificate today. I have not seen a graph for arc errors before. Notice that the values were probably measured every 15° since they then fall right on the graph's primary lines, ignoring some drawing "bumps", in the entire range from 0° to 120° except at 105°. The graphic visually implies what most of us imagine to be true anyway: that we can interpolate linearly between values in a certification table. Is that true? Hard to say. I should add that the value at 0° usually has no significance and should always be zero since index error is separate from arc error.